Non-proportionality and energy resolution of Xe gas scintillator in gamma-rays spectrometry

Xe sealed under pressure of 50 bar inside a titanium cylinder closed with glass windows was tested as a scintillator for γ-ray detection. Taking advantage of Xe high atomic number of 54, high pressure Xe was used for γ-ray spectrometry in the range between 50 keV and 1.5 MeV. Compton electron response was also measured down to 7 keV by means of a Compton coincidence technique. The non-proportionality curve of the Xe scintillator turned out to be of similar shape to the one characteristic for doped alkali iodide crystals. Along the non-proportionality studies, energy resolution at a wide energy range was also measured. The Xe gas detector showed an energy resolution of 7.0% at 662 keV γ-rays, with a photoelectron yield of 3700 phe/MeV.