Initial measurements of edge plasma turbulence on ATF

T. Uckan, C. Hidalgo, J. D. Bell, G. R. Dyer, J. H. Harris, J. B. Wilgen, C. P. Ritz, K. Carter, T. L. Rhodes, A. J. Wootton

Research output: Contribution to conferencePaperpeer-review

Abstract

Summary form only given. Initial measurements of the electrostatic turbulence on the edge of the ATF torsatron are carried out in order to study their effect on the particle transport in this currentless magnetic configuration. Spatial profiles of the plasma electron density ne, temperature Te, and fluctuations in density (ne*) and in the plasma potential (φ) are measured around the last closed flux surface (LCFS) using a fast reciprocating Langmuir probe. Measurements made on electron cyclotron heated (ECH) plasmas indicate that at the LCFS Te approximately 20-40 eV and ne approximately 1012 cm-3 for a line-average electron density of (3-5) × 1012 cm-3 at 1 T operation. The fluctuations depart increasingly from the Boltzman relation eφ/Te = ne*/ne as the probe is moved into plasma where Te > 20 eV, with ne*/ne approximately 5%, eφ/Te approximately 2ne*/ne about 2 cm inside the LCFS. The radial variation of the DC radial electric field results in a velocity shear layer whose position is independent of the limiter location. The particle flux estimated from the global particle balance is comparable with the fluctuation-driven particle flux.

Original languageEnglish
Pages79
Number of pages1
DOIs
StatePublished - 1990
Event1990 IEEE International Conference on Plasma Science - Oakland, CA, USA
Duration: May 21 1990May 23 1990

Conference

Conference1990 IEEE International Conference on Plasma Science
CityOakland, CA, USA
Period05/21/9005/23/90

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