A power modulation experiment was conducted in the third campaign of the LHD.In a conventional analysis of the modulation experiments, the energyconfinement time and heating efficiency are taken as constant, disregardingtheir dependence on the plasma parameters. In this paper, their dependence onthe plasma temperature and heating power is taken into consideration toimprove the analysis of the power modulation experiments. Several models, withdiffering dependence on the plasma parameters, have been examined. There havebeen several reports suggesting that the transport coefficients obtained fromthe dynamical method are different from those obtained from power balanceanalyses. This paper finally concludes that the energy confinement timeobtained from the power modulation experiments well agrees with that obtainedfrom the power balance analysis, made including temperature dependence both inenergy confinement time and heating efficiency.
The impact of improved confinement on fusion research