μ-Strip photosensors for gas proportional scintillation counters

The results of a comparative study of a xenon gas proportional scintillation counter instrumented with photosensors based on two variants of a CsI photocathode and a microstrip plate are reported. The photosensors were isolated from the gas proportional scintillation counter by a quartz window and operated in P-10 gas at one atmosphere. The CsI photocathode is deposited either in the reflective or semitransparent mode. In the reflective mode, the CsI is deposited directly onto the micro strip plate and we observe gain fluctuations due to a geometric factor that degrades the energy resolution. In the semitransparent mode, the CsI is deposited onto the surface of the quartz window. Both modes of operation were evaluated and their performance characteristics reported.