Very Large, High Gain APDs for Particle Physics

73066S03-I 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 will demonstrate the feasibility of producing large, high gain APDs. An extensive characterization of these large APDs also will be conducted. 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.