Nuclear reaction study for long-lived fission products in nuclear waste: Proton- and deuteron-induced reactions on ¹⁰⁷Pd and ⁹³Zr at 20 - 30 MeV/u

The nuclear transmutation of long-lived fission products (LLFPs), which are produced in nuclear reactors, is one of the candidate techniques for the reduction and/or reuse of LLFPs. To design optimum pathways of the transmutation process, several nuclear reactions have been studied using LLFPs as secondary beams. The studies indicate that proton- and/or deuteron-induced spallation reactions at intermediate energy (100 - 200 MeV/u) are effective for the LLFP transmutation. 

For a systematic study, we performed an experiment for the proton- and deuteron-induced reactions on ¹⁰⁷Pd and ⁹³Zr at 20 − 30 MeV/u. In this energy region, the fusion evaporation process is dominant. Thus, the reaction-mechanism dependence can be studied by comparison with the high-energy spallation data. The experiment was performed at RIKEN RIBF. The degraded RI beams at 20 - 30 MeV/u were produced by a newly developed beam line, OEDO. To induce the reactions, the high-pressure cooled gas targets (H₂ and D₂) were used. Reaction residues were analyzed by the SHARAQ spectrometer. 

In this talk, we will present the details of the experiments and the obtained results.