A generalization is made of the Ohmic energy confinement scaling by Pfeiffer and Waltz and the neo-Alcator scaling. The global energy confinement time is obtained by integrating the conduction dominated steady state total heat balance equation with the thermal conduction coefficient derived from Pfeiffer and Waltz type scaling, retaining the temperature scaling exponent. The model includes analytic approximations to the heating profile effect for a variety of heating methods, a sawtooth effect as well as a correction for non-conductive losses near the maximum obtainable density. A systematic calibration to experimental data from limiter discharges with Ohmic, electron cyclotron, and neutral beam heating is done to determine the adjustable free parameters. With considerably fewer explicitly adjustable free parameters, the model appears to give a better fit to the available data than the Goldston model.
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Condensed Matter Physics