This title appears in the Scientific Report :
2008
Please use the identifier:
http://dx.doi.org/10.1088/0741-3335/50/11/115004 in citations.
Status of electron temperature and density measurement with beam emission spectroscopy on thermal helium at TEXTOR
Status of electron temperature and density measurement with beam emission spectroscopy on thermal helium at TEXTOR
Beam emission spectroscopy on thermal helium is used at the TEXTOR tokamak as a reliable method to obtain radial profiles of electron temperature T-e(r, t) and electron density ne(r, t). In this paper the experimental realization of this method at TEXTOR and the status of the atomic physics employed...
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Personal Name(s): | Schmitz, O. |
---|---|
Beigman, I. / Vainshtein, L. A. / Pospieszczyk, A. / Schweer, B. / Krychowiak, M. / Samm, U. / Uzgel, E. | |
Contributing Institute: |
Plasmaphysik; IEF-4 JARA-ENERGY; JARA-ENERGY |
Published in: | Plasma physics and controlled fusion, 50 (2008) S. 115004 |
Imprint: |
Bristol
IOP Publ.
2008
|
Physical Description: |
115004 |
DOI: |
10.1088/0741-3335/50/11/115004 |
Document Type: |
Journal Article |
Research Program: |
Fusion |
Series Title: |
Plasma Physics and Controlled Fusion
50 |
Subject (ZB): | |
Publikationsportal JuSER |
Beam emission spectroscopy on thermal helium is used at the TEXTOR tokamak as a reliable method to obtain radial profiles of electron temperature T-e(r, t) and electron density ne(r, t). In this paper the experimental realization of this method at TEXTOR and the status of the atomic physics employed as well as the major factors for the measurement's accuracy are evaluated. On the experimental side, the hardware specifications are described and the impact of the beam atoms on the local plasma parameters is shown to be negligible. On the modeling side the collisional-radiative model (CRM) applied to infer ne and Te from the measured He line intensities is evaluated. The role of proton and deuteron collisions and of charge exchange processes is studied with a new CRM and the impact of these so far neglected processes appears to be of minor importance. Direct comparison to Thomson scattering and fast triple probe data showed that for high densities ne > 3.5 x 10(19) m(-3) the T-e values deduced with the established CRM are too low. However, the new atomic data set implemented in the new CRM leads in general to higher Te values. This allows us to specify the range of reliable application of BES on thermal helium to a range of 2.0 x 10(18) < n(e) < 2.0 x 10(19) m(-3) and 10eV < T-e < 250eV which can be extended by routine application of the new CRM. |