Generation of auroral kilometric radiation by a finite-size source in a dipole magnetic field. Part II

Journal Article · Fri Sep 15 04:00:00 EDT 2017 · Plasma Physics Reports

DOI:https://doi.org/10.1134/S1063780X1709001X· OSTI ID:22760305

Shevelev, M. M. ^[1]

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1. Russian Academy of Sciences, Space Research Institute (Russian Federation)

Propagation and amplification of extraordinary electromagnetic waves in a dipole magnetic field in a narrow 3D plasma cavity in which a weakly relativistic electron beam propagates along the magnetic field in the direction of the gradient of the magnetic field strength is investigated. The domain of wave vectors at the starting point for which the wave amplification factors at the output of the density cavity reach their maximum values is found, and the amplification factor as a function of the wave frequency is determined. It is shown that the longitudinal velocity of fast electrons, which enables generation of waves in a broader frequency range, plays an important role in the formation of the spectrum of the auroral kilometric radiation (AKR). In this case, waves with the largest amplification factors at the output of the cavity have frequencies exceeding the cutoff frequency of the background plasma at the wave generation altitude. The global inhomogeneity of the magnetic field and plasma density, which governs the residence time of the waves in the amplification region, plays a key role in the formation of the AKR spectrum. It is shown that this time is the main factor determining the energy of the waves emerging from the source.

• OSTI ID: 22760305
• Journal Information: Plasma Physics Reports, Journal Name: Plasma Physics Reports Journal Issue: 9 Vol. 43; ISSN PPHREM; ISSN 1063-780X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
AMPLIFICATION
DIPOLES
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
FREQUENCY RANGE
MAGNETIC FIELDS
PLASMA DENSITY
RELATIVISTIC RANGE