Plasma Simulation And Optimization For A Miniaturized Antenna Ecr Ion Source

At Peking University (PKU), a miniaturized 2.45 GHz antenna permanent magnet electron cyclotron resonance (PMECR) ion source, capable of generating a several-mA H+ beam, was produced and tested. The dimensions of the plasma chamber were empty set30 mm x40 mm, and the entire size of the ion source (including the extraction system) supply was empty set150 mm x160 mm. A 4.5 mA CW H+ beam was extracted at 35 kV with 200 W of microwave power supplied by a compact microwave generator with a coaxial cable. For a better understanding and optimization of the miniaturized ion source, plasma simulations were conducted to research the electromagnetic coupling of the antennas and the generation of ECR plasmas. The experimental and simulation results of the H+, H2+, and H3+ fractions of cylindrical-type and "T''-type antenna microwave ion sources were presented and compared. Based on a series of comparisons between the experimental and simulation results, the impedance of the miniaturized antenna ECR ion source plasma and the real pressure in the plasma chamber were accurately calculated. An optimized microwave coupling system was designed for the new miniaturized antenna ECR ion source. From the plasma simulation results, the transmission efficiency of microwaves increased from 32% to 89% (coupled to plasma), 15 mA H+ @ 150 W can be expected in the future.