Measurement of the photon detection efficiency of Hamamatsu VUV4 SiPMs at cryogenic temperature

Abstract

Liquid argon time projection chambers play a crucial role in neutrino oscillation and dark matter experiments. Detecting scintillation light in these chambers is challenging due to the short wavelengths in the VUV range and the extremely low cryogenic temperatures (˜87 K) at which sensors operate. To take advantage of the higher photon detection efficiency (PDE) at the visible range, the use of wavelength shifters (WLS) is extended along the community. The Hamamatsu VUV4 S13370-6075CN Silicon PhotoMultiplier (SiPM) are VUV-sensitive sensors that can directly detect VUV light without the use of WLS, providing an improved PDE at these short wavelengths, and at the same time can detect the visible light from WLS if needed. The manufacturer provides a complete characterization of these sensors at room temperature. In this work we present the developed experimental setups used to measure the PDE of VUV4 SiPMs at cryogenic temperatures for different wavelengths in the range from 127 nm to 570 nm.