Advanced Photodetector for Dark Matter Studies

Optical detectors are very important components of existing and future particle physics experiments, including those being developed for dark matter studies. However, the performance of experimental systems used in dark matter studies is limited by the properties of presently-available optical detectors. This project will investigate new, robust, large area avalanche photodiodes (APDs) for the detection of scintillation light emitted by liquid xenon, for eventual use in dark matter studies. Phase I demonstrated the feasibility of applying the new APDs towards dark matter experimentation: (1) the proposed photodetector was built and tested; (2) the performance of the new APDs in detecting scintillation light from liquid xenon was evaluated; and (3) noise, energy resolution, and temporal response were measured. Phase II will optimize the performance of the new, robust APDs for dark matter detection. The optimization will include reducing noise and improving UV response. An extensive evaluation of the detection of liquid xenon scintillation in large APDs will be conducted. Commercial Applications and Other Benefits as described by the awardee: A low cost, robust, high gain APD with large areas should have a major impact on a variety of particle physics experiments, including the detection of scintillation light from liquid xenon in projects aimed at the search for dark matter. Over and above the use in particle physics, the new detectors should be applicable to nuclear medicine, space research, homeland security, environmental monitoring, and material science studies.