The Radiochemical Analysis of Gaseous Samples (RAGS) apparatus for nuclear diagnostics at the National Ignition Facility (invited).

The Radiochemical Analysis of Gaseous Samples (RAGS) diagnostic apparatus was recently installed at the National Ignition Facility (NIF). Following a NIF shot, RAGS is used to pump the gas load from the NIF chamber for purification and isolation of the noble gases. After collection, the activated gaseous species are counted via gamma spectroscopy for measurement of the capsule areal density and fuel-ablator mix. Collection efficiency was determined by injecting a known amount of 135Xe into the NIF chamber, which was then collected with RAGS. Commissioning was performed with an exploding pusher capsule filled with isotopically enriched 124Xe and 126Xe added to the DT gas fill. Activated xenon species were recovered post-shot and counted via gamma spectroscopy. Results from the collection and commissioning tests are presented. The performance of RAGS allows us to establish a noble gas collection method for measurement of noble gas species produced via neutron and charged particle reactions in a NIF capsule. [ABSTRACT FROM AUTHOR]