A new developed in-between shots lithium evaporation coating system for improving plasma performance in EAST

Xu, W.; Hu, J. S.; Zuo, G. Z.; Sun, Z.; Lunsford, R.; Meng, X. C.; Huang, M.

doi:10.1016/j.fusengdes.2018.05.061

A new developed in-between shots lithium evaporation coating system for improving plasma performance in EAST

Journal Article · Tue Jun 12 00:00:00 EDT 2018 · Fusion Engineering and Design

DOI:https://doi.org/10.1016/j.fusengdes.2018.05.061· OSTI ID:1461184

Xu, W. ^[1]; Hu, J. S. ^[2]; Zuo, G. Z. ^[3]; Sun, Z. ^[3]; Lunsford, R. ^[4]; Meng, X. C. ^[5]; Huang, M. ^[3]

Chinese Academy of Sciences, Hefei (China); Univ. of Science and Technology of China, Hefei (China)
Chinese Academy of Sciences, Hefei (China); CAS Key Lab of Photovoltaic and Energy Conservation Materials, Hefei (China)
Chinese Academy of Sciences, Hefei (China)
Princeton Univ., Princeton, NJ (United States)
Hunan Univ., Changsha (China)

A new in-between shots evaporative lithium coating system has been successfully developed and implemented on the Experimental Advanced Superconducting Tokamak (EAST) for the 2017 campaign. This paper describes a novel technique for the introduction of lithium into the EAST vessel allowing evaporative coatings to be applied between discharges without requiring a significant amount of time to insert and retract the lithium source. This newly designed system utilizes a rotating axis driven by a vacuum dynamic sealing feedthough under remote control to open and close a shutter. A compression bellows, which drives the delivery tube, guarantees accurate position of the oven thus avoiding possible direct contact with the plasma. This allows the new evaporation system to be operated in two distinct modes. One mode is operated in-between shots to refresh pre-coated lithium film, the other is a real-time lithium vapor injection during plasma operations to provide active wall conditioning during long pulse plasma discharges. In this paper, operation of this new lithium deposition system in the in-between shots replenishment mode is described. Initial experiments show that this system worked well during the interval of discharges in EAST, and the in-between shots lithium coating effectively reduced the wall recycling and impurity concentrations. Furthermore, the application of fresh lithium coating lead to sustain the plasma stored energy and confinement, as well as a reduction of impurity radiation.

View Accepted Manuscript (DOE)

Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: USDOE

OSTI ID:: 1461184

Alternate ID(s):: OSTI ID: 22850476

Journal Information:: Fusion Engineering and Design, Journal Name: Fusion Engineering and Design Journal Issue: C Vol. 133; ISSN 0920-3796

Publisher:: ElsevierCopyright Statement

Country of Publication:: United States

Language:: English

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