APD Injected Vacuum Photomultiplier

75403-The detection and identification of particles and nuclei is important in high energy, cosmic ray, and nuclear physics. Photodetectors play an important role in particle tracking and identification. The important issues for future photodetectors are improved detection efficiency, higher rate capability, improvements in aging, improved reliability, and timing resolution in the sub 100 ps range. This project will develop a new, limited-Geiger-mode, microcell avalanche injected vacuum photodetector, based on using III-V nitride semiconductor materials. The III-V nitride compounds are robust semiconductors with significant advantages over Si, such as higher saturated electron drift velocity, higher breakdown voltage, higher temperature operation, and higher quantum efficiency in the UV and near UV spectral region. In Phase I, a design study will be conducted to determine critical device parameters such as doping levels, epitaxial layer thickness, and device lateral dimensions. These parameters will be used to fabricate a test device, whose performance will be characterized. Commercial Applications and Other Benefits as described by the awardee: In addition to its Nuclear Physics applications, a high gain, high speed detector operated at lower voltage, and with a large dynamic range, should have high value for medical imaging using time-of-flight positron emission tomography, compact detectors for biomedical lab-on-chip systems, nuclear security, and surveillance applications.