Temporal evolution of confined fast-ion velocity distributions measured by collective Thomson scattering in TEXTOR

TitleTemporal evolution of confined fast-ion velocity distributions measured by collective Thomson scattering in TEXTOR
Publication TypeJournal Article
Year of Publication2008
AuthorsS.K. Nielsen, H. Bindslev, L. Porte, J.A Hoekzema, S.B Korsholm, F. Leipold, F. Meo, P.K Michelsen, S. Michelsen, J.W Oosterbeek, E.L Tsakadze, G. van Wassenhove, E. Westerhof, P. Woskov
JournalPhysical Review E
Volume77
Number1
Pagination11
Date PublishedJan
Type of ArticleArticle
ISBN Number1539-3755
Accession NumberISI:000252861600043
Keywordsdiagnostics, EXCITATION, FLUCTUATIONS, JET, PARTICLE ENERGY, RADIATION, TEMPERATURE, TOKAMAK, TOROIDAL PLASMAS, WAVES
Abstract

Fast ions created in the fusion processes will provide up to 70% of the heating in ITER. To optimize heating and current drive in magnetically confined plasmas insight into fast-ion dynamics is important. First measurements of such dynamics by collective Thomson scattering (CTS) were recently reported [Bindslev , Phys. Rev. Lett. 97, 205005 2006]. Here we extend the discussion of these results which were obtained at the TEXTOR tokamak. The fast ions are generated by neutral-beam injection and ion-cyclotron resonance heating. The CTS system uses 100-150 kW of 110-GHz gyrotron probing radiation which scatters off the collective plasma fluctuations driven by the fast-ion motion. The technique measures the projected one-dimensional velocity distribution of confined fast ions in the scattering volume where the probe and receiver beams cross. By shifting the scattering volume a number of scattering locations and different resolved velocity components can be measured. The temporal resolution is 4 ms while the spatial resolution is similar to 10 cm depending on the scattering geometry. Fast-ion velocity distributions in a variety of scenarios are measured, including the evolution of the velocity distribution after turnoff of the ion heating. These results are in close agreement with numerical simulations.

URL<Go to ISI>://000252861600043
Division

Fusion Physics

PID

4dd2d63d6926dd2deb884c7009a019c9

Alternate TitlePhys. Rev. E

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