Plasma heating by ion gyro-scale blobs in the kinetic and fluid regimes

Gingell, P.W., Chapman, S.C. and Dendy, R.O. (2013) Plasma heating by ion gyro-scale blobs in the kinetic and fluid regimes. Plasma Physics and Controlled Fusion, 55 (5), 1-6, [055010]. (doi:10.1088/0741-3335/55/5/055010).

Record type: Article

Abstract

Strongly localized concentrations of plasma density ('blobs') are ubiquitous in the near-edge region of tokamak plasmas. They contribute significantly to heating and transport in that region, and therefore to overall energy confinement. The blob population may include some whose characteristic length scales are on the order of the ion gyro-scale, and cannot be resolved by contemporary diagnostics. Using simulations of ion gyro-scale blobs that include full ion kinetics, we perform the first comparison between the heating ability of ions in small, kinetic blobs and in larger, fluid ones. We find that, embedded in a flowing plasma, small scale blobs contribute more heating per ion than larger blobs, as a result of ion pick-up at the upstream blob-background boundary. This may result in significant excess plasma heating by an ion population that is not yet directly observable.

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Plasma heating by ion gyro-scale blobs in the - Accepted Manuscript

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