Field structure and electron life times in the MEFISTO Electron Cyclotron Resonance Ion Source

TL;DR

This study uses detailed 3D simulations to analyze the magnetic field and electron trajectories in the MEFISTO ECR ion source, revealing new insights into electron lifetimes and ion sputtering patterns.

Contribution

First detailed 3D simulation of the MEFISTO ECR ion source’s magnetic field and electron trajectories, uncovering unexpected electron lifetime phenomena.

Findings

Identified the magnetized volume suitable for ECR at 2.45 GHz and 87.5 mT.

Revealed characteristic ion sputtering patterns in the field and electron distribution.

Discovered unexpectedly long electron trajectory lifetimes.

Abstract

The complex magnetic field of the permanent-magnet electron cyclotron resonance (ECR) ion source MEFISTO located at the University of Bern have been numerically simulated. For the first time the magnetized volume qualified for electron cyclotron resonance at 2.45 GHz and 87.5 mT has been analyzed in highly detailed 3D simulations with unprecedented resolution. New results were obtained from the numerical simulation of 25211 electron trajectories. The evident characteristic ion sputtering trident of hexapole confined ECR sources has been identified with the field and electron trajectory distribution. Furthermore, unexpected long electron trajectory lifetimes were found.