中国物理B ›› 2021, Vol. 30 ›› Issue (10): 104103-104103.doi: 10.1088/1674-1056/ac192f

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Physical properties of relativistic electron beam during long-range propagation in space plasma environment

Bi-Xi Xue(薛碧曦)1,2, Jian-Hong Hao(郝建红)1,†, Qiang Zhao(赵强)2, Fang Zhang(张芳)2, Jie-Qing Fan(范杰清)1, and Zhi-Wei Dong(董志伟)2   

  1. 1 School of Electrical and Electronic Engineering Department, North China Electric Power University, Beijing 102206, China;
    2 Institute of Applied Physics and Computational Mathematics, Beijing 100094, China
  • 收稿日期:2021-06-06 修回日期:2021-07-21 接受日期:2021-07-30 出版日期:2021-09-17 发布日期:2021-09-30
  • 通讯作者: Jian-Hong Hao E-mail:jianhonghao@ncepu.edu.cn
  • 基金资助:
    Project supported by the Joint Funds of the National Natural Science Foundation of China (Grant Nos. 61372050 and U1730247).

Physical properties of relativistic electron beam during long-range propagation in space plasma environment

Bi-Xi Xue(薛碧曦)1,2, Jian-Hong Hao(郝建红)1,†, Qiang Zhao(赵强)2, Fang Zhang(张芳)2, Jie-Qing Fan(范杰清)1, and Zhi-Wei Dong(董志伟)2   

  1. 1 School of Electrical and Electronic Engineering Department, North China Electric Power University, Beijing 102206, China;
    2 Institute of Applied Physics and Computational Mathematics, Beijing 100094, China
  • Received:2021-06-06 Revised:2021-07-21 Accepted:2021-07-30 Online:2021-09-17 Published:2021-09-30
  • Contact: Jian-Hong Hao E-mail:jianhonghao@ncepu.edu.cn
  • Supported by:
    Project supported by the Joint Funds of the National Natural Science Foundation of China (Grant Nos. 61372050 and U1730247).

摘要: It is known that ion channel can effectively limit the radial expansion of an artificial electron beam during its long-range propagation in the space plasma environment. Most prior studies discussed the focusing characteristics of the beam in the ion channel, but the establishment process and transient properties of the ion channel itself, which also plays a crucial role during the propagation of the relativistic electron beam in the plasma environment, were commonly neglected. In this study, a series of two-dimensional (2D) particle-in-cell simulations is performed and an analytical model of ion channel oscillation is constructed according to the single-particle motion. The results showed that when the beam density is higher than the density of plasma environment, ion channel can be established and always continues to oscillate periodically over the entire propagation. Multiple factors, including the beam electron density, initial beam radius, and the plasma density can affect the oscillation properties of ion channel. Axial velocity of the beam oscillates synchronously with the ion channel and this phenomenon will finally develop into a two-stream instability which can seriously affect the effective transport for relativistic electron beam. Choosing appropriate beam parameters based on various plasma environments may contribute to the improvement of the stability of ion channel. Additionally, radial expansion of the beam can be limited by ion channel and a stable long-range propagation in terrestrial atmosphere may be achieved.

关键词: ion channel, space plasma environment, long-range propagation, particle-in-cell (PIC) simulation

Abstract: It is known that ion channel can effectively limit the radial expansion of an artificial electron beam during its long-range propagation in the space plasma environment. Most prior studies discussed the focusing characteristics of the beam in the ion channel, but the establishment process and transient properties of the ion channel itself, which also plays a crucial role during the propagation of the relativistic electron beam in the plasma environment, were commonly neglected. In this study, a series of two-dimensional (2D) particle-in-cell simulations is performed and an analytical model of ion channel oscillation is constructed according to the single-particle motion. The results showed that when the beam density is higher than the density of plasma environment, ion channel can be established and always continues to oscillate periodically over the entire propagation. Multiple factors, including the beam electron density, initial beam radius, and the plasma density can affect the oscillation properties of ion channel. Axial velocity of the beam oscillates synchronously with the ion channel and this phenomenon will finally develop into a two-stream instability which can seriously affect the effective transport for relativistic electron beam. Choosing appropriate beam parameters based on various plasma environments may contribute to the improvement of the stability of ion channel. Additionally, radial expansion of the beam can be limited by ion channel and a stable long-range propagation in terrestrial atmosphere may be achieved.

Key words: ion channel, space plasma environment, long-range propagation, particle-in-cell (PIC) simulation

中图分类号:  (Particle beam transport)

  • 41.85.Ja
41.75.Ht (Relativistic electron and positron beams) 52.35.-g (Waves, oscillations, and instabilities in plasmas and intense beams) 42.65.Jx (Beam trapping, self-focusing and defocusing; self-phase modulation)