Cyclotron resonance phenomena in a pure electron plasma
- Creators
- Gould, Roy W.
- LaPointe, Michael A.
Abstract
An experiment designed to elucidate the features of cyclotron resonance in a rotating cylindrical pure electron plasma column is described. The density is well below the Brillouin limit and varies with radius, as does the rotational angular velocity. Thus the steady state is not the rigid‐rotor equilibrium which is frequently studied theoretically. The readily observed modes are found to have kz≊0 and m=1,2,3,4... (eikzz+im θ) with frequencies which are within a few percent of the cyclotron frequency (140 MHz). A single m=1 mode is found that is downshifted from the cyclotron frequency by an amount equal to the m=1 diocotron frequency. For each of the higher m values, bands of closely spaced discrete modes are found which are upshifted from the cyclotron frequency by the Doppler effect of rotation. The bands of discrete modes are explained as radially trapped azimuthally propagating Bernstein modes in a rotating plasma and approximate theories for these modes are outlined. By comparing the results with experiments, plasma parameters such as the ratio of Larmor radius to plasma scale length, the central rotation frequency, and the ratio of peak to average density can be inferred.
Additional Information
© 1992 American Institute of Physics. The insights into the behavior of non-neutral plasmas of Fred Driscoll, John Malmberg, and Thomas O'Neil were very helpful in the early stages of this work. We are pleased to acknowledge the support of the U.S. Office of Naval Research and the assistance of Sateesh Pillai in the conduct of this research.Attached Files
Published - 2038_1_online.pdf
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Additional details
- Eprint ID
- 121848
- Resolver ID
- CaltechAUTHORS:20230612-708650000.26
- Office of Naval Research (ONR)
- Created
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2023-06-15Created from EPrint's datestamp field
- Updated
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2023-06-15Created from EPrint's last_modified field