2023年度核データ+PHITS合同研究会/Joint Symposium on Nuclear Data and PHITS in 2023

Palladium is one of the nuclides targeted for recycling from spent nuclear fuel. Reasonable nuclear reaction paths for ${}^{107}$Pd and the cross-sections for proton- and deuteron-induced spallation in inverse kinematics have been investigated [1]. However, a transmutation experiment using long-lived fission products as the target would be required for an actual system. To experimentally demonstrate the feasibility of ${}^{107}$Pd transmutation by deuteron irradiation under continuous irradiation with the existing azimuthally varying field (AVF) ring cyclotron at RIKEN RIBF, we conducted a test with macroscopic quantities to transmute ${}^{107}$Pd by deuteron beams produced by the accelerator [2].
To effectively detect the reaction products of the ${}^{107}$Pd + d reaction, we prepared a material with a ${}^{107}$Pd-concentration of almost 100\% by ion implantation. The implanted samples were irradiated for several days with deuterons produced by the AVF ring Cyclotron at RIKEN RIBF. After cooling, gamma-ray measurements of the irradiated sample were conducted. ${}^{105}$Pd and ${}^{106}$Pd produced from transmutation of ${}^{107}$Pd were estimated using DCHAIN. The ${}^{107}$Pd in the irradiated samples were measured by ICP-MS. The isotopic ratios ${}^{105}$Pd/${}^{107}$Pd and ${}^{106}$Pd/${}^{107}$Pd obtained from the experimental results were compared with those obtained by calculation using PHITS.
In this paper, an outline of the test of ${}^{107}$Pd transmutation with macroscopic quantities is presented and certain experimental results are reported.

References
[1] H. Wang et al., “Spallation reaction study for the long-lived fission product ${}^{107}$Pd”, Prog. Theor. Exp. Phys. (2017) 021D01.
[2] Y. Miyake et al., “Test of 107Pd transmutation with macroscopic quantities”, J. Nucl. Sci. Technol., 59:12 (2022) pp. 1536-1545.