|Title||Temporal evolution of confined fast-ion velocity distributions measured by collective Thomson scattering in TEXTOR|
|Publication Type||Journal Article|
|Year of Publication||2008|
|Authors||S.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|
|Journal||Physical Review E|
|Type of Article||Article|
|Keywords||diagnostics, EXCITATION, FLUCTUATIONS, JET, PARTICLE ENERGY, RADIATION, TEMPERATURE, TOKAMAK, TOROIDAL PLASMAS, WAVES|
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|
|Alternate Title||Phys. Rev. E|
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