Detailed measurements of momentum balance during the periodic collapse of a transport barrier

M. Hron, P. Peleman, M. Spolaore, R. Dejarnac, O. Bilykova, J. Brotankova, J. Sentkerestiova, I. Duran, L. Van De Peppel, J. Gunn, J. Stockel, G. Van Oost, J. Horacek, J. Adamek, M. Stepan

Research output: Contribution to conferencePaper

Abstract

The onset of relaxation events is observed at the plasma edge of the CASTOR tokamak during the biasing experiments at high enough electrode voltages. These relaxations were studied with high spatial and temporal resolution by using several probe arrays. The transport barrier is periodically created and relaxes with frequency -10 kHz. The maximum radial electric field within the transport barrier is up to 70 kV/m, which causes strong ExB rotation in the poloidal direction. The resulting poloidal velocity (up to 50 km/s) is comparable with the ion sound velocity. The observation of plasma flows confirms their periodic redistribution between the parallel and perpendicular directions. The measurements of Mach numbers confirm that the M∥and M⊥are in anti-phase. The radial transport of the plasma towards the wall during the relaxations causes an enhancement of the influx of the neutrals into the plasma, which is in good agreement with the observed increase of the Hαline radiation. The poloidally resolved measurements have also demonstrated that the relaxation events are poloidally symmetric (both in their electric and magnetic components).
Original languageEnglish
Publication statusPublished - 2006
Externally publishedYes
Event33rd European Physical Society Conference on Plasma Physics 2006, EPS 2006 - , Italy
Duration: 1 Jan 2006 → …

Conference

Conference33rd European Physical Society Conference on Plasma Physics 2006, EPS 2006
CountryItaly
Period1/1/06 → …

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All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

Cite this

Hron, M., Peleman, P., Spolaore, M., Dejarnac, R., Bilykova, O., Brotankova, J., ... Stepan, M. (2006). Detailed measurements of momentum balance during the periodic collapse of a transport barrier. Paper presented at 33rd European Physical Society Conference on Plasma Physics 2006, EPS 2006, Italy.