2D/3D electron temperature fluctuations near explosive MHD instabilities accompanied by minor and major disruptions. (25th May 2016)

• Record Type: Journal Article
• Authors: Choi, M.J.; Park, H.K.; Yun, G.S.; Lee, W.; Luhmann, N.C.; Lee, K.D.; Ko, W.-H.; Park, Y.-S.; Park, B.H.; In, Y.
• Is Part Of: Nuclear fusion. Volume 56:Number 6(2016:Jun.)
• Publication Date: 2016-05-25
• Subjects: disruption -- 3D imaging diagnostics -- MHD instability; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/56/6/066013
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: Minor and major disruptions by explosive MHD instabilities were observed with the novel quasi 3D electron cyclotron emission imaging (ECEI) system in the KSTAR plasma. The fine electron temperature ( T e ) fluctuation images revealed two types of minor disruptions: a small minor disruption is a q ∼ 2 localized fast transport event due to a single m / n = 2/1 magnetic island growth, while a large minor disruption is partial collapse of the q ⩽ 2 region with two successive fast heat transport events by the correlated m / n = 2/1 and m / n = 1/1 instabilities. The m / n = 2/1 magnetic island growth during the minor disruption is normally limited below the saturation width. However, as the additional interchange-like perturbation grows near the inner separatrix of the 2/1 island, the 2/1 island can expand beyond the limit through coupling with the cold bubble formed by the interchange-like perturbation.