Investigation of Electron Beam Characteristics Emitted From Various Gases Employing the Vlasov–Maxwell Equations With the Forward Semi-Lagrangian Method

Abstract

The characteristics of the electron beams emitted from the hydrogen ( $H$ ), nitrogen ( $N$ ), neon (Ne), and argon plasma pinches have been numerically investigated and compared by solving the Vlasov–Maxwell system with the forward semi-Lagrangian approach. Several outcomes have been obtained. For examples, it was found that, in the case of 1-mbar H, the electron current density reached a value of about $1.431\times 10^{9} \,\,\text {A}\cdot \text {m}^{-2}$ due to turbulence, while it reached ${2.554} \times {10}^{7} \,\,\text {A}\cdot \text {m}^{-2}$ due to other phenomena. For 2-mbar $N$ , the calculated voltage drops across the $m = 0$ regions ranged from about 817 kV to 4 MV. Among these gases, Ne had the biggest upstream emission current of about 9.7 kA, while $N$ emitted the least electron beam current of about 4.1 kA. Computations showed that the total charge delivered by each gas beam was of order 0.1 mC. The method of modeling, presented in this article, can be efficiently used to study the dynamics of a plasma pinch. Since the estimated electron beam currents for various gases are in good agreement with the measured ones, the proposed method can be used for designing the plasma focus devices for the electron beam source purpose.