Determination of component activation and radiation environment in the second stripping region of a highpower heavy-ion linear accelerator

In supporting pre-conceptual research and development of the Rare-Isotope Accelerator (RIA) facility or similar next-generation exotic beam facilities, one critical focus area is to estimate the level of activation and radiation in the linear accelerator second stripping region and to determine if remote handling is necessary in this area. A basic geometric layout of the second stripping region having beamline magnets, beam pipes and boxes, a stripper foil, beam slits, and surrounding concrete shielding was constructed for Monte Carlo simulations. Beam characteristics were provided within the stripping region based on this layout. Radiation fields, radioactive inventories, levels of activation, heat loads on surrounding components, and prompt and delayed radiation dose rates were simulated using Monte-Carlo radiation transport code PHITS[1]. Results from simulations using a simplified geometry show that remote handling of foils and slits will be necessary. Simulations using a more realistic geometry were performed and the results agree well with the estimation by the simple model.