Test of ¹⁰⁷Pd transmutation with macroscopic quantities

ABSTRACT

A test of ¹⁰⁷Pd transmutation with macroscopic quantities was conducted. Palladium is an essential material for industrial use and is one of the nuclides targeted for recycling from spent nuclear fuel. Reasonable nuclear reaction paths for ¹⁰⁷Pd and the cross-sections for proton- and deuteron-induced spallation in inverse kinematics have been investigated. However, a transmutation experiment using long-lived fission products (LLFPs) as the target would be required for an actual system. To effectively detect the reaction products of the ¹⁰⁷Pd + d reaction, we prepared a material with a ¹⁰⁷Pd-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. These revealed ¹⁰⁵Ag and ^106mAg originating from the ¹⁰⁷Pd + d reaction. Furthermore, ¹⁰⁵Pd and ¹⁰⁶Pd produced from transmutation of ¹⁰⁷Pd were estimated using DCHAIN. The ¹⁰⁷Pd in the irradiated samples were measured by ICP-MS. The isotopic ratios ¹⁰⁵Pd/¹⁰⁷Pd and ¹⁰⁶Pd/¹⁰⁷Pd obtained from the experimental results are consistent with those obtained by calculation using PHITS. Furthermore, the ¹⁰⁷Pd transmutation using deuteron was verified.

Graphical Abstract

KEYWORDS:

• Pd107
• nuclear transmutation
• deuteron
• long-lived fission products
• AVF cyclotron

Acknowledgments

We wish to thank the accelerator staff of the RIKEN Nishina Center for providing deuteron beams. We express our gratitude to Dr. Hiroyuki Matsuzaki (University of Tokyo) for helping with the start-up of the ion source. This study was funded by the ImPACT Program of the Council for Science, Technology, and Innovation (Cabinet Office, Government of Japan).

Disclosure statement

No potential conflict of interest was reported by the author(s).