Vlasov-Poisson studies of sheaths in the presence of biased potential walls

The shear flow stabilized Z-pinch is being studied for its potential as a thermonuclear fusion reactor. The pinch current is generated via two electrodes with a potential bias. The sheath formation between the plasma and the electrode walls is studied to understand its effects on the upstream current as well as the fluxes to the electrode walls. Simulations are performed using the 1X-1V Vlasov-Poisson system for a proton-electron plasma in the code Gkeyll in regimes of relevance to pulsed-power fusion concepts including FuZE (Fusion Z-pinch Experiment). The electrodes are modeled as perfectly absorbing walls. The impact of bias potential on sheath formation is investigated by a parametric scan ranging from 0 to 10 kV. The results indicate that the current density in the domain is spatially constant with the ions dominating at the lower potential wall and the electrons dominating at the higher potential wall. Furthermore, the current density reaches an asymptotic limit with increasing bias potential. The particle and heat fluxes at the electrode walls are also presented. The results generally follow theoretical trends with differences attributed to kinetic effects. Initial work on more realistic boundary conditions that include secondary electron emissions is also presented.