High-pressure xenon GPSC/LAAPD for hard X-ray spectrometry

The performance of a xenon high-pressure gas proportional scintillation counter (GPSC) instrumented with a large area avalanche photodiode (LAAPD) has been investigated for hard x-ray spectrometry. The LAAPD was placed in direct contact with the filling gas. Filling-pressures in the 2- to 6-atm range have been studied. The results obtained are similar to those achieved with large-volume GPSCs at atmospheric pressure. Energy resolutions of 8.2%, 4.3%, and 2.8% were obtained for photon energies of 5.9-, 22.1-, and 59.6-keV, respectively. Additionally, the smaller scale of this GPSC allows increasing the detector count-rate capability by at least one order of magnitude.