Measurements and modelling of plasma response field to RMP on the COMPASS tokamak

Measurements and modelling of plasma response field to RMP on the COMPASS tokamak

Measurements and modelling of plasma response field to RMP on the COMPASS tokamak 150 150 Mathew
CCFE-PR(15)90

Measurements and modelling of plasma response field to RMP on the COMPASS tokamak

It has been shown on several tokamaks that application of a Resonant Magnetic Perturbation (RMP) eld on plasma can under certain conditions lead to suppression or mitigation of Edge-Localized Mode (ELM) instabilities. Due to the rotation of the plasma in the RMP eld reference system, currents are induced on resonant surfaces within the plasma, consequently, screening the original perturbation. In this work, the extensive set of 104 saddle loops installed on the COMPASS tokamak [1] is utilized to measure the plasma response field for two n = 2 RMP configurations of different m spectrum. It is shown that spatially the response field is in anti-phase to the original perturbation, and that the poloidal profile of the measured response field does not depend on the m profile of used RMP. Simulations of the plasma response by linear MHD code MARS-F [2] reveal that both studied RMP configurations are well screened by the plasma. Comparison of measured plasma response field to the simulated one shows a good agreement across the majority of angle, with exception of 0 low-field side area, where discrepancy is seen.

Collection:
Journals
Journal:
Nuclear Fusion
Publisher:
IOP
Published date:
07/01/2016