Turbulence and energy confinement during ohmic discharges in Tore Supra
In numerous tokamaks, energy confinement time increases with mean density and then reaches saturation. This phenomenon may be due to an increase in heat transported by electrons or ions. This study investigated the causes of this saturation, and in particular into the development of ion turbulence. Transport, propagation times and temperature fluctuations were analysed and electron density fluctuations measured. Changes in the mean density correlated strongly with the electron diffusion coefficient. The coefficient of ionic heat diffusion was well below the neoclassical value, even at low density. There was no deterioration in ion confinement when confinement time reached saturation. Results show that saturation of confinement time is not due to development of ion turbulence with increasing mean density. It appears therefore that energy confinement time in Tore Supra is mainly influenced by electron behaviour.
Bibliographic Reference: Paper presented: Troisième Congrès de la Société Française de Physique - Plasma, Nancy (FR), September 16-18, 1992
Availability: Available from (1) as Paper FR 37072 ORA
Record Number: 199211485 / Last updated on: 1994-11-29
Original language: fr
Available languages: fr