Development and first results of large area radio frequency plasma source for EAST neutral beam injector

Abstract

A large area radio frequency (RF) ion source was developed for neutral beam injector in Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). An experiment of RF source was installed in the test facility. The dimension of large area RF source is 862 mm (L) × 472 mm (W) × 420 mm (D). Six turns of coil is used to transfer RF power to the plasma. The plasma density was measured by the movable Langmuir probe in front of the plasma grid. The electron density of 6 × 1017 m−3 was achieved with RF power of 30 kW and source pressure of 0.5 Pa. The density uniformity was estimated as 95%. The heat loading on the Faraday shield and coil were also measured and acceptable for the long pulse operation with high power in the future. The details of the first tests of large area RF plasma source are presented in this paper.