The next generation of nucleon-decay and neutrino experiments are limited in sensitivity by the current generation of large-area light sensors. Through the development of the next generation of economical, large-area, high sensitivity light sensors, these experiments will become practical The next generation of nucleon-decay and neutrino experiments will require high sensitivity photo detectors with a total active area of at least 10,000 m2. Existing photomultiplier tubes would impose severe limitations on the size and sensitivity of these experiments, due to their cost and manufacturing leadtime. This project will develop a large area, low-cost photomultiplier tube for these next-generation experiments. During Phase I a preliminary design for a low cost, 20" diameter photomultiplier tube was completed and major components were quoted by industry. The performance of the preliminary design was verified using computer modelling. Testing of key developments required to realize this photomultiplier tube were initiated. In Phase II, prototype 5", 8", and 20" photomultiplier tubes will be fabricated and tested. A detailed plan for full-scale production of the 20" PMT will be completed, and detailed quotes will be obtained for all capital equipment required in Phase III. Commercial Applications and Other Benefits as described by awardee: The large area photomultiplier tube should find applications in High Energy Physics and Nuclear Physics experiments that require a large photodetector area
