Charged particle-induced gamma excitation as a possible diagnostic technique for escaping MeV ions on ITER

The knowledge of the flux of energetic ions to the first wall and their energy and pitch angle distributions are important for ITER. We study the possibility of using charged particle-induced activation which provides an attractive, simple, and robust technique to measure escaping million electron volt ions. For time resolved measurements, prompt gamma rays emitted by the target are directly viewed with a spectrometer. In this preliminary study we assess the possibility to fulfill the requirements necessary for the ITER alpha loss detectors. Test experiments are under preparation and simulations with the Monte Carlo MCNP4C code are used to assess the performance (signal-to-noise ratio) of the detectors.