Dense Plasma Focus Simulations at LLNL

Dense plasma focus (DPF) Z-pinches are compact pulse power driven devices consisting of two coaxial electrodes, separated by an insulator and filled with a low-density gas. The discharge of DPF consists of three distinct phases: first generation of a plasma sheath, plasma rail gun phase where the sheath is accelerated down the electrodes and finally an implosion phase where the plasma stagnates into a z-pinch geometry. A DPF is similar in nature to a traditional gas puff z-pinch, with the rail gun phase serving as an opening switch for a fast-current rise into an imploding load. MHD/XMHD, Hybrid Kinetic and Fully Kinetic techniques are employed in simulating dense plasma focus (DPF) loads at LLNL for optimizing neutron generation. Simulations of two of LLNL's DPFs will be presented: a 300 J, 80 kA small scale DPF and the newly commissioned MJOLNIR DPF which operates at 1 MJ and 2.25 MA. Simulations and results from the 2019-20 commissioning campaign of MJOLNIR will be presented.

This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (LLNL) under Contract DE-AC52- 07NA27344 and with support from the Computing Grand Challenge program at LLNL. LLNL-ABS- 811850.