|Title||Charge exchange spectroscopy as a fast ion diagnostic on TEXTOR|
|Publication Type||Conference Proceedings|
|Year of Publication||2008|
|Authors||E. Delabie, R.JE Jaspers, M.G von Hellermann, S.K. Nielsen, O. Marchuk|
|Publisher||Amer Inst Physics|
|Keywords||charge exchange, diagnostics, Doppler shift, fusion reactor instrumentation, PLASMA, SPECTROSCOPY, Tokamak devices|
An upgraded charge exchange spectroscopy diagnostic has been taken into operation at the TEXTOR tokamak. The angles of the viewing lines with the toroidal magnetic field are close to the pitch angles at birth of fast ions injected by one of the neutral beam injectors. Using another neutral beam for active spectroscopy, injected counter the direction in which fast ions injected by the first beam are circulating, we can simultaneously measure a fast ion tail on the blue wing of the D-alpha spectrum while the beam emission spectrum is Doppler shifted to the red wing. An analysis combining the two parts of the spectrum offers possibilities to improve the accuracy of the absolute (fast) ion density profiles. Fast beam modulation or passive viewing lines cannot be used for background subtraction on this diagnostic setup and therefore the background has to be modeled and fitted to the data together with a spectral model for the slowing down feature. The analysis of the fast ion D-alpha spectrum obtained with the new diagnostic is discussed.
|URL||<Go to ISI>://000260573500104|
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