Upgrade of the HADES RICH photon detector with H12700 MAPMTs

Abstract The HADES RICH detector is designed for efficient electron identification (electron momenta up to few GeV) in relativistic heavy ion collisions, and successfully in operation since 1999 at the SIS18 accelerator facility, GSI, Darmstadt, Germany. It uses a gaseous photon detector with reflective CsI cathode deposited on the MWPC pad plane. The CBM experiment at the future FAIR facility in Darmstadt will install a RICH detector utilizing 1100 Hamamatsu H12700 Multianode Photomultiplier tubes. In a joint effort the HADES RICH photon detector will be replaced by a subset of these MAPMTs together with a new FPGA-TDC based readout chain resulting in a significant improvement of e + e − - pair reconstruction efficiency for near future measurement campaigns.