| 具有非广延分布电子的碰撞等离子体磁鞘的结构 |
| |
| 引用本文： | 邹秀,刘惠平,张小楠,邱明辉.具有非广延分布电子的碰撞等离子体磁鞘的结构[J].物理学报,2021(1):312-318. |
| |
| 作者姓名： | 邹秀 刘惠平 张小楠 邱明辉 |
| |
| 作者单位： | 大连交通大学理学院 |
| |
| 基金项目： | 国家自然科学基金(批准号:10605008);辽宁省教育厅科研项目(批准号:L2011069,JDL2017012)资助的课题. |
| |
| 摘 要： | 很多关于等离子体鞘层的研究工作都是基于电子满足经典的麦克斯韦速度分布函数,而等离子体中的粒子具有长程电磁相互作用,使用Tsallis提出的非广延分布来描述电子更为恰当.本文建立一个具有非广延分布电子的碰撞等离子体磁鞘模型,理论推导出受非广延参数q影响的玻姆判据,离子马赫数的下限数值会随着参数q的增大而减小.经过数值模拟,发现与具有麦克斯韦分布(q=1)电子的碰撞等离子体磁鞘对比,具有超广延分布(q<1)和亚广延分布(q>1)电子的碰撞等离子体磁鞘的结构各有不同,包括空间电势分布、离子电子密度分布、空间电荷密度分布.模拟结果显示非广延分布的参数q对碰撞等离子体磁鞘的结构具有不可忽略的影响.希望这些结论对相关的天体物理、等离子体边界问题的研究有参考价值.
|
| 关 键 词： | 非广延分布 等离子体 鞘层 |
Structure of collisional magnetized plasma sheath with nonextensive distribution of electrons |
| |
| Zou Xiu,Liu Hui-Ping,Zhang Xiao-Nan,Qiu Ming-Hui.Structure of collisional magnetized plasma sheath with nonextensive distribution of electrons[J].Acta Physica Sinica,2021(1):312-318. |
| |
| Authors: | Zou Xiu Liu Hui-Ping Zhang Xiao-Nan Qiu Ming-Hui |
| |
| Affiliation: | (School of Science,Dalian Jiaotong University,Dalian 116028,China) |
| |
| Abstract: | Many previous researches on the plasma sheath were based on the fact that the electrons satisfy the classical Maxwell velocity distribution function, while the particles in the plasma have long-range electromagnetic interactions. It is more appropriate to use the non-extensive distribution proposed by Tsallis to describe the electrons. In this paper, a collisional magnetized plasma sheath model with non-extensive distribution of electrons is established. Bohm criterion is derived theoretically. With the ion drift motion in the plasma pre-sheath region taken into consideration, the ion Mach number is only related to the angle of the magnetic field, the collision parameters, the electric field at the sheath edge, and non-extensive parameter q.The influence of parameter q on the criterion is discussed in this paper. The lower limit of the ion Mach number changes with the value of parameter q. The lower limit of the ion Mach number increases for q < 1.And the lower limit of the ion Mach number decreases for q > 1. With the increase of q, the number of electrons with lower speed increases, ions need less kinetic energy to enter into the sheath and thus enter into the sheath more easily. Through numerical simulation, it is found that compared with the structure of the plasma magnetized sheath with Maxwell distribution( q = 1), the structure of the plasma magnetized sheath with super-extensive distribution( q < 1) and that with sub-extensive( q > 1) are different, including the distribution of the space potential, the ion density, the electron density, and the space charge density. When q < 1, the space potential, the electron density and the ion density fall more slowly, and the peak of the space charge density curve is closer to the wall. When q > 1, the space potential and the ion electron density fall faster, especially the electron density drops to zero faster, and the peak of the space charge density curve is far away from the wall. The simulation results show that the non-extensive parameter q has a significant influence on the structure of collisional plasma magnetized sheath. The influence of the collision on the magnetized plasma sheath with non-extensive distribution is similar to that with the Maxwell distribution. These conclusions may be useful in solving the problems of plasma boundary. |
| |
| Keywords: | non-extensive distribution plasma sheath |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《物理学报》浏览原始摘要信息 |
|
点击此处可从《物理学报》下载免费的PDF全文 |
|
