Improved recent simulations of nozzle gas flow and gas-puff z-pinch implosions with recesses in the Weizmann z-pinch*

Recent measurements [1] of densities and temperatures at various R and Z-locations near stagnation seem to be inconsistent with earlier 2D simulations using MACH2-TCRE as well as simple snowplow models. New simulations of the oxygen pinch will be presented that address some of these inconsistencies. Simulations of magnetic field evolution using the 2D radiation-magneto-hydrodynamic code, MACH2-TCRE are presented in two steps as follows. In the first step, initial density is modeled the by neutral gas-flow through nozzles. In the second step, the density profile from the previous step is used as initial condition for simulating the gas-puff implosion. It is shown that simulating the detailed nozzle geometry and outflow significantly improves the comparison of magnetic field radial distribution, temperature and spectroscopic data between the measurements and the pinch simulations. Density and magnetic field in the anode recess will also be compared with experiments.

[1]. G. Rosenzweig, et al. Phys. Plasmas 27, 022705 (2020)