Heavy Ion Target Area Fast Neutron Dose Equivalent Rates

Abstract

It is sometimes necessary for personnel to work in areas where heavy ions interacting with targets, target holders or beam transport equipment produce radiation levels significantly above background. Since neutrons are responsible for a major part of this background, it would be helpful to be able to predict neutron radiation levels as a function of ion mass and energy. Consequently, we have measured fast neutron dose equivalent rates at one meter from medium mass targets 90° from the beam direction while the targets were bombarded with energetic C, N, O or Ne ions. The ion energies ranged from 3 MeV/amu to 16 MeV/amu. The measured dose equivalent rates follow a general pattern which appears to be insensitive to the heavy ion species.