BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Overview and Current Status of the X-ARAPUCA Light Collection Syst em in SBND DTSTART;VALUE=DATE-TIME:20210914T215500Z DTEND;VALUE=DATE-TIME:20210914T221000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-42@indico.physics.ucsd.edu DESCRIPTION:Speakers: Polina Abratenko ()\nThe Short-Baseline Near Detecto r (SBND) is a Liquid-Argon Time Projection Chamber (LArTPC) currently unde r construction at Fermilab. SBND is one of three detectors that make up th e Short Baseline Neutrino (SBN) program\, which aims to investigate the ex cess of low-energy electron-like events observed by the MiniBooNE and LSND experiments\, as well as perform high-precision neutrino-argon cross sect ion measurements. SBND plans to use a novel light collection system which includes X-ARAPUCA devices\, made up of a series of dichroic and wavelengt h-shifting filters that collect photons using SiPMs. This X-ARAPUCA system is also the light collection technology planned for the future DUNE exper iment. This talk will give an overview of the X-ARAPUCA system in SBND as well as cover the current status of testing and implementation.\n\nhttps:/ /indico.physics.ucsd.edu/event/1/contributions/42/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/42/ END:VEVENT BEGIN:VEVENT SUMMARY:The DUNE Vertical Drift Photon Detection System DTSTART;VALUE=DATE-TIME:20210914T204000Z DTEND;VALUE=DATE-TIME:20210914T205500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-14@indico.physics.ucsd.edu DESCRIPTION:Speakers: Laura Paulucci\, for the DUNE Collaboration ()\nThe Deep Underground Neutrino Experiment (DUNE) is a long baseline neutrino ex periment designed to mainly investigate oscillation parameters\, supernova physics and proton decay. Its far detector will be composed of four liqui d argon time projection chamber (LArTPC) underground modules\, in South Da kota-USA\, which will detect a neutrino beam produced at Fermilab\, 1300 k m away\, where a near detector will be in place. The second DUNE far detec tor module\, Vertical Drift\, will be a single phase LArTPC with electron drift along the vertical axis with two volumes of 13.5 m x 6.5 m x 60 m di mensions separated by a cathode plane. The charge collection will be perfo rmed by two anode planes\, each composed by stacked layers of a perforated PCB technology with electrode strips placed at the top and bottom ends of the module. The photon detection system (PDS) will make use of large size X-Arapuca tiles distributed over three detection planes. One plane will c onsist of a horizontal arrangement of double side tiles installed on the h igh voltage cathode plane and two vertical planes\, each placed on the lon gest cryostat membrane walls. A light active coverage of 14.8% over the ca thode and 7.4% over the laterals should allow improvements in the low ener gy physics range that can be probed in DUNE\, especially regarding superno va neutrinos (~10 MeV). We present the initial characterization of the Ver tical Drift PDS using a Monte Carlo simulation and preliminary studies on its reconstruction capabilities at the MeV scale. The information obtained with the PDS alone should allow determination of a neutrino interaction r egion with a precision of at least 65 cm for events with deposited energy above 5 MeV and the deposited energy can be reconstructed with precision b etter than 10%.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/1 4/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of analog signal transmission in LAr for DUNE DTSTART;VALUE=DATE-TIME:20210916T170000Z DTEND;VALUE=DATE-TIME:20210916T171500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-19@indico.physics.ucsd.edu DESCRIPTION:Speakers: Sabrina Sacerdoti (APC-Paris\,France)\nThe Deep Unde rground Neutrino Experiment (DUNE) is currently investigating a new protot ype design for its second Far Detector module. The new concept proposes a Vertical Drift LArTPC\, with a cathode at mid-height in the detector and a nodes made of printed circuit boards\, located at the top and bottom of th e detector. \nIn this context\, the design of the Photo-Detection System ( PDS) needs to be revisited\, opening a window of opportunity for further o ptimization and new developments. It is envisaged to distribute the photo- sensors (x-Arapuca) on the cathode surface. Such a system is required to o perate within high-voltage surfaces\, with both power supply and signal de livered using non-conductive materials. The aim of this talk is to describ e the on-going work to collect and read-out the signal of the photo-sensor s\, which are re-shaped into large tiles containing 160 SiPMs each. A new ganging scheme for the SiPMs is introduced. In particular\, this talk will focus on the proposed option to read out the sensors using an analog opti cal transmitter\, that should ensure the transmission of the signals - wit h a wide dynamic range - to the outside of the cryostat to be digitized.\n \nhttps://indico.physics.ucsd.edu/event/1/contributions/19/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Improved quality tests of R11410-21 photomultiplier tubes DTSTART;VALUE=DATE-TIME:20210917T141500Z DTEND;VALUE=DATE-TIME:20210917T143000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-69@indico.physics.ucsd.edu DESCRIPTION:Speakers: Luisa Hoetzsch (Max-Planck-Institut für Kernphysik) \nPhotomultiplier tubes (PMTs) are often used in low-background particle p hysics experiments\, which rely on an excellent response to single-photon signals and stable long-term operation. In particular\, the Hamamatsu R114 10 model is the light sensor of choice for many detectors utilising xenon as target material. In the past\, this PMT model has shown issues affectin g its long-term operation\, including light emission and the degradation o f the PMT vacuum through small leaks\, which can lead to spurious signals known as afterpulses. In this talk\, we present an improved PMT testing pr ocedure that includes newly developed tests targeted at the detection of i ntermittent light emission as well as vacuum degradation. The use of both new and upgraded facilities allowed us to test in total 368 new PMTs for t he XENONnT detector in a cryogenic xenon environment. We exclude the use o f 26 of the 368 tested PMTs and categorise the remainder according to thei r performance. Given that we have improved the testing procedure compared to XENON1T\, yet we rejected fewer PMTs\, we expect significantly better P MT performance in XENONnT.\n\nhttps://indico.physics.ucsd.edu/event/1/cont ributions/69/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/69/ END:VEVENT BEGIN:VEVENT SUMMARY:Band and Time - Resolved Scintillation for Alpha and Beta Particle s in Xenon\, as a Function of Pressure and Electric Field DTSTART;VALUE=DATE-TIME:20210915T141500Z DTEND;VALUE=DATE-TIME:20210915T143000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-72@indico.physics.ucsd.edu DESCRIPTION:Speakers: Sara Leardini (IGFAE\, Universidade de Santiago de C ompostela)\nIn standard conditions\, Xenon is the only gaseous element wit h a naturally occurring isotope undergoing double-beta decay. Hence exploi ting a gaseous TPC as a tool for accurately reconstructing the topology of bb0nu events is very natural. When considering i) sensitivity to the life time of the decay and ii) energy resolution to separate it from regular bb 2nu events\, a high pressure electroluminescence TPC self-suggests. At the moment\, the NEXT TPC is the most advanced implementation of this idea\, relying deeply on common-wisdom assumptions like the monochromaticity of b oth primary and secondary scintillation (around 172nm)\, the lack of charg e recombination for beta-events\, or the validity of density-scalings for secondary scintillation. Looking into the future\, the unambiguous elucida tion of these phenomena becomes necessary in view of the upcoming ton and multi-ton scale experiments aimed at completely exploring the inverted hie rarchy of neutrino masses.\n\nMotivated by this\, we conducted systematic measurements of S1 and S2\nsignals in a mini-TPC read out with wires\, for varying pressures (1-10bar)\, pressure-reduced electric fields (0-100V/cm /bar) and wire voltages (up to 4kV). Systematic measurements of the time c onstants and scintillation yields obtained in these conditions will be pre sented\, for alpha and beta sources in the VUV\, UV and visible bands\, an d its impact on next generation xenon TPCs discussed.\n\nhttps://indico.ph ysics.ucsd.edu/event/1/contributions/72/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/72/ END:VEVENT BEGIN:VEVENT SUMMARY:The Bubble-Free Liquid Hole-Multiplier: a New Concept for Primary and Secondary Scintillation Detection in Noble-Liquid Detectors DTSTART;VALUE=DATE-TIME:20210917T150000Z DTEND;VALUE=DATE-TIME:20210917T151500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-68@indico.physics.ucsd.edu DESCRIPTION:Speakers: Arindam Roy (Unit of Nuclear Engineering\, Ben-Gurio n University\, Beer-Sheva\, Israel)\nThe bubble-assisted liquid hole-multi plier (LHM) concept\, introduced several years ago\, has been thoroughly i nvestigated as a detection element for primary (S1) and secondary (S2) sci ntillation light detection in noble-liquid TPCs. The basic LHM idea relies on a CsI-coated perforated electrode immersed in the liquid\, with a bubb le of the liquid vapor trapped underneath. Radiation-induced Ionization el ectrons liberated in the liquid and S1 VUV-induced photoelectrons from the CsI photocathode are collected into the holes\; as they cross the liquid- vapor interface into the bubble they generate intense electroluminescence (EL) signals. \nIn this contribution\, we will discuss a new\, simpler\, c oncept – the *bubble-free* LHM. Here\, the liquid-vapor interface lies a bove the perforated electrode\, which now has CsI on its bottom face\; the electrode is fully immersed within the liquid\, with no bubble underneath . Ionization electrons created in the drift volume below the electrode and S1-induced photoelectrons emitted from the photocathode are focused into the holes from below and pass through them with nearly no losses. A strong field above the electrode (taking here the role of the “gate” in conv entional dual-phase TPCs) ensures transmission of the electrons into the v apor phase\, where they produce intense S1 and S2 EL signals. The main adv antages of this concept are that single-VUV photon detection efficiencies can potentially be of the order of 20%\, and that individual VUV photons g enerate large EL signals which cannot be faked by dark counts. Bubble-free imaging LHMs can therefore allow the use of VUV SiPMs or CMOS sensors\, d espite their high dark-count rates. \nThe talk will describe the basic pr inciples of the new concept and summarize our current experimental results in LXe. These include photoelectron extraction efficiency into LXe\, elec tron focusing efficiency into the LHM holes of both ionization electrons a nd photoelectrons\, and the transfer efficiency of electrons towards the l iquid-vapor interface. These results validate the new concept\, providing a promising basis towards further studies and future applications.\n\nhttp s://indico.physics.ucsd.edu/event/1/contributions/68/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/68/ END:VEVENT BEGIN:VEVENT SUMMARY:Characterizing electroluminescence region of the NEXT high pressur e gaseous xenon TPC with Kr gas DTSTART;VALUE=DATE-TIME:20210915T203000Z DTEND;VALUE=DATE-TIME:20210915T204500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-93@indico.physics.ucsd.edu DESCRIPTION:Speakers: Jonathan Haefner (Harvard University)\nThe NEXT expe riment is a neutrino physics program searching for neutrinoless double bet a decay using high pressure gaseous xenon time projection chambers (HPGXeT PC). The HPGXeTPC technology offers several advantages\, including excelle nt energy resolution\, topological event discrimination\, and calibration with gaseous\, radioactive krypton. We will discuss the power of this cali bration technique for characterizing the electroluminescence region\, wher e S2 signals are produced. We discuss the impact of variation in the volta ge on light production and event detection\, as well as demonstrating capa bility to extract structural information about the EL gap from Kr calibrat ion data. We will furthermore show an improved understanding of diffusion related effects in our detector.\n\nhttps://indico.physics.ucsd.edu/event/ 1/contributions/93/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/93/ END:VEVENT BEGIN:VEVENT SUMMARY:GammaTPC: a LAr TPC for MeV Gamma Rays DTSTART;VALUE=DATE-TIME:20210914T160000Z DTEND;VALUE=DATE-TIME:20210914T161500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-57@indico.physics.ucsd.edu DESCRIPTION:Speakers: Tom Shutt (SLAC)\nI will describe GammaTPC\, a propo sed new LArTPC MeV gamma ray instrument concept. The MeV gamma ray sky is essentially unexplored due to the challenge of measuring multiple Compton scatters over a large detector volume. A TPC with low Z material has sign ificant advantages for this measurement\, and enables a relatively inexpen sive detector with large mass and thus high sensitivity in the current era of sharply reduced costs of launching mass to space. A novel ultra low po wer\, fine-grained charge readout is needed to match or exceed the imaging capabilities of currently proposed missions based on Si (or Ge) strip tec hnology. Key developments are also needed for space deployment.\n\nhttps:/ /indico.physics.ucsd.edu/event/1/contributions/57/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/57/ END:VEVENT BEGIN:VEVENT SUMMARY:Scintillation light yield of solid Xenon DTSTART;VALUE=DATE-TIME:20210915T160000Z DTEND;VALUE=DATE-TIME:20210915T170000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-26@indico.physics.ucsd.edu DESCRIPTION:Speakers: Marco Guarise (University of Ferrara)\nScintillation properties of rare gas materials are of primary importance for the next g eneration dark matter and neutrino experiments. Above the liquid phase of such elements\, also solid crystals can be used for suitable detection sch emes but unfortunately only sporadic data regarding the luminescence prope rties of Xenon at temperatures uder its melting point are present in liter ature. In this contribution\, we present a study of the scintillation ligh t yield of Xenon in the solid phase at different temperatures in the range (30−160)K. This study has been carried out exploiting the light emissio n from solid Xenon consequent to the energy release of cosmic rays in the crystal.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/26/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/26/ END:VEVENT BEGIN:VEVENT SUMMARY:XENONnT light sensors: performance and reliability DTSTART;VALUE=DATE-TIME:20210917T140000Z DTEND;VALUE=DATE-TIME:20210917T141500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-12@indico.physics.ucsd.edu DESCRIPTION:Speakers: Giovanni Volta (University of Zurich)\nXENONnT is a dark matter direct detection experiment\, currently in commissioning phase \, located at Laboratori Nazionali del Gran Sasso. It utilizes a TPC fille d with 8.5 t of liquid xenon of which 5.9 t instrumented with 494 3-inch H amamatsu R11410-21 photomultiplier tubes (PMTs) divided into two arrays\, placed at the top and bottom of the active volume. The light sensors have been selected after a testing campaign to ensure a reliable response and a time-stable functioning. These operations are briefly summarized\, while the discussion is focused on the current PMT performance.\n\nhttps://indic o.physics.ucsd.edu/event/1/contributions/12/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/12/ END:VEVENT BEGIN:VEVENT SUMMARY:HeRALD: A Superfluid Helium Sub-GeV Dark Matter Detector DTSTART;VALUE=DATE-TIME:20210915T181500Z DTEND;VALUE=DATE-TIME:20210915T183000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-61@indico.physics.ucsd.edu DESCRIPTION:Speakers: Roger Romani (UC Berkeley)\nHeRALD\, an experiment w ithin the SPICE/HeRALD collaboration\, is a proposed sub-GeV scale dark ma tter detector based on a target of superfluid helium 4 and monitored by a Transition Edge Sensor based readout system. Several promising readout cha nnels exist\, including through monitoring quasiparticle (phonon and roton ) and atomic (singlet photon and triplet) excitations. The quasiparticle c hannel (measured through the detection of quantum evaporated helium atoms) is of particular interest for low mass dark matter direct detection\, wit h sensitivity to DM as light as 1 MeV. I will describe the proposed experi ment and the potential reach of both shovel ready and future detectors\, a s well as recent R&D progress.\n\nhttps://indico.physics.ucsd.edu/event/1/ contributions/61/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/61/ END:VEVENT BEGIN:VEVENT SUMMARY:R&D and characterization of wavelength-shifting reflectors for LEG END-200 and for future LAr-based detectors DTSTART;VALUE=DATE-TIME:20210917T154500Z DTEND;VALUE=DATE-TIME:20210917T160000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-34@indico.physics.ucsd.edu DESCRIPTION:Speakers: Gabriela Rodrigues Araujo (University of Zurich)\nTh e new design of the LAr veto of the LEGEND-200 neutrinoless double beta de cay experiment\, as well as many other LAr-based detectors\, require mater ials that can efficiently shift VUV light to the visible range while being reflective to visible light. For the LAr veto of LEGEND-200\, 14 square m eters of the reflector Tetratex (TTX) were coated in-situ with tetraphenyl butadiene (TPB). For even larger detectors\, TPB coating becomes more ch allenging and plastic films of polyethylene naphthalate (PEN) could be an option to ease scalability. In this context\, we characterized the specifi c sample of the wavelength-shifting reflector (WLSR) from LEGEND-200 and investigated the light yield from the combination of a PEN film with the r eflector TTX. Samples from both WLSRs were measured with spectrophotometer s\, observed with a microscope\, and then characterized in a LAr setup equ ipped with a VUV sensitive photomultiplier. Parameters such as the reflect ance\, absorption length and light yield of the samples (as well as of the setup and its materials) were measured\, such that the intrinsic quantum efficiency of PEN and TPB in LAr (at 87K) could be estimated.\n\nhttps:// indico.physics.ucsd.edu/event/1/contributions/34/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/34/ END:VEVENT BEGIN:VEVENT SUMMARY:Long afterglow: physical and chemical effects of impurities in bul k media and on surfaces in Ar and Xe detectors. DTSTART;VALUE=DATE-TIME:20210914T191500Z DTEND;VALUE=DATE-TIME:20210914T193000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-96@indico.physics.ucsd.edu DESCRIPTION:Speakers: Sergey Pereverzev (Lawrence Livermore National Labor atory)\nAs field of application of noble elements detectors is expanding\ , it is becoming important to understand effects related to presence of im purities. Here we present several examples of known energetic long-living molecules which can be produced in detectors under action of ionizing radi ation and UV light.\nThis work was performed under the auspices of the U.S . Department of Energy by Lawrence Livermore National Laboratory under Con tract DE-AC52-07NA27344. LLNL-ABS-824442-DRAFT\n\nhttps://indico.physics.u csd.edu/event/1/contributions/96/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/96/ END:VEVENT BEGIN:VEVENT SUMMARY:Organic photosensors for detection of VUV scintillation light DTSTART;VALUE=DATE-TIME:20210916T171500Z DTEND;VALUE=DATE-TIME:20210916T173000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-64@indico.physics.ucsd.edu DESCRIPTION:Speakers: Michael Febbraro (Oak Ridge National Laboratory)\nOr ganic semiconductors have gained considerable attention in recent years fo r use in a wide range of applications from OLEDs\, OFETs\, to optical sens ors. They can be prepared on rigid as well as flexible substrates over la rge areas through low-cost fabrication techniques with performance rivalin g low-noise silicon photodiodes. These properties make them a potentially attractive option for future large-area noble element detectors. In this talk\, we will address the feasibility of using organic semiconductors fo r vacuum ultraviolet (VUV) scintillation light detection. The prospects a nd challenges of using organic semiconductor technologies will be discusse d. We will present first measurements on cryogenic operation of organic p hotodiodes and ongoing R&D into making these devices sensitive to VUV scin tillation light.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/ 64/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/64/ END:VEVENT BEGIN:VEVENT SUMMARY:Status and perspectives of the PETALO project DTSTART;VALUE=DATE-TIME:20210915T173000Z DTEND;VALUE=DATE-TIME:20210915T174500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-53@indico.physics.ucsd.edu DESCRIPTION:Speakers: Paola Ferrario (Donostia International Physics Cente r (DIPC))\nPETALO (Positron Emission Tof Apparatus with Liquid xenOn) is a novel concept for positron emission tomography scanners\, which uses liqu id xenon as a scintillation medium and silicon photomultipliers as a reado ut. The large scintillation yield and the fast scintillation time of liqui d xenon makes it an excellent candidate for PET scanners with Time-of-Flig ht measurements. In this talk I will review the status of the PETALO proje ct\, which is now commissioning the first prototype\, devoted to demonstra te the potential of the concept\, measuring the energy and time resolution and to test technical solutions for a complete ring. The prototype consis ts in an aluminum box filled with liquid xenon\, with two arrays of SiPMs on opposite sides facing the xenon. A beta+ emitter source generating 511- keV pairs of gammas is placed in a central port and the SiPMs record the s cintillation light produced by the gamma interactions\, allowing for the r econstruction of the position\, the energy and the time of the interaction s. Finally\, I will discuss the potential of a total-body PET based on thi s technology.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/53/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/53/ END:VEVENT BEGIN:VEVENT SUMMARY:Precision CEvNS measurements with liquid argon scintillators for C OHERENT DTSTART;VALUE=DATE-TIME:20210915T184500Z DTEND;VALUE=DATE-TIME:20210915T190000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-63@indico.physics.ucsd.edu DESCRIPTION:Speakers: Daniel Joseph Salvat (Indiana University)\nThe COHER ENT collaboration has deployed a suite of low-threshold detectors in a low -background corridor of the ORNL Spallation Neutron Source to measure cohe rent elastic neutrino nucleus scattering (CEvNS) on an array of nuclear ta rgets employing different technologies. This has produced CEvNS cross sect ion measurements with CsI and liquid argon scintillator detectors. These m easurements confirm the $N^2$-dependence predicted by the Standard Model a nd have enabled searches for non-standard interactions and accelerator-pro duced dark matter. We aim to construct and deploy a ton-scale liquid argon detector to provide precision measurements of the CEvNS cross section\, i mprove our search for dark matter\, and investigate charged-current intera ctions in argon. In this talk\, we will present an overview of the COHEREN T experiment with a focus on our liquid argon program.\n\nhttps://indico.p hysics.ucsd.edu/event/1/contributions/63/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/63/ END:VEVENT BEGIN:VEVENT SUMMARY:Purification of large volume of liquid argon for the LEGEND-200 ex periment DTSTART;VALUE=DATE-TIME:20210917T171500Z DTEND;VALUE=DATE-TIME:20210917T173000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-74@indico.physics.ucsd.edu DESCRIPTION:Speakers: Grzegorz Zuzel (Jagiellonian University)\nThe LEGEND -200 experiment is under construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. Its main goal is a background-free search for neut rinoless double beta decay of Ge-76. Up to 200 kg of bare high purity germ anium (HPGe) detectors with enrichment in Ge-76 beyond 86% will be deploye d in liquid argon (LAr). The LAr will serve as cooling medium for the dete ctors as well as a passive and an active shield. For the latter the LAr in strumentation will be composed of light guiding fibers connected to silico n photomultipliers detecting scintillation light of argon. It has been alr eady shown in the GERDA experiment that the LAr veto was a very powerful t ool for background rejection and minimization. Details of the LAr veto sys tem will be presented in a dedicated talk. \n The scintillation properti es of LAr (attenuation length\, triplet life time) are worsened by presenc e (at a sub-ppm level) of electronegative impurities such as oxygen\, wate r and nitrogen due to quenching and absorption processes. As a consequence \, the efficiency of the LAr veto may be significantly influenced. In orde r to achieve best possible performance of the veto\, LAr will be purified during initial filling of the LEGEND-200 cryostat. \n The design\, const ruction and performance of a system capable to purify 65 m3 (91 tons) of l iquid argon to sub-ppm level will be presented. The quality of the process ed liquid is monitored in real time by measuring the triplet life time and simultaneous direct measurement of concentrations of impurities like wate r\, oxygen and nitrogen down to 0.1 ppm. Scintillation properties of LAr f illed into the cryostat are also be determined in real time by a dedicated apparatus (LLAMA). For the LAr filled into the cryostat the measured trip let life time is in the range of 1.3 mico_s. If needed\, the LAr purificat ion system may be also used later to purify LAr filled in the cryostat in the loop mode. A dedicated cryogenic pump has been installed on its bottom . The pump is capable to circulate the LAr between the purification system and the cryostat.\n\nhttps://indico.physics.ucsd.edu/event/1/contribution s/74/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/74/ END:VEVENT BEGIN:VEVENT SUMMARY:Simulations of Geometric Aspects for ARAPUCA Designs DTSTART;VALUE=DATE-TIME:20210916T200000Z DTEND;VALUE=DATE-TIME:20210916T201500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-6@indico.physics.ucsd.edu DESCRIPTION:Speakers: Marcio Rostirolla Adames (UTFPR)\nThe photon detecti on system of DUNE Far Detector (FD) is based on ARAPUCA technology. The ne w version of ARAPUCA\, named X-ARAPUCA\, will be used in the first and sec ond modules. As the second module is based on vertical drift\, the design of the X-ARAPUCA needed to be changed and simulation studies are fundament al for the optimization of the device. This work presents the simulation s tudies of the design\, size\, shape\, and SiPM positioning inside the refl ective cavity.\n\nWe designed a Python module that creates the geometry fo r the simulations based on given parameters such as size of the detector\, numbers of SiPM and others. The physics of photons inside the X-ARAPUCA i s simulated by a ray-tracer written in C++ using an uniform grid as accele ration structure. Our simulations focus on reflections and refractions usi ng Snell's law on the interfaces and the total internal reflections inside the Wavelength Shifting Plate\, that absorbs every incoming photon and re -emits them in a random direction.\n\nThe simulation shows that the highes t efficiency is reached for thin X-ARAPUCA with a square shape. Better eff iciency is obtained for larger modules if one considers the number of SiPM per cm$^2$ of the active collection area. Rectangular modules are more ef ficient when the SiPMs are positioned on the short side.\n\nhttps://indico .physics.ucsd.edu/event/1/contributions/6/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Direct detection of argon scintillation light using VUV-sensitive silicon photomultipliers DTSTART;VALUE=DATE-TIME:20210914T214000Z DTEND;VALUE=DATE-TIME:20210914T215500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-23@indico.physics.ucsd.edu DESCRIPTION:Speakers: Teal Pershing (Lawrence Livermore National Lab)\nIn recent decades\, argon-based particle detectors have become a widely-used technology for numerous applications\, including dark matter searches and neutrino measurements. For these detector designs\, WaveLength Shifters (W LS) such as tetraphenylbutadiene (TPB) are used to shift argon's scintilla tion light from the hard UV (128 nm) to visible wavelengths. In particular \, the use of PhotoMultiplier Tubes (PMTs) in argon-based detectors can re quire WLS for successful light detection and event reconstruction. Recentl y\, Hamamatsu has produced a line of Silicon PhotoMultipliers (SiPMs) whic h show appreciable photon detection efficiencies down to 100 nm\; deployin g such photosensors in an argon-based detector could bypass the need for w avelength shifting materials. This talk will present the measurement ongoi ng at LLNL to demonstrate direct detection of argon scintillation light us ing Hamamatsu's VUV-sensitive SiPMs\, as well as quantify their performanc e (gain\, cross-talk\, photon detection efficiency\, etc.) for future depl oyment in argon-based detectors.\n\nThis work was performed under the ausp ices of the U.S. Department of Energy by Lawrence Livermore National Labor atory under Contract DE-AC52-07NA27344.\n\nhttps://indico.physics.ucsd.edu /event/1/contributions/23/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/23/ END:VEVENT BEGIN:VEVENT SUMMARY:Measurement of the Scintillation Light Triggering Efficiency in Mi croBooNE DTSTART;VALUE=DATE-TIME:20210915T213000Z DTEND;VALUE=DATE-TIME:20210915T214500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-89@indico.physics.ucsd.edu DESCRIPTION:Speakers: Vincent Basque (Fermilab)\nThe MicroBooNE Liquid Arg on Time Projection Chamber (LArTPC) has been collecting data since 2015 as part of the Short-Baseline Neutrino (SBN) program using the Booster Neutr ino Beam (BNB) at Fermilab. Its primary physics goal is to contribute to a ddressing the elusive eV-scale sterile neutrino anomaly. MicroBooNE record s and utilises both the ionisation charge and scintillation light produced inside the TPC to reconstruct its events. The latter is collected through a plane of PhotoMultiplier Tubes (PMTs) and is used for accurate event ti ming and cosmic muon rejection. A data-driven method to estimate the scint illation light triggering efficiency from prompt scintillation light for l ow energy cosmic muons will be presented. Results obtained from this metho d are crucial for many analyses that aim to measure low energy interaction s\, and inform triggering strategies in LArTPCs in the SBN and future DUNE programmes.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/89/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/89/ END:VEVENT BEGIN:VEVENT SUMMARY:Measurement of the underground argon radiopurity for Dark Matter d irect searches DTSTART;VALUE=DATE-TIME:20210917T174500Z DTEND;VALUE=DATE-TIME:20210917T180000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-8@indico.physics.ucsd.edu DESCRIPTION:Speakers: Pablo Garcia Abia (CIEMAT)\nA major worldwide effort is underway to procure the radiopure argon needed for DarkSide-20k (DS-20 k)\, the first large scale detector of the new Global Argon Dark Matter Co llaboration. The Urania project will extract and purify underground argon (UAr) from CO2 wells in the USA at a production rate of 300 kg/day. Additi onal chemical purification of the UAr will be required prior to its use in the DS-20k LAr-TPC. The Aria project will purify UAr using a cryogenic di stillation column (Seruci-I)\, located in Sardinia (Italy). Assessing the UAr purity in terms of Ar-39 is crucial for the physics program of the Dar kSide-20k experiment. DArT is a small (1 litre) radiopure chamber that wil l measure the Ar-39 depletion factor in the UAr. The detector will be imme rsed in the active liquid Ar volume of ArDM (LSC\, Spain)\, which will act as a veto for gammas from the detector materials and the surrounding rock . In this talk\, I will review the status and prospects of the UAr project s for DarkSide-20k.\n\nhttps://indico.physics.ucsd.edu/event/1/contributio ns/8/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Demonstration of ~ns timing resolution in MicroBooNE Photon Detect ion System DTSTART;VALUE=DATE-TIME:20210916T201500Z DTEND;VALUE=DATE-TIME:20210916T203000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-22@indico.physics.ucsd.edu DESCRIPTION:Speakers: Dante Totani (University of California\, Santa Barbr a)\nThe MicroBooNE detector\, located in the Booster Neutrino Beamline (BN B) at Fermilab\, has been operating since 2015 as part of the Short Baseli ne Neutrino (SBN) program. MicroBooNE's Liquid Argon Time Projection Chamb er is accompanied by a Photon Detection System (consisting of 32 PMTs) use d to measure the argon scintillation light and determine the timing of the neutrino interactions. This work will demonstrate the analysis techniques developed to improve the timing resolution of the light signals to $\\mat hcal{O}$(ns). The result obtained allows MicroBooNE to access the 2ns neut rino pulse structure of the BNB for the first time\, which enables signifi cant enhancement of cosmic background rejection for all neutrino analyses. Furthermore\, the ns timing resolution opens the door for searching new long-lived-particles (i.e. Heavy Neutral Lepton\, Higgs Portal Scalars) a s we develop light-based trigger systems for future large LArTPC experimen ts\, namely SBN and DUNE.\n\nhttps://indico.physics.ucsd.edu/event/1/contr ibutions/22/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/22/ END:VEVENT BEGIN:VEVENT SUMMARY:LArTPC for Neutrino Detection (Keynote) DTSTART;VALUE=DATE-TIME:20210914T140500Z DTEND;VALUE=DATE-TIME:20210914T144500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-104@indico.physics.ucsd.edu DESCRIPTION:Speakers: Elena Gramellini (Fermi National Accelerator Laborat ory)\nThe Liquid Argon Time Projection Chamber (LArTPC) represents one of the most advanced experimental technologies for physics at the Intensity F rontier due to its full 3D-imaging\, excellent particle identification and precise calorimetric energy reconstruction. Reviewing current experiment al efforts and potential technology upgrades\, this talk summarizes the ex citing physics we can explore using LArTPCs.\n\nhttps://indico.physics.ucs d.edu/event/1/contributions/104/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/104/ END:VEVENT BEGIN:VEVENT SUMMARY:Scintillation-based background rejection methods in large scale LA rTPCs DTSTART;VALUE=DATE-TIME:20210915T160000Z DTEND;VALUE=DATE-TIME:20210915T170000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-21@indico.physics.ucsd.edu DESCRIPTION:Speakers: Anyssa Navrer-Agasson (The University of Manchester) \nLarge scale single-phase liquid argon time projection chambers (LArTPCs) such as DUNE can achieve MeV-scale thresholds\, making them sensitive to solar and supernova neutrinos. In this energy region\, low energy activity from radiological sources can be a dominant background. LArTPCs can make use of the scintillation light to discriminate against radiological backgr ounds. This talk will present rejection methods exploiting the scintillati on light in LArTPCs. We studied a range of detector configurations and rej ection approaches based on the properties of the light (pulse shape discri mination) and/or on the detector design.\n\nhttps://indico.physics.ucsd.ed u/event/1/contributions/21/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/21/ END:VEVENT BEGIN:VEVENT SUMMARY:Measuring the Rayleigh Scattering Length of Liquid Argon in ProtoD UNE-SP DTSTART;VALUE=DATE-TIME:20210914T181500Z DTEND;VALUE=DATE-TIME:20210914T183000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-17@indico.physics.ucsd.edu DESCRIPTION:Speakers: Kyle Spurgeon (Syracuse University)\nProtoDUNE-SP wa s a single-phase liquid argon time projection chamber - a prototype for th e first far detector module of the Deep Underground Neutrino Experiment (D UNE) with an active volume of 700 tons operating until 2020. It was instal led at the CERN Neutrino Platform and took particle beam and cosmic ray da ta over its two year lifespan. Liquid argon scintillation light is still a n active subject of study with open questions about the impact of scatteri ng and absorption in such a large detector. Here\, we combine ProtoDUNE-SP cosmic-ray data with its large photon detector coverage and large drift v olume to measure the Rayleigh scattering length of liquid argon. We also l ay the groundwork for investigating Rayleigh scattering of scintillation l ight from xenon-doped liquid argon.\n\nhttps://indico.physics.ucsd.edu/eve nt/1/contributions/17/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/17/ END:VEVENT BEGIN:VEVENT SUMMARY:Usage of PEN as self-vetoing structural material with wavelength s hifting capabilities in the LEGEND experiment DTSTART;VALUE=DATE-TIME:20210917T151500Z DTEND;VALUE=DATE-TIME:20210917T153000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-35@indico.physics.ucsd.edu DESCRIPTION:Speakers: Luis Manzanillas (Max Planck Institute for Physics)\ nPolyethylene naphthalate (PEN) is an interesting industrial plastic for t he physics community as a wavelength-shifting scintillator. Recently\, PEN structures with excellent radiopurity have been successfully produced usi ng injection compression molding technology. This opens the possibility fo r the usage of optically active structural components with wavelength shif ting capabilities in low-background experiments. Thus\, PEN holders will b e used to mount the Germanium detectors in the LEGEND-200 experiment. The ongoing R&D on PEN will be outlined with a focus on the evaluation of its optical properties. In addition\, the ongoing efforts for further applicat ion of PEN in the LEGEND-1000 experiment will be presented.\n\nhttps://ind ico.physics.ucsd.edu/event/1/contributions/35/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/35/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of a Pulsed VUV Light Source With Adjustable Intensity DTSTART;VALUE=DATE-TIME:20210917T183000Z DTEND;VALUE=DATE-TIME:20210917T184500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-30@indico.physics.ucsd.edu DESCRIPTION:Speakers: Austin McDonald (University of Texas at Arlington)\n Precise characterization of photodetectors sensitive to vacuum ultraviolet (VUV) require a calibration source able to:i) produce and transmit photon s in the VUV (128nm - 200nm)\, ii) control the light intensity and reliabl y obtain single photon transmission\, iii) produce a pulsed photon emissi on so as to correlate the source with the VUV readout.In this talk\, we w ill present the development of gas based pulsed spark. This source emits V UV light in the range produced by noble element detectors and is coupled w ith a gas based attenuator capable of delivering single photon intensities to the device under test. We will present the first data taken with this device as well as highlight some of its recent applications in the develop ment of novel VUV photon detectors.\n\nhttps://indico.physics.ucsd.edu/eve nt/1/contributions/30/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/30/ END:VEVENT BEGIN:VEVENT SUMMARY:Amorphous Selenium based VUV Photodetector for use in Liquid Noble Detectors DTSTART;VALUE=DATE-TIME:20210914T211000Z DTEND;VALUE=DATE-TIME:20210914T212500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-29@indico.physics.ucsd.edu DESCRIPTION:Speakers: Jonathan Asaadi (University of Texas at Arlington)\n Photon detectors which are sensitive to the vacuum ultraviolet (VUV) scint illation light produced in noble element particle detectors is an area of active research and development. In particular\, searching for photoconduc tive materials which are capable of converting VUV light to charge could o pen the doorway to a potentially game changing solution of an integrated c harge and light (Q+L) sensor for large area pixel based noble element dete ctors.In this talk\, we present the study of amorphous selenium based phot odetectors capable of operating at cryogenic temperatures and show the fir st measurements and characterizations made with these devices using a VUV source in a cryogenic environment.\n\nhttps://indico.physics.ucsd.edu/even t/1/contributions/29/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/29/ END:VEVENT BEGIN:VEVENT SUMMARY:Measurement of the Light-Yield in MicroBooNE with Isolated Protons DTSTART;VALUE=DATE-TIME:20210915T160000Z DTEND;VALUE=DATE-TIME:20210915T170000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-101@indico.physics.ucsd.edu DESCRIPTION:Speakers: Jiaoyang Li (the University of Edinburgh)\nThe Micro BooNE detector is an 85-ton active mass Liquid Argon Time Projection Chamb er (LArTPC) located on-axis along the Booster Neutrino Beam (BNB). It serv es as a part of the Short-Baseline Neutrino (SBN) program at Fermilab\, wh ich was primarily designed to address the eV-scale sterile neutrinos. The primary signal channel in the LArTPC is ionisation\, but the argon also em its large quantities of scintillation light. Prompt scintillation light in MicroBooNE is recorded with an array of 32 PhotoMultiplier Tubes (PMTs). The scintillation light is used to determine the timing of neutrino intera ctions and to reject cosmic-ray activity.We present a new method of measur ing the light-yield using isolated proton events\, which enables a positio n-dependent light-yield measurement to map the response of the detector ac ross its volume. This method can be used to calibrate the light response i n large-scale LArTPC detectors as well as to test assumptions used in simu lating scintillation light.\n\nhttps://indico.physics.ucsd.edu/event/1/con tributions/101/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/101/ END:VEVENT BEGIN:VEVENT SUMMARY:Electronic versus nuclear recoil discrimination in liquid xenon wi th PIXeY DTSTART;VALUE=DATE-TIME:20210915T150000Z DTEND;VALUE=DATE-TIME:20210915T151500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-32@indico.physics.ucsd.edu DESCRIPTION:Speakers: Vetri Velan (University of California\, Berkeley)\nT he two-phase liquid/gas xenon time projection chamber is one of the leadin g technologies for dark matter direct detection. A crucial part of using t his technology is being able to classify energy deposits as nuclear recoil s (NR) or electronic recoils (ER). This allows upcoming experiments like X ENONnT and LZ to mitigate ER backgrounds like Rn daughters and solar neutr inos. I will present an analysis of ER-NR discrimination\, using data from the PIXeY (Particle Identification in Xenon at Yale) experiment. PIXeY wa s an R&D-scale xenon TPC that operated at drift fields between 50 and 2000 V/cm\; its data allows us to study discrimination across this wide range of fields\, as well as its dependence on recoil energy.\n\nhttps://indico. physics.ucsd.edu/event/1/contributions/32/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/32/ END:VEVENT BEGIN:VEVENT SUMMARY:Low Energy Physics Sensitivity in a Radiopure DUNE-like Detector DTSTART;VALUE=DATE-TIME:20210915T190000Z DTEND;VALUE=DATE-TIME:20210915T191500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-28@indico.physics.ucsd.edu DESCRIPTION:Speakers: Eric Church (PNNL)\nWith radiopurity controls and sm all design modifications a kton-scale liquid argon time projection chamber similar to DUNE could be used for enhanced low energy physics searches. T his includes improved sensitivity to supernova and solar neutrinos\, and e ven weakly interacting massive particle dark matter\, and a possibility of 0nubb detection with large Xe316 doping. This talk will present initial s imulation studies to optimize the design and evaluate physics sensitivitie s. It will also discuss the tools being developed to support a large-scale radiopurity assay campaign necessary to construct such a detector.\n\nhtt ps://indico.physics.ucsd.edu/event/1/contributions/28/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/28/ END:VEVENT BEGIN:VEVENT SUMMARY:Salting as a bias mitigation technique in LUX-ZEPLIN (LZ) DTSTART;VALUE=DATE-TIME:20210915T204500Z DTEND;VALUE=DATE-TIME:20210915T210000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-24@indico.physics.ucsd.edu DESCRIPTION:Speakers: Tyler Anderson (SLAC)\nAs LZ prepares to push the li mits of known physics and improve our understanding of the nature of dark matter\, it is important to ensure that these gains are not mistakenly inf luenced by human biases towards achieving such results. Such biases often appear in the process of analysis when unconsciously or consciously expect ing certain outcomes. Many techniques for avoiding these biases have been employed over the years including blinding and using hidden parameters. LZ will be using a method known as salting\, in which fake signal events are injected into our data stream and removed after analysis is complete. In this presentation I will explain the historical motivations for pursuing b ias mitigation\, the process through which LZ salts its data\, and some re sults after salting LZ’s simulated mock data challenges.\n\nhttps://indi co.physics.ucsd.edu/event/1/contributions/24/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/24/ END:VEVENT BEGIN:VEVENT SUMMARY:Assembly and characterization of a large area VUV sensitive SiPM a rray for the nEXO TPC teststand at Stanford DTSTART;VALUE=DATE-TIME:20210914T212500Z DTEND;VALUE=DATE-TIME:20210914T214000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-37@indico.physics.ucsd.edu DESCRIPTION:Speakers: Jacopo Dalmasson (Stanford University)\nOne of the i mportant variables to optimize for a successful detection of the neutrinol ess double-beta decay is the energy resolution at its Q-value. nEXO is a p roposed tonne-scale experiment aiming to search such decay for the isotope Xe-136. It exploits the anticorrelation between ionization and scintillat ion of xenon to improve the ultimate energy resolution. A major factor aff ecting the resolution is the fluctuation of charge and light ultimately co llected.\nIn a time projection chamber (TPC) detector\, the electron colle ction efficiency is usually close to one. Conversely\, the collection of p hotons can vary dramatically depending\, along with other factors\, on the overall light-sensitive area of the detector.\nThe Stanford liquid xenon TPC is a teststand planning to host the first VUV large area (~200cm2) SiP M array. The setup firstly aims to study the feasibility of such system wi th dedicated readout electronics and ultimately to investigate how a bette r light collection affects the detector performances\, important prototypi ng step for nEXO.\nIn this talk\, I will report on the status of the assem bly of this photodetector array\, along with characterization measurements and comparison with simulation.\n\nhttps://indico.physics.ucsd.edu/event/ 1/contributions/37/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/37/ END:VEVENT BEGIN:VEVENT SUMMARY:Characterization of alpha and beta interactions in liquid xenon DTSTART;VALUE=DATE-TIME:20210915T143000Z DTEND;VALUE=DATE-TIME:20210915T144500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-38@indico.physics.ucsd.edu DESCRIPTION:Speakers: Florian Jörg (Max-Planck-Insitut für Kernphysik)\n Experiments used for rare-event searches have seen an impressive increase of sensitivity over the past decades. Among the most sensitive detector ty pes used in direct dark matter searches are dual-phase xenon time projecti on chambers (TPCs). To develop a signal model for such detectors\, the res ponse of the medium to interactions of different particle types needs to b e known to a high accuracy. While several measurements for interactions of electrons\, photons and neutrons were reported in the past\, the literat ure is sparse when it comes to the interaction of alpha particles with liq uid xenon.\n\nThe Heidelberg Xenon (HeXe) dual-phase xenon TPC has been us ed to study the relative scintillation and ionization yield of low energy electrons from a $\\mathrm{^{83m}Kr}$ source\, as well as from alpha parti cles emitted by dissolved $\\mathrm{^{222}Rn}$. Furthermore\, a measuremen t of the electron drift velocity has been carried out. The different elect ric field configurations applied during the measurements were simulated by a detailed three dimensional model of the TPC using COMSOL Multiphysics. The measurements span over a wide range of fields within 7.5$\\\,$V/cm up to 1.64$\\\,$kV/cm\, whereas special emphasis was put on the low-field reg ime.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/38/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/38/ END:VEVENT BEGIN:VEVENT SUMMARY:The LZ Krypton Removal Chromatography System DTSTART;VALUE=DATE-TIME:20210917T180000Z DTEND;VALUE=DATE-TIME:20210917T181500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-82@indico.physics.ucsd.edu DESCRIPTION:Speakers: Andrew Ames (SLAC\, Stanford University)\nTrace radi oactive noble gases are a source of electron recoil backgrounds in liquid xenon dark matter experiments\, and cannot be mitigated by self-shielding. Naturally occurring krypton\, which contains trace amounts of the beta em itter krypton-85\, is found in commercially available research-grade xenon at a level of 1-100 parts-per-billion. In the LZ dark matter experiment\, we require the xenon in the detector to contain no more than 300 parts pe r quadrillion krypton. This limit reduces the rate of electron recoil even ts from krypton-85 to be comparable to the solar neutrino contribution. To achieve this\, krypton is removed from the xenon using gas charcoal chrom atography prior to its deployment in the detector. In this talk\, I will p resent an overview of the krypton removal chromatography system\, which wa s designed\, built and operated by LZ at SLAC.\n\nhttps://indico.physics.u csd.edu/event/1/contributions/82/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/82/ END:VEVENT BEGIN:VEVENT SUMMARY:A proposal to use neutron captures as a source of ultra-low energy nuclear-recoils in liquid xenon DTSTART;VALUE=DATE-TIME:20210916T161500Z DTEND;VALUE=DATE-TIME:20210916T163000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-36@indico.physics.ucsd.edu DESCRIPTION:Speakers: Chami Amarasinghe (University of Michigan)\nWe propo se a technique for an ultra-low energy nuclear-recoil measurement in liqui d xenon using thermal neutron capture. The measurement uses the recoils im parted to xenon nuclei during the de-excitation process following neutron capture\, where the promptly emitted $\\gamma$ cascade can leave the nucle i with up to $0.3$ keV$_\\text{nr}$ of recoil energy. A successful measure ment of the quanta yields below this point will contribute to a greater se nsitivity for liquid xenon experiments that will benefit from a lower ener gy threshold\, mainly those searching for light WIMPs and coherent neutrin o-nucleus scattering. We describe the proposed measurement and its feasibi lity for a small (sub-kilogram) LXe detector that is optimized for a high scintillation gain\, and a pulsed neutron source.\n\nhttps://indico.physic s.ucsd.edu/event/1/contributions/36/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/36/ END:VEVENT BEGIN:VEVENT SUMMARY:Latest Results from the Xenon Breakdown Apparatus DTSTART;VALUE=DATE-TIME:20210916T151500Z DTEND;VALUE=DATE-TIME:20210916T153000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-11@indico.physics.ucsd.edu DESCRIPTION:Speakers: Reed Watson (University of California\, Berkeley)\nT he Liquid Xenon Time-Projection Chamber (LXe TPC) is a leading technology in the fields of dark matter direct detection and neutrinoless double-beta decay searches\, due in no small part to its scalability. The next genera tion of LXe TPCs intend to extend their drift lengths while maintaining th eir high operational electric fields (100s of Volts per cm). This increas e in high voltage requires understanding how the risk of electrostatic dis charge (ESD) correlates with various engineered quantities. To this end\, the Xenon Breakdown Apparatus (XeBrA)\, a 5 Liter spark chamber with adjus table large area electrodes and transparent viewports\, collected data on ESD in LXe under a variety of different conditions. Effects such as condit ioning\, pressure\, ramp rate\, stressed area\, and surface finish were in vestigated. Data regarding the production of light and charge preceding an ESD were collected\, along with novel position reconstruction of the asso ciated plasma streamers using a pair of high frame rate cameras. In this t alk\, I present preliminary results from XeBrA and discuss the evidence co llected for field-emission initiating breakdowns.\n\nhttps://indico.physic s.ucsd.edu/event/1/contributions/11/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Proposal of a Geiger-geometry Single Phase Time Projection Chamber as Potential Detector Technique for next-generation large-scale dark matt er search detector DTSTART;VALUE=DATE-TIME:20210916T143000Z DTEND;VALUE=DATE-TIME:20210916T144500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-10@indico.physics.ucsd.edu DESCRIPTION:Speakers: Qing Lin (University of Science and Technology of Ch ina)\nDual phase time projection chamber using liquid xenon as target mate rial is one of most successful detectors for dark matter direct search\, a nd has improved the sensitivities of searching for weakly interacting mass ive particles by almost five orders of magnitudes in past several decades. However\, it still remains a great challenge for dual phase liquid xenon time projection chamber to be used as the detector in next-generation dark matter search experiments (~50 tonne sensitive mass)\, in terms of reachi ng sufficiently high field strength for drifting electrons\, and sufficien tly low background rate. Here we propose a single phase liquid xenon time projection chamber with detector geometry similar to a Geiger counter\, as a potential detector technique for future dark matter search\, which trad es off field uniformity for less isolated charge signals. In this talk\, I will talk about the concept of such Geiger-geometry single phase TPC (GG- TPC). I’ll show preliminary studies of field simulation and signal recon struction\, which show that such single phase time projection chamber is t echnically feasible and can have sufficiently good signal reconstruction p erformance for dark matter direct search.\n\nhttps://indico.physics.ucsd.e du/event/1/contributions/10/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Development and characterization of a slow wavelength shifting coa ting for background rejection in liquid argon detectors DTSTART;VALUE=DATE-TIME:20210917T190000Z DTEND;VALUE=DATE-TIME:20210917T191500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-40@indico.physics.ucsd.edu DESCRIPTION:Speakers: David Gallacher (Carleton University)\nAlpha decays occurring on surfaces of a liquid argon (LAr) detector\, particularly in l ocations where light collection is incomplete\, can result in prompt appar ent low-energy events that reconstruct similar to dark-matter induced nucl ear recoil events. Alphas and nuclear recoils preferentially excite argon into the singlet state\, which decays with a characteristic time of ~6 ns. To convert the argon scintillation light to visible\, a wavelength shifte r\, TPB\, is typically used due to its short (O(ns)) re-emission time\, th at will preserve the LAr scintillation timing. By coating the problematic detector surface with a wavelength shifting coating with a decay time cons tant much longer than the LAr singlet time\, the pulse-shape of alpha deca ys from these regions will be modified by the coating\, with O(10^5) rejec tion efficiency expected. We describe the development of a pyrene-doped p olymeric wavelength shifting film for the DEAP-3600 experiment\, which wil l be deployed in the next major physics run after the completion of a suit e of hardware upgrades to the detector. We will present an overview of the alpha background rejection technique using the long-time constant wavelen gth shifter coating\, the development and testing of the films to ensure c ryogenic stability for operation in a LAr environment\, and the suite of c haracterization measurements of the film’s critical operational paramete rs\, including relative photo-luminescent quantum yield\, emission spectru m\, and characteristic decay time\n\nhttps://indico.physics.ucsd.edu/event /1/contributions/40/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/40/ END:VEVENT BEGIN:VEVENT SUMMARY:Status of the LZ Dark Matter Experiment DTSTART;VALUE=DATE-TIME:20210914T152500Z DTEND;VALUE=DATE-TIME:20210914T154500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-31@indico.physics.ucsd.edu DESCRIPTION:Speakers: Sally Shaw (UCSB)\nThe fundamental nature of our uni verse is still mostly unknown: 84% of the matter in the universe is dark a nd qualitatively different to everything we understand via the Standard Mo del. Terrestrial experiments devoted to detecting interactions of dark mat ter particles have not yet seen a convincing signal\, but we may be on the cusp of discovery. The LUX-ZEPLIN experiment (LZ) will be the largest dar k matter detector of its kind\, consisting of a 7T liquid xenon target\, a n 2T active skin veto and a 17T gadolinium-loaded liquid scintillator neut ron veto. With science data taking beginning this year\, LZ will probe the oretically well-motivated regions of dark matter phase space to reach area s currently unexplored\; the predicted spin-independent cross section is 1 .4x10-48cm2 for a 40 GeV/c2 mass WIMP. I will give an overview of the LZ e xperiment and its current status.\n\nhttps://indico.physics.ucsd.edu/event /1/contributions/31/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/31/ END:VEVENT BEGIN:VEVENT SUMMARY:Primary Scintillation in Ar-based Mixtures Aimed at Providing a To -signal in DUNE ND-GAr DTSTART;VALUE=DATE-TIME:20210914T174500Z DTEND;VALUE=DATE-TIME:20210914T180000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-62@indico.physics.ucsd.edu DESCRIPTION:Speakers: Diego González-Díaz (University of Santiago de Com postela)\nThe usage of optical information is ubiquitous in neutrino detec tors\, essential for spill-assignment\, background suppression\, and trig gering. Enabling an independent and complete physics program at the ND-GAr  component of DUNE’s near detector suite will undoubtedly benefit from this feature. We discuss in this presentation the prospects towards simult aneous readout of ionization and scintillation signals in ND-GAr and the R &D currently performed in this direction. In particular\, we will focus o n the scintillation of Ar-based mixtures at high pressure.\n\nhttps://indi co.physics.ucsd.edu/event/1/contributions/62/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/62/ END:VEVENT BEGIN:VEVENT SUMMARY:A new high voltage cable feedthrough concept for future dark matte r and neutrino experiments DTSTART;VALUE=DATE-TIME:20210916T154500Z DTEND;VALUE=DATE-TIME:20210916T160000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-46@indico.physics.ucsd.edu DESCRIPTION:Speakers: Luca Pagani (University of California at Davis)\nPhy sics experiments featuring liquid noble gas time projection chambers are b ecoming larger in scale. Consequently\, their high voltage (HV) requiremen ts have increased as well\, making conventional design HV feedthrough (FT) impracticable. A new concept for an HV cable FT usable in a cryogenic env ironment is presented in this talk. It features a co-extruded multi-layere d coaxial cable fabricated with a single material and relies on the abilit y to develop a plastic material with tunable resistivity.\n\nhttps://indic o.physics.ucsd.edu/event/1/contributions/46/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/46/ END:VEVENT BEGIN:VEVENT SUMMARY:Fluorescence light yield and time constants of acrylic (PMMA) exci ted with UV light DTSTART;VALUE=DATE-TIME:20210917T184500Z DTEND;VALUE=DATE-TIME:20210917T190000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-45@indico.physics.ucsd.edu DESCRIPTION:Speakers: Emma Ellingwood (Queen's University)\nRare-event sea rches\, like those for dark matter or neutrinoless double-beta decay\, go to extreme lengths to mitigate various forms of background. Acrylic (poly (methyl methacrylate) or PMMA) is frequently used as a container for scint illating liquids in rare-event searches. Weak fluorescence has been obser ved in certain types of PMMA at room temperature\, introducing a potential source of background. Building on previous work presented at LIDINE 2019 \, by using the optical cryostat with large numerical aperture located at Queen’s University\, we quantify the light yield of the acrylic used in the DEAP dark matter search from room-temperature down to 4 K\, and expres s it relative to the common wavelength shifter TPB. We also study the tim e constants involved.\n\nhttps://indico.physics.ucsd.edu/event/1/contribut ions/45/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/45/ END:VEVENT BEGIN:VEVENT SUMMARY:Delayed electron emission in DarkSide-50 double phase liquid argon TPC DTSTART;VALUE=DATE-TIME:20210914T190000Z DTEND;VALUE=DATE-TIME:20210914T191500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-47@indico.physics.ucsd.edu DESCRIPTION:Speakers: Masayuki Wada (AstroCeNT)\nDual-phase noble gas Time Projection Chambers (TPCs) suffer from spurious electron background event s at the lowest detectable energy region. This background is reported in l iquid xenon TPCs and some of the causes are discussed in the literature. U nderstanding its origin is of paramount importance as this background sets the analysis threshold and affects the most sensitive part of the region of interest for low mass dark matter searches.\n\nWe report the spurious e lectron background events observed in the liquid argon TPC in the DarkSide -50 experiment. We found two different electron populations based on time correlation with preceding events: simultaneous emission and delayed emiss ion. The majority of the former can be associated with photoionization eff ects. The mechanism of the latter is not clear\, but our observations indi cate that they are related to the impurity level in the TPC measured via t he electron lifetime.\n\nhttps://indico.physics.ucsd.edu/event/1/contribut ions/47/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/47/ END:VEVENT BEGIN:VEVENT SUMMARY:Charge and Light Sensing in Noble Liquid TPCs (Keynote) DTSTART;VALUE=DATE-TIME:20210914T200000Z DTEND;VALUE=DATE-TIME:20210914T204000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-103@indico.physics.ucsd.edu DESCRIPTION:Speakers: Veljko Radeka (Brookhaven National Laboratory )\nNob le liquid time projection chambers (TPCs) are of interest for experiments in the quest to answer some most basic questions in both particle and nucl ear physics. The charge and light in both LAr and LXe in response to parti cles of interest are at the limits of detection sensitivity and accuracy o f their respective charge sensing electrodes and light sensors\, such as s ilicon photomultipliers (SiPMs). Both will be applied on a large scale in terms of the sensitive areas covered with fine segmentation and large numb ers of signal channels. All TPCs under design or planned will depend criti cally on the use of low noise electronics immersed in the cryogenic liquid (“cold electronics”) to be operated for a decade or longer. Valuable experience has been gained from the already seven years of operation of th e TPC with the lowest noise so far\, the MicroBooNE. Some highlights of th e experience with charge sensing in that TPC will be presented. The two pr oposed and planned experiments\, DUNE second 10-kton LAr module and nEXO 5 -ton LXe TPC will present similar charge sensing signal-to-noise challenge s\, but much more severe light sensing challenges. This is due to the very large areas of SiPMs required. Methods to address the light sensing chall enge\, to achieve single-photoelectron sensitivity on an array of SiPMs wh ere the avalanche charge signal is deposited on a capacitance of tens of n anofarads\, will be described and the results presented.\n\nhttps://indico .physics.ucsd.edu/event/1/contributions/103/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/103/ END:VEVENT BEGIN:VEVENT SUMMARY:Increasing photodetector light collection with metalenses DTSTART;VALUE=DATE-TIME:20210916T174500Z DTEND;VALUE=DATE-TIME:20210916T180000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-50@indico.physics.ucsd.edu DESCRIPTION:Speakers: Chris Stanford (Harvard University)\nWe present a de sign concept and preliminary results for a method to increase the light co llected by a sparse array of SiPMs by placing a metalens in front of each photodetector. A metalens is a flat lens that uses nanostructures on the s urface to focus incident light. Metalenses offer similar focusing power to traditional lenses\, but with reduced bulk and cost\, and can be mass-pro duced in industry nanofabrication facilities. Their use could allow the ne xt generation of large-scale physics detectors to obtain an increase in th eir light collection and further their science reach while simultaneously reducing the required number of readout channels needed to meet their desi gn goals.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/50/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/50/ END:VEVENT BEGIN:VEVENT SUMMARY:Scintillation yield from electronic and nuclear recoils in superfl uid helium-4 DTSTART;VALUE=DATE-TIME:20210915T151500Z DTEND;VALUE=DATE-TIME:20210915T153000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-56@indico.physics.ucsd.edu DESCRIPTION:Speakers: Ryan Smith (UC Berkeley)\nSuperfluid He-4 is a promi sing target material for direct detection of low mass (\n\nhttps://indico. physics.ucsd.edu/event/1/contributions/56/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/56/ END:VEVENT BEGIN:VEVENT SUMMARY:The liquid argon scintillation detection system for LEGEND-200 DTSTART;VALUE=DATE-TIME:20210915T170000Z DTEND;VALUE=DATE-TIME:20210915T171500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-67@indico.physics.ucsd.edu DESCRIPTION:Speakers: Stefan Schönert (TUM)\nThe LEGEND-200 experiment at LNGS will search quasi-background free for the neutrinoless double-beta d ecay in $^{76}$Ge. Bare high-purity Ge detectors enriched in the isotope $ ^{76}$Ge are operated in liquid argon\, which serves as a coolant and acti ve shielding. Background events are identified by their interaction typolo gies. The key to search background-free for $0\\nu\\beta\\beta$ decays is the identification of events which deposit simultaneously energy in the ge rmanium detectors and in the liquid argon. The latter interactions are ide ntified by scintillation light at 128 nm wavelength. The LAr instrumentati on consists of two concentric\, wavelength-shifting green fiber barrels co ated with TPB that shift the photons from the primary LAr light at 128 nm to the green. The photons are read out with arrays of SiPMs at the ends of the fibers. Due to the close proximity of the LAr instrumentation to the Ge detectors\, strong restrictions apply with respect to the radioactivity of the components. Many commercially available components (e.g.\, packagi ng of SiPMs) exceed this limitation. This talk will present the design\, c onstruction\, and first performance of a wavelength-shifting\, ultrahigh-p urity LAr scintillation detection system which will be operated in the LEG END-200 experiment.\n\nhttps://indico.physics.ucsd.edu/event/1/contributio ns/67/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/67/ END:VEVENT BEGIN:VEVENT SUMMARY:Measurement of the total neutron cross section on argon in the 30 to 70 keV energy range DTSTART;VALUE=DATE-TIME:20210915T214500Z DTEND;VALUE=DATE-TIME:20210915T220000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-52@indico.physics.ucsd.edu DESCRIPTION:Speakers: Tyler Erjavec (University of California Davis)\nThe use of liquid argon as a detection and shielding medium for neutrino and d ark matter experiments has made the precise knowledge of the cross section for neutron interactions on argon an important design and operational par ameter. Nevertheless\, there has been a lingering discrepancy between the total cross-section in the 30-70 keV region given in the Evaluated Nuclear Data File (ENDF) and the single measurement done in the 1990's by an expe riment optimized for higher energy. This discrepancy is significant in tha t the former predicts a large negative resonance in the region while the m easurement did not report such a feature\, giving rise to significant unce rtainty in the penetration depth of neutrons through liquid argon. This ta lk presents results from the Argon Resonant Transport Interaction Experime nt (ARTIE) at the Los Alamos Neutron Science Center (LANSCE)\, the first d edicated experiment optimized for this energy region. The ARTIE measuremen t of the total cross-section as a function of energy confirms the existenc e of a negative resonance in this region\, but not quite as deep as the EN DF prediction.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/52 / LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/52/ END:VEVENT BEGIN:VEVENT SUMMARY:CrystaLiZe: A Solid Future for LZ DTSTART;VALUE=DATE-TIME:20210917T181500Z DTEND;VALUE=DATE-TIME:20210917T183000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-51@indico.physics.ucsd.edu DESCRIPTION:Speakers: Scott Kravitz (Lawrence Berkeley National Lab)\nRado n and its daughter decays continue to limit the sensitivity of WIMP direct dark matter searches\, despite extensive screening programs\, careful mat erial selection and specialized Rn-reduction systems. This problem is only expected to worsen as experiments grow in size. For liquid xenon TPCs\, w e propose to address this through crystallizing the xenon. Once solid\, th e xenon will no longer admit external Rn into the bulk\, allowing existing Rn to decay away. These decays can also be efficiently vetoed using the t ime structure of the decay sequence and the fixed position of daughter iso topes. In this case\, the limiting background for WIMP searches would be n eutrinos from the sun and from cosmic ray muons. In this talk\, I will arg ue that an instrumental radon tag in a crystalline xenon TPC\, perhaps as an upgrade to LZ\, may be the quickest path to reaching the neutrino floor and present preliminary results from a solid xenon test stand which indic ate its viability as a detector medium.\n\nhttps://indico.physics.ucsd.edu /event/1/contributions/51/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/51/ END:VEVENT BEGIN:VEVENT SUMMARY:Introduction DTSTART;VALUE=DATE-TIME:20210914T140000Z DTEND;VALUE=DATE-TIME:20210914T140500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-105@indico.physics.ucsd.edu DESCRIPTION:Speakers: Kaixuan Ni (UCSD)\nhttps://indico.physics.ucsd.edu/e vent/1/contributions/105/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/105/ END:VEVENT BEGIN:VEVENT SUMMARY:A Monte Carlo detector response model for solar neutrino absorptio n on 40Ar in DEAP-3600 DTSTART;VALUE=DATE-TIME:20210915T160000Z DTEND;VALUE=DATE-TIME:20210915T170000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-73@indico.physics.ucsd.edu DESCRIPTION:Speakers: Andrew Erlandson (Carleton University)\nDEAP-3600 is a liquid argon (LAr) scintillation detector designed to search for Weakly Interacting Massive Particles (WIMPs) at SNOLAB. Beyond the search for da rk matter\, the DEAP-3600 detector is also intrinsically sensitive to char ged current interactions on 40Ar from 8B solar neutrinos. Here we present the expected detector response to high energy delayed coincidence events r esulting from neutrino absorption on the ~3.2 tonne target mass. We exploi t the Marley event generator in conjunction with a full optical simulation of the DEAP-3600 detector using the Reactor Analysis Tool (RAT). Through the delayed coincidence channel\, we expect an event yield of (4.69 ± 0.4 3) events in a 7.20 tonne-year exposure in DEAP-3600.\n\nhttps://indico.ph ysics.ucsd.edu/event/1/contributions/73/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/73/ END:VEVENT BEGIN:VEVENT SUMMARY:Scintillation and optical properties of xenon-doped liquid argon DTSTART;VALUE=DATE-TIME:20210915T144500Z DTEND;VALUE=DATE-TIME:20210915T150000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-54@indico.physics.ucsd.edu DESCRIPTION:Speakers: Christoph Vogl (Technical University of Munich)\nLiq uid argon (LAr) is widely employed as a scintillator in rare-event searche s. Its optical and scintillation properties\, as well as the impact of imp urities\, are being studied extensively by many groups world-wide. LAr sci ntillation light exhibits a main emission wavelength of 128 nm\, which mak es propagation and detection challenging because of short attenuation leng ths and low quantum efficiencies of photo sensors in the VUV spectral rang e. \n\nPreviously\, we have determined the attenuation length of purified liquid argon for its own scintillation light to be larger than 110 cm at a wavelength of 128 nm [1\, 2]. Already in 1982 Kubota et al. [3] investiga ted the impact of xenon doping of LAr. Recently\, we have studied the emis sion spectrum and time distribution dependent on the xenon concentration [ 4]. \n\nHere\, we present our latest study of xenon-doped LAr with focus o n the primary photon yield\, the effective triplet lifetime and attenuatio n length\, with xenon concentrations ranging from 3 ppm to 300 ppm. The sc intillation and optical properties were measured simultaneously with the * LLAMA* [5] instrument operated inside *SCARF*\, a 1 ton LAr test stand\, a nd the xenon concentrations using *IDEFIX*\, a dedicated mass spectrometer setup.\n\n[1] A. Neumeier et al. “Attenuation of Vacuum Ultraviolet Lig ht in Liquid Argon”. In: Eur. Phys. J. C72.10 (Oct. 2012).\n\n[2] A. Neu meier et al. “Attenuation of Vacuum Ultraviolet Light in Pure and Xenon- Doped Liquid Argon — An Approach to an Assignment of the near-Infrared E mission from the Mixture”. In: EPL 111.1 (July 2015).\n\n[3] Shinzou Kub ota et al. “Liquid and Solid Argon\, Krypton and Xenon Scintillators”. In: Nucl. Inst. Meth. Phys. Res. 196.1 (May 1982).\n\n[4] A. Neumeier et al. “Intense Vacuum Ultraviolet and Infrared Scintillation of Liquid Ar- Xe Mixtures”. In: EPL 109.1 (Jan. 2015).\n\n[5] Mario Schwarz et al. “ Liquid Argon Instrumentation and Monitoring in LEGEND-200”. In: ANIMMA 2 021 (July 2021)\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/5 4/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/54/ END:VEVENT BEGIN:VEVENT SUMMARY:A first-principles approach to electron-ion recombination in liqui d xenon DTSTART;VALUE=DATE-TIME:20210915T201500Z DTEND;VALUE=DATE-TIME:20210915T203000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-33@indico.physics.ucsd.edu DESCRIPTION:Speakers: Olivia Piazza ()\nA simulation was developed to expl ore the micro-physics of electron-ion recombination and recombination fluc tuations in liquid xenon detectors. Generating primary mono-energetic par ticles between 100eV and 10keV with a drift field of 50V/cm to 2000V/cm\, the model characterizes recombination events and predicts ionization yield s. Of particular interest\, the simulation utilizes realistic electron tra nsport kinematics and the Cohen-Lekner ‘hot electron’ framework to des cribe the reduced influence of the liquid structure of xenon on the scatte ring of low energy electrons. Results obtained can be useful in the search for dark matter candidates and neutrino detections.\n\nhttps://indico.phy sics.ucsd.edu/event/1/contributions/33/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/33/ END:VEVENT BEGIN:VEVENT SUMMARY:Results from the Xeclipse Liquid Purification Test System for XENO NnT DTSTART;VALUE=DATE-TIME:20210917T170000Z DTEND;VALUE=DATE-TIME:20210917T171500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-83@indico.physics.ucsd.edu DESCRIPTION:Speakers: Joseph Howlett ()\nAs liquid xenon detectors grow in scale\, novel techniques are required to maintain sufficient purity for c harges to survive across longer drifts. The Xeclipse test facility at Colu mbia University was built to test the removal of electronegative impuritie s through cryogenic filtration powered by a liquid xenon pump\, making pos sible a far higher mass flow rate than gas-phase purification through hot getters. This talk will outline the results of this R&D\, which were used to guide the design and commissioning of the XENONnT liquid purification s ystem. Thanks to this innovation\, XENONnT has achieved an electron lifeti me greater than 10 milliseconds in an 8.5 ton target mass\, perhaps the hi ghest purity ever measured in a liquid xenon detector.\n\nhttps://indico.p hysics.ucsd.edu/event/1/contributions/83/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/83/ END:VEVENT BEGIN:VEVENT SUMMARY:Understanding the impact of high voltage electrodes on low-energy dark matter searches with the LZ dual phase xenon TPC DTSTART;VALUE=DATE-TIME:20210916T150000Z DTEND;VALUE=DATE-TIME:20210916T151500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-59@indico.physics.ucsd.edu DESCRIPTION:Speakers: Ryan Linehan ()\nTo observe signals from low-energy nuclear recoils\, including WIMP-xenon scatters\, the LZ dark matter detec tor must maintain strong drift and extraction fields within its dual-phase xenon time projection chamber (TPC). These fields are established by a se t of four stainless steel wire mesh high voltage electrode grids that span the full width of the TPC. During operation at their design voltages\, th ese grids will achieve wire surface fields well above 20 kV/cm. These high fields can produce spurious charge signals and signals from real radioact ive decays with atypical light-to-charge ratios\, both of which can lead t o low-energy backgrounds in LZ science data. This talk will present studie s of possible grid contributions to electron backgrounds in the low-energy regime\, with a focus on two specific sources: field-induced emission and radiogenic emission.\n\nhttps://indico.physics.ucsd.edu/event/1/contribut ions/59/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/59/ END:VEVENT BEGIN:VEVENT SUMMARY:Sensitivity of the nEXO neutrinoless double beta decay experiment DTSTART;VALUE=DATE-TIME:20210914T154500Z DTEND;VALUE=DATE-TIME:20210914T160000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-60@indico.physics.ucsd.edu DESCRIPTION:Speakers: Brian Lenardo (Stanford University)\nThe nEXO experi ment is a proposed next-generation search for the neutrinoless double beta decay ($0\\nu\\beta\\beta$) of Xe-136. The detector will be a 5-tonne\, m onolithic liquid xenon TPC with a target enriched to 90% in the isotope of interest. In this talk\, we will discuss a new evaluation of the experime nt’s sensitivity to $0\\nu\\beta\\beta$\, given recent updates to the de tector design and improved modeling of the signal readout. Specific improv ements include detailed\, data-driven modeling of signal development in th e charge readout tiles (and subsequently improved modeling of the energy a nd position reconstruction)\, the development of new machine-learning anal yses to improve signal/background separation\, and an updated detector geo metry. We will discuss how these changes lead to a projected 90% CL exclus ion sensitivity on the $0\\nu\\beta\\beta$ halflife of $1.35\\times10^{28} $ yrs in nEXO\, approximately two orders of magnitude beyond existing expe rimental limits.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/ 60/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/60/ END:VEVENT BEGIN:VEVENT SUMMARY:Preliminary Tests of Dual-Phase Xenon-Doped Argon Mixtures in the CHILLAX Detector DTSTART;VALUE=DATE-TIME:20210915T153000Z DTEND;VALUE=DATE-TIME:20210915T154500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-41@indico.physics.ucsd.edu DESCRIPTION:Speakers: Ethan Bernard (Lawrence Livermore National Laborator y)\nUtilizing xenon as a dopant at the $10^{-5}$ level in the gas region o f a dual-phase argon time projection chamber (TPC) presents the enticing p rospects of faster and longer wavelength electroluminescence response to i onization electrons. This light can then be directly detected by UV-sensit ive SiPMs without the use of fluorescent wavelength-shifting materials. Th ese advantages would improve sensitivity to low energy nuclear recoils\, w hich kinetically favor argon over xenon\; examples include coherent neutri no-nucleus scattering (CENNS)\, and the possibility of light WIMP dark mat ter interactions. However\, operating such a detector imposes the novel te chnical requirement of cryogenic systems which must prevent xenon from par titioning between the liquid and gas phases. This has compelled the develo pment of CoHerent Ionization Limits in Liquid Argon and Xenon (CHILLAX)\, a new xenon-doped\, dual-phase argon detector. This talk will survey the p hysics implications of xenon-doped argon TPCs\, and describe the special c ooling and circulation systems in CHILLAX. It will conclude with an overvi ew of the current status of the detector and recent cryogenic tests perfor med..\n\nPrepared by LLNL under Contract DE-AC52-07NA27344. Release number LLNL-ABS-824388. The SCGSR program is administered by ORISE under Contrac t DE-SC0014664.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/4 1/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/41/ END:VEVENT BEGIN:VEVENT SUMMARY:Assembly and test of a prototype nEXO charge-readout module with b uilt-in\, cryogenic ASIC readout DTSTART;VALUE=DATE-TIME:20210916T180000Z DTEND;VALUE=DATE-TIME:20210916T181500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-66@indico.physics.ucsd.edu DESCRIPTION:Speakers: Evan Angelico (Stanford University)\nThe nEXO experi ment aims to discover neutrinoless double beta decay of xenon 136\, with a lifetime sensitivity goal of greater than 10^28 years. Compared to using long cables to transmit signals outside of the detector\, mounting amplifi cation and digitization circuitry directly on detector submodules reduces noise and improves measurement fidelity. A cryogenic application specific integrated circuit (ASIC) called CRYO ASIC has been designed by SLAC and f abricated for direct attachment to the nEXO charge readout modules. In thi s talk\, the electrical characteristics of the nEXO charge readout will be discussed along with ASIC performance considerations. A prototype nEXO ch arge-readout module with attached ASIC has been assembled and operated in a liquid xenon time projection chamber\; this module’s performance using a full chain of ASIC-controlling circuit boards will be presented.\n\nhtt ps://indico.physics.ucsd.edu/event/1/contributions/66/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/66/ END:VEVENT BEGIN:VEVENT SUMMARY:Closing Remarks\, Poster Awards\, Next Conference\, etc. DTSTART;VALUE=DATE-TIME:20210917T193000Z DTEND;VALUE=DATE-TIME:20210917T194500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-106@indico.physics.ucsd.edu DESCRIPTION:https://indico.physics.ucsd.edu/event/1/contributions/106/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/106/ END:VEVENT BEGIN:VEVENT SUMMARY:Track imaging in noble liquid detectors DTSTART;VALUE=DATE-TIME:20210916T173000Z DTEND;VALUE=DATE-TIME:20210916T174500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-91@indico.physics.ucsd.edu DESCRIPTION:Speakers: Valerio Pia ()\nLarge volumes of liquid Argon or Xen on constitute an excellent medium for the detection of Neutrino interactio ns and for Dark Matter searches. The established readout method for large noble liquid detectors is based on charge collection in a Time Projection Chamber\, triggered by the scintillation light produced by Ar (128~nm) or Xe (185~nm).\nThis scintillation light can however also be used to attempt a direct reconstruction of charged particle tracks\, provided the photon sensor has imaging capabilities. The primary benefit of this technique is rate capability\, especially relevant for the near detectors of accelerato r based experiments.\nThe design of such an imaging detector\, however\, p resents several challenges: the performance of both current single photon detectors and conventional optical elements in the Vacuum UV is generally inferior compared to the visible spectrum\; a large number of densely pack ed detectors and their dedicated readout electronics must be operated at c ryogenic temperatures\; the optical system must provide a sufficiently wid e and deep field of vision and a large aperture\, in order to minimize the amount of detectors for a given fiducial volume.\nSilicon PhotoMultiplier s (SiPMs) are the ideal photosensor for this application\, since their noi se is suppressed at cryogenic temperature and they can be fabricated in la rge arrays composed of many small pixels\; their lower VUV sensitivity is also being addressed by suppliers with optimized designs. The large channe l count requires the development of a dedicated cryogenic ASIC\, for which several steps have been taken. Multiple options exist for optical systems \, which offer different compromises between ease of construction\, perfor mance and deployment on specific detector geometries. In this contribution we will present the simulation of novel optical systems and the performan ce of small scale prototypes. The progress on larger prototypes and the si mulation of realistic detector geometries will also be reported.\n\nhttps: //indico.physics.ucsd.edu/event/1/contributions/91/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/91/ END:VEVENT BEGIN:VEVENT SUMMARY:Photon detection probability predictionusing one-dimensional gener ative neural network DTSTART;VALUE=DATE-TIME:20210916T203000Z DTEND;VALUE=DATE-TIME:20210916T204500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-48@indico.physics.ucsd.edu DESCRIPTION:Speakers: Wei Mu (Fermilab)\nPhoton detection is important for liquid argon detectors for direct dark matter searches or neutrino proper ty measurements. Precise simulation of photon transport is widely used to understand the probability of photon detection in liquid argon detectors. Traditional photon transport simulation within the framework ofGeant4bring s extreme challenge to computing resources with kilo-tonne-scale liquid ar gon detectors and GeV-level energy depositions. In this work\, we propose a one-dimensional generative model which bypasses photon transport simula tion and predicts the number of photons detected by particular photon dete ctors at the same level of detail asGeant4simulation.The application to ph oton detection systems in kilo-tonne-scale liquid argon detectors demonstr ates this novel generative model is able to reproduceGeant4simulation with good accuracy and 20x-50xfaster. This generative model can be used to fas t predict photon detection probability in huge liquid argon detectors like ProtoDUNE or DUNE.\n\nhttps://indico.physics.ucsd.edu/event/1/contributio ns/48/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/48/ END:VEVENT BEGIN:VEVENT SUMMARY:Noble Element Detectors for Rare Event Searches (Keynote) DTSTART;VALUE=DATE-TIME:20210914T144500Z DTEND;VALUE=DATE-TIME:20210914T152500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-94@indico.physics.ucsd.edu DESCRIPTION:Speakers: Jingke Xu (Lawrence Livermore National Laboratory)\n Particle detectors with noble element targets have grown increasingly popu lar in rare event search physics experiments. The use of noble gases as th e interaction medium enables high purity\, large mass\, and multi-channel signal detection in these experiments. When operated underground\, noble e lement detectors have achieved extremely low background levels\, and unpre cedented sensitivity to rare interactions such as those arising from neutr inos and (as yet hypothetical) dark matter particles. In this presentation \, I will review the benefits and challenges of rare event detection with noble elements\, and discuss their applications in ongoing and planned exp eriments. In particular\, I will focus on the experiments in which the int eractions do not deposit significant energy\, and discuss the R&D required to further lower the achievable energy thresholds in these experiments.\n This work was performed under the auspices of the U.S. Department of Energ y by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA273 44.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/94/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/94/ END:VEVENT BEGIN:VEVENT SUMMARY:Detection of Electroluminescence in Liquid Xenon with a Radial Tim e Projection Chamber DTSTART;VALUE=DATE-TIME:20210916T144500Z DTEND;VALUE=DATE-TIME:20210916T150000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-77@indico.physics.ucsd.edu DESCRIPTION:Speakers: Jianyang Qi (UCSD)\nThe dual-phase xenon Time Projec tion Chamber (TPC) is one of the most successful techniques for rare event searches. It detects both primary scintillation and ionization signals fr om particle interactions in liquid xenon (LXe) . The ionization electrons are converted into electroluminescence in the gas xenon\, subsequently det ected by the same photo-sensors for the primary scintillation. However\, i t gradually becomes more and more challenging to build the TPCs with very large diameter while requiring sub-mm flatness of the gas gap. Here we dev eloped a Radial TPC (RTPC) which can create and detect the electroluminesc ence directly in liquid xenon. It can simplify the design of the TPC by re placing the large diameter electrodes with a single wire in the axial cent er. The design of a liquid xenon RTPC and its first performance will be pr esented.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/77/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/77/ END:VEVENT BEGIN:VEVENT SUMMARY:Neutrino Backgrounds in Future Liquid Noble Element Dark Matter Di rect Detection Experiments DTSTART;VALUE=DATE-TIME:20210916T210000Z DTEND;VALUE=DATE-TIME:20210916T211500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-25@indico.physics.ucsd.edu DESCRIPTION:Speakers: Pietro Giampa (SNOLAB)\nExperiments that use liquid noble gasses as target materials\, such as argon and xenon\, play a signif icant role in direct detection searches for WIMP(-like) dark matter. As th ese experiments grow in size\, they will soon encounter a new background t o their dark matter discovery potential from neutrino scattering off nucle i and electrons in their targets. Therefore\, a better understanding of th is new source of background is crucial for future large-scale experiments such as ARGO and DARWIN. In this work\, we study the impact of atmospheric neutrino flux uncertainties\, electron recoil rejection efficiency\, reco il energy sensitivity\, and other related factors on the dark matter disco very reach. We also show that a significant improvement in sensitivity can potentially be obtained\, at large exposures\, by combining data from ind ependent argon and xenon experiments.\n\nhttps://indico.physics.ucsd.edu/e vent/1/contributions/25/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/25/ END:VEVENT BEGIN:VEVENT SUMMARY:Very-thick transparent GEMs with wavelength-shifting capability fo r noble element TPCs DTSTART;VALUE=DATE-TIME:20210917T144500Z DTEND;VALUE=DATE-TIME:20210917T150000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-71@indico.physics.ucsd.edu DESCRIPTION:Speakers: Marcin Kuźniak (AstroCeNT / CAMK PAN)\nA new concep t for the simultaneous detection of primary and secondary scintillation i n time projection chambers is described. Its core element is a type of ve ry thick GEM structure machined from a wavelength shifting material and su pplied with PEDOT:PSS-based transparent electrodes.\n\nSuch a device is sc alable to very large surface areas needed by future generations of noble e lement TPCs. Because of its optical properties it can significantly improv e the light collection efficiency\, energy threshold and resolution of con ventional micropattern gas detectors as well as wire mesh TPCs.\n\nProduct ion\, optical and electrical characterization\, first measurements perfor med with the new device will be reported. Further tests and R&D steps wil l also be discussed.\n\nhttps://indico.physics.ucsd.edu/event/1/contributi ons/71/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/71/ END:VEVENT BEGIN:VEVENT SUMMARY:Scintillation and ionisation response of the ReD double-phase argo n TPC DTSTART;VALUE=DATE-TIME:20210914T170000Z DTEND;VALUE=DATE-TIME:20210914T171500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-15@indico.physics.ucsd.edu DESCRIPTION:Speakers: Marco Rescigno (INFN/Roma)\nThe Recoil Directionalit y (ReD) experiment aims to investigate the directional sensitivity of argo n-based Time Projection Chambers (TPCs) via columnar recombination to nucl ear recoils in the energy range of interest (20–200 keV) for direct dark matter searches. Directional information is an essential requisite for co rrelating a candidate dark matter signal with the expected “wind” of d ark matter from the Cygnus constellation. As part of the DarkSide programm e\, the ReD collaboration has designed and constructed a double-phase argo n TPC and fully characterised its performance using various gamma-ray and neutron sources. The key novel feature of the ReD TPC is a readout system based on cryogenic Silicon Photomultipliers (SiPMs)\, which offer a higher photon detection efficiency relative to typical cryogenic photomultiplier s. Here we report on measurements of the scintillation light yield and ion ization gain performed over five months of continuous operation. We presen t a phenomenological parameterisation of the electron-ion recombination pr obability in liquid argon (LAr) that describes the anti-correlation betwee n scintillation and ionisation signals measured by ReD as a function of dr ift field for electron recoils between 50–500 keV and fields up to 1000 V/cm. Finally\, a likelihood analysis is performed in order to study the d irectional response of the ReD TPC to neutrons of known energy and directi on.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/15/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Predicting transport effects of scintillation light signals in lar ge-scale liquid argon detectors DTSTART;VALUE=DATE-TIME:20210914T180000Z DTEND;VALUE=DATE-TIME:20210914T181500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-20@indico.physics.ucsd.edu DESCRIPTION:Speakers: Patrick Green (The University of Manchester)\nLiquid argon is being employed as a detector medium in neutrino physics and dark matter searches. A recent push to expand the applications of scintillatio n light in Liquid Argon Time Projection Chamber neutrino detectors has nec essitated the development of new methods of simulating this light. The pre sently available methods tend to be prohibitively slow or imprecise due to the combination of detector size and the amount of energy deposited by ne utrino beam interactions. In this talk we present a semi-analytical model to predict the quantity of argon scintillation light observed by a light d etector based only on the relative positions between the scintillation and light detector. Our proposed method can be used to simulate light propaga tion in large-scale liquid argon detectors such as DUNE or SBND. This talk is based on Eur. Phys. J. C 81\, 349 (2021)\, and will expand on the meth ods presented there applying them to other detector mediums such as liquid xenon or xenon-doped liquid argon.\n\nhttps://indico.physics.ucsd.edu/eve nt/1/contributions/20/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Optical Modeling and Position Reconstruction for DarkSide-20k DTSTART;VALUE=DATE-TIME:20210915T211500Z DTEND;VALUE=DATE-TIME:20210915T213000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-76@indico.physics.ucsd.edu DESCRIPTION:Speakers: Michael Poehlmann (University of California\, Davis) \nDarkSide-20k is a next-generation direct dark matter search experiment u nder construction at the Gran Sasso National Laboratory (LNGS) in Italy. T he core of the detector is a two-phase liquid argon time projection chambe r designed to probe WIMP interactions down to the neutrino floor. To ensur e the 200 ton-year exposure has zero instrumental backgrounds\, low-radioa ctivity underground argon is used as the detector medium. Backgrounds from detector surfaces are primarily rejected through fiducialization\, which requires accurate reconstruction of event vertices. Monte Carlo simulation s of interactions within the detector have been used to study the position reconstruction resolution of DarkSide-20k. In this talk\, I present the d etector optical model and discuss the performance of machine learning-base d position reconstruction algorithms on simulated DarkSide-20k datasets.\n \nhttps://indico.physics.ucsd.edu/event/1/contributions/76/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/76/ END:VEVENT BEGIN:VEVENT SUMMARY:Modeling the Effect of Impurities on the Electron Lifetime in Liqu id Xenon for nEXO DTSTART;VALUE=DATE-TIME:20210917T173000Z DTEND;VALUE=DATE-TIME:20210917T174500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-79@indico.physics.ucsd.edu DESCRIPTION:Speakers: Ako Jamil (Yale University)\nnEXO is a 5 tonne liqui d xenon (LXe) time projection chamber (TPC) planned to search for the neut rinoless double beta decay of $^{136}$Xe with a target half-life sensitivi ty of about $10^{28}$ years. Electrons from an event within the TPC will b e drifted up to $1.3\\\,\\mathrm{m}$ and to ensure minimal charge loss nEX O aims to reach an electron lifetime of $10\\\,\\mathrm{ms}$. This lifetim e is inversely proportional to the concentration of electro-negative impur ities\, for which multiple species with different attachment cross-section s may be important. Various sources for impurities such as diffusion out o f commonly used plastics\, desorption from metal surfaces and leaks to atm osphere were investigated. This talk will go over measurements of outgassi ng from plastics and relevant parameters to extrapolate to the effect impu rities have on the electron lifetime in large liquid xenon detectors.\n\nh ttps://indico.physics.ucsd.edu/event/1/contributions/79/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/79/ END:VEVENT BEGIN:VEVENT SUMMARY:Boosting background suppression in the NEXT experiment through Ric hardson-Lucy deconvolution DTSTART;VALUE=DATE-TIME:20210916T204500Z DTEND;VALUE=DATE-TIME:20210916T210000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-88@indico.physics.ucsd.edu DESCRIPTION:Speakers: Ander Simón Estévez (Ben-Gurion University of the Negev)\nThe NEXT collaboration aims to observe neutrinoless double beta de cay in gaseous 136Xe using a high pressure gaseous Xe time projection cham ber with signal amplification by means of electroluminescence (EL). One of the advantages of the technique is that it allows for track reconstructio n making use of a sensor plane equipped with SiPMs located nearby the EL r egion. However\, the signals recorded in the TPC are degraded by electron diffusion and spread of light produced in the EL process\, limiting the po tential of the detection scheme. \n\nWe have recently developed an improve d reconstruction procedure based on the Richardson-Lucy deconvolution\, an iterative algorithm well-known in image processing and de-blurring. Decon volution allows reversing the smearing mechanisms in the NEXT TPC and sign ificantly enhances the definition of reconstructed tracks. Consequently\, detector performance is strongly boosted\, with a five-fold improvement in background rejection demonstrated on experimental data.\n\nIn the talk we will detail the algorithm application in the context of the NEXT experime nt with a focus on the performance in NEXT-White\, a 50 cm TPC currently o perating underground at Laboratorio Subterráneo de Canfranc. We will desc ribe the procedure applied to characterize the optical response of the cha mber by obtaining the point spread function that best describes the observ ed signals. We will also discuss the potential of the algorithm to ease th e tracking hardware requirements of future detector iterations.\n\nhttps:/ /indico.physics.ucsd.edu/event/1/contributions/88/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/88/ END:VEVENT BEGIN:VEVENT SUMMARY:Neutral bremsstrahlung calculations for TPCs DTSTART;VALUE=DATE-TIME:20210916T211500Z DTEND;VALUE=DATE-TIME:20210916T213000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-81@indico.physics.ucsd.edu DESCRIPTION:Speakers: Pablo Amedo (Instituto Galego de Física de Altas En erxías (IGFAE\, USC))\nNeutral bremsstrahlung (NBrS) in the gas phase of Argon and Xenon TPCs has been measured recently\, with little ambiguity\, by groups in Novosibirsk and Coimbra/Santiago. While its implications for future experiments are intriguing\, and so far open-ended\, a lack of reli able calculations precludes the full exploitation of the phenomenon.\n\nWe have recently created a simulation module in the electron-transport code Pyboltz\,implementing the original theoretical framework introduced by Buz ulutskov et al.\, and showed an excellent description of NBrS data. The fr amework\, soon to be accessible through GitHub\, allows calculations of NB rS in any noble element mixture\, as well as in weakly-quenched mixtures\, at all electrical fields of interest below the excitation thresholds. For illustration purposes\, we will present results obtained in cases of inte rest\, discuss the analytical limits\, future improvements\, and the scope of this project.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions /81/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/81/ END:VEVENT BEGIN:VEVENT SUMMARY:Optical Light Collection Amount Studies for Dedicated Measurements DTSTART;VALUE=DATE-TIME:20210916T191500Z DTEND;VALUE=DATE-TIME:20210916T193000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-107@indico.physics.ucsd.edu DESCRIPTION:Speakers: A. Carolina Garcia B. ()\nIn long baseline Neutrino experiments like T2K\, NOVA and the future DUNE\, the Far Detector include s a Photon Detection System to help identify the physics signals from the noise presented. The signals correspond to the physical processes produced when a neutrino or antineutrino beam is sent from the near detector. When data is taken\, one or multiple processes can be presented in a signal\, and also one or multiple neutrinos can produce a signal\, therefore\, High Energy Physics methods and others are used to establish the correspondenc es and to identify the properties and characteristics of the processes. I n the case of NOVA and DUNE\, the photon detection system is built for a Liquid Argon chamber\, and they share a common analysis tool which is LArS oft. In this presentation\, one of the variables of the Photon Detection s ystem is discussed\, the Optical Hits module\, which gives us the Optical Light Collection Amount. A fictitious detector is used to show how dedicat ed measurements can be done and how this variable can be used for the Cali bration and Commissioning of the Photon Detection System.\n\nhttps://indic o.physics.ucsd.edu/event/1/contributions/107/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/107/ END:VEVENT BEGIN:VEVENT SUMMARY:Conference Photo on Zoom DTSTART;VALUE=DATE-TIME:20210915T154500Z DTEND;VALUE=DATE-TIME:20210915T155500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-108@indico.physics.ucsd.edu DESCRIPTION:https://indico.physics.ucsd.edu/event/1/contributions/108/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/108/ END:VEVENT BEGIN:VEVENT SUMMARY:Status and prospects of the NEXT experiment DTSTART;VALUE=DATE-TIME:20210915T171500Z DTEND;VALUE=DATE-TIME:20210915T173000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-55@indico.physics.ucsd.edu DESCRIPTION:Speakers: Lior Arazi (Unit of Nuclear Engineering\, Ben-Gurion University\, Beer-Sheva\, Israel)\nNEXT is a staged experimental program aiming at the detection of neutrinoless double beta ($\\beta\\beta0\\nu$) decay in $^{136}$Xe using successive generations of high-pressure gaseous xenon time projection chambers. The collaboration is presently concluding four years of operation of NEXT-White\, a radiopure 50-cm diameter and len gth TPC operated with enriched xenon at 10 bar\, at the Laboratorio Subter ráneo de Canfranc. NEXT-White has successfully demonstrated the two key f eatures of the technology\, namely excellent energy resolution (1% FWHM at the Q-value of the decay) and highly effective topological-based backgrou nd discrimination and served to provide an independent measurement of the $^{136}$Xe two-neutrino double beta decay half-life. The next stage of the program is NEXT-100\, planned for construction in 2022\, which will be tw ice larger than NEXT-White\, and operated with 97 kg of enriched xenon at 15 bar\, with half-life sensitivity on the scale of $10^{26}$ y. NEXT-100 will be superseded by a tonne-scale detector with a sensitivity of $10^{27 }$ y around 2026. Parallel to the incremental increase in TPC size\, the c ollaboration pursues an extensive R&D program to develop the capability of detecting the $^{136}$Ba daughter resulting from $^{136}$Xe double beta d ecays inside a running TPC using single molecule fluorescence imaging. Thi s effort can lead to a background-free search for $\\beta\\beta0\\nu$ deca y on the tonne-scale\, with half-life sensitivities close to $10^{28}$ y. This talk will present the status of the program\, summarizing our experie nce with the NEXT-White TPC\, provide an overview of the barium-tagging ac tivities\, and outline the future steps of the experiment.\n\nhttps://indi co.physics.ucsd.edu/event/1/contributions/55/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/55/ END:VEVENT BEGIN:VEVENT SUMMARY:Prospects of S2 analysis in single-phase liquid xenon TPCs DTSTART;VALUE=DATE-TIME:20210916T141500Z DTEND;VALUE=DATE-TIME:20210916T143000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-80@indico.physics.ucsd.edu DESCRIPTION:Speakers: Fabian Kuger (Albert-Ludwigs Universität Freiburg)\ nProportional scintillation in liquid is a possible alternative scheme for charge-to-light signal conversion in future large-size liquid xenon TPCs. Based on detailed simulations we explore the implications on charge signa l (S2) analysis arising from this fast scintillation process. The peaked s ignals allow precise reconstruction of the individual electrons and thus a quantized measure of the S2 strength. Counting the number of electrons si gnificantly improves the S2 resolution for small signals\, relevant for lo w-energy ER studies and sub-GeV WIMP searches. The direct measurement of t he electron arrival times improves S2-only reconstruction of the event dep th and allows for powerful discrimination between single site and multiple site interactions. We discuss these prospects in the context of a future multi-ton liquid xenon experiment such as DARWIN\, assuming a single-phase design with minimal change compared to state-of-the-art dual-phase detect ors.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/80/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/80/ END:VEVENT BEGIN:VEVENT SUMMARY:Study of the luminescence of He/CF4 mixture for the CYGNO detector DTSTART;VALUE=DATE-TIME:20210916T213000Z DTEND;VALUE=DATE-TIME:20210916T214500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-78@indico.physics.ucsd.edu DESCRIPTION:Speakers: Andrea Messina (Sapienza Università di Roma & INFN) \nInnovative experimental techniques are needed to further search for dark matter weakly interacting massive particles. The ultimate limit is repres ented by the ability to efficiently reconstruct and identify nuclear and e lectron recoil events at the experimental energy threshold. Gaseous Time Projection Chambers (TPC) with optical readout are very promising candidat es thanks to the 3D event reconstruction capability of the TPC technique a nd the high sensitivity and granularity of last generation scientific lig ht sensors. The Cygno experiment is pursuing this technique by developing a TPC operated with He/CF4 gas mixture at atmospheric pressure equipped wi th a Gas Electron Multipliers (GEM) amplification stage that produces visi ble light collected by scientific CMOS camera. The optical approach has so far only exploited the light produced during the avalanche processes in t he GEM channels. In this contribution\, we discuss recent measurements per formed by the CYGNO collaboration which show the first evidence of additio nal luminescence in He/CF4 induced by electrons accelerated by a suitable electric field. The electron and photon yield has also been studied for ga s mixtures with a small percentage of isobutane. We give an overview of th e CYNGO project presenting the performances in terms of energy and spacial resolution of prototype detectors that have been built and operated so fa r. Finally\, we illustrate the plan to construct a 1m3 demonstrator expect ed in 2021/22 aiming at a larger scale apparatus in a later stage.\n\nhttp s://indico.physics.ucsd.edu/event/1/contributions/78/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/78/ END:VEVENT BEGIN:VEVENT SUMMARY:Dielectric Strength of Noble and Quenched Gases for High Pressure Time Projection Chambers DTSTART;VALUE=DATE-TIME:20210916T153000Z DTEND;VALUE=DATE-TIME:20210916T154500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-85@indico.physics.ucsd.edu DESCRIPTION:Speakers: Logan Norman ()\nDielectric breakdown strength is on e of the critical performance metrics for gases and mixtures used in large \, high pressure gas time projection chambers. We have experimentally stud ied dielectric breakdown strengths of several important time projection ch amber working gases and gas-phase insulators over the pressure range 100 m bar to 10 bar\, and gap sizes ranging from 0.1to 10 mm. Gases characterize d include argon\, xenon\, CO2\, CF4\, and mixtures 90-10 argon-CH4\,90-10 argon-CO2and 99-1 argon-CF4. We developed a theoretical model for high vol tage breakdown based on microphysical simulations that use PyBoltz electro n swarm Monte Carlo results as input to Townsend- and Meek-like discharge criteria. This model is shown to be highly predictive at high pressure\, o ut-performing traditional Paschen-Townsend and Meek-Raether models signifi cantly. At lower pressure-times-distance\, the Townsend-like model is an e xcellent description for noble gases whereas the Meek-like model provides a highly accurate prediction for insulating gases.\n\nhttps://indico.physi cs.ucsd.edu/event/1/contributions/85/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/85/ END:VEVENT BEGIN:VEVENT SUMMARY:A 10-kg LAr bubble chamber for sub-keV nuclear recoil detection -- Update and Calibration Strategies DTSTART;VALUE=DATE-TIME:20210915T183000Z DTEND;VALUE=DATE-TIME:20210915T184500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-84@indico.physics.ucsd.edu DESCRIPTION:Speakers: Eric Dahl (Northwestern University)\nThe Scintillati ng Bubble Chamber (SBC) Collaboration is developing noble liquid bubble ch ambers for the detection of sub-keV nuclear recoils\, enabling both high-e xposure GeV-scale dark matter searches and CEvNS measurements using reacto r neutrinos. Nuclear recoils (NRs) in these chambers produce both a singl e bubble and a coincident flash of scintillation light\, while electron-re coil (ER) backgrounds produce scintillation only. The physics reach of th ese chambers depends critically on what NR bubble nucleation threshold can be achieved while remaining ER-blind. This threshold will be explored wit h SBC’s first physics-scale device: a 10-kg LAr bubble chamber\, now und er construction\, that will operate in the MINOS tunnel at Fermilab. I wi ll give an update on the status of this chamber and describe the calibrati on strategies we will use to measure the chamber’s sensitivity to nuclea r recoils with energies down to 100-eV.\n\nhttps://indico.physics.ucsd.edu /event/1/contributions/84/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/84/ END:VEVENT BEGIN:VEVENT SUMMARY:Study of Charge and Light Correlation in Electron Beam Energy Resp onse in DUNE's prototype ProtoDUNE-SP LArTPC DTSTART;VALUE=DATE-TIME:20210914T171500Z DTEND;VALUE=DATE-TIME:20210914T173000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-97@indico.physics.ucsd.edu DESCRIPTION:Speakers: Zelimir Djurcic (Argonne National Lab)\nThe Deep Und erground Neutrino Experiment (DUNE) is a cutting-edge experiment for neutr ino science and proton decay studies. The single-phase liquid argon protot ype detector at CERN (ProtoDUNE-SP) is a crucial milestone for DUNE that w ill inform the construction and operation of the first\, and possibly subs equent 17-kt DUNE far detector modules. We have studied the response of DU NE LArTPC prototype detector ProtoDUNE-SP to test beam positrons via both ionization and scintillation signals. We searched for (anti) correlation b etween fluctuations of both scintillation and ionization in liquid argon\, on event-by-event basis. Preliminary results\, to be presented at the con ference\, reveal anti-correlated statistical fluctuation between scintilla tion and ionization in liquid argon.\n\nhttps://indico.physics.ucsd.edu/ev ent/1/contributions/97/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/97/ END:VEVENT BEGIN:VEVENT SUMMARY:Simulating and Validating the X-ARAPUCA light sensors DTSTART;VALUE=DATE-TIME:20210915T160000Z DTEND;VALUE=DATE-TIME:20210915T170000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-5@indico.physics.ucsd.edu DESCRIPTION:Speakers: Gustavo Valdiviesso (Universidade Federal de Alfenas Unifal-MG)\nBrazil's native people have an ingenious trap to catch birds called arapuca. Our ARAPUCA is a light trap that increases the collection area of regular SiPMs by making use of wavelength shifters and a dichroic filter. Its latest iteration\, the X-ARAPUCA\, will be used alongside PMTs in Short-Baseline Near Detector (SBND) and as the standalone photon detec tor in the Deep Underground Neutrino Experiment (DUNE). The SBND is part o f the three-detectors Short-Baseline Neutrino (SBN) Program\, search for a possible sterile neutrino in short-baseline oscillations (with SBND locat ed at 100m from the source)\, while DUNE will look for signs of CP-violati on in long-baseline (1300km) oscillations\, among other items in a rich ph ysics program. Contributing with both experiments\, we developed detailed simulations of each optical element\, from which we highlight the dichroic filter and the wavelength shifters. While the backbone of the simulation uses Geant4\, these two elements were implemented from scratch to ensure t hey would represent our device. The models were individually validated usi ng dedicated characterization data and the resulting simulation reproduces the physical device behavior without the need for a back-fitting calibrat ion. In this presentation we will elaborate on the computer models and the validation processes for each element and compare the resulting full simu lation with the X-ARAPUCA's most recent tests.\n\nhttps://indico.physics.u csd.edu/event/1/contributions/5/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Barium Tagging for the NEXT Neutrinoless Double Beta Decay Program DTSTART;VALUE=DATE-TIME:20210917T191500Z DTEND;VALUE=DATE-TIME:20210917T193000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-87@indico.physics.ucsd.edu DESCRIPTION:Speakers: Karen Navarro (University of Texas at Arlington)\nTh e NEXT collaboration is pursuing a phased program to search for neutrinole ss double beta decay (0nubb) using high pressure xenon gas time projection chambers. The power of electroluminescent xenon gas TPCs for 0nubb deriv es from their excellent energy resolution (\n\nhttps://indico.physics.ucsd .edu/event/1/contributions/87/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/87/ END:VEVENT BEGIN:VEVENT SUMMARY:Low Threshold Operation of the Scintillating Xenon Bubble Chamber DTSTART;VALUE=DATE-TIME:20210916T160000Z DTEND;VALUE=DATE-TIME:20210916T161500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-95@indico.physics.ucsd.edu DESCRIPTION:Speakers: Matthew Bressler (Drexel University)\nA scintillatin g bubble chamber with pure xenon was first operated in 2016 and has previo usly demonstrated coincident bubble nucleation and scintillation detection at thermodynamic thresholds above 4 keV. We now report on operation of th e xenon bubble chamber at thermodynamic thresholds as low as 0.5 keV\, inc luding tests of bubble nucleation associated with gammas\, and sensitivity to low energy neutrons from a $^{88}$Y-Be photoneutron source at threshol ds around 1 keV. Additionally\, these results again demonstrate coincident bubble nucleation and scintillation with 252Cf and background neutrons\, and the scintillation channel allows us to make an efficient background-re ducing cut for a nuclear recoil efficiency analysis\, which is ongoing.\n\ nhttps://indico.physics.ucsd.edu/event/1/contributions/95/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/95/ END:VEVENT BEGIN:VEVENT SUMMARY:Measurements of the X-Arapuca single-cell light detection efficien cy. DTSTART;VALUE=DATE-TIME:20210915T160000Z DTEND;VALUE=DATE-TIME:20210915T170000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-44@indico.physics.ucsd.edu DESCRIPTION:Speakers: Henrique Souza (University of Campinas)\, Ettore Seg reto (Unicamp)\nThe X-Arapuca (XA) supercell is the basic unit of the Phot on Detection System (PDS) of the Deep Underground Neutrino Experiment (DUN E). In total\, 1\,500 X-Arapuca with approximate dimensions of 210 x 12 cm $^2$ will be installed on the anode planes of the liquid argon time projec tion chamber (LArTPC). In the XA light trap device\, the liquid argon scin tillation light (with wavelength around 127 nm) is absorbed by a thin laye r of para-Terphenyl (pTP) coated on a dichroic filter window which constit utes its acceptance window. PTP re-emits photons around 350 nm\, above the filter cutoff. The light which enters the XA is downshifted again by the inner wavelength shifter plate (WLS plate) to a wavelength around 430 nm. The cut-off of the dichroic filter is placed at 400 nm: this allows the pT P shifted light to enter in the X-Arapuca and to trap the fraction of phot ons which escape from total internal reflection in the WLS plate. The ligh t is collected by an array of silicon photo-sensors (SiPM) coupled at the edges of the WLS plate. In this work\, we present the first characterizati on of the photon detection efficiency of an X-Arapuca prototype sizing 10 x 7.5 cm$^2$ in Brazil\, where the X-Arapuca was exposed to alpha particle s\, cosmic muons and gammas in liquid argon. Operating the SiPMs at +5 and +5.5 V over the breakdown voltage\, an efficiency ranging from 2.2% to 2. 3% and from 2.7% to 3.1% was found\, respectively.\n\nhttps://indico.physi cs.ucsd.edu/event/1/contributions/44/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/44/ END:VEVENT BEGIN:VEVENT SUMMARY:The SBND Photon Detection System DTSTART;VALUE=DATE-TIME:20210916T181500Z DTEND;VALUE=DATE-TIME:20210916T183000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-90@indico.physics.ucsd.edu DESCRIPTION:Speakers: Vincent Basque (Fermilab)\nThe Short-Baseline Near D etector (SBND) is a 112 ton Liquid Argon Time Projection Chamber (LArTPC) that will be part of the Short-Baseline Neutrino (SBN) program at Fermilab . The SBN programme's main goal is to resolve the eV-scale sterile neutrin o short-baseline anomaly. SBND will measure the un-oscillated beam flavour composition at an unprecedented number of neutrinos due to its proximity to the beam target. One of the major features of SBND will be its state of the art photon detection system. The active system will consist of photom ultiplier tubes\, as well as X-ARAPUCA devices\, placed behind the wire pl anes providing a high granularity light collection. The active system will be enhanced by highly reflective panels covered with the wavelength shift ing compound tetra-phenyl butadiene (TPB) inserted into the cathode plane. The combination of the active system and enhancers in SBND will ensure a high and more uniform light yield throughout the detector which will help to enable low energy physics triggering. This talk will provide an overvie w of the photon detection system of SBND and its current status.\n\nhttps: //indico.physics.ucsd.edu/event/1/contributions/90/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/90/ END:VEVENT BEGIN:VEVENT SUMMARY:LArQL: A phenomenological model for treating light and charge gene ration in liquid argon DTSTART;VALUE=DATE-TIME:20210914T173000Z DTEND;VALUE=DATE-TIME:20210914T174500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-13@indico.physics.ucsd.edu DESCRIPTION:Speakers: Franciole Marinho (UFSCar)\nExperimental data shows that both ionization charge and scintillation light in LAr depend on the d eposited energy density (dE/dx) and electric field (𝜉). Moreover\, free ionization charge and scintillation light are anticorrelated\, complement ary at a given (dE/dx\, 𝜉) pair. We present a phenomenological model\, called LArQL\, that provides the anticorrelation between light and charge and also its dependency on the deposited energy as well as on the electric field applied. The model is built with three parameters to be fitted to d ata: ionizations per energy unit\, number of excitations/ionizations\, and the fraction of escaping electrons\, as function of deposited energy. LAr QL modifies the Birks (or Box) charge model considering three aspects: 1. at 𝜉 = 0\, escaping electrons are taken into account\; 2. just above 𝜉 = 0 field extracted electrons are added\; 3. at higher fields\, escap ing electrons tend to zero and the Birks model is recovered. Deviations fr om current Birks Law are observed only for LArTPC operating at low ξ and for heavily ionizing particle (stopping protons). The model presents a sat isfactory description at dE/dx and field ranges for interacting particles in LArTPCs and fits well the available data. Improvements via data sets co mpilation and “global” fits are also interesting features of the model .\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/13/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Searches for new physics with a stopped-pion source at the Fermila b accelerator complex DTSTART;VALUE=DATE-TIME:20210915T191500Z DTEND;VALUE=DATE-TIME:20210915T193000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-58@indico.physics.ucsd.edu DESCRIPTION:Speakers: Jacob Zettlemoyer (Fermilab)\nThe PIP-II complex at Fermilab is slated for operation later this decade and can support a MW-cl ass $\\mathcal{O}$(1 GeV) proton fixed-target program in addition to the b eam required for DUNE. Proton collisions with a fixed target could produce a bright stopped-pion neutrino source. The addition of an accumulator rin g allows for a pulsed neutrino source with a high duty factor to suppress backgrounds. The neutrino source supports a program of using coherent elas tic neutrino-nucleus scattering (CEvNS) to search for new physics\, such a s sensitive searches for accelerator-produced light dark matter and active -to-sterile neutrino oscillations. A key feature of a program at the Fermi lab complex is the ability to design the detector hall specifically for HE P physics searches. In this talk I will present the PIP-II project and upg rades towards a stopped-pion neutrino source at Fermilab and studies showi ng the sensitivities of a $\\mathcal{O}$(100 ton) liquid argon scintillati on detector with a standard PMT-based light detection system to the physic s accessible with this source.\n\nhttps://indico.physics.ucsd.edu/event/1/ contributions/58/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/58/ END:VEVENT BEGIN:VEVENT SUMMARY:Lightmap reconstruction in nEXO with an internal xenon 127 source DTSTART;VALUE=DATE-TIME:20210915T210000Z DTEND;VALUE=DATE-TIME:20210915T211500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-99@indico.physics.ucsd.edu DESCRIPTION:Speakers: Clarke Hardy (Stanford University)\nThe nEXO experim ent is a planned ton-scale liquid xenon time projection chamber (TPC) desi gned to search for neutrinoless double beta decay (0vBB) with a half-life sensitivity beyond 10$^{28}$ years. Optimal energy resolution in nEXO requ ires the precise reconstruction of the scintillation light signal\, correc ted by the position- and time-dependent light collection efficiency (or “lightmap”) throughout the active volume. An injected xenon 127 source is being considered for the lightmap reconstruction as it allows for in-s itu calibrations of the light response\, particularly in the center of the TPC where the use of external sources is limited by the attenuation of ga mmas in the liquid xenon. Multiple potential techniques for lightmap recon struction are being explored\, including a neural net and a kernel smoothi ng algorithm. This talk will present projections of the lightmap reconstru ction capability from simulated xenon 127 decays and a discussion of the t echniques involved.\n\nhttps://indico.physics.ucsd.edu/event/1/contributio ns/99/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/99/ END:VEVENT BEGIN:VEVENT SUMMARY:Role of a-Se device configuration in UV detection efficiency chara cterized by Time of Flight DTSTART;VALUE=DATE-TIME:20210915T160000Z DTEND;VALUE=DATE-TIME:20210915T170000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-86@indico.physics.ucsd.edu DESCRIPTION:Speakers: Kaitlin Hellier (University of California\, Santa Cr uz)\nAmorphous selenium (a-Se) detectors have made significant advances in the last few decades\, with applications in X-ray\, UV\, and visible ligh t detection and potential for high energy particle detection. A vertical a rchitecture\, in which light passes through a transparent conductor to the a-Se layer\, is common in commercial devices\; however\, a lateral struct ure\, in which light passes only through the selenium positioned between t wo contacts\, presents an opportunity for improved device performance and application. In this work we compare the performance of vertical devices w ith a-Se thicknesses of 5\, 10\, and 15 um and lateral devices with electr ode spacing of the same distances\, using time of flight (TOF) and convers ion efficiency\, and introduce optical slits for lateral structures as a w ay to better perform carrier specific TOF in a-Se devices.\n\nhttps://indi co.physics.ucsd.edu/event/1/contributions/86/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/86/ END:VEVENT BEGIN:VEVENT SUMMARY:Xenon-Doped Liquid Argon Scintillation for Positron Emission Tomog raphy DTSTART;VALUE=DATE-TIME:20210915T180000Z DTEND;VALUE=DATE-TIME:20210915T181500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-1@indico.physics.ucsd.edu DESCRIPTION:Speakers: Alejandro Ramirez (University of Houston)\nPositron Emission Tomography (PET) is used to observe metabolic processes within pa tients. It works by reconstructing the annihilation origin of incident gam ma rays produced by a positron emitting tracer. However\, inefficiencies o f current PET technology\, such as the use of photomultiplier tubes\, can result in poor imaging. In addition\, current PET scanners possess a small field of view which limits the sensitivity. We propose 3Dπ: a full body\ , Time of Flight (TOF) PET scanner using Silicon Photomultipliers (SiPM) c oupled with a Xenon-doped Liquid Argon (LAr+Xe) scintillator.\n \nWe simul ated this design using Geant4 while following the National Electrical Manu facturers Association’s evaluation tests for performance assessment. We will present results that highlight a 200-fold increase in sensitivity\, s patial resolutions comparable to commercial PET scanners and produce PET i mages from 15-30 second scans\, faster than traditional 30-35-minute scans . Further studies will involve optimizing the layer thickness of LAr+Xe. M oreover\, scintillation induced ionization electrons can produce Cherenkov radiation along with the LAr+Xe scintillation light.\n\n We will discuss strategies to characterize this other signal in Geant4 to improve the timi ng resolution of our scanner. With the LAr+Xe scintillator and SiPMs of 3D π\, we can use the precise TOF info of gamma rays to improve the localiza tion of individual positron annihilations\, and as one example benefit\, p rovide low-dose PET scans for patients who may be at high risk for exposur e to radiation.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/1 / LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Nucleation efficiency of nuclear recoils in bubble chambers DTSTART;VALUE=DATE-TIME:20210916T214500Z DTEND;VALUE=DATE-TIME:20210916T220000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-100@indico.physics.ucsd.edu DESCRIPTION:Speakers: Daniel Durnford (University of Alberta)\nBubble cham bers using liquid xenon (and liquid argon) have been operated (resp. plann ed) by the Scintillating Bubble Chamber (SBC) collaboration for GeV-scale dark matter searches and CEvNS from reactors. This will require a robust c alibration program of the nucleation efficiency of low-energy nuclear reco ils in these target media. Such a program has been carried out by the PICO collaboration\, which aims to directly detect dark matter using $\\mathrm {C_3 F_8}$ bubble chambers. Neutron calibration data from mono-energetic n eutron beam and AmBe source has been collected and analyzed\, leading to a global fit of a generic nucleation efficiency model for carbon and fluori ne recoils\, at thermodynamic thresholds of $2.45$ and $3.29\\\,\\mathrm{k eV}$. Fitting the many-dimensional model to the data ($34$ free parameters ) is a non-trivial computational challenge\, addressed with a custom Marko v Chain Monte Carlo approach\, which will be presented. Parametric MC stud ies undertaken to validate this methodology are also discussed. This fit p aradigm demonstrated for the PICO calibration will be applied to existing and future scintillating bubble chamber calibration data.\n\nhttps://indic o.physics.ucsd.edu/event/1/contributions/100/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/100/ END:VEVENT BEGIN:VEVENT SUMMARY:Polyethylene naphthalate wavelength shifter development and compar ison with TPB using 2PAC DTSTART;VALUE=DATE-TIME:20210917T153000Z DTEND;VALUE=DATE-TIME:20210917T154500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-102@indico.physics.ucsd.edu DESCRIPTION:Speakers: Cenk Turkoglu (AstroCeNT)\nThe number of rare event search experiments using liquid argon as the active volume is increasing. As the scintillation light emitted from liquid argon following the interac tions peaks at 128 nm\, a wavelength shifter (WLS) is required for efficie nt detection of such signals. In the experimental setup dubbed 2PAC (2 Par allel Argon Chambers) operated at LNGS\, two identical liquid argon detect ors are used to compare two WLS candidate materials: PolyEthylene Naphthal ate (PEN) and TetraPhenyl Butadiene (TPB). In each chamber\, the inner sur face is covered with specular reflectors and one of the candidate WLS\, wh ile SiPMs are used as photosensors\, covering approximately 1% of surface area\, in order to imitate the configuration of the future large scale det ectors. Experimental results of the light yield from both chambers\, suppo rted by the Geant4 simulations\, will be discussed and compared\, giving t he first low temperature comparison of the wavelength shifting efficiencie s of PEN and TPB in a true 4pi geometry\, and the highest reported so far PEN conversion efficiency from an industrial grade of PEN. Future R&D plan s for PEN as WLS will also be discussed.\n\nhttps://indico.physics.ucsd.ed u/event/1/contributions/102/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/102/ END:VEVENT BEGIN:VEVENT SUMMARY:Wavelength-Shifting Performance of Polyethylene Naphthalate Films in a Liquid Argon Environment DTSTART;VALUE=DATE-TIME:20210914T205500Z DTEND;VALUE=DATE-TIME:20210914T211000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-7@indico.physics.ucsd.edu DESCRIPTION:Speakers: Ryan Dorrill (Illinois Institute of Technology)\nLiq uid argon is commonly used as a detector medium for neutrino physics and d ark matter experiments in part due to its copious scintillation light prod uction in response to its excitation and ionization by charged particle in teractions. As argon scintillation appears in the vacuum ultraviolet (VUV) regime and is difficult to detect\, wavelength-shifting materials are typ ically used to convert VUV light to visible wavelengths more easily detect able by conventional means. Here we present recent measurements of the wav elength-shifting and optical properties of poly(ethylene naphthalate) (PEN )\, a proposed alternative to tetraphenyl butadiene (TPB)\, the most widel y-used wavelength-shifter in argon-based experiments. The measurements wer e performed in a custom cryostat system with well-demonstrated geometric a nd response stability\, with 128~nm argon scintillation light used to exam ine various PEN-including reflective samples' light-producing capabilities \, as well as their stability. The best-performing PEN-including test refl ector was found to produce 34% as much visible light as a TPB-including re ference sample\, with widely varying levels of light production between di fferent PEN-including test reflectors.\n\nhttps://indico.physics.ucsd.edu/ event/1/contributions/7/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Preliminary studies towards spectroscopic-based particle discrimin ation in Ar DTSTART;VALUE=DATE-TIME:20210914T183000Z DTEND;VALUE=DATE-TIME:20210914T184500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-9@indico.physics.ucsd.edu DESCRIPTION:Speakers: Vicente Pesudo Fortes (CIEMAT)\nNoble elements are t he active medium of choice for several among the most important neutrino a nd dark matter experiments being built now. The foreseen next generation\, besides going bigger\, would benefit from any feature not-yet exploited o f this technology.\n\nWith this goal\, we performed a time-resolved spectr oscopic study of the VUV/UV scintillation of gaseous argon as a function o f pressure and electric field\, by means of a wavelength sensitive detecto r operated with different radioactive sources.\n\nOur work conveys new evi dence of distinctive features of the argon light which are in contrast wit h the general assumption that\, for particle detection purposes\, the sc intillation can be considered to be largely monochromatic at 128 nm (seco nd continuum).\nThe wavelength and time-resolved analysis of the photon em ission reveal that the dominant component of the argon scintillation durin g \\blue{the} first tens of ns is in the range [160\, 325] nm. This light is consistent with the third continuum emission from highly charged argo n ions/molecules. This component of the scintillation is field-independent up to 25 V/cm/bar and shows a very mild dependence with pressure in the r ange [1\, 16] bar. The dynamics of the second continuum emission is domina ted by the excimer formation time\, whose variation as a function of press ure has been measured. Additionally\, the time and pressure-dependent feat ures of electron-ion recombination\, in the second continuum band\, have b een measured. This study opens new paths toward a novel particle identific ation technique based on the spectral information of the noble-elements sc intillation light.\n\nhttps://indico.physics.ucsd.edu/event/1/contribution s/9/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Mind the (gas) gap: a single-phase liquid xenon TPC DTSTART;VALUE=DATE-TIME:20210916T140000Z DTEND;VALUE=DATE-TIME:20210916T141500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-2@indico.physics.ucsd.edu DESCRIPTION:Speakers: Adam Brown (University of Freiburg)\nOne of the most significant challenges for future dual-phase xenon TPCs is achieving the high\, uniform electric field needed in the gas layer. One solution is to avoid using gaseous xenon and instead to create the secondary scintillatio n within the liquid itself\, in a single-phase xenon TPC. Within micrometr es of thin wires\, the electric field is high enough to enable VUV scintil lation. Avoiding the gas gap can provide a workaround to some of the techn ical challenges facing larger TPCs. At the same time\, it opens up new det ector design possibilities by relaxing the requirement that electrons are drifted upwards and facilitates analysis based on counting electrons. We d iscuss some of these advantages and present experimental results from a sm all single-phase demonstrator TPC with 10 µm anode wires.\n\nhttps://indi co.physics.ucsd.edu/event/1/contributions/2/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/2/ END:VEVENT BEGIN:VEVENT SUMMARY:The ABALONE Photosensor DTSTART;VALUE=DATE-TIME:20210917T143000Z DTEND;VALUE=DATE-TIME:20210917T144500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-4@indico.physics.ucsd.edu DESCRIPTION:Speakers: Valerio D'Andrea (UnivAQ & LNGS)\nThe ABALONE is a n ew type of photosensor produced by PhotonLab with cost effective mass prod uction\, robustness and high performance. This modern technology provides sensitivity to visible and UV light\, exceptional radio-purity and excelle nt detection performance in terms of intrinsic gain\, afterpulsing rate\, timing resolution and single-photon sensitivity.\nThe new hybrid photosens or\, that works as light intensifier\, is based on the acceleration in vac uum of photoelectrons generated in a traditional photosensor cathode and g uided towards a window of scintillating material that can be read from the outside through a silicon photomultiplier (SiPM).\nIn this contribute we present the characterization of the ABALONE operated at room temperature f or the evaluation of the gain as function of the electric field\, the resp onse in time and the single-photoelectron spectrum. In order to better und erstand the experimental results\, we performed the simulation of the phot osensor by reproducing the electrostatic field\, by tracking the accelerat ed photoelectrons and their interaction in the scintillation window.\nSoon we plan to operate the ABALONE in a Xe environment. Details of future tes ts and possible applications in the context of next-generation astropartic le physics experiments (e.g.\, DARWIN) will be also discussed.\n\nhttps:// indico.physics.ucsd.edu/event/1/contributions/4/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/4/ END:VEVENT BEGIN:VEVENT SUMMARY:First Results from the Light only Liquid Xenon experiment DTSTART;VALUE=DATE-TIME:20210915T174500Z DTEND;VALUE=DATE-TIME:20210915T180000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-27@indico.physics.ucsd.edu DESCRIPTION:Speakers: Austin de St. Croix (Queens University/TRIUMF)\nThis talk will present results from the first liquid xenon dataset of the Ligh t only Liquid Xenon (LoLX) experiment\, collected in June of 2021. LoLX ai ms to investigate both scintillation and Cherenkov light emission in liqui d xenon for applications in rare event searches and PET. The detector cons ists of 24 Hamamatsu VUV4 Silicon Photomultipliers (SiPM) arranged in an o ctagonal cylinder. A needle holds a Strontium 90 beta source in the detect or center\, which produces the scintillation and Cherenkov light. Longpass optical filters are placed in front of 22 SiPMs to separate the less abun dant Cherenkov light from the VUV scintillation light. In addition to stud ying light production in liquid xenon\, LoLX also aims to characterize ext ernal cross-talk (eXT) between SiPMs at various geometries. eXT occurs whe n IR photons produced during a charge avalanche in one SiPM trigger avalan ches in a different SiPM. This acts as correlated noise across channels\, thus characterizing eXT is crucial for rare event searches using large arr ays of SiPMs. Future experimental phases of LoLX will upgrade the SiPM and digitizer scheme to attain sub nanosecond timing resolution with the goal of performing temporal separation of the Cherenkov and scintillation ligh t\, which may lead to improving time-of-flight PET imaging.\n\nhttps://ind ico.physics.ucsd.edu/event/1/contributions/27/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/27/ END:VEVENT BEGIN:VEVENT SUMMARY:Physics Modeling of Xenon and Argon detectors with the Noble Eleme nt Simulation Technique (NEST) DTSTART;VALUE=DATE-TIME:20210915T200000Z DTEND;VALUE=DATE-TIME:20210915T201500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-75@indico.physics.ucsd.edu DESCRIPTION:Speakers: Kirsten McMichael (Rensselaer Polytechnic Institute) \nThe Noble Element Simulation Technique (NEST) is a C++ package with opti onal GEANT4 integration and a Python equivalent (nestpy) that accurately s imulates the scintillation\, ionization\, and electroluminescence processe s in xenon and argon. Using a combination of empirical and first principle methods\, NEST models the intrinsic physics of noble detectors while main taining a format that is accessible and customizable for users. I will pre sent key results including energy resolution and light and charge yields o f various interactions with noble elements. I will also discuss recent and future updates to the code including further development of the argon mod el\, improvements to the ER model\, and new modeling to describe the W-val ue discrepancy between NEST and the EXO-200 results.\n\nhttps://indico.phy sics.ucsd.edu/event/1/contributions/75/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/75/ END:VEVENT BEGIN:VEVENT SUMMARY:Scintillation light detection in the 6-m drift length ProtoDUNE Du al Phase liquid argon TPC DTSTART;VALUE=DATE-TIME:20210916T183000Z DTEND;VALUE=DATE-TIME:20210916T184500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-18@indico.physics.ucsd.edu DESCRIPTION:Speakers: Inés Gil-Botella (CIEMAT Madrid)\nThe Deep Undergro und Neutrino Experiment (DUNE) is a leading-edge experiment for long-basel ine neutrino oscillation studies\, neutrino astrophysics and nucleon decay searches. ProtoDUNE-Dual Phase (DP) is a 6x6x6 m3 liquid argon time-proje ction-chamber (LArTPC) operated at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. In ProtoDUNE-DP\, the scintillat ion and electroluminescence light produced by cosmic muons in the LArTPC i s collected by photomultiplier tubes placed up to 7 m away from the ionizi ng track. In this talk\, we will present the performance of the ProtoDUNE- DP photon detection system\, comparing different wavelength-shifting techn iques and the use of xenon-doped LAr as a promising option for future larg e LArTPCs. The scintillation light production and propagation processes ar e analyzed and compared to simulations\, improving understanding of the li quid argon properties.\n\nhttps://indico.physics.ucsd.edu/event/1/contribu tions/18/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/18/ END:VEVENT BEGIN:VEVENT SUMMARY:Absolute experimental primary scintillation yield in Xe for electr ons and alpha particles DTSTART;VALUE=DATE-TIME:20210915T140000Z DTEND;VALUE=DATE-TIME:20210915T141500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-39@indico.physics.ucsd.edu DESCRIPTION:Speakers: C. M. B. Monteiro (Departament of Physics\, Universi ty of Coimbra)\nXenon scintillation has been widely used in recent particl e physics experiments. However\, information on primary scintillation yiel d in the absence of recombination is still scarce and dispersed. The mean energy required to produce a VUV scintillation photon (Wsc) in gaseous Xe has been measured to be in the range of 30-120 eV. Lower Wsc-values are of ten reported for alpha particles when compared to those for electrons prod uced by gamma or x-rays\, being this difference still not fully understood .\nWe performed a systematic experimental study of the absolute primary sc intillation yield in Xe at 1.2 bar\, using a Gas Proportional Scintillatio n Counter. The simulation model of the detector's geometric efficiency was benchmarked through the primary and secondary scintillation produced at d ifferent distances from the photosensor. Wsc-values were obtained for gamm a- and x-rays with energies in the range of 5.9-60 keV\, and for 2-MeV alp ha particles. No significant differences were found in the values for alph a particles and for electrons.\n\nAcknowledgment\nThis work is funded by F EDER\, through the Programa Operacional Factores de Competitividade — CO MPETE and by National funds through FCT - Fundação para a Ciência e Tec nologia\, Lisbon\, Portugal\, in the frame of project UID/FIS/04559/2020 (LIBPhys).\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/39/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/39/ END:VEVENT BEGIN:VEVENT SUMMARY:Characterization of the DUNE photodetectors and study of the event burst phenomenon DTSTART;VALUE=DATE-TIME:20210916T184500Z DTEND;VALUE=DATE-TIME:20210916T190000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-43@indico.physics.ucsd.edu DESCRIPTION:Speakers: Tommaso Giammaria ()\nThe Deep Underground Neutrino Experiment (DUNE) is an upcoming neutrino physics experiment that will ans wer some of the most compelling questions in particle physics and cosmolog y. \nThe DUNE far detectors employ silicon photomultipliers (SiPMs) to det ect light produced by charged particles interacting in a large liquid argo n time projection chamber (LArTPC).\nThe SiPMs are photosensors consisting of an array of single-photon avalanche diodes (SPAD) operating in Geiger mode. The choice of employing solid state photodetectors stems from their high sensitivity and dynamic range\, as well as the possibility to fill la rge surfaces with high granularity.\nAn international consortium of resear ch groups is currently engaged in a systematic comparison of the performan ces of the SiPM models that have been custom developed for DUNE by two man ufacturers. Such detailed studies\, which include gain measurements and a structure study of the dark count rate at 77K\, are meant to determine the best choice of the photodetection system for DUNE\, as well as characteri ze the response of the chosen detectors for the DUNE simulation. Moreover\ , an investigation of a newly observed phenomenon\, consisting in fast bur sts of events separated by a short time interval and collected in individu al SiPMs\, is being carried out\, which potentially impacts the design of future models and their implementation in particle physics experiments. Th is poster presents the main results in terms of characterization of the Si PMs that will be employed in DUNE\, as well as of our studies of the novel bursts phenomenon.\n\nhttps://indico.physics.ucsd.edu/event/1/contributio ns/43/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/43/ END:VEVENT BEGIN:VEVENT SUMMARY:Pyrene-polystyrene wavelength shifters for liquid argon experiment s DTSTART;VALUE=DATE-TIME:20210916T190000Z DTEND;VALUE=DATE-TIME:20210916T191500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-49@indico.physics.ucsd.edu DESCRIPTION:Speakers: Hicham Benmansour (Queen's University)\nSome WIMP da rk matter experiments use liquid argon (LAr) as the target material for it s high\nscintillation light yield and good background discrimination. Part icle interactions in the LAr produce\nscintillation light at 128 nm which must go through a wavelength shifting (WLS) material to be\ndetected by st andard photomultiplier tubes. Tetraphenyl-butadiene (TPB) is a common WLS for LAr\nbased detectors\, including DEAP-3600\, due to its high light yie ld and fast scintillation time.\nPyrene-polystyrene thin films have been p roposed as a complementary WLS for rejection of\npathological backgrounds in the detector because it has a long scintillation time and high light yi eld\nrelative to TPB. Light from particle interactions that reach the pyre ne coating will produce a pulse\nsignature distinct from interactions of l ight with TPB.\nWe present the characterization of the fluorescence proper ties of these pyrene coatings\, such as the\nlight yield\, fluorescence ti me\, and spectra\, as a function of temperature. These measurements were\n taken at the Queen’s University optical cryogenic test facility to chara cterize these films down to 4 K.\n\nhttps://indico.physics.ucsd.edu/event/ 1/contributions/49/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/49/ END:VEVENT BEGIN:VEVENT SUMMARY:Xenon doping of Liquid Argon in ProtoDUNE Single Phase DTSTART;VALUE=DATE-TIME:20210914T184500Z DTEND;VALUE=DATE-TIME:20210914T190000Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-16@indico.physics.ucsd.edu DESCRIPTION:Speakers: Niccolo' Gallice (Università degli Studi di Milano - INFN Milano)\nThe Deep Underground Neutrino Experiment (DUNE) will be th e next generation long-baseline neutrino experiment. The far detector is d esigned as a complex of four LAr-TPC (Liquid Argon Time Projection Chamber ) modules with 17 t of LAr each. The development and validation of its te chnology is pursued through ProtoDUNE Single Phase (ProtoDUNE-SP)\, a 770 t LAr-TPC at CERN Neutrino Platform. Crucial in DUNE is the Photon Detecti on System that will enable the trigger of non-beam events - proton decay\, supernova neutrino burst\, solar neutrinos and BSM searches - and will im prove the timing and calorimetry for neutrino beam events. Doping Liquid A rgon (LAr) with Xenon is a well known technique to shift the light emitted by Argon (128 nm) to a longer wavelength (175 nm) to ease its detection. The largest Xenon doping test ever performed in a LArTPC was carried out i n ProtoDUNE-SP. From February to May 2020\, a gradually increasing amount of Xenon was injected to compensate for the light loss due to air contamin ation. The response of such a large TPC (770 t of Liquid Argon and 440 t o f fiducial mass) has been studied using the ProtoDUNE-SP Photon Detection System (PDS) and a dedicated setup installed before the run.\nHere we intr oduce the Xenon doping technique as well as the specific detector componen ts developed for this campaign and the results of the study with particula r regard to the modification of the scintillation signal\, the uniformity of the light collection and the efficiency of the wavelength-shifting mech anism.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/16/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/16/ END:VEVENT BEGIN:VEVENT SUMMARY:CMOS based SPAD Arrays for light detection in rare event search ex periments DTSTART;VALUE=DATE-TIME:20210917T160000Z DTEND;VALUE=DATE-TIME:20210917T161500Z DTSTAMP;VALUE=DATE-TIME:20260418T142116Z UID:indico-contribution-1-70@indico.physics.ucsd.edu DESCRIPTION:Speakers: Michael Keller (Heidelberg University)\nExperiments searching for rare physics events using scintillation in liquid noble gase s are steadily increasing in size. They require detector systems capable o f measuring individual optical photons with excellent efficiency while cov ering large areas. In addition\, the radioactive background introduced by such systems must be extremely low. We propose SPAD arrays based on CMOS t echnology as a possible solution for such an application case. This techno logy allows for manufacturing SPADs and the associated CMOS readout logic side by side\, creating a fully functional photon detector system one a si ngle silicon die. No further discrete components in direct vicinity and on ly few digital signals are required to operate a chip so that large areas can be covered in a straight forward way with very low material budget. We have developed a chip architecture which offers a very low power dissipat ion and a high fill factor. We have operated a prototype chip with differe nt SPAD geometries at low temperatures of $100/160 \\mathrm{K}$ and measur ed dark count rates of $0.01/0.1\\\,\\mathrm{Hz}$ per $\\mathrm{mm}^2$ of active SPAD area\, respectively. Our data driven readout architecture has an idle power consumption of only $1.75\\\,\\mathrm{m W}$ and a signal dep endent contribution of about $15\\\,\\mathrm{\\mu W}$ per 1000 hits per se cond. Based on these results we propose a full detector concept to cover l arge areas with high fill factor requiring only 7 electrical signals for o peration.\n\nhttps://indico.physics.ucsd.edu/event/1/contributions/70/ LOCATION: URL:https://indico.physics.ucsd.edu/event/1/contributions/70/ END:VEVENT END:VCALENDAR