Alfvén waves in the solar corona: resonance velocity, damping length, and charged particles acceleration by kinetic Alfvén waves

太阳日冕中的阿尔芬波:共振速度、阻尼长度以及动能阿尔芬波对带电粒子的加速

阅读:1

Abstract

Recent advances in heliospheric exploration spurred by NASA's Parker Solar Probe (PSP) mission require a deeper understanding of the intricate dynamics of the solar corona and wind. This study provides a detailed examination of kinetic Alfvén waves (KAWs) within the 0 - 10 R(Sun) range, a region only briefly explored in future PSP passages. Employing the framework of kinetic plasma theory and incorporating a non-thermal Cairns velocity distribution, we investigate the impact of the non-thermal index parameter Λ on the resultant resonance velocity vres . The results reveal a notable change in the distance (R(Sun)) over which the particles transport energy and the magnitude of resonance velocity for Λ > 0 . We also derive the perpendicular resonance velocity vres⊥ and the group velocity vg expressions of particles and KAWs, respectively. We find that vres⊥ and the normalized group velocity vg/vA are significantly influenced by Λ . In contrast to the resonance speed and group velocity, the damping length LD of KAWs is evaluated for different parameters. We find that KAWs experience accelerated damping and exhibit an increased damping length for Λ > 0 . We evaluate KAWs by the influence of the magnetic field, variation in height relative to the solar radius R(Sun), and the electron-to-ion temperature ratio Te/Ti . Collectively, these findings illustrate that KAWs not only are important for heating processes but also accelerate charged particles across considerable distances within the solar corona and solar wind regions. The analytical insights gleaned from this study find practical application in understanding wave phenomena in the solar and heliospheric regimes, particularly exploring the role of non-thermal particles in observed heating processes.

特别声明

1、本页面内容包含部分的内容是基于公开信息的合理引用;引用内容仅为补充信息,不代表本站立场。

2、若认为本页面引用内容涉及侵权,请及时与本站联系,我们将第一时间处理。

3、其他媒体/个人如需使用本页面原创内容,需注明“来源:[生知库]”并获得授权;使用引用内容的,需自行联系原作者获得许可。

4、投稿及合作请联系:info@biocloudy.com。