Charge exchange neutral particle analysis on ICRF-heated plasmas in the GAMMA10 tandem mirror

The ion energy balance in the central cell of the GAMMA10 tandem mirror is investigated for ICRF-heated plasmas on the basis of ion temperatures determined from charge exchange neutral particle measurements. The radial profiles of perpendicularly heated ions are measured using a neutral particle energy analyser (NPA). An experiment on ICRF power modulation is performed in order to evaluate the energy confinement. The resultant temporal change in the ion temperature is analysed from the charge exchange neutrals and central cell diamagnetism. A time evolution code of ion energy balance based on the radial profiles of measured plasma parameters is developed to predict the temporal behaviour of the ion stored energy and the calculated results are compared with the measurements. (C) 1997 Elsevier Science S.A.