Test of a dual-type gridded ionization chamber using liquid xenon

Abstract A liquid xenon dual-type gridded ionization chamber designed as a gamma-ray spectrometer was constructed and some tests for gamma-rays were made by using highly purified xenon gas. The energy resolution of 8.6% at fwhm was obtained for collimated gamma-rays of 662 keV. The resolutions at fwhm for non-collimated gamma-rays were (9.6 ± 0.4)% at 662 keV, (6.5 ± 0.3)% at 1332 keV and (4.5 ± 0.3)% at 2614 keV. These results show that, for gamma-ray energies above 1600 keV, the energy resolution for the liquid xenon ionization chamber is better than that for a conventionally available 1 3 4 ″ diameter × 2″ NaI(Tl) crystal. This characteristic of the chamber was kept nearly constant for more than 24 h. The resolution obtained experimentally were compared with the theoretical values and the causes of the differences between them are discussed.