Measurement of Displacement Cross-Section for Structural Materials in High-Power Proton Accelerator Facility

For damage estimation of structural material in the accelerator facility, displacement per atom (DPA) is widely employed as an index of the damage calculated based on the displacement cross-section obtained with the calculation model. Although the DPA is employed as the standard, the experimental data of displacement cross-section are scarce for a proton in the energy region above 20 MeV. Among the calculation models, the difference about 8 times exists so that experimental data of the displacement cross-section is crucial. To obtained the displacement cross-section, an experiment has started in J-PARC. As a preliminary result, the displacement cross-section of copper was successfully obtained for 3-GeV proton. The present results showed that the widely utilized NRT model overestimates the cross-section as suggested by the previous experiment in the lower energy region.