Speaker
Description
Large volumes of liquid Argon or Xenon constitute an excellent medium for the detection of Neutrino interactions 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).
This 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 accelerator based experiments.
The design of such an imaging detector, however, presents 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 packed detectors and their dedicated readout electronics must be operated at cryogenic temperatures; the optical system must provide a sufficiently wide and deep field of vision and a large aperture, in order to minimize the amount of detectors for a given fiducial volume.
Silicon PhotoMultipliers (SiPMs) are the ideal photosensor for this application, since their noise is suppressed at cryogenic temperature and they can be fabricated in large arrays composed of many small pixels; their lower VUV sensitivity is also being addressed by suppliers with optimized designs. The large channel 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, performance and deployment on specific detector geometries. In this contribution we will present the simulation of novel optical systems and the performance of small scale prototypes. The progress on larger prototypes and the simulation of realistic detector geometries will also be reported.
