Measurement of the displacement cross-section of copper irradiated with 125 MeV protons at 12 K

作者：Iwamoto Yosuke^*; Yoshiie Toshimasa; Yoshida Makoto; Nakamoto Tatsushi; Sakamoto Masaaki; Kuriyama Yasutoshi; Uesugi Tomonori; Ishi Yoshihiro; Xu Qiu; Yashima Hiroshi; Takahashi Fumiaki; Mori Yoshiharu; Ogitsu Toru

来源：Journal of Nuclear Materials, 2015, 458: 369-375.

DOI：10.1016/j.jnucmat.2014.12.125

To validate Monte Carlo codes for the prediction of radiation damage in metals irradiated by >100 MeV protons, the defect-induced electrical resistivity changes related to the displacement cross-section of copper were measured with 125 MeV proton irradiation at 12 K. The cryogenic irradiation system was developed with a Gifford-McMahon cryocooler to cool the sample via an oxygen-free high-conductivity copper plate by conduction cooling. The sample was a copper wire with a 250-lm diameter and 99.999% purity sandwiched between two aluminum nitride ceramic sheets. The electrical resistivity changes of the copper wire were measured using the four-probe technique. After 125 MeV proton irradiation with 1.45 x 10(18) protons/m(2) at 12 K, the total resistivity increase was 4.94 x 10(-13) Omega m (resistance increase: 1.53 mu Omega), while the resistivity of copper before irradiation was 9.44 x 10(-12) Omega m (resistance: 29.41 mu Omega). The resistivity increase did not change during annealing after irradiation below 15 K. The experimental displacement cross-section for 125 MeV irradiation shows similar results to the experimental data for 1.1 and 1.94 GeV. Comparison with the calculated results indicated that the defect production efficiency in Monte Carlo codes gives a good quantitative description of the displacement cross-section in the energy region >100 MeV.

• 出版日期2015-3