Simulations of Nozzle Gas Flow and Gas-Puff Z-Pinch Implosions with Magnetic Fields in the Weizmann Z-Pinch

Till recently, measurements of the magnetic field in gas-puff z-pinch implosions were limited to low density and temperatures typically found at very early times and outside the pinch radius ( $r$ $\ge $9 mm and $t$ $\le -$90 ns). However, recent, more accurate measurements at higher densities and temperatures at various R and Z-locations on the generator at the Weizmann Institute of Science (WIS) have yielded information close to stagnation and beyond. These measurements seem to be inconsistent with earlier 2D radiation-magneto-hydrodynamics simulations using MACH2-TCRE as well as simple snowplow models when using the inductive current notch, pinch length the pinch radius. It is shown that some of these inconsistencies can be resolved by simulating the entire gap of 18mm. Simulations of magnetic field evolution using the 2D radiation-magneto-hydrodynamic code, MACH2-TCRE are presented. Comparisons are made with the measured data of magnetic field and radius. It is shown that simulating the nozzle geometry and outflow significantly improves the comparison between the measurements and the pinch simulations.