Experimental observations and modelling of radiation asymmetries during N2 seeding in LHD

B.J. Peterson; G. Kawamura; P.L. van de Giessen; K. Mukai; H. Tanaka; R. Sano; S.N. Pandya; S.Y. Dai; S. Masuzaki; T. Akiyama; M. Kobayashi; M. Goto; G. Motojima; R. Sakamoto; N. Ohno; T. Morisaki; J. Miyazawa

Nuclear Materials and Energy (Mar 2021)

Experimental observations and modelling of radiation asymmetries during N2 seeding in LHD

B.J. Peterson,
G. Kawamura,
P.L. van de Giessen,
K. Mukai,
H. Tanaka,
R. Sano,
S.N. Pandya,
S.Y. Dai,
S. Masuzaki,
T. Akiyama,
M. Kobayashi,
M. Goto,
G. Motojima,
R. Sakamoto,
N. Ohno,
T. Morisaki,
J. Miyazawa

Affiliations

B.J. Peterson: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
G. Kawamura: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
P.L. van de Giessen: Eindhoven University of Technology, 5612 AZ Eindhoven, the Netherlands
K. Mukai: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
H. Tanaka: Graduate School of Engineering, Nagoya Univ., Nagoya, Aichi-ken 464-8603, Japan
R. Sano: National Institutes for Quantum and Radiological Sci. and Tech., Naka 311-0193, Japan
S.N. Pandya: Institute for Plasma Research, Gandhinagar, Gujarat 382 428, India
S.Y. Dai: School of Physics, Dalian University of Technology, Dalian 116024, PR China
S. Masuzaki: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
T. Akiyama: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; General Atomics, San Diego, CA, USA
M. Kobayashi: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
M. Goto: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
G. Motojima: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
R. Sakamoto: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
N. Ohno: Graduate School of Engineering, Nagoya Univ., Nagoya, Aichi-ken 464-8603, Japan
T. Morisaki: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan
J. Miyazawa: National Institute for Fusion Science, Toki, Gifu-ken 509-5292, Japan; Graduate University for Advanced Studies SOKENDAI, Hayama 240-0163, Japan

Journal volume & issue: Vol. 26
p. 100848

Abstract

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N2 gas has been seeded in the Large Helical Device (LHD) to reduce the divertor heat load through enhanced radiation. Radiation is observed by two imaging bolometers, viewing the same poloidal cross-section from top and bottom ports, at a location which is 36° toroidally removed from the N2 gas puff nozzle located at the bottom of the machine. During N2 seeding, these measurements both confirm that additional radiation from the outboard side is coming exclusively from the top of the cross-section, indicating up/down asymmetry, which is also reproduced by modelling with EMC3-EIRENE using a half torus model. In addition, a toroidally localized, magnetic field direction-dependent radiation enhancement is observed with N2 seeding, but is not reproducible by the model.

Published in Nuclear Materials and Energy

ISSN: 2352-1791 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Nuclear engineering. Atomic power
Website: http://www.journals.elsevier.com/nuclear-materials-and-energy/

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