Multiple irradiation experiment of tungsten materials by negative hydrogen ion beam, 1; Study of beam target materials

Hirano, Koichiro  ; Fukuda, Makoto*; Ezato, Koichiro*; Tokunaga, Kazutoshi*

The beam targets of the J-PARC linac are multiply irradiated by hydrogen negative ion beams with beam energy of 3 MeV. The purpose of this study is to clarify the pulsed heat load conditions that can withstand multiple irradiations when beam targets made of tungsten materials are used. Using an off-line beam test-stand with a 3 MeV hydrogen negative ion beam, multiple irradiation tests were conducted on tungsten materials for ITER, in which temperature changes of heating (3200 degree) and cooling (160 degree) were repeatedly given at a period of 5 Hz. This paper reports on the surface observation of the tungsten materials and the partial pressure measurements by a quadrupole mass spectrometer.