Johnson, Connor, authorBuchanan, Norm, advisorWilson, Robert, committee memberBrandl, Alexander, committee member2018-06-122018-06-122018https://hdl.handle.net/10217/189282The study of neutrinos is a major component of modern High Energy Physics research. Neutrinos have been shown to have properties not predicted by the Standard Model, such as having non-zero mass. The Deep Underground Neutrino Experiment (DUNE) is a project in development which seeks to better understand neutrino physics. Part of the project includes designing a prototype detector for testing at CERN, which has been dubbed protoDUNE. Both DUNE and protoDUNE will consist of liquid argon time projection chambers, and a photon detection system. The photosensors used in the photon detection system will need to be submerged in cryogenic liquid, and will have to undergo thermal cycling as many as 5 times through their lifetime. The design installed in protoDUNE will use SensL C-Series SiPMs as photosensors, which have not been rated to operate below −40°C. This project sought to determine how these devices operate under repeated thermal cycles. Mounting boards were designed to measure the SiPM operation, and a cold test system was built which allows for repeated thermal cycling of these boards and their SiPMs. The data were closely examined to search for any issues arising, in particular searching for any problems consistent with damage to the SiPMs.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.photosensorsilicon photomultiplierthermal shockprotoDUNEneutrinoSiPMText