Speaker
Description
As a material-damage index due to the radiation, displacement per atom (dpa) is used widely, which is given by the particle fluence and the displacement cross section, which can be obtained by the electrical resistivity change of target materials due to the proton irradiation by the Matthiessen rule. The sample had to be cooled at cryo-temperature to observe the very small resistivity change and sustain the damage. To obtain the cross section data, J-PARC and JAEA conducted experiments using protons in the kinetic energy range from 100 MeV to 120 GeV. The experimental results were compared with the calculation based on the Norgett-Robinson-Torrens model (NRT-dpa), which is widely utilized to determine the dpa. It was found that the NRT-dpa overestimated the experiment by a factor of 3-8, depending on the target materials. A recent model based on athermal recombination corrected model (arc-dpa) showed good agreement with the experiment. It is of interest to compare the experimental cross section with the calculation model at high energy, such as 440 GeV, where the energy deposition increases due to relativistic effects. To obtain the experimental data, we conducted an experiment at CERN HiRadMat using the 440 GeV protons. In this session, the preliminary displacement cross sections results are shown compared with the calculation results. It was found that PHITS calculations with arc-dpa reproduced the experiment well. On the contrary, the NRT-dpa calculation overestimates the experimental data.
Acknowledgments:
This project has been supported by JSPS KAKENHI Grant Numbers JP22K04992 and has also received funding from the European Union’s Horizon Europe research and innovation program under grant agreement No 101057511.
