Performance and behaviour of photomultiplier tubes at cryogenic temperature

Noble-gas liquids, such as xenon and argon, have been recently proposed as scintillators in some experiments dedicated to neutrino physics and dark matter research. These experiments need to use large-area high-sensitivity light detectors directly immersed in the liquid phase and operating at cryogenic temperature.We carried out a detailed investigation on the use of conventional and dedicated photomultiplier tubes in collaboration with two manufacturers: Electron Tubes Ltd. and Hamamatsu Photonics K.K. Once verified the capability to withstand thermal shocks from room to cryogenic temperature, we studied the device characteristics in different temperature conditions.Good quantum efficiencies can be achieved with multialkali photocathodes or bialkali photocathodes on platinum under-coatings. Gain losses and an increase of the dark count rate at low temperature are also observed.