ION SOURCE WITH ION BEAM ACCELERATING PART INCLUDING SUPPRESSOR FOR ABNORMAL VOLTAGE DUE TO INTERELECTRODE BREAKDOWN IN NEUTRAL PARTICLE INJECTION DEVICE OF NUCLEAR FUSION APPARATUS

摘要

PROBLEM TO BE SOLVED: To suppress deterioration in insulation performance and reduce interelectrode breakdown to stabilize acceleration of charged particle beams by constituting an insulation tube of an ion beam accelerating part in a double structure comprising an outer layer for insulation and an inner layer for an arrester. SOLUTION: An ion beam accelerating part (b) provided in an ion source comprises electrodes 1 to 6 for generating an electrostatic field for accelerating charged particle ions and several insulation tubes 11 to 13 for insulating/fixing respective electrodes from/to the ion beam accelerating part (b). Each insulation tube is made in a double structure comprising an outer layer for insulation made of FRP (glass epoxy resin) and an inner layer for arrester made of zinc oxide and includes an insulation function by the outer layer and a lightening arresting function by the inner layer. Such a double structure can exhibit the lightening arresting function of the inner layer of the insulation tube before insulation performance of the outer layer of the insulation tube is broken when abnormal voltage occurs, so as to eliminate the abnormal voltage. Thus facility breakdown occurring between electrodes can be reduced to stabilize acceleration of charged particle beams.