中国物理B ›› 2017, Vol. 26 ›› Issue (10): 105201-105201.doi: 10.1088/1674-1056/26/10/105201

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

Modulation of absorption manner in helicon discharges by changing profile of low axial magnetic field

Gao Zhao(赵高), Yu Wang(王宇), Chen Niu(牛晨), Zhong-Wei Liu(刘忠伟), Jiting Ouyang(欧阳吉庭), Qiang Chen(陈强)   

  1. 1. School of Physics, Beijing Institute of Technology, Beijing 100081, China;
    2. Laboratory of Plasma Physics & Materials, Beijing Institute of Graphic Communication, Beijing 102600, China
  • 收稿日期:2017-05-05 修回日期:2017-06-15 出版日期:2017-10-05 发布日期:2017-10-05
  • 通讯作者: Jiting Ouyang, Qiang Chen E-mail:jtouyang@bit.edu.cn;lppmchenqiang@hotmail.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11175024, 11375031, and 11505013), the Beijing Natural Science Foundation of China (Grant No. KZ201510015014), and the Beijing Municipal Natural Science Foundation, China (Grant No. 4162024).

Modulation of absorption manner in helicon discharges by changing profile of low axial magnetic field

Gao Zhao(赵高)1, Yu Wang(王宇)1, Chen Niu(牛晨)2, Zhong-Wei Liu(刘忠伟)2, Jiting Ouyang(欧阳吉庭)1, Qiang Chen(陈强)2   

  1. 1. School of Physics, Beijing Institute of Technology, Beijing 100081, China;
    2. Laboratory of Plasma Physics & Materials, Beijing Institute of Graphic Communication, Beijing 102600, China
  • Received:2017-05-05 Revised:2017-06-15 Online:2017-10-05 Published:2017-10-05
  • Contact: Jiting Ouyang, Qiang Chen E-mail:jtouyang@bit.edu.cn;lppmchenqiang@hotmail.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11175024, 11375031, and 11505013), the Beijing Natural Science Foundation of China (Grant No. KZ201510015014), and the Beijing Municipal Natural Science Foundation, China (Grant No. 4162024).

摘要: The modulation of absorption manner in helicon discharge by changing the profile of low axial magnetic field is explored experimentally in this work. The experiments are carried out in Boswell-type antenna driven by 13.56-MHz power source in 0.35-Pa argon environment. The peak of the external non-uniform magnetic field (Bex) along the axis is observed in a range from 0 Gs to 250 Gs (1 Gs=10-4 T), where the electron density varies from 0.5×1016 m-3 to 9×1016 m-3. When Bex is located near the tube upper end sealed by a dielectric plate, or near the tube bottom end connected with a diffusion chamber, the plasmas are centralized in the tube in the former case while the strong luminance appears between the edge of the tube and the axial line in the latter case. When Bex is located in the middle of the antenna, moreover, an effective resistance (Reff) peak appears apparently with increasing magnetic field. The glow moves toward first the edge of the tube and then the two antenna legs as the magnetic field increases. The discharge in this case is caused by the absorption of Trivelpiece-Gould (TG) wave. It is suggested that Bex is located in the middle of the antenna to obtain a higher efficiency of power transfer.

关键词: helicon discharge, absorption manner, low supply power, low axial magnetic field

Abstract: The modulation of absorption manner in helicon discharge by changing the profile of low axial magnetic field is explored experimentally in this work. The experiments are carried out in Boswell-type antenna driven by 13.56-MHz power source in 0.35-Pa argon environment. The peak of the external non-uniform magnetic field (Bex) along the axis is observed in a range from 0 Gs to 250 Gs (1 Gs=10-4 T), where the electron density varies from 0.5×1016 m-3 to 9×1016 m-3. When Bex is located near the tube upper end sealed by a dielectric plate, or near the tube bottom end connected with a diffusion chamber, the plasmas are centralized in the tube in the former case while the strong luminance appears between the edge of the tube and the axial line in the latter case. When Bex is located in the middle of the antenna, moreover, an effective resistance (Reff) peak appears apparently with increasing magnetic field. The glow moves toward first the edge of the tube and then the two antenna legs as the magnetic field increases. The discharge in this case is caused by the absorption of Trivelpiece-Gould (TG) wave. It is suggested that Bex is located in the middle of the antenna to obtain a higher efficiency of power transfer.

Key words: helicon discharge, absorption manner, low supply power, low axial magnetic field

中图分类号:  (Plasma heating by radio-frequency fields; ICR, ICP, helicons)

  • 52.50.Qt
52.40.Db (Electromagnetic (nonlaser) radiation interactions with plasma)