Enhanced particle transport caused by resonant magnetic perturbations in the J-TEXT tokamak

The effect of resonant magnetic perturbations (RMPs) on particle transport is studied in the J-TEXT tokamak. It is found that for the discharges with an existing saturated 2/1 resistive tearing mode (TM), applied RMPs of moderate amplitude lead to a decrease in electron density with a relative amplitude Delta(n) over bar (e)/(n) over bar (e0) ranging from -3% to -10% in the plasma core, and the mode stabilization and electron temperature increase are observed simultaneously in this case. Sufficiently large amplitude of RMPs, however, leads to locked modes and much larger decrease in the electron density as well as in the electron temperature, with Delta(n) over bar (e)/(n) over bar (e0) approximate to -20%. For the discharges without 2/1 TMs, applied RMPs cause a relative density decrease Delta(n) over bar (e)/(n) over bar (e0) similar to -10% (-30%) before (after) field penetration. Using the two-fluid equations and experimental parameters as input, the nonlinear numerical results approximately agree with experimental observations.