American Institute of Physics, Physics of Plasmas, 12(10), p. 4737-4743, 2003
DOI: 10.1063/1.1623271
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Changes in the edge profile of soft x-ray emission during pulsed poloidal current drive (PPCD) experiments are in agreement with the modifications of the plasma surface, as seen from magnetic measurements. In particular, the m = 0 modes resonant at the reversal radius have been analyzed. A comparison with an m = 0 island reconstruction model shows that PPCD reduces the bulging associated with the m = 0 modes by shifting inward the reversal surface, where the m = 0 island is located. Regarding the total m = 0 amplitude, there are evidences that during PPCD, on average, it does not change significantly. Additional data coming from standard discharges support the idea that two competing phenomena act during PPCD: one is the inward shift of the reversal, which destabilizes the m = 0 modes; the other one is the decrease of the m = 1 fluctuations, which acts in the opposite direction. © 2003 American Institute of Physics.