Helicon wave plasma generated by a resonant birdcage antenna: magnetic field measurements and analysis in the RAID linear device

被引:18
作者
Guittienne, Ph [1 ]
Jacquier, R. [1 ]
Pouradier Duteil, B. [1 ]
Howling, A. A. [1 ]
Agnello, R. [1 ]
Furno, I [1 ]
机构
[1] Ecole Polytech Fed Lausanne EPFL, Swiss Plasma Ctr SPC, CH-1015 Lausanne, Switzerland
基金
瑞士国家科学基金会;
关键词
resonant birdcage antenna; helicon plasma; magnetic field; hydrogen plasma; WHISTLER WAVES; PROPAGATION; MODES; EQUATION;
D O I
10.1088/1361-6595/ac0da3
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
This paper describes a helicon-wave-sustained plasma generated by a novel birdcage antenna with cosine azimuthal current distribution. The resonant birdcage source maintains a stable intense plasma column from low (300 W) to high (10 kW) steady-state RF power in hydrogen or argon, enabling plasma diagnostic measurements over the whole volume. The plasma density, 10(18) to 10(19) m(-3), and uniform static magnetic field, 200-800 G, are typical of high density, low B-field helicon sources where the RF excitation frequency, 13.56 MHz here, is far above the ion cyclotron frequency and much lower than the electron cyclotron and plasma frequencies. Magnetic field measurements of the unbounded plasma column show a helicon wave propagating from the birdcage source to the target 1.5 m away. The axial wavelength, measured for a range of plasma density and magnetic field, is described by the whistler dispersion relation; it is not determined by the antenna length but varies smoothly as a function of electron density irrespective of the gas type, and shows no discontinuous transitions. This wavelength was compared with semi-analytical and purely numerical models, showing a good fit with the m = +1 helicon eigenvalue of shortest axial wavelength. The birdcage resonant antenna is a suitable source for continuous helicon-sustained plasma experiments, from fundamental wave studies up to high power applications in hydrogen or deuterium.
引用
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页数:14
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共 57 条
  • [1] Application of Thomson scattering to helicon plasma sources
    Agnello, R.
    Andrebe, Y.
    Arnichand, H.
    Blanchard, P.
    De Kerchove, T.
    Furno, I
    Howling, A. A.
    Jacquier, R.
    Sublet, A.
    [J]. JOURNAL OF PLASMA PHYSICS, 2020, 86 (03)
  • [2] Negative ion characterization in a helicon plasma source for fusion neutral beams by cavity ring-down spectroscopy and Langmuir probe laser photodetachment
    Agnello, R.
    Bechu, S.
    Furno, I
    Guittienne, Ph
    Howling, A. A.
    Jacquier, R.
    Plyushchev, G.
    Barbisan, M.
    Pasqualotto, R.
    Morgal, I
    Simonin, A.
    [J]. NUCLEAR FUSION, 2020, 60 (02)
  • [3] Cavity ring-down spectroscopy to measure negative ion density in a helicon plasma source for fusion neutral beams
    Agnello, R.
    Barbisan, M.
    Furno, I.
    Guittienne, Ph.
    Howling, A. A.
    Jacquier, R.
    Pasqualotto, R.
    Plyushchev, G.
    Andrebe, Y.
    Bechu, S.
    Morgal, I.
    Simonin, A.
    [J]. REVIEW OF SCIENTIFIC INSTRUMENTS, 2018, 89 (10)
  • [4] Agnello R., 2020, THESIS EPFL LAUSNNE, DOI [10.5075/epfl-thesis-7817, DOI 10.5075/EPFL-THESIS-7817]
  • [5] Power coupling to helicon and Trivelpiece-Gould modes in helicon sources
    Borg, GG
    Boswell, RW
    [J]. PHYSICS OF PLASMAS, 1998, 5 (03) : 564 - 571
  • [6] RADIOFREQUENCY POWER COMBINER FOR CW AND PULSED APPLICATIONS
    BORG, GG
    JAHREIS, T
    [J]. REVIEW OF SCIENTIFIC INSTRUMENTS, 1994, 65 (02) : 449 - 452
  • [7] Boswell R. W., 1970, Physics Letters A, V33, P457, DOI 10.1016/0375-9601(70)90606-7
  • [8] Boswell R W., 1970, PhD Thesis
  • [9] Helicons - The early years
    Boswell, RW
    Chen, FF
    [J]. IEEE TRANSACTIONS ON PLASMA SCIENCE, 1997, 25 (06) : 1229 - 1244
  • [10] EFFECT OF BOUNDARY-CONDITIONS ON RADIAL MODE STRUCTURE OF WHISTLERS
    BOSWELL, RW
    [J]. JOURNAL OF PLASMA PHYSICS, 1984, 31 (APR) : 197 - 208