Investigation of fast particle driven instabilities by 2D electron cyclotron emission imaging on ASDEX Upgrade
SCIE
SCOPUS
- Title
- Investigation of fast particle driven instabilities by 2D electron cyclotron emission imaging on ASDEX Upgrade
- Authors
- Classen, IGJ; Lauber, P; Curran, D; Boom, JE; Tobias, BJ; Domier, CW; Luhmann, NC; Park, HK; Munoz, MG; Geiger, B; Maraschek, M; Van Zeel; , MA; da Graca, S
- Date Issued
- 2011-12
- Publisher
- IOP PUBLISHING LTD
- Abstract
- Detailed measurements of the 2D mode structure of Alfven instabilities in the current ramp-up phase of neutral beam heated discharges were performed on ASDEX Upgrade, using the electron cyclotron emission imaging (ECEI) diagnostic. This paper focuses on the observation of reversed shear Alfven-eigenmodes (RSAEs) and bursting modes that, with the use of the information from ECEI, have been identified as beta-induced Alfven eigenmodes (BAEs). Both RSAEs with first and second radial harmonic mode structures were observed. Calculations with the linear gyro-kinetic code LIGKA revealed that the ratio of the damping rates and the frequency difference between the first and second harmonic modes strongly depended on the shape of the q-profile. The bursting character of the BAE type modes, which were radially localized to rational q surfaces, was observed to sensitively depend on the plasma parameters, ranging from strongly bursting to almost steady state.
- Keywords
- ALFVEN MODES; TOKAMAK; EIGENMODES; STABILITY; CASCADES
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/16671
- DOI
- 10.1088/0741-3335/53/12/124018
- ISSN
- 0741-3335
- Article Type
- Article
- Citation
- PLASMA PHYSICS AND CONTROLLED FUSION, vol. 53, no. 12, page. 124018, 2011-12
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