Comparison of edge plasma perturbation during ELM control using one vs. two toroidal rows of RMP coils in ITER similar shaped plasmas on DIII-D

• Published in: Journal of nuclear materials Vol. 390; pp. 793 - 796
• Main Authors: Fenstermacher, M.E., Evans, T.E., Osborne, T.H., Schaffer, M.J., deGrassie, J.S., Gohil, P., Groebner, R.J., Moyer, R.A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15.06.2009; Elsevier
• Subjects: Applied sciences; Controled nuclear fusion plants; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Nuclear fuels; Australia, Queensland, Magnetic I; 52.55.Fa; 52.35.Py; 52.55.Dy; 28.52.−s; Tokamak; Plasma; Nuclear fusion reactor; Neutral beam; Edge localized modes; Safety; Magnetic field; Nuclear reactor
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2009.01.210

Large Type-I edge localized modes (ELMs) were suppressed by n = 3 resonant magnetic perturbations (RMPs) from a set of internal coils in plasmas with an ITER similar shape at the ITER pedestal collisionality, ν e ∗ ∼ 0.1 and low edge safety factor ( q 95 ≈ 3.6), with either a single toroidal row of the internal RMP coils or two poloidally separated rows of coils. ELM suppression with a single row of internal coils was achieved at approximately the same q 95 surface-averaged perturbation field as with two rows of coils, but required higher current per coil. Maintaining complete suppression of ELMs using n = 3 RMPs from a single toroidal row of internal coils was less robust to variations in input neutral beam injection torque than previous ELM suppression cases using both rows of internal coils. With either configuration of RMP coils, maximum ELM size is correlated with the width of the edge region having good overlap of the magnetic islands from vacuum field calculations.