Speaker
Description
The presentation will focus on the challenges faced in detecting scintillation photons in liquid argon TPCs related to their short wavelength and the cryogenic temperatures (~87K) at which the sensors need to be effective. To enhance the photon detection efficiency (PDE) of the photon detectors it is common the use of wavelength shifters. This leads to the introduction of the studied sensors, the Hamamatsu VUV4 S13370 - 6075CN SiPMs, that are VUV-sensitive sensors that have the potential to directly detect VUV light without the use of wavelength shifters, which among other advantages have an improved photon detection efficiency. The manufacturer provides a complete characterization of these sensors at room temperature (RT); however, previous studies showed a decrease off the efficiency with temperature. The CIEMAT neutrino group have developed experimental setups to measure this decrease in PDE of VUV4 SiPMs at 87K for different wavelengths in the range (270nm to 570nm). The results of these measurements, demonstrating the PDE decrease, will be discussed and compared with the manufacturer's characterization data at RT. A dedicated measurement at 128nm will be also shown.
