Radioactive Isotope Induced by Beam Loss in Particle Accelerator for Heavy-Ion Inertial Fusion

We investigated radiation distributions, fluences, generation rates, and radioactive isotopes induced by heavyion impact into a vacuum vessel wall for a particle accelerator in the heavy-ion inertial fusion (HIF). Numerical results showed that the radiation management should be considered for neutrons and photons during the HIF system operation. Compared to the detailed numerical simulation, estimations in total reaction cross-sections and threshold kinetic energy for interaction in the Coulomb barrier were expected to provide criteria as a safer side for radiation management in the HIF accelerator. The activation and the isotopes generated by the interaction between the heavy-ion and the wall material were obtained from the calculation results, which showed that the generation rate and the variation of the generated isotope increased with the incident kinetic energy of the heavyion beam. The calculation results also indicated that the management of radioactive materials is important for the HIF accelerator system's safe operation. (C) 2021 The Japan Society of Plasma Science and Nuclear Fusion Research