Measurements of MeV energy ICRF driven minority ions in JET

Measurements have been made of flux and energy spectra of 0.5-2 MeV hydrogen atoms, produced during H-minority ICRF heating in JET, using a high energy neutral particle analyzer (NPA). The ions, neutralized by charge-exchange and recombination processes, exit the plasma and reach the NPA installed at the top of the torus with its line of sight intercepting the plasma center at R=3.07m. The NPA has eight energy channels spanning 0.5≤E (MeV)≤3.5, with common mass selection, enabling time resolved measurements of the flux and energy spectra of hydrogenic and helium atoms emitted by the plasma. (author) 3 refs., 6 figs