Performance of VUV-sensitive MPPC for Liquid Argon Scintillation Light

Abstract: A new type of the Multi-Pixel Photon Counter (MPPC), sensitive to Vacuum Ultra-Violet (VUV) light (wavelength {\lambda} < 150 nm), is recently developed and produced by Hamamatsu Photonics K.K. The basic properties of the new MPPC are measured at cryogenic facility of Waseda university using liquid nitrogen. Temperature dependence of breakdown voltage, capacitance, and dark count rate of the MPPC are also evaluated. In addition, the absolute photon detection efficiency (PDE) for liquid argon (LAr) scintillation light ({\lambda} = 128 nm) is estimated to be about 7% with uncertainty of 2% by using 241 Am {\alpha}-ray source. Based on these basic measurements a possible application of the new MPPC to LAr detector for dark matter search is discussed.