In order to play a more important role in the OSI activities organized by CTBTO, such as inspector training, the single technique test or exercise, build-up exercises (BUEs) and the OSI integrated filed exercise (IFE), et cetera, the Northwest Institute of Nuclear Technology (NINT) manufactured one brand new OSI radioxenon processing system (or XESPM-III Mark II). Comparing with the XESPM-III Mark I, four aspects of modifications have been made. First, sufficient amounts of switchable parts installed before each running can fulfill the aim of automatic processing without an attendant. Second, the refrigerating temperature has been lowered further to increase the sampling volume per trap due to the enlarged adsorption efficiency. Third, the processing volume is doubled to the amount of 8m3, consequently the least minimum detectable activity concentration (MDC) can be halved. Fourth, the processing time is shortened, so the daily processing throughput can be further increased. The technical specifications of XESPM-III Mark II has obviously been improved, such as more sensitive, faster in processing and more adaptable for field use, et cetera.
Three-generation OSI radioxenon systems have developed, and participated in some activities organized by PTS since 2002. In order to play more important role in the build-up exercise, one modified XESPM-III was manufactured, whose specifications have been improved a lot.