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Moderation of target loads using fuelling and impurity seeding on JET

Author
Abstract

Operation with an all metal, ITER-like wall on JET is scheduled from 2011. Adaptation particularly of baseline ELMy H-mode (q(95) approximate to 3.5) to the new exhaust constraints involved has been explored by systematic scans of deuterium fuelling and seeding with extrinsic impurities neon or nitrogen. Peak heat load between ELMs on the outboard target can be strongly reduced by fuelling (recycling), and approach detachment with either seed species, for only approximate to 10% loss of normalised energy confinement. Simultaneously, normalised plasma density and total radiation averaged between ELMs are not simply increased, but at stronger fuelling can actually fall with increasing seeding, indicating some redistribution of efflux power temporally and spatially. At highest nitrogen seeding, ELMs can also be mitigated, even while the electron pedestal and confinement are largely preserved. Charge-exchange recombination spectroscopy indicates a substitution of intrinsic carbon with extrinsic species. (C) 2010 EURATOM. Published by Elsevier B.V. All rights reserved.

Year of Publication
2011
Journal
Journal of Nuclear Materials
Volume
415
Number
1
Issue
1, Suppl.
Number of Pages
S313-S317
Date Published
Aug
Type of Article
Article; Proceedings Paper
ISBN Number
0022-3115
DOI
10.1016/j.jnucmat.2010.08.059
PId
8d83f5b5cfb0081dac434500d27b5dd4
Alternate Journal
J. Nucl. Mater.
Journal Article
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