A method for the estimate of the wall diffusion for non-axisymmetric fields using rotating external fields
2013 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 55, no 8, 084001- p.Article in journal (Refereed) Published
A new method for the estimate of the wall diffusion time of non-axisymmetric fields is developed. The method based on rotating external fields and on the measurement of the wall frequency response is developed and tested in EXTRAP T2R. The method allows the experimental estimate of the wall diffusion time for each Fourier harmonic and the estimate of the wall diffusion toroidal asymmetries. The method intrinsically considers the effects of three-dimensional structures and of the shell gaps. Far from the gaps, experimental results are in good agreement with the diffusion time estimated with a simple cylindrical model that assumes a homogeneous wall. The method is also applied with non-standard configurations of the coil array, in order to mimic tokamak-relevant settings with a partial wall coverage and active coils of large toroidal extent. The comparison with the full coverage results shows good agreement if the effects of the relevant sidebands are considered.
Place, publisher, year, edition, pages
2013. Vol. 55, no 8, 084001- p.
Resistive-Wall, Feedback Stabilization, Active Control, DIII-D, Modes, Pinch, Device
IdentifiersURN: urn:nbn:se:kth:diva-127495DOI: 10.1088/0741-3335/55/8/084001ISI: 000322702700002ScopusID: 2-s2.0-84881511440OAI: oai:DiVA.org:kth-127495DiVA: diva2:644814
17th Annual Workshop on Magnetohydrodynamic (MHD) Stability Control - Addressing the Disruption Challenge for ITER, NOV 05-07, 2012, New York, NY
QC 201309022013-09-022013-08-302016-01-11Bibliographically approved