Kinetic theory and simulation of collisionless tearing in bifurcated current sheets
| Autor: | William Daughton, Tatsuki Matsui |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Physics of Plasmas. 15:012901 |
| ISSN: | 1089-7674 1070-664X |
| DOI: | 10.1063/1.2832679 |
| Popis: | Observations from the Earth’s geomagnetic tail have established that the current sheet is often bifurcated with two peaks in the current density. These so-called bifurcated current sheets have also been reported in a variety of simulations and often occur in conjunction with significant temperature anisotropy. In this work, a new self-consistent Vlasov equilibrium is developed that permits both the current profile and temperature anisotropy to be independently adjusted. The stability of these layers with respect to the collisionless tearing mode is examined using both standard analytic techniques and a formally exact treatment involving a numerical evaluation of the full orbit integral. The resulting linear growth rate and mode structure are verified with fully kinetic particle-in-cell simulations. These results demonstrate that a bifurcated current profile has a strong stabilizing influence on the tearing mode in comparison to centrally peaked layers with a similar thickness. In contrast, electron temper... |
| Databáze: | OpenAIRE |
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