Numerical modelling of error field penetration

Abstract

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Effect of resonant helical magnetic fields on plasma rotation

“…Recently it was shown on TEXTOR that the relative frequency between the mode and the helical field is important in determining the field penetration [5,6], being in agreement with theoretical results [7][8][9].…”

“…(a) Helical field penetration: For the plasma being originally stable to tearing modes, an applied resonant helical field (or error fields of experimental devices) can penetrate through the resonant surface and generate a magnetic island there [1][2][3][4][5][6][7][8][9]. Recently it was shown on TEXTOR that the relative frequency between the mode and the helical field is important in determining the field penetration [5,6], being in agreement with theoretical results [7][8][9].…”

“…It would be of interest to study whether the intrinsic machine error field is resonant at the plasma edge and large enough to cause such a rotation. In the tokamak core region the parallel transport is much faster, and 8 *e begins to decrease due to the flattening of the radial electron pressure profile even before field penetration [8]. In this case a rotating helical field would still be able to drive plasma rotation.…”

“…Recently, two fluids equations were utilized to study helical field penetration [8,9,14], including the linear study on the effect of a rotating helical field on plasma rotation [9]. As plasma rotation is very important for, e.g., the stability of the resistive wall modes, a better understanding of the experimental results given in Ref.…”

Understanding the effect of resonant magnetic perturbations on tearing mode dynamics

“…6 To explain the changed TM dynamics caused by applied RMPs, many theoretical and numerical studies related to RMPs have been carried out. 2,[19][20][21][22][23][24][25][26][27][28][29][30][31][32] Some authors supposed that RMPs changed ∆' so as to stabilize tearing instability. 19 However, only the active RMPs experiment could be explained in which RMPs had a constant phase with respect to the a) Author to whom correspondence should be addressed.…”