A further development of the fluorescent gated gas scintillation proportional counter

Recent results from a K gated gas scintillation proportional counter filled with a xenon/helium mixture to a pressure of about 3 bar have already shown that a background rejection efficiency in excess of 99.3% can be achieved in the energy range 35-100 keV. In addition the application of the technique of fluorescent gating also provides energy resolutions below 3% at about 60 keV. Experimental results are presented for a gas scintillation counter filled with a krypton/xenon mixture which, through the use of the krypton K fluorescent gate, enables a high background rejection and improved energy resolution, for the energy range above 14 keV, to be achieved.