Effects of Ion Magnetization on the Farley–Buneman Instability in the Solar Chromosphere
Effects of Ion Magnetization on the Farley–Buneman Instability in the Solar Chromosphere
复制标题
离子磁化对太阳色球层法利-布尼曼不稳定性的影响
DOI：
10.3847/1538-4357/aab71a
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
J. Fontenla
中科院分区：
文献类型：
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作者：
A. Fletcher;Y. Dimant;M. Oppenheim;J. Fontenla
安静太阳色球层的强烈加热使温度从 4000 K 升高到 6500 K，但尽管经过了数十年的研究，其潜在机制仍然是个谜。这项研究继续探索法利-布尼曼不稳定性导致色球加热的可能性。这种不稳定性发生在弱电离碰撞等离子体中，其中电子被磁化，但离子没有。金属离子的混合物在色球层最冷的部分产生等离子体密度；有些离子被弱磁化，而另一些离子则因中性碰撞而消磁。本文将多种任意磁化离子种类的影响纳入法利-布内曼不稳定性理论中，并研究了色球层不稳定性的影响。磁化离子的加入对色球层中可能发生不稳定性的区域引入了新的限制——事实上，它将不稳定性限制在观察到加热的区域。对于 30 G 的磁场，在最低温度下能够驱动不稳定性的最小环境电场为 13.5 V/m。
Intense heating in the quiet-Sun chromosphere raises the temperature from 4000 to 6500 K but, despite decades of study, the underlying mechanism remains a mystery. This study continues to explore the possibility that the Farley–Buneman instability contributes to chromospheric heating. This instability occurs in weakly ionized collisional plasmas in which electrons are magnetized, but ions are not. A mixture of metal ions generate the plasma density in the coolest parts of the chromosphere; while some ions are weakly magnetized, others are demagnetized by neutral collisions. This paper incorporates the effects of multiple, arbitrarily magnetized species of ions to the theory of the Farley–Buneman instability and examines the ramifications on instability in the chromosphere. The inclusion of magnetized ions introduces new restrictions on the regions in which the instability can occur in the chromosphere—in fact, it confines the instability to the regions in which heating is observed. For a magnetic field of 30 G, the minimum ambient electric field capable of driving the instability is 13.5 V/m at the temperature minimum.