Modeling of ion extraction from a toroidal Electron Cyclotron Resonance Ion Source

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 modeling suggests: single-particle tracings showed successful extraction by at least two techniques, making use respectively of a magnetic extractor and of E×BE×B drifts. Additional techniques are briefly discussed.