中国物理B ›› 2018, Vol. 27 ›› Issue (1): 15201-015201.doi: 10.1088/1674-1056/27/1/015201

• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇    下一篇

Excitation of chorus-like waves by temperature anisotropy in dipole research experiment (DREX): A numerical study

Hua Huang(黄华), Zhi-Bin Wang(王志斌), Xiao-Gang Wang(王晓钢), Xin Tao(陶鑫)   

  1. 1 Department of Physics, Harbin Institute of Technology, Harbin 150001, China;
    2 Laboratory for Space Environment and Physical Sciences, Harbin Institute of Technology, Harbin 150001, China;
    3 Chinese Academy of Sciences Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2017-07-11 修回日期:2017-08-17 出版日期:2018-01-05 发布日期:2018-01-05
  • 通讯作者: Zhi-Bin Wang E-mail:wangzhibin@hit.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 41674165, 41631071, 41474142, and 41674174) and the China Postdoctoral Science Foundation (Grant No. 2015M570283).

Excitation of chorus-like waves by temperature anisotropy in dipole research experiment (DREX): A numerical study

Hua Huang(黄华)1, Zhi-Bin Wang(王志斌)1,2, Xiao-Gang Wang(王晓钢)1, Xin Tao(陶鑫)3   

  1. 1 Department of Physics, Harbin Institute of Technology, Harbin 150001, China;
    2 Laboratory for Space Environment and Physical Sciences, Harbin Institute of Technology, Harbin 150001, China;
    3 Chinese Academy of Sciences Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026, China
  • Received:2017-07-11 Revised:2017-08-17 Online:2018-01-05 Published:2018-01-05
  • Contact: Zhi-Bin Wang E-mail:wangzhibin@hit.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 41674165, 41631071, 41474142, and 41674174) and the China Postdoctoral Science Foundation (Grant No. 2015M570283).

摘要:

Due to their significant roles in the radiation belts dynamics, chorus waves are widely investigated in observations, experiments, and simulations. In this paper, numerical studies for the generation of chorus-like waves in a launching device, dipole research experiment (DREX), are carried out by a hybrid code. The DREX plasma is generated by electron cyclotron resonance (ECR), which leads to an intrinsic temperature anisotropy of energetic electrons. Thus the whistler instability can be excited in the device. We then investigate the effects of three parameters, i.e., the cold plasma density nc, the hot plasma density nh, and the parallel thermal velocity of energetic electrons, on the generation of chorus-like waves under the DREX design parameters. It is obtained that a larger temperature anisotropy is needed to excite chorus-like waves with a high nc with other parameters fixed. Then we fix the plasma density and parallel thermal velocity, while varying the hot plasma density. It is found that with the increase of nh, the spectrum of the generated waves changes from no chorus elements, to that with several chorus elements, and then further to broad-band hiss-like waves. Besides, different structures of chorus-like waves, such as rising-tone and/or falling-tone structures, can be generated at different parallel thermal velocities in the DREX parameter range.

关键词: dipole research experiment (DREX), chorus-like waves, temperature anisotropy

Abstract:

Due to their significant roles in the radiation belts dynamics, chorus waves are widely investigated in observations, experiments, and simulations. In this paper, numerical studies for the generation of chorus-like waves in a launching device, dipole research experiment (DREX), are carried out by a hybrid code. The DREX plasma is generated by electron cyclotron resonance (ECR), which leads to an intrinsic temperature anisotropy of energetic electrons. Thus the whistler instability can be excited in the device. We then investigate the effects of three parameters, i.e., the cold plasma density nc, the hot plasma density nh, and the parallel thermal velocity of energetic electrons, on the generation of chorus-like waves under the DREX design parameters. It is obtained that a larger temperature anisotropy is needed to excite chorus-like waves with a high nc with other parameters fixed. Then we fix the plasma density and parallel thermal velocity, while varying the hot plasma density. It is found that with the increase of nh, the spectrum of the generated waves changes from no chorus elements, to that with several chorus elements, and then further to broad-band hiss-like waves. Besides, different structures of chorus-like waves, such as rising-tone and/or falling-tone structures, can be generated at different parallel thermal velocities in the DREX parameter range.

Key words: dipole research experiment (DREX), chorus-like waves, temperature anisotropy

中图分类号:  (Laboratory studies of space- and astrophysical-plasma processes)

  • 52.72.+v
94.05.Pt (Wave/wave, wave/particle interactions) 94.20.Fg (Plasma temperature and density)