The Physics of Bounded Plasma Systems (BPS's): Simulation and Interpretation

Abstract

The dynamical behavior of a bounded plasma system (BPS) is, by definition, characterized by the simultaneous and self-consistent interaction of the plasma itself, its material boundaries, and whatever external circuit(s) there may be. A full theoretical description of these systems, which are of relevance in a variety of fields (e.g., plasma technology), must involve (microscopic or macroscopic) evolution equations for the plasma, Maxwell's equations for the fields, boundary conditions for the plasma and the fields, and the external-circuit equation(s). By "BPS simulation" we mean obtaining theoretical (including numerical) results from models accounting, at least conceptually, for all the basic features mentioned above.This paper is exclusively concerned with microscopic (i.e., kinetic and particle) BPS simulation. A very general system of basic equations for kinetic BPS simulation is proposed. With the PD ("plasma device") codes from U.C. Berkeley [BIRDSALL, C. K., IEEE Trans. Plasma Sci. 19 (1991) 651, particle simulations of (14 3 4 BPS's can now be routinely performed by everybody. Particular emphasis is laid on an alternative method called "trajectory simulation", which has shown great potential for kinetic BPS simulation with high accuracy and resolution. From the point of view of nonlinear dynamics, BPS's are rather complex dissipative systems exhibiting, in particular, regular and chaotic attractor states. For their proper interpretation, an advisable (if not indispensable) first step is to carefully study relatively simple, but still representative "archetypal" BPS's, such as the Pierce diode [GODFREY, B. B., Phys. Fluids 30 (1987) I5531 and the single-emitter plasma diode or "KDSI" [CRYSTAL. T. L., et al., Phys. Fluids B 3 (1991) 2441. These systems and representative results obtained therewith are surveyed, and both recent developments and future perspectives of BPS physics are addressed.

Potential of a plasma bound between two biased walls

“…While in some relatively simple cases, the underlying physical mechanism has been understood, 13 the exact general relation between the currents measured at the sheaths, the applied bias, and the resulting potential in the plasma bulk is not well established, and remains to date a challenging general problem of plasma physics. 14 The goal of the present article is to address this problem in a relatively simple framework, focusing on a onedimensional, steady-state, plasma bound between two perfectly absorbing walls that are biased with respect to each other. In particular, we derive an analytical expression relating the bulk plasma potential with the wall currents, showing that the plasma potential undergoes an abrupt transition when currents cross a critical value.…”

Multiple Floating Potentials of an Electron Emitting Electrode that Terminates a Bounded Plasma System with Hot Electrons

“…When the distribution functions (8) - (11) are inserted into the first of the equations (12) the particle densities are obtained. These densities are then inserted into the Poisson equation (1). The following equation is obtained:…”

“…Graduate development of the kinetic models and related particle in cell computer simulation for such bounded plasma systems is described extensively in a review paper by Kuhn [1]. Very nice overviews can be found also in [2] and [3].…”

Analytic‐Numerical Matching of the Sheath and Plasma Solutions for a Spherical Probe in a Low‐Density Plasma

“…In Sec. 2, the latter is formally solved by means of trajectory integration [2] and the different types of trajectories in the PPT region are identified. In Sec.…”