Investigation of Hamamatsu H8500 phototubes as single photon detectors
  We have investigated the response of a significant sample of Hamamatsu H8500 MultiAnode PhotoMultiplier Tubes (MAPMTs) as single photon detectors, in view of their use in a ring imaging Cherenkov counter for the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility. For this, a laser working at 407.2nm wavelength was employed. The sample is divided equally into standard window type, with a spectral response in the visible light region, and UV-enhanced window type MAPMTs. The studies confirm the suitability of these MAPMTs for single photon detection in such a Cherenkov imaging application. 
M. Hoek, V. Lucherini, M. Mirazita, R.A. Montgomery, A. Orlandi, S.   Anefalos Pereira, S. Pisano, P. Rossi, A. Viticchi\`e,...
physics.ins-det nucl-ex