Measurement of displacement cross section on tungsten for 0.4 - 3 GeV proton projectile

Meigo, Shinichiro   ; Matsuda, Hiroki  ; Iwamoto, Yosuke   ; Iwamoto, Hiroki   ; Hasegawa, Shoichi   ; Maekawa, Fujio  ; Yoshida, Makoto*; Ishida, Taku*; Makimura, Shunsuke*; Nakamoto, Tatsushi*

R&D of the structural material such as a beam window, which serves as a partition between the accelerator and the target region, is crucial in the ADS. Although the displacement per atom (DPA) is widely used to evaluate the damage on the window, experimental data on the displacement cross section is scarce in the energy region above 20 MeV for proton projectile. We started to measure the displacement cross section for the protons in the energy region between 0.4 to 3 GeV. The displacement cross section can be derived by resistivity change divided by the proton flux and the resistivity change per Frankel pair on the cryo-cooled sample to maintain damage. Experiments were conducted at the 3 GeV proton synchrotron at the J-PARC Center, and a tungsten wire sample was applied. It was found that the calculation of the NRT model, which is a widely utilized to calculate DPA, predicted the cross section by about 3 times of the present experiment.