Modeling of gas puff Z-pinch experiments at the ZR facility

Summary form only given. Gas puff z-pinch experiments have been proposed for the refurbished Z (ZR) facility for CY2011. Previous gas puff experiments on pre-refurbishment Z established a record for laboratory fusion neutron yield; new experiments will establish gas puff capability on ZR and should surpass previous neutron and X-ray yields. We present ALEGRA resistive-MHD simulations of planned experiments with deuterium and high-Z gases such as argon. We also attempt to quantify the chaotic nature of implosions by evaluating Lyapunov exponents, and consider the implications for shot-to-shot variability in experiments and for the sensitivity of simulations to initial conditions.