Effect on confinement of edge-localized modes in TCV
H Weisen; M J Dutch; F Hofmann; Y Martin; J-M Moret; C Nieswand; Z A Pietrzyk; R A Pitts; A Pochelon; H Weisen; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne; M J Dutch; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne; F Hofmann; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne; Y Martin; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne; J-M Moret; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne; C Nieswand; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne; Z A Pietrzyk; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne; R A Pitts; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne; A Pochelon; Centre de Recherches en Physique des Plasmas, EPFL, Association EURATOM-Confédération Suisse, CH-1015 Lausanne
Журнал:
Plasma Physics and Controlled Fusion
Дата:
1996-08-01
Аннотация:
The effect of ELMs on confinement in ohmic H-modes has been investigated by analysing the rates of change of global parameters such as the electron content and the stored energy as a function of ELM frequency. In double-null H-modes, ELMs are found to expel on average 2% of the electron content and 2.5% of the stored energy. In single-null discharges which are separated by more than 2.2 cm from the inner wall, larger ELMs are observed which expel on average 3 - 7% of the electron content and 3 - 12% of the stored energy. When the plasma - wall distance is reduced, ELM frequencies increase and ELM amplitudes decrease. Quasi-stationary H-modes are obtained for Hz in double-null plasmas and for in the range 50 - 300 Hz in single-null plasmas, depending upon the plasma - wall distance and the ELM amplitude. The reduction in particle confinement due to the ELMs is sufficient to bring the ratio of particle to energy confinement times below 8 - 12 depending upon the ELM size and frequency.
92.50Кб