Magnetic System with Adjustable Characteristics for Electron Cyclotron Resonance Ion Source with Operating Frequency of 2.45 GHz

Abstract

This paper presents a description of the magnetic system of the developed electron cyclotron resonance (ECR) ion source with an operating frequency of 2.45 GHz for producing protons and doubly charged helium ions. The results of numerical simulations of the magnetic system of the ECR source built on permanent magnets are presented. A configuration with the possibility of moving the ring magnets of the injection and extraction area to adjust the magnetic field distribution, in particular, the maximum values of B_inj and B_ext at the plasma chamber axis, and with the possibility of moving the bars of the sextupole magnet in the radial direction to adjust the magnetic field B_rad at the chamber boundary is presented. To obtain the magnetic field profile corresponding to the mode of the microwave source, the design of the magnetic system with the use of additional solenoids providing adjustment of B_inj and B_ext values within the required limits as well as adjustment of the minimum magnetic field B_min on the chamber axis at fixed position of all ring magnets is considered.