Collisional damping of plasma waves on a pure electron plasma column
- Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)
The collisional damping of electron plasma waves (or Trivelpiece-Gould waves) on a pure electron plasma column is discussed. The damping in a pure electron plasma differs from that in a neutral plasma, since there are no ions to provide collisional drag. A dispersion relation for the complex wave frequency is derived from Poisson's equation and the drift-kinetic equation with the Dougherty collision operator--a Fokker-Planck operator that conserves particle number, momentum, and energy. For large phase velocity, where Landau damping is negligible, the dispersion relation yields the complex frequency {omega}=(k{sub z}{omega}{sub p}/k)[1+(3/2)(k{lambda}{sub D}){sup 2}(1+10i{alpha}/9)(1+2i{alpha}){sup -}{sup 1}], where {omega}{sub p} is the plasma frequency, k{sub z} is the axial wavenumber, k is the total wavenumber, {lambda}{sub D} is the Debye length, {nu} is the collision frequency, and {alpha}{identical_to}{nu}k/{omega}{sub p}k{sub z}. This expression spans from the weakly collisional regime ({alpha}<<1) to the moderately collisional regime ({alpha}{approx}1) and in the weakly collisional limit yields a damping rate which is smaller than that for a neutral plasma by the factor k{sup 2}{lambda}{sub D}{sup 2}<<1. In the strongly collisional limit ({alpha}>>1), the damping is enhanced by long-range interactions that are not present in the kinetic theory (which assumes pointlike interactions); the effect of these long-range collisions on the damping is discussed.
- OSTI ID:
- 21069882
- Journal Information:
- Physics of Plasmas, Vol. 14, Issue 11; Other Information: DOI: 10.1063/1.2807220; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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