Prediction of activation products and resulting dose rates for the magnetic septum in heavy-ion medical accelerator

Abstract

In high-energy heavy-ion medical accelerator facility, the induced activity due to primary and secondary interactions of the lost beams is the most concerned issue in view point of nuclear safety because long-lived radioactive nuclides cause problems of radiation exposure for staff involved in the repair or maintenance work and in decommissioning the facility. This paper presents activation of a thick magnetic septum by modeling the copper coils which are heavily showered by the lost carbon ion beams with the energy of 430 MeV/u. The activation takes place by all possible interaction modes which include direct interaction of the carbon ion beam with the elements, the interaction of backscattered neutrons from the concrete walls, and isotope production as a result of the decay of other isotopes produced in these interactions. The prediction of the radionuclide inventory and induced activation are performed by using the combination of MCNPX2.7.0 and CINDER’90 codes.