Measurements of displacement cross section of tungsten under 389-MeV proton irradiation and thermal damage recovery

Iwamoto, Yosuke   ; Yoshida, Makoto*; Matsuda, Hiroki  ; Meigo, Shinichiro   ; Satoh, Daiki   ; Yashima, Hiroshi*; Yabuuchi, Atsushi*; Shima, Tatsushi*

To predict the lifetime of target materials in high-energy radiation environments at spallation neutron sources, radiation transport codes such as PHITS are used to calculate the displacements per atom (DPA) value. In this work, to validate calculated DPA values of tungsten, we implemented 0.25-mm-diameter wire sample of tungsten in a proton irradiation device with a Gifford-McMahon cryocooler and measured the defect-induced electrical resistivity changes related to the displacement cross section using 389-MeV protons at 10 K. As well as our previous results for aluminum and copper, calculated results with defect production efficiencies provided good agreements with experimental data. Based on measurements of recovery of the defects through annealing, about 85% of the damage remained at 60 K, and the same tendency is observed in other experimental result for reactor neutron irradiation.