Full-Particle Simulation on Beam Electron Plasma in Linear Confinement System

Abstract

Three-dimensional full particle simulation is performed on the electron beam plasma electrostatically confined in a linear chamber. Sausage instability and kink instability occurred within 1 µs from the initial state, and a twisted structure is also observed. The density distribution flattened with time and resultantly diffused in the radial direction. However, large scale collapse phenomenon until the beam plasma disappeared is not observed.

Global Instability Structure in a Linear Beam Confinement System

“…Matsui et al showed the characteristic change of the structure in the electron density distribution of the linear electron beam plasma [6]. Starting the calculation with the equilibrium state as the initial condition, 1 µs has 1) a structure in which the plasma pinches radially at a certain point in the z axis direction: sausage instability, 2) a structure in which the cross section (i.e., xy plane) at a certain z position deviates in different directions: kink instability, 3) the shape of cross section deforms, and the phase of deformation shifts along the z axis, so it turns out that it changes to a twisted structure, and so on.…”

“…Matsui et al conducted a full particle simulation on a beam plasma in a linear magnetic field [6]. From this study, electron behaviors are dominant in a global motion of the beam plasma, and a change of density distribution was observed within 1 µs after its equilibrium state was given.…”

“…The calculation model used in this study is described in detail in Matsui's paper [6]. We adopt a full particle simulation model that handles particles of both electrons and ions as particles.…”

Monte-Carlo Simulation of Dissipation Processes in Ion Beam Plasma

“…Since a plasma consists of opposing beams, the occurrence of two stream instability causes the beam component to disappear [3], with a consequentially significant reduction in the nuclear reaction rate. Moreover, since the beam plasma is a linear plasma, its macroscopic structural change [4] needs to be investigated.…”