A large area room temperature gas proportional scintillation counter for soft X-Rays with Ar-Xe mixtures: Preliminary results

A room temperature Gas Proportional Scintillation Counter (GPSC) optimized for soft X-ray detection in the 0.2 keV to 10 keV range is presented. The detector is filled with Ar-Xe mixtures, at atmospheric pressure, in order to reduce spectrum distortion due to electron losses to the radiation entrance window. It has a large area radiation window for soft X-rays and uses a 2” diameter VUV photomultiplier tube and the curved grid technique for compensation of solid angle scintillation losses. The preliminary results for its performance for soft X-rays are presented and compared with GPSCs filled with pure Xe.