Ion source for tests of ion behavior in the KATRIN beam line

TL;DR

This paper presents a new electron-impact ion source designed for low-pressure gas ionization in high magnetic fields, suitable for sensitive equipment, with successful testing and simulation-based understanding.

Contribution

The paper introduces a DC-only electron-impact ion source optimized for high magnetic fields and low-pressure gases, with comprehensive testing and simulation analysis.

Findings

Successful operation at pressures below 1e-4 mbar

Effective ionization in 5 T magnetic fields

Potential for further optimization identified

Abstract

An electron-impact ion source based on photoelectron emission was developed for ionization of gases at pressures below 1e-4 mbar in an axial magnetic field in the order of 5 T. The ion source applies only DC fields, which makes it suitable for use in the presence of equipment sensitive to radio-frequency (RF) fields. The ion source was succesfully tested under varying conditions regarding pressure, magnetic field and magnetic-field gradient, and the results were studied with the help of simulations. The processes in the ion source are well understood and possibilities for further optimization of generated ion currents are clarified.