Instabilities and the Implosion Dynamics of Gas-Puff Z-Pinch Experiments

The dynamics of argon and neon gas puff z-pinch plasmas are studied on COBRA, Cornell's pulsed power generator. COBRA can produce current pulses with rise times ranging from ~100 ns, with 0.7 MA – 1.1 MA peak current, to ~240 ns with about 0.9MA peak current. This provides a way to drive gas-puff plasmas that do not have time to pinch during the current rise time, as well as plasmas that are imploded by the current pulse. Radial tailoring of the gas puff mass-density profile using a triple-nozzle coaxial valve (two annular gas puffs and a central jet) enables production of both more stable and less stable (in regards to the magneto-Rayleigh Taylor instability) z-pinch implosions. A 527nm, 10J Thomson scattering diagnostic laser enables probing of the flow dynamics and plasma conditions of these implosions at a single time but at multiple spatial locations and with spatial resolution ranging from ~0.25 – 1mm. Extreme ultraviolet imaging and laser schlieren imaging at multiple times enable monitoring of the implosion morphology as a function of time.