Comparative study on lifetime of stripper foil using 650 keV H- Ion beam

Thick carbon stripper foils of >300 mug/cm² will be used as a stripping of H-ion beam for 3 GeV rapid cycling synchrotron (3 GeV-RCS) of the J-PARC. The carbon foils with long lifetime even at >1800degK are required. For this purpose, we have developed a new irradiation system for the lifetime measurement using high current pulsed and dc H^- beams of the KEK Cockcroft-Walton accelerator. These high power 750 keV H^- Ion beams can simulate the high energy deposition in carbon stripper foils at the J-PARC RCS. An automatic data acquisition system is also developed for recording the data of foil temperature and irradiated beam current. The hybrid boron mixed carbon (HBC) stripper foils, which are developed at KEK are irradiated by high current H^- ion beam up to 2000degK. A few SNS-diamond and commercially available carbon (CM) foils are also tested for comparing with HBC-foils. The results of the lifetime measurement of HBC and SNS-diamond including CM stripper foils are reported.