A hadron-blind-detector for PHENIX
C. Aidala, S. Stoll and C. Woody,
B. Azmoun and T. Hemmick,
A. Kozlov, Z Fraenkel, B. Khachaturov, A. Milov, I. Ravinovich, I. Tserruya and S. Zhou,
A Hadron Blind Detector (HBD) is proposed as upgrade of the PHENIX detector at RHIC, BNL. The HBD will allow the measurement of low-mass
e+e- pairs --the light vector mesons rho, omega, phi and the low-mass continuum- in Au-Au collisions at sqrt(s_NN)= 200 GeV. From general considerations, the HBD has to identify electrons with a high efficiency (>90%) and with a double hit recognition power better then 90%, it must have a pion rejection factor
of ~200 and a very low radiation budget, of the order of 1% of a radiation length. The choice that emerges is a windowless Cherenkov detector, operated with a CF4 based gas mixture in a special proximity focus configuration with a CsI cathode evaporated on GEMs. This talk presents the current status and recent results of the HBD R&D program.