This title appears in the Scientific Report :
2003
Please use the identifier:
http://hdl.handle.net/2128/1780 in citations.
Please use the identifier: http://dx.doi.org/10.1088/0741-3335/45/7/319 in citations.
Mechanism of central temperature peaking in impurity seeded plasmas
Mechanism of central temperature peaking in impurity seeded plasmas
Formation of a centrally peaked profile of the ion temperature by impurity seeding has been observed in all the largest tokamaks: JET, JT-60U, TFTR. A possible explanation of this phenomenon is proposed, which takes into account the suppression of ion temperature gradient instability induced anomalo...
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Personal Name(s): | Tokar, M. Z. |
---|---|
Contributing Institute: |
Institut für Plasmaphysik; IPP |
Published in: | Plasma physics and controlled fusion, 45 (2003) S. 1323 - 1332 |
Imprint: |
Bristol
IOP Publ.
2003
|
Physical Description: |
1323 - 1332 |
DOI: |
10.1088/0741-3335/45/7/319 |
Document Type: |
Journal Article |
Research Program: |
Kernfusion und Plasmaforschung |
Series Title: |
Plasma Physics and Controlled Fusion
45 |
Subject (ZB): | |
Link: |
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Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1088/0741-3335/45/7/319 in citations.
Formation of a centrally peaked profile of the ion temperature by impurity seeding has been observed in all the largest tokamaks: JET, JT-60U, TFTR. A possible explanation of this phenomenon is proposed, which takes into account the suppression of ion temperature gradient instability induced anomalous transport through increasing ion effective charge Z(eff) and Doppler shift of unstable modes, S-perpendicular to. The particular importance of the S-perpendicular to component proportional to the temperature gradient, which stems from the pressure gradient and neoclassical poloidal rotation, is elucidated. It is demonstrated that this contribution grows significantly by impurity seeding when the rotation regime changes due to increased collisionality. An interrelation between the heating power density and Z(eff) necessary for the transition to a peaked ion temperature is found. The modification of radial profiles by impurity seeding is modelled numerically and the results are in agreement with the experimental data from JET. |