中国物理B ›› 2018, Vol. 27 ›› Issue (5): 55201-055201.doi: 10.1088/1674-1056/27/5/055201

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

Upstream ion wave excitation in an ion-beam-plasma system

Kai-Yang Yi(弋开阳), Jin-Xiu Ma(马锦秀), Zi-An Wei(卫子安), Zheng-Yuan Li(李政元)   

  1. Department of Modern Physics and Chinese Academy of Sciences Key Laboratory of Geospace Environment, University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2018-01-30 出版日期:2018-05-05 发布日期:2018-05-05
  • 通讯作者: Jin-Xiu Ma E-mail:jxma@ustc.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos.11575183 and 11705201).

Upstream ion wave excitation in an ion-beam-plasma system

Kai-Yang Yi(弋开阳), Jin-Xiu Ma(马锦秀), Zi-An Wei(卫子安), Zheng-Yuan Li(李政元)   

  1. Department of Modern Physics and Chinese Academy of Sciences Key Laboratory of Geospace Environment, University of Science and Technology of China, Hefei 230026, China
  • Received:2018-01-30 Online:2018-05-05 Published:2018-05-05
  • Contact: Jin-Xiu Ma E-mail:jxma@ustc.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos.11575183 and 11705201).

摘要:

Plasma normal modes in ion-beam-plasma systems were experimentally investigated previously only for the waves propagating in the downstream (along the beam) direction. In this paper, the ion wave excitation and propagation in the upstream (against the beam) direction in an ion-beam-plasma system were experimentally studied in a double plasma device. The waves were launched by applying a ramp voltage to a negatively biased excitation grid. Two kinds of wave signals were detected, one is a particle signal composed of burst ions and the other is an ion-acoustic signal arising from the background plasma. These signals were identified by the dependence of the signal velocities on the characteristics of the ramp voltage. The velocity of the burst ion signal increases with the decrease of the rise time and the increase of the peak-to-peak amplitude of the applied ramp voltage while that of the ion-acoustic signal is independent of these parameters. By adjusting these parameters such that the burst ion velocity approaches to the ion-acoustic velocity, the wave-particle interaction can be observed.

关键词: ion-beam-plasma system, upstream direction, ion-acoustic wave, burst ion

Abstract:

Plasma normal modes in ion-beam-plasma systems were experimentally investigated previously only for the waves propagating in the downstream (along the beam) direction. In this paper, the ion wave excitation and propagation in the upstream (against the beam) direction in an ion-beam-plasma system were experimentally studied in a double plasma device. The waves were launched by applying a ramp voltage to a negatively biased excitation grid. Two kinds of wave signals were detected, one is a particle signal composed of burst ions and the other is an ion-acoustic signal arising from the background plasma. These signals were identified by the dependence of the signal velocities on the characteristics of the ramp voltage. The velocity of the burst ion signal increases with the decrease of the rise time and the increase of the peak-to-peak amplitude of the applied ramp voltage while that of the ion-acoustic signal is independent of these parameters. By adjusting these parameters such that the burst ion velocity approaches to the ion-acoustic velocity, the wave-particle interaction can be observed.

Key words: ion-beam-plasma system, upstream direction, ion-acoustic wave, burst ion

中图分类号:  (Waves, oscillations, and instabilities in plasmas and intense beams)

  • 52.35.-g
52.35.Fp (Electrostatic waves and oscillations (e.g., ion-acoustic waves)) 52.35.Qz (Microinstabilities (ion-acoustic, two-stream, loss-cone, beam-plasma, drift, ion- or electron-cyclotron, etc.))