Studies on the radio frequency power supply system for the ITER NB injector ion source

In the framework of the European activities on the ITER neutral beam (NB) injector, the design of a 1 MHz, 1 MW power supply (PS) system for the radio frequency (RF) driven ion source, has been developed in cooperation between IPP and RFX laboratories. This paper describes the studies performed with particular emphasis on the system design, the definition of the best modularity level to be adopted and the integration of the RF PS in the overall power supply system of the NB injector. Dedicated analyses were addressed to the RF matching network optimization which led to an improved and simplified solution without both matching transformers and remotely controlled variable capacitors in the source.