High resolution room temperature ionization chamber xenon gamma radiation detector

A unique thin walled dual-type gridded ionization chamber gamma radiation detector using ultra pure Xe gas as the detection medium is described. The detector was operated at room temperature and the energy spectra of 60Co, 137Cs, 22Na and 133Ba were obtained. An energy resolution of (16 keV) 2.4% FWHM was determined for the 662 keV 137Cs gamma peak which is substantially better than the resolution of conventional NaI(Tl) detectors. The effect of electric field strength, grid field ratio, gamma energy, and electronegative impurities on energy resolution are discussed.