Excitation, conversion and damping of waves in a helicon plasma source driven by an<b><i>m</i></b>= 0 antenna

Shamrai, K. P.; Павленко, В. Б.; Taranov, V. B.

doi:10.1088/0741-3335/39/3/011

Cited by 58 publications

(77 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the low field regions, less than 100 G, the dependence of antenna loading on the RF power did not change very much with the change in the field. The present results for the loading resistance and P th are consistent with the analytical results [22] in that the resistance decreases rapidly with k z , and are also in good agreement with the calculation results [20], showing the maximum resistance at the low k z value.…”

Section: Dispersion Relationsupporting

confidence: 91%

Discharge modes and wave structures using loop antennae in a helicon plasma source

Shinohara

Yonekura

1999

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

Discharge modes separated by density jumps in a helicon plasma source were controlled successfully by changing the antenna wavenumber spectrum with a two-loop antenna, in addition to varying the filling pressure P and the magnetic field B. For the case of wave excitation with the anti-parallel antenna current direction, the threshold power P th for a density jump, regardless of B and P , was larger than in the case of a parallel direction, and P th became larger with the increase in B in both cases. From the excited wave structures, it was found that the helicon wave plasma was observed after the jump with the high field, while with the low field regardless of the density region or with the high field before the jump, an inductively coupled plasma was found. No indication of a major role of the lower hybrid wave and Trivelpiece-Gould wave on the plasma production was observed.

show abstract

Section: Dispersion Relationsupporting

confidence: 91%

Discharge modes and wave structures using loop antennae in a helicon plasma source

Shinohara

Yonekura

1999

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

show abstract

“…For reasons which will become clear, our design uses m = 0 antennas. The behavior of such antennas has also been studied by numerous authors [35][36][37] .…”

Section: Methodsmentioning

confidence: 99%

Permanent Magnet Helicon Source for Ion Propulsion

Chen

2008

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

Helicon sources have been proposed by at least two groups for generating ions for space propulsion: the HDLT concept at the Australian National University (ANU), and the VASIMR concept at the Johnson Space Center in Houston. These sources normally require a large electromagnet and power supply to produce the magnetic field. At this stage of research, emphasis has been on the plasma density and ion current that can be produced, but not much on the weight, size, impulse, and gas efficiency of the thruster. This paper concerns the source itself and shows that great savings in size and weight can be obtained by using specially designed permanent magnets (PMs). This PM helicon design, originally developed for plasma processing of large substrates, is extended here for ion thrusters of both the HDLT and VASIMR types. Measured downstream densities are of order 10 12 cm -3 , which should yield much higher ion currents than reported so far. The design principles have been checked experimentally, showing that the predictions of the theory and computations are reliable. The details of two new designs are given here to serve as examples to stimulate further research on the use of such sources as thrusters.

show abstract

“…͑6͒ in the radially uniform plasma are readily found as combinations of the Bessel functions J 0,1 (k Ќ r) where the perpendicular wave number k Ќ acquires the two values, k H and k TG , which relate to the helicon and TG waves. 31 These values are the roots of an exact biquadratic ͑relative to both k Ќ and k͒ dispersion equation. 36 With a nonuniform plasma profile, Eqs.…”

Section: Theoretical Modelmentioning

confidence: 99%

Spectral and spatial characterization of a radio frequency power absorption in high pressure helicon plasmas

Shamrai

Shinohara

2001

Physics of Plasmas

View full text Add to dashboard Cite

A power absorption in helicon plasma excited by double m=0 antenna is considered at high argon pressures, when the electron collision frequency exceeds the driving frequency. The influence of various factors is examined, including the plasma density and nonuniformity, magnetic field, gas pressure, and antenna spectrum. The wave dispersion curves and absorbed power spectra are comparatively examined to find out the scaling laws. The spatial distribution of the deposited power is characterized both qualitatively and quantitatively by considering the absorption profiles and fractions of the total power absorbed in the under antenna and edge regions of the plasma column. Dependencies of the plasma load resistance on various parameters and magnetic field profiles are examined and compared with experimental results. Computations are performed using two alternative models, either taking into account or neglecting the excitation of quasi-electrostatic Trivelpiece–Gould (TG) waves. Results on the plasma resistance are found to be close in both models provided collisional damping of helicons is not so low as to give rise to the cavity resonances. Inclusion of the TG waves yields magnetic field profiles which are substantially localized near the antenna, and absorption profiles strongly peaking in the peripheral plasma, underneath the antenna. With neglect of the TG waves, the magnetic fields and absorption profiles are found to be much more extended in both axial and radial directions from the antenna. Theory accounting for the TG waves gives a better fit over a broad range of parameters to the measured data, especially regarding the magnetic field profiles.

show abstract

Excitation, conversion and damping of waves in a helicon plasma source driven by anm= 0 antenna

Cited by 58 publications

References 22 publications

Discharge modes and wave structures using loop antennae in a helicon plasma source

Discharge modes and wave structures using loop antennae in a helicon plasma source

Permanent Magnet Helicon Source for Ion Propulsion

Spectral and spatial characterization of a radio frequency power absorption in high pressure helicon plasmas

Contact Info

Product

Resources

About