Energy balance in plasma detachment. (August 2017)

• Record Type: Journal Article
• Authors: Pshenov, A.A.; Kukushkin, A.S.; Krasheninnikov, S.I.
• Is Part Of: Nuclear materials and energy. Volume 12(2017)
• Page Start: 948
• Page End: 952
• Publication Date: 2017-08
• Subjects: Divertor -- Detachment -- Impurity -- Recombination; Nuclear energy -- Periodicals; Nuclear fuels -- Periodicals; Nuclear reactors -- Materials -- Periodicals; Radioactive substances -- Periodicals; 621.4833
• DOI: 10.1016/j.nme.2017.03.019
• Languages: English
• ISSNs: 2352-1791

Abstract

Highlights: Volumetric plasma recombination and impurity radiation cause the "rollover". Plasma-neutral friction is not directly involved in reduction of plasma flux. Increase of impurity radiation results in a smooth transition to detachment. Detachment onset in a specific flux tube happens when P up q recycl > ( P up q recycl ) crit . The latter holds for both pure deuterium and impurity-seeded plasmas. Abstract: Divertor plasma detachment is analyzed from the viewpoint of energy and particle balance in the edge plasma. It is shown that volumetric recombination and impurity radiation losses are responsible for the transition to the detached plasma regime, whereas "momentum removal" plays although important, but auxiliary role providing conditions necessary for the first two to become efficient. A criterion of the local (on an isolated flux tube) detachment onset is studied for both pure and impurity-seeded plasmas.