Observation of Double Impurity Critical Gradients for Electromagnetic Turbulence Excitation in Tokamak Plasmas.
Phys Rev Lett
; 117(4): 045001, 2016 Jul 22.
Article
in En
| MEDLINE
| ID: mdl-27494476
ABSTRACT
The impact of impurity ions on a pedestal has been investigated in the HL-2A Tokamak, at the Southwestern Institute of Physics, Chengdu, China. Experimental results have clearly shown that during the H-mode phase, an electromagnetic turbulence was excited in the edge plasma region, where the impurity ions exhibited a peaked profile. It has been found that double impurity critical gradients are responsible for triggering the turbulence. Strong stiffness of the impurity profile has been observed during cyclic transitions between the I-phase and H-mode regime. The results suggest that the underlying physics of the self-regulated edge impurity profile offers the possibility for an active control of the pedestal dynamics via pedestal turbulence.
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01-internacional
Database:
MEDLINE
Language:
En
Journal:
Phys Rev Lett
Year:
2016
Document type:
Article