The Radiochemical Analysis of Gaseous Samples (RAGS) apparatus for nuclear diagnostics at the national ignition facility

Summary form only given. Radiochemical diagnostic methods are currently under development for the National Ignition Facility (NIF). Samples in the gas-phase offer a direct method of collection by pumping out the large target chamber following a NIF shot and transporting the gas down-stream for further analysis. Ignition capsules will have a small amount (roughly 10¹⁵ atoms) of dopant added to the inner-most layers of the ablator shell. These elements will undergo nuclear activation from neutrons, deuterons, or alpha particles produced via the fusion process. For example, doping ¹²⁴Xe and ¹²⁷I in the shell will create activated xenon isotopes that can be correlated to the amount of fuel ρR and long-range mix in the capsule. We are building the Radiochemical Analysis of Gaseous Samples (RAGS) apparatus for collecting and analyzing activated gases produced via the ignition process. Following a shot, gases will be pumped out of the chamber and transported to a two-part system. The first part consists of a pre-filter that will remove particulates and other reactive gases. The second part is a cryogenic xenon collection station where xenon will be isolated, and will then either be removed for mass spectrometric analysis, or counted via gamma spectroscopy. Preliminary results from RAGS commissioning will be presented and future improvements to the apparatus will also be discussed.