Modeling the fringe field of permanent magnet multipoles using numerical simulations.

Permanent magnet multipoles (PMMs) are widely used in accelerators to either focus particle beams or confine plasma in ion sources. The real magnetic field created by PMMs is calculated by magnetic field simulation software and then used in particle tracking codes by means of a three dimensional magnetic field map. A common alternative is to use the so-called "hard-edge" model, which gives an approximation of the magnetic field inside the PMM assuming a null fringe field.

Plasma diagnostic tools for ECR ion sources-What can we learn from these experiments for the next generation sources.

The order-of-magnitude performance leaps of ECR ion sources over the past decades result from improvements to the magnetic plasma confinement, increases in the microwave heating frequency, and techniques to stabilize the plasma at high densities. Parallel to the technical development of the ion sources themselves, significant effort has been directed into the development of their plasma diagnostic tools. We review the recent results of Electron Cyclotron Resonance Ion Source (ECRIS) plasma diagnostics highlighting a number of selected examples of plasma density, electron energy distribution, and ion confinement time measurements, obtained mostly with the second-generation sources operating at frequencies from 10 to 18 GHz.

Prospect for a 60 GHz multicharged ECR ion source.

The conceptual design of a fourth generation hybrid electron cyclotron resonance (ECR) ion source operated at 60 GHz is proposed. The axial magnetic mirror is generated with a set of three NbSn coils, while the hexapole is made with room temperature (RT) copper coils. The motivations for such a hybrid development are to study further the ECR plasma physics and the intense multicharged ion beams' production and transport at a time when a superconducting (SC) hexapole appears unrealistic at 60 GHz.