STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTS
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...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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CTU Central Library
2015-08-01
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| Series: | Acta Polytechnica |
| Subjects: | |
| Online Access: | https://ojs.cvut.cz/ojs/index.php/ap/article/view/2263 |
| _version_ | 1818282513257201664 |
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| author | Boonyarit Chatthong Thawatchai Onjun |
| author_facet | Boonyarit Chatthong Thawatchai Onjun |
| author_sort | Boonyarit Chatthong |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-12-13T00:22:12Z |
| format | Article |
| id | doaj.art-e359be5ab02f4f1eb4860006cb891337 |
| institution | Directory Open Access Journal |
| issn | 1210-2709 1805-2363 |
| language | English |
| last_indexed | 2024-12-13T00:22:12Z |
| publishDate | 2015-08-01 |
| publisher | CTU Central Library |
| record_format | Article |
| series | Acta Polytechnica |
| spelling | doaj.art-e359be5ab02f4f1eb4860006cb8913372022-12-22T00:05:32ZengCTU Central LibraryActa Polytechnica1210-27091805-23632015-08-0155421522210.14311/AP.2015.55.02152750STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTSBoonyarit ChatthongThawatchai OnjunThe 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.https://ojs.cvut.cz/ojs/index.php/ap/article/view/2263plasmatokamakfusionL–H transitionbifurcation |
| spellingShingle | Boonyarit Chatthong Thawatchai Onjun STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTS Acta Polytechnica plasma tokamak fusion L–H transition bifurcation |
| title | STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTS |
| title_full | STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTS |
| title_fullStr | STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTS |
| title_full_unstemmed | STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTS |
| title_short | STUDY OF L–H TRANSITION AND PEDESTAL WIDTH BASED ON TWO-FIELD BIFURCATION AND FIXED POINT CONCEPTS |
| title_sort | study of l h transition and pedestal width based on two field bifurcation and fixed point concepts |
| topic | plasma tokamak fusion L–H transition bifurcation |
| url | https://ojs.cvut.cz/ojs/index.php/ap/article/view/2263 |
| work_keys_str_mv | AT boonyaritchatthong studyoflhtransitionandpedestalwidthbasedontwofieldbifurcationandfixedpointconcepts AT thawatchaionjun studyoflhtransitionandpedestalwidthbasedontwofieldbifurcationandfixedpointconcepts |