Simulation Dynamics of a Multi-Material Pinch for Neutron Production on the Refurbished Z Simulator*

Previous Radiation MHD (RMHD) simulation studies of deuterium (D) double-shell gas-puff Z-pinch implosions driven by the Sandia refurbished Z have shown that their performance can be substantially affected by an introduction of a dense high-Z gas at the outer shell. One of the physical mechanisms playing an important role in the process is the development of multi-D structure {\&} nonuniform gradients due to the RT instabilities. Here, we present the results from the simulations of the multimaterial (MM) gas puff Z-pinch loads from the multiphase version of the Mach2-DDTCRE code. The MM radiation transport is included to account for the radiation emission, absorption {\&} transport from/into different materials. We will investigate the effects of different load materials/configurations such as argon-on-D on the multi-D structures, nonuniform gradients {\&} RT formation/development. We will then characterize various performance metrics, in particular the neutron yields, of the loads as a function of mass ratio and/or radius. A comprehensive analysis of 1D/2D RMHD results will be also made to gauge the operation parameter regime {\&} design of MM gas-puff loads.