Edge plasma physics/plasma–wall interactions during high density operation in LHD

• Published in: Journal of nuclear materials Vol. 390; pp. 232 - 237
• Main Authors: Komori, A., Morisaki, T., Masuzaki, S., Kobayashi, M., Suzuki, Y., Sakamoto, R., Morita, S., Chowdhuri, M.B., Goto, M., Miyazawa, J., Yamada, I., Narihara, K., Ohyabu, N., Sagara, A., Yamada, H., Motojima, O.
• 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; 52.55.Hc; Plasma; Nuclear fusion reactor; Internal diffusion; Impurity; Divertor; Diffusion barrier; Surface plasma interaction; Recycling; Stellarator; Reactor core; Nuclear reactor
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2009.01.064

Superdense plasma with a highly peaked electron density profile was obtained in the reduced recycling discharge in the Large Helical Device (LHD). During the discharge, a core region with a density as high as ∼5
×
10
20
m
−3 and a temperature of ∼0.8
keV is maintained by an Internal Diffusion Barrier (IDB) with a steep density gradient. In spite of such a high density at the core region, no serious impurity accumulation has been observed. According to the numerical calculation with the EMC3–EIRENE code, downstream parallel flow in the ergodic region plays an important role to screen the influx of impurities with its strong friction force. The divertor flux distribution and global recycling properties do not change so much as against the change in the dense core plasma.