Squeezed State of an Electron Cloud as a "Quasi-Neutral'' One-Component Plasma

TL;DR

This paper models a one-dimensional electron cloud in a potential well under a strong magnetic field, revealing a force-free steady-state called a squeezed state, with implications for plasma physics and electron beam dynamics.

Contribution

It introduces a novel one-dimensional model of an electron cloud in a potential well, interpreting a squeezed state as a force-free equilibrium with specific density and perturbation characteristics.

Findings

Electron density distribution correlates with the potential well shape.

Steady-state is force-free and stable under certain conditions.

Perturbations propagate as Trivelpiece-Gould modes.

Abstract

We present a one-dimensional model which gives a novel physical interpretation to the specific state of an ensemble of electrons continuously injected into an electrostatic potential well immersed in a strong applied magnetic field preventing radial expansion. When the space-charge field of the electrons accumulated in the potential well compensates the external electrostatic field, a force-free steady-state of the electron cloud forms. This state of equilibrium is known in another context as a squeezed state of an electron beam. It is shown that the spatial distribution of the electron number density in this steady-state correlates with the shape of the potential well. Perturbations of the steady-state propagate along the electron cloud in the form of Trivelpiece-Gould modes.