ELECTRON TEMPERATURE ANISOTROPY IN AN EXPANDING PLASMA: PARTICLE-IN-CELL SIMULATIONS
ELECTRON TEMPERATURE ANISOTROPY IN AN EXPANDING PLASMA: PARTICLE-IN-CELL SIMULATIONS
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DOI：
10.1088/0004-637x/710/2/1848
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发表时间：
2010-02
期刊：
影响因子：
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通讯作者：
E. Camporeale;D. Burgess
中科院分区：
文献类型：
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作者：
E. Camporeale;D. Burgess
我们对热等离子体进行了完全动力学的胞内粒子模拟，该等离子体在柱面几何形状中径向膨胀。本文的目的是研究无碰撞恒星风中膨胀等离子体流中电子温度各向异性的发展。动能等离子体理论和模拟表明，电子温度各向异性是由电磁动能不稳定性驱动的涨落控制的。在这项研究中，温度各向异性是由膨胀自洽驱动的。虽然膨胀有利于增加平行各向异性(T∥>；T⊥)，但消防水带不稳定性的开始将倾向于降低它。我们给出了超音速、亚音速和静态膨胀流的结果，并建议将结果应用于太阳风和其他恒星风。
We perform fully kinetic particle-in-cell simulations of a hot plasma that expands radially in a cylindrical geometry. The aim of the paper is to study the consequent development of the electron temperature anisotropy in an expanding plasma flow as found in a collisionless stellar wind. Kinetic plasma theory and simulations have shown that the electron temperature anisotropy is controlled by fluctuations driven by electromagnetic kinetic instabilities. In this study, the temperature anisotropy is driven self-consistently by the expansion. While the expansion favors an increase of parallel anisotropy (T∥ > T⊥), the onset of the fire-hose instability will tend to decrease it. We show the results for supersonic, subsonic, and static expansion flows and suggest possible applications of the results for the solar wind and other stellar winds.