Conceptual design of first toroidal electron cyclotron resonance ion source and modeling of ion extraction from it

TL;DR

This paper proposes a novel toroidal ECR ion source design to enhance ion confinement and extraction, supported by modeling that demonstrates feasible ion extraction methods using magnetic and electric field techniques.

Contribution

Introduction of a toroidal ECRIS geometry to improve confinement and ion extraction, with modeling showing successful extraction strategies.

Findings

Successful ion extraction via magnetic extractor

Feasible ion extraction using ExB drifts

Potential for higher ion currents and charge states

Abstract

Electron Cyclotron Resonance Ion Sources (ECRIS) progressed to higher and higher ion currents and charge states by adopting stronger magnetic fields (beneficial for confinement) and proportionally higher ECR frequencies. Further improvements would require the attainment of "triple products" of density, temperature and confinement time comparable with major fusion experiments. For this, we propose a new, toroidal rather than linear, ECRIS geometry, which would at the same time improve confinement and make better use of the magnetic field. Ion extraction is more complicated than from a linear device, but feasible, as our modelling suggests: single-particle tracings showed successful extraction by at least two techniques, making use respectively of a magnetic extractor and of ExB drifts. Additional techniques are briefly discussed.