Ideal plasma response to vacuum magnetic fields with resonant magnetic perturbations in non-axisymmetric tokamaks. (3rd September 2015)

• Record Type: Journal Article
• Authors: Kim, Kimin; Ahn, J-W; Scotti, F; Park, J-K; Menard, J E
• Is Part Of: Plasma physics and controlled fusion. Volume 57:Number 10(2015:Oct.)
• Publication Date: 2015-09-03
• Subjects: resonant magnetic perturbation -- field line tracing -- plasma response; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/0741-3335/57/10/104002
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: Ideal plasma shielding and amplification of resonant magnetic perturbations in non-axisymmetric tokamak is presented by field line tracing simulation with full ideal plasma response, compared to measurements of divertor lobe structures. Magnetic field line tracing simulations in NSTX with toroidal non-axisymmetry indicate the ideal plasma response can significantly shield/amplify and phase shift the vacuum resonant magnetic perturbations. Ideal plasma shielding for n = 3 mode is found to prevent magnetic islands from opening as consistently shown in the field line connection length profile and magnetic footprints on the divertor target. It is also found that the ideal plasma shielding modifies the degree of stochasticity but does not change the overall helical lobe structures of the vacuum field for n = 3. Amplification of vacuum fields by the ideal plasma response is predicted for low toroidal mode n = 1, better reproducing measurements of strong striation of the field lines on the divertor plate in NSTX.