A metastable xenon isotope detector for treaty verification

A system to selectively detect and quantify the xenon metastable isotopes Xe-131m, Xe-133m, Xe-133, and Xe-135 has been designed, fabricated, and tested. The system combines high-resolution electron and gamma-ray spectrometry with coincidence/anti-coincidence timing for signal selectivity and background rejection. By utilizing X-ray-fluorescence gating, backgrounds from other sources are expected to be reduced to the sub-becquerel level. Coincidence and anti-coincidence triggers are formed from the several individual detectors that comprise the system and used to identify K-shell conversion electrons and fluorescence X-rays from a Cd-109 test source with good efficiencies and energy resolutions (20 keV for the low-energy electrons, similar to1.2 keV for the fluorescence X-rays, respectively). (C) 2003 Elsevier Science B.V. All rights reserved.