STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTS
| Autor: | B. Chatthong, Thawatchai Onjun |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
fusion
Field (physics) Chemistry business.industry L–H transition General Engineering Magnetic confinement fusion Flux Mechanics Plasma Optics Pedestal Transition point Physics::Plasma Physics lcsh:TA1-2040 bifurcation Jump business lcsh:Engineering (General). Civil engineering (General) tokamak Bifurcation plasma |
| Zdroj: | Acta Polytechnica, Vol 55, Iss 4, Pp 215-222 (2015) |
| ISSN: | 1805-2363 1210-2709 |
| Popis: | The L–H transition in magnetic confinement plasmas is investigated on the basis of concepts of two-field bifurcation and fixed-point stability. A set of heat and particle transport equations with both neoclassical and anomalous effects included is used to study ETB formation and also pedestal width and dynamics. It is found that plasmas can exhibit bifurcation where a sudden jump in the gradients can be achieved at the transition point corresponding to the critical flux. Furthermore, it is found that the transport barrier expands inward, whereby the radial growth of the pedestal initially appears to be superdiffusive but later slows down and stops. In addition, the time of barrier expansion is found to be much longer than the time that plasma takes to evolve from L-mode to H-mode. A sensitivity study is also performed, in which the barrier width is found to be sensitive to various parameters, e.g. heating, transport coefficients and suppression strength. |
| Databáze: | OpenAIRE |
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