D-on-D and Ar-on-D gas puff Z-pinch simulations on ZR for neutron source

摘要

Summary form only given. Over the last few years, numerous 1D and 2D MHD simulation studies of deuterium (D) based double-shell gas-puff Z-pinch implosions driven by the Sandia ZR accelerator have been carried out to assess the Z-pinch as a pulsed, thermal fusion neutron source. In these studies, an ad-hoc time-dependent shunt impedance model was used within the external driving circuit model in order to account for the unresolved current loss in the MITL. In this study, we incorporate an improved ZR circuit model based on the recent Sandia argon 8cm gas-puff experiment circuit data into the multi-material version of the Mach+DDTCRE RMHD code. We investigate the effects of multidimensional structure, nonuniform gas distribution as well as the outer- and inner-shell material interaction on the implosion physics and dynamics of both D-on-D and argon-on-D 12cm Z-pinch loads. We characterize the neutron production performance of the Z-pinch loads as a function of total mass, mass ratio and/or radius toward their optimization as a pulsed thermonuclear neutron source.