ISSN:
1089-7666
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The weakly relativistic dielectric tensor for a system of electrons comprised of cold and energetic populations, embedded in a neutralizing background, is reformulated in terms of an infinite series representation in powers of λ=αck⊥/ωc, where α2 is a parameter proportional to the average thermal energy of the energetic electrons, k⊥ is the perpendicular component of the wave vector k, and ωc is the electron gyrofrequency. The energetic electrons are assumed to have a loss-cone feature in the perpendicular momentum space. The present formalism can be used in the problem of cyclotron maser (i.e., emissions near the fundamental ω≈ωc) as well as more general gyroharmonic maser (i.e., multiharmonics) emissions resulting from weakly relativistic loss-cone electrons. This is because, unlike the previous theories in which certain approximations such as the single-harmonic approximations are made, the present formalism retains contributions from the entire harmonics. As a result, the present formalism is valid for arbitrary ωp/ωc, where ωp is the total electron plasma frequency. As an application, growth rates for the X-mode and Z-mode gyroharmonic maser instabilities are calculated for a propagation angle θ=90° at various energies, and for ωp/ωc ranging from 0.1 to 1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.859463
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