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

We present recent predictions from simulations¹ as well as planned experiments² that confirm the modeling of the oxygen Z-pinch located at Weizmann Institute of Science through new access ports. Our simulations predict that the plasma undergoes a strong pinch within the hidden anode recess. This exercise was motivated by earlier 2D simulations using MACH2-TCRE as well as simple snowplow models³ that seemed to predict a shallower inductive notch compared to experiments. We present updated simulations using the 2D radiation-magneto-hydrodynamic code, MACH2-TCRE consisting of two steps as follows. In the first step, the initial density is obtained by modelling the hydrodynamic neutral gas-flow through nozzles. In the second step, this density profile is used as initial condition for simulating the gas-puff implosion. It is shown that simulating the detailed nozzle geometry and gas outflow significantly improves the comparison of inductive notch data between the measurements and the pinch simulations. These simulations support the notion that a consideration of nozzle and chamber geometry details greatly improves the agreement between the simulated and measured data. Finally, we present an overview of the experiments in progress.

1. V. Tangri, et al. Phys. Plasmas, Accepted (2024)

2. T. Queller, et al. private communication (2024).

3. G. Rosenzweig, et al. Phys. Plasmas 27, 022705 (2020).