Kinetic study of dynamic Z-pinches with an energy-conserving particle code*

Simulations of dynamic Z-pinches in a deuterium gas are conducted using the energy-conserving implicit particle-in-cell (PIC) code PICNIC. One-dimensional simulations are used to examine how the pinch formation process depends on the initial plasma density for a fixed initial radius and pinch current. The density is varied to explore from weakly to strongly collisional regimes and to study the so-called shock-flash yield produced at stagnation. Two-dimensional RZ simulations are performed to investigate the significance of 1) anomalous resistivity in the low-density periphery of the pinch and 2) neutron yield associated with beam-target fusion that occurs during the nonlinear stage of unstable m=0 sausage modes. In addition to the physics studies, a performance analysis of the implicit PIC code when applied to the dynamic Z-pinch is presented.