Investigation of a Radiofrequency Plasma Generator for Multi-Second Pulse Operation

This paper presents the test results of a radiofrequency (RF) plasma generator, developed for neutral beam injectors. A water cooled faraday screen is installed into the generator for multi-second pulse operation. Consistent operation achieved for 20-second long pulses with input power of 38 kW is described. The density of the ion current was measured. The experiments were conducted to measure the density of the ion current at the driver’s output and to evaluate the heating of the driver’s elements. Main factors affecting the power losses were determined. The power loss caused by the eddy currents in the driver’s clamping flanges were reduced.