Electron heat transport analysis of FTU ohmic plasmas
The energy confinement time Tau(E) for ohmic discharges increases linearly with neo-ALCATOR scaling up to a saturation value, above which Tau(E) remains constant (saturated regime). When auxiliary heating is applied, Tau(E) decreases according to the L-mode scaling, but exceptions exist to this basic behaviour. Energy confinement in FTU follows neo-ALCATOR scaling and then saturates. Ion temperature profiles computed assuming neoclassical ion transport agree with ion temperature diagnostics both in the linear and in the saturated regime. The best fitting to FTU confinement data is provided by the L-mode Lackner-Gottardi scaling; this prompts the existence of a strict connection between ohmic and L-mode confinement. In order to examine this connection more closely, the electron thermal diffusivity obtained from local power balance analysis was compared with the predictions of transport models that represent L-mode data from experiments with strong auxiliary heating. Such a comparison requires accurate measurement of the electron temperature gradient, but is more direct than the comparison with calculated temperature profiles.
Bibliographic Reference: Paper presented: Workshop on Local Transport Studies in Fusion Plasmas, Varenna (IT), August 30 - September 3, 1993
Availability: Available from (1) as Paper EN 37905 ORA
Record Number: 199311437 / Last updated on: 1994-11-28
Original language: en
Available languages: en