Current profile modification experiments in EXTRAP T2R

M Cecconello, J-A Malmberg, G Spizzo, B E Chapman, R M Gravestjin, P Franz, P Piovesan, P Martin, J R Drake
2003 Plasma Physics and Controlled Fusion  
Pulsed poloidal current drive (PPCD) experiments have been conducted in the resistive shell EXTRAP T2R reversed-field pinch experiment. During the current profile modification phase, the fluctuation level of the m = 1 internally resonant tearing modes decreases, and the velocity of these modes increases. The m = 0 modes are not affected during PPCD, although termination occurs with a burst in the m = 0 amplitude. The PPCD phase is characterized by an increase in the central electron temperature
more » ... (up to 380 eV) and in the soft x-ray signal. Spectroscopic observations confirm an increase in the central electron temperature. During PPCD, the plasma poloidal beta increases to 14%, and the estimated energy confinement time doubles, reaching 380 µs. The reduction in the fluctuation level and the corresponding increase in the energy confinement time are qualitatively consistent with a reduction in parallel transport along stochastic magnetic field lines.
doi:10.1088/0741-3335/46/1/009 fatcat:zymqtxfctjgw3beqwpbguhdhuu