Gyroharmonic maser instability for weakly relativistic electrons with a loss-cone distribution

Journal Article · Wed Aug 01 00:00:00 EDT 1990 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859463· OSTI ID:6642552

Yoon, P H; Krauss-Varban, D ^[1]

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1. Institute for Physical Science and Technology University of Maryland, College Park, Maryland 20742 (USA)

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 {lambda}={alpha}{ital ck}{sub {perpendicular}}/{omega}{sub {ital c}}, where {alpha}{sup 2} is a parameter proportional to the average thermal energy of the energetic electrons, {ital k}{sub {perpendicular}} is the perpendicular component of the wave vector {bold k}, and {omega}{sub {ital c}} 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 {omega}{approx}{omega}{sub {ital c}}) 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 {omega}{sub {ital p}}/{omega}{sub {ital c}}, where {omega}{sub {ital p}} 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 {theta}=90{degree} at various energies, and for {omega}{sub {ital p}}/{omega}{sub {ital c}} ranging from 0.1 to 1.

• OSTI ID: 6642552
• Journal Information: Physics of Fluids B; (USA), Vol. 2:8; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
RELATIVISTIC PLASMA
INSTABILITY
BEAM NEUTRALIZATION
CYCLOTRON RADIATION
HARMONICS
LOSS CONE
MASERS
RELATIVISTIC RANGE
TENSORS
AMPLIFIERS
BREMSSTRAHLUNG
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ENERGY RANGE
EQUIPMENT
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
OSCILLATIONS
PLASMA
RADIATIONS
640410* - Fluid Physics- General Fluid Dynamics