Diagnostic application of magnetic islands rotation in JETShow others and affiliations
Number of Authors: 11142016 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 56, no 7, article id 076004Article in journal (Refereed) Published
Abstract [en]
Measurements of the propagation frequency of magnetic islands in JET are compared with diamagnetic drift frequencies, in view of a possible diagnostic application to the determination of markers for the safety factor profile. Statistical analysis is performed for a database including many well-diagnosed plasma discharges. Propagation in the plasma frame, i.e. with subtracted E x B Doppler shift, results to be in the ion diamagnetic drift direction, with values ranging from 0.8 (for islands at the q = 2 resonant surface) to 1.8 (for more internal islands) times the ion diamagnetic drift frequency. The diagnostic potential of the assumption of island propagation at exactly the ion diamagnetic frequency is scrutinised. Rational-q locations obtained on the basis of this assumption are compared with the ones measured by equilibrium reconstruction including motional Stark effect measurements as constraints. Systematic shifts and standard deviations are determined for islands with (poloidal, toroidal) periodicity indexes of (2, 1), (3, 2), (4, 3) and (5, 3) and possible diagnostic applications are indicated.
Place, publisher, year, edition, pages
IOP PUBLISHING LTD , 2016. Vol. 56, no 7, article id 076004
Keywords [en]
tearing mode, magnetic islands rotation, magnetic reconnection
National Category
Fusion, Plasma and Space Physics
Identifiers
URN: urn:nbn:se:kth:diva-272026DOI: 10.1088/0029-5515/56/7/076004ISI: 000378928600006Scopus ID: 2-s2.0-84978804547OAI: oai:DiVA.org:kth-272026DiVA, id: diva2:1424093
Note
QC 20200416
2020-04-162020-04-162024-03-15Bibliographically approved