Towards realistic parametrization of the kinetic anisotropy and the resulting instabilities in space plasmas. Electromagnetic electron–cyclotron instability in the solar wind
Towards realistic parametrization of the kinetic anisotropy and the resulting instabilities in space plasmas. Electromagnetic electron–cyclotron instability in the solar wind
复制标题
实现动力学各向异性的实际参数化以及由此产生的太阳风中电磁电子回旋不稳定性。
DOI：
10.1093/mnras/stu2312
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发表时间：
2015
影响因子：
4.8
通讯作者：
C. Dumitrache
中科院分区：
文献类型：
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作者：
M. Lazar;S. Poedts;R. Schlickeiser;C. Dumitrache
在现场测量，在太阳风等离子体中的粒子速度分布揭示了两个不同的组成部分：麦克斯韦（热）核心，和密度较小，但更热的超热晕与幂律分布描述的洛伦兹/卡帕分布函数。尽管有这样的证据，现有的尝试参数化各向异性分布和由此产生的波不稳定性仅限于理想化的模型，它要么忽略超热人口，或最小化核心，假设它是冷的。在这里，一个更现实的方法被确定，结合各向同性麦克斯韦核心和各向异性双卡帕晕。这个模型是相关的大日心距离和慢风，当场对准strahl是不太明显的和动能密度的核心和晕是可比的。与冷核模型进行了比较研究的电子哨声，
Measuredin situ, the particle velocity distributions in the solar wind plasma reveal two distinct components: a Maxwellian (thermal) core, and a less dense but hotter suprathermal halo with a power-law distribution described by Lorentzian/Kappa distribution function. Despite this evidence, the existing attempts to parametrize anisotropic distributions and the resulting wave instabilities are limited to idealized models, which either ignore the suprathermal populations, or minimize the core, assuming it is cold. Here, a more realistic approach is identified, combining an isotropic Maxwellian core and an anisotropic bi-Kappa halo. This model is relevant at large heliocentric distances and for the slow winds, when the field-aligned strahl is less pronounced and kinetic energy densities in the core and halo are comparable. A comparative study with the cold-core-based model is performed on the electron whistler–