Angular Distribution of Ion Beam Emission From Dense Plasma Focus Device: An Investigation by the Vlasov–Maxwell Equations

Abstract

The Vlasov–Maxwell (VM) equations have been solved by the forward semi-Lagrangian (FSL) method to calculate the argon ion beam angular distribution in the dense plasma focus (DPF) device. The validity of the VM employment was investigated through the Dreicer field, the mean free path, and the Debye length of the plasma pinch. The simulations have shown that the ion beams were emitted in a direct way at the initial pressures of 10 and 20 Pa. The ion beam angular distribution expanded for pressures bigger than 20 Pa. It has been shown that this was because the radial component of the electric field inside the pinch was increased and the axial component of the electric field was decreased by increasing the initial pressure of the working gas. The places of the ion beam micro-sources (hotspots) have been illustrated by means of the ion and electron density profiles.