Next-Generation Visible Light Photon Counters

65568 The successful development of high quality plastic wavelength-shifting optical fibers coupled to a plastic scintillator for nuclear and high energy particle detection applications has created a need for compact, high-gain, high efficiency detectors in the visible and near-infrared. Visible light photon counters (VLPCs), fabricated several years ago, showed significant promise but suffered from significant variations in gain. This project will utilize epitaxial process expertise to develop a new generation of VPLCs with improved properties, including much narrower gain dispersion and lower cost. In Phase I, eighty 5-inch wafers were produced, 10 each of 8 different combinations of donor and acceptor doping. Low defect density and excellent uniformity were demonstrated. In Phase II, visible light photon counters will be fabricated from the Phase I wafers and tested. Based on the results, the design will be modified and a second round of epitaxial wafers will be grown. Devices fabricated from the second round will be provided to end-users. Commercial Applications and Other Benefits as described by the awardee: Applications for visible light photon counters in combination with plastic scintillator include electromagnetic and hadronic calorimetry, shower max detectors, preshower detectors, photon vetos, large-scale neutrino detectors, muon hodoscopes, and high resolution tracking systems.