Confinement Bifurcations by Poloidal Magnetic Flux Perturbations in the TUMAN-3M
Abstract
In experiments performed in TUMAN-3M, the possibility of switching on/off the H-mode by poloidal magnetic flux perturbations has been observed. The flux perturbations were created by fast current ramp up/down or by magnetic compression/decompression produced by fast increase/decrease in the toroidal magnetic field. It was found that the current ramp up and magnetic compression are robust means of H-mode triggering. The current ramp down and magnetic decompression allow termination of the H-mode. The transitions between the confinement modes in these experiments might be understood in terms of a unified mechanism in which E× B sheared flow variation is induced by strong change in the toroidal electric field E_\varphi connected with poloidal magnetic flux perturbations. Possible roles of variations of the current density profile j(r) and power input in the L-H and H-L transitions in the above experiments are discussed as well.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 2004
- Bibcode:
- 2004APS..DPPCP1071L