Radiation Environment in the ITER Neutral Beam Injector Prototype

We study the radiation environment in MITICA, the prototype of the ITER neutral beam injector, during deuterium operation. ITER is a scientific challenge: one of the several critical issues to solve is the compatibility to ionizing radiation of diagnostics components placed near the plasma vessel. In fact, non negligible fluxes of neutrons and photons are expected from deuterium-deuterium reactions, also from a major peripheral component such as the Neutral Beam Injector. After evaluating the results of Monte Carlo simulations on the expected environment, we determine the risk of malfunctions due to ionizing radiation in control and diagnostic electronics placed close to the injector vessel. The risk on different families of electronic devices is assessed, focusing separately on displacement damage, total ionizing dose, and single event effects.