Journal Article

PreJuSER-28008

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Mechanism of central temperature peaking in impurity seeded plasmas

Tokar, M. Z.FZJ*

2003
IOP Publ. Bristol

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/1780  doi:10.1088/0741-3335/45/7/319

Abstract: 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.

Keyword(s): J

Note: Record converted from VDB: 12.11.2012

---

Contributing Institute(s):

1. Institut für Plasmaphysik (IPP)

Research Program(s):

1. Kernfusion und Plasmaforschung (E05)

Appears in the scientific report 2003
Notes: This version is available at the following Publisher URL: http://stacks.iop.org/0741-3335/45/1323

---

Database coverage:

---