Electrostatic normal modes in nonneutral plasmas
- Enigmatix, Inc., P.O. Box 11834, Washington DC 20008 (United States)
A fluid description is employed to derive the dispersion relation for modes near the cyclotron frequency {omega} in a nonuniform cylindrical nonneutral plasma of radius R with finite temperature confined by a uniform magnetic field B=B0ez. In contrast to the theory of Gould and LaPointe, the model includes the diamagnetic drift but omits finite-Larmor-radius effects. The eigenfrequencies for high-frequency electrostatic modes with wavevectors satisfying k {center_dot} B=0 (Bernstein modes) are found in the form {omega}=-{omega}+{delta}{omega}. Solutions are obtained and compared with experiment and the theory of Gould and LaPointe. The present theory predicts that at a given temperature modes with m > or approx.1 propagate only when the density is less than a critical value that increases with m, and that {delta}{omega} normalized by the diocotron frequency depends only on the ratio of the Debye length to the plasma radius and hence is independent of B and the particle mass.
- OSTI ID:
- 21153816
- Journal Information:
- AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 331; ISSN APCPCS; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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