Detachment stabilization with n/m=1/1 resonant magnetic perturbation field applied to the stochastic magnetic boundary of the Large Helical Device

Journal Article · Sat May 15 04:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3368681· OSTI ID:21371196

Kobayashi, M; Masuzaki, S; Yamada, I; Tamura, N; Sato, K; Goto, M; Narushima, Y; Akiyama, T; Miyazawa, J; Shoji, M; Morita, S; Peterson, B J; Funaba, H; Ohyabu, N; Narihara, K; Morisaki, T; Yamada, H; Komori, A ^[1]; Feng, Y ^[2]; Reiter, D ^[3]

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1. National Institute for Fusion Science, Oroshi-cho 322-6, Toki city, Gifu 509-5292 (Japan)
2. Max-Planck-Institut fuer Plasmaphysik, EURATOM-IPP Association, D-17491 Greifswald (Germany)
3. Institut fuer Plasmaphysik, Forschungszentrum Juelich Gmbh, D-52425 Juelich (Germany)

It is found that the remnant island structure created by n/m=1/1 resonant magnetic perturbation field in the stochastic magnetic boundary of the Large Helical Device (LHD) [A. Komori et al., Nucl. Fusion 49, 104015 (2009)] has a stabilizing effect on formation of radiating plasma, realizing stably sustained divertor detachment operation with the core plasma being unaffected. The data from the several diagnostics, (profiles of electron temperature and density, radiation and temporal evolution of divertor particle flux) indicate selective cooling around X-point of the island and thus peaked radiation there, which is stabilized outside of the last closed flux surface throughout the detachment phase. The vacuum ultraviolet spectroscopy measurements of high Z impurity (iron) emission shows significant decrease during the detachment, indicating core plasma decontamination. The results from the three-dimensional (3D) edge transport code, edge Monte Carlo 3D (EMC3) [Y. Feng et al., Contrib. Plasma Phys. 44, 57 (2004)]-EIRENE [D. Reiter et al., Fusion Sci. Technol. 47, 172 (2005)] show similar tendency in the radiation pattern. The island size and its radial location are varied to investigate the magnetic topology effects on the detachment control. The divertor particle flux and neutral pressure exhibit intermittent oscillation as well as modification of recycling pattern during the detachment, which are found to reflect the island structure.

• OSTI ID: 21371196
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CALCULATION METHODS
CLOSED PLASMA DEVICES
DISTURBANCES
DIVERTORS
ELECTRON TEMPERATURE
IMPURITIES
LHD DEVICE
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC SURFACES
MONTE CARLO METHOD
PLASMA DIAGNOSTICS
PLASMA IMPURITIES
SPECTROSCOPY
STABILIZATION
STOCHASTIC PROCESSES
THERMONUCLEAR DEVICES