Pedestal stability analysis on MAST in preparation for MAST-U
- 18 March 2021
- journal article
- research article
- Published by IOP Publishing in Nuclear Fusion
- Vol. 61 (4), 046041
- https://doi.org/10.1088/1741-4326/abe804
Abstract
In preparation for the upcoming MAST-U campaign, pedestal stability of spherical tokamaks is revisited by investigating standard H-mode discharges on MAST. As a step beyond previous studies, both ion and electron profiles are used for obtaining equilibria and a diverse set of pedestals is evaluated. Stability analysis with the ELITE and CGYRO codes shows that MAST pedestals are constrained by kinetic ballooning modes and medium toroidal mode number peeling-ballooning modes, with most unstable modes ranging from n = 25 to n = 45. In discharges with a steep q profile at the edge a larger number of poloidal harmonics is excited for each toroidal mode. A comparison with discharges on DIII-D with matched shape and similar non-dimensional parameters indicates that the increased shear at lower aspect ratio stabilizes low n peeling modes.Keywords
Funding Information
- Fusion Energy Sciences (DE-FC02-04ER54698 DE-SC0018030 DE-SC0018287 DE-SC0018990)
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