X-point collapse and saturation in the nonlinear tearing mode reconnection.
We study the nonlinear evolution of the resistive tearing mode in slab geometry in two dimensions. We show that, in the strongly driven regime (large delta'), a collapse of the X point occurs once the island width exceeds a certain critical value approximately 1/delta'. A current sheet is...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2005
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| _version_ | 1826289143928324096 |
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| author | Loureiro, N Cowley, S Dorland, W Haines, MG Schekochihin, A |
| author_facet | Loureiro, N Cowley, S Dorland, W Haines, MG Schekochihin, A |
| author_sort | Loureiro, N |
| collection | OXFORD |
| description | We study the nonlinear evolution of the resistive tearing mode in slab geometry in two dimensions. We show that, in the strongly driven regime (large delta'), a collapse of the X point occurs once the island width exceeds a certain critical value approximately 1/delta'. A current sheet is formed and the reconnection is exponential in time with a growth rate proportional eta(1/2), where eta is the resistivity. If the aspect ratio of the current sheet is sufficiently large, the sheet can itself become tearing-mode unstable, giving rise to secondary islands, which then coalesce with the original island. The saturated state depends on the value of delta'. For small delta', the saturation amplitude is proportional delta' and quantitatively agrees with the theoretical prediction. If delta' is large enough for the X-point collapse to have occurred, the saturation amplitude increases noticeably and becomes independent of delta'. |
| first_indexed | 2024-03-07T02:24:25Z |
| format | Journal article |
| id | oxford-uuid:a519e68f-908e-4b95-8e8d-394f4ed7b94b |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:24:25Z |
| publishDate | 2005 |
| record_format | dspace |
| spelling | oxford-uuid:a519e68f-908e-4b95-8e8d-394f4ed7b94b2022-03-27T02:38:06ZX-point collapse and saturation in the nonlinear tearing mode reconnection.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a519e68f-908e-4b95-8e8d-394f4ed7b94bEnglishSymplectic Elements at Oxford2005Loureiro, NCowley, SDorland, WHaines, MGSchekochihin, AWe study the nonlinear evolution of the resistive tearing mode in slab geometry in two dimensions. We show that, in the strongly driven regime (large delta'), a collapse of the X point occurs once the island width exceeds a certain critical value approximately 1/delta'. A current sheet is formed and the reconnection is exponential in time with a growth rate proportional eta(1/2), where eta is the resistivity. If the aspect ratio of the current sheet is sufficiently large, the sheet can itself become tearing-mode unstable, giving rise to secondary islands, which then coalesce with the original island. The saturated state depends on the value of delta'. For small delta', the saturation amplitude is proportional delta' and quantitatively agrees with the theoretical prediction. If delta' is large enough for the X-point collapse to have occurred, the saturation amplitude increases noticeably and becomes independent of delta'. |
| spellingShingle | Loureiro, N Cowley, S Dorland, W Haines, MG Schekochihin, A X-point collapse and saturation in the nonlinear tearing mode reconnection. |
| title | X-point collapse and saturation in the nonlinear tearing mode reconnection. |
| title_full | X-point collapse and saturation in the nonlinear tearing mode reconnection. |
| title_fullStr | X-point collapse and saturation in the nonlinear tearing mode reconnection. |
| title_full_unstemmed | X-point collapse and saturation in the nonlinear tearing mode reconnection. |
| title_short | X-point collapse and saturation in the nonlinear tearing mode reconnection. |
| title_sort | x point collapse and saturation in the nonlinear tearing mode reconnection |
| work_keys_str_mv | AT loureiron xpointcollapseandsaturationinthenonlineartearingmodereconnection AT cowleys xpointcollapseandsaturationinthenonlineartearingmodereconnection AT dorlandw xpointcollapseandsaturationinthenonlineartearingmodereconnection AT hainesmg xpointcollapseandsaturationinthenonlineartearingmodereconnection AT schekochihina xpointcollapseandsaturationinthenonlineartearingmodereconnection |