Very Large, High Gain APDs for Particle Physics

73066-For several decades, photo-multiplier tubes (PMT) have been the key technology for sensing light in most high energy physics research operations. Although extraordinarily successful, PMT technology has a number of limitations: large PMTs cannot be mass produced, they cannot operate under pressures exceeding a few atmospheres, their sensitivity is limited over a small wavelength band, their optical quantum efficiency is low, they cannot operate under high magnetic fields, and they are bulky. This project effort will investigate very large avalanche photodiodes (APDs) as optical detectors for eventual use in particle physics studies. These APDs are planned for operation under conditions where single optical photon detection is possible. Phase I demonstrated the feasibility of producing large, high gain APDs using the planar process. Extensive characterization of these large APDs was performed. During Phase II, the large APD technology will characterized, and their applicability for to high energy physics experiments and systems (e.g., water Cherenkov detectors, calorimetry (KOPIO and MECO), and liquid Xe detectors) will be determined. Commercial Applications and Other Benefits as described by awardee: The detector technology should be very promising for high energy physics experiments. It also should be applicable in medical imaging systems (such as PET and SPECT), nuclear physics, astronomy, diffraction, non-destructive studies, safeguards, and bore hole logging.