Adiabatic Focuser with Ion Motion

TL;DR

This paper investigates the impact of ion motion on the performance of an adiabatic focuser, demonstrating that it remains effective under typical conditions despite potential ion effects.

Contribution

The study provides a numerical analysis showing ion motion does not significantly impair adiabatic focuser operation in practical scenarios.

Findings

Adiabatic focuser remains effective despite ion motion.

Ion effects are negligible for typical parameters.

Long electron pulses highlight ion motion effects.

Abstract

In this paper, after reviewing the concept of an adiabatic focuser we numerically study the effect of ion motion. Our work has been motivated by a recent suggestion that ion motion in an adiabatic focuser might be significant and even preclude operation of the focuser as previously envisioned. It is shown that for parameters associated with cases in which the adiabatic lens would be used, despite ion motion, the adiabatic focuser should work as well as originally envisioned. We then extend the study by considering a very long electron pulse (which accentuates the effect of ion motion).