Effects of Gas Configuration and Initial Conditions on Implosion Dynamics and Neutron Production in Gas Puff Z-Pinches

A series of experiments investigating the effect of gas configuration, injection time, and plenum pressure on neutron production and implosion dynamics in gas puff Z-pinches were conducted on CESZAR, the 500 kA, 160 ns rise time LTD at UCSD. A double nozzle gas injector was used to test deuterium target only, deuterium liner only, deuterium liner on deuterium target, and krypton liner on deuterium target. The highest neutron yields, up to 5.0 ± 0.8 × 10⁸ neutrons, were measured in deuterium target only shots with long injection times that exhibited strong zippering instabilities. Deuterium liner only shots produced up to 1.8 ± 0.2 × 10⁷ neutrons, though the implosion was significantly disrupted by the Magneto Rayleigh-Taylor Instability (MRTI). Combining a deuterium liner with a deuterium target reduced MRTI and zippering instability growth; however, neutron yields remained comparable to the liner only configuration, reaching 1.8 ± 0.2 × 10⁷ neutrons. Up to 1.1 ± 0.4 × 10⁸ neutrons were produced in krypton on deuterium shots. In this configuration we observed the formation of two distinct structures, with the more unstable structure producing more neutrons. Images and analysis of the implosion will be presented along with the neutron yields.