Stimulated Electromagnetic Emissions and Anomalous HF Wave Absorption Near Electron Gyroharmonics.

Stubbe, P. and Stocker, A. J. and Honary, Farideh and Robinson, T. R. and Jones, T. B. (1994) Stimulated Electromagnetic Emissions and Anomalous HF Wave Absorption Near Electron Gyroharmonics. Journal of Geophysical Research, 99 (A4). pp. 6233-6246. ISSN 0148-0227

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Abstract

Simultaneous observations are presented of stimulated electromagnetic emission (SEE) spectra and the anomalous absorption of a diagnostic HF wave, caused by powerful radio waves generated by the Tromsø heating facility. The pump frequency was varied in small steps around the third, fourth, and fifth harmonic of the electron gyrofrequency. Systematic variations with pump frequency were observed in the anomalous absorption data and the entirety of SEE properties. The anomalous absorption exhibits a pronounced minimum at a certain pump frequency near (or at) the gyroharmonic in question. Of the SEE properties the strength and discreteness of the downshifted maximum and the width of the downshifted continuum minimize together with the anomalous absorption. Other SEE properties (namely the broad upshifted maximum, the downshifted peak, and the broad symmetrical structure) exist only in well-defined narrow pump frequency ranges near the absorption minimum. Significant quantitative and qualitative differences are found between the SEE properties around the third gyroharmonic on the one hand, and the fourth and fifth gyroharmonics on the other hand.

Item Type: Journal Article
Journal or Publication Title: Journal of Geophysical Research
Additional Information: Copyright (1994) American Geophysical Union.
Uncontrolled Keywords: /dk/atira/pure/subjectarea/asjc/1900/1912
Subjects:
Departments: Faculty of Science and Technology > Engineering
Faculty of Science and Technology > Physics
Faculty of Science and Technology > School of Computing & Communications
ID Code: 9982
Deposited By: Dr Steve Marple
Deposited On: 24 Jun 2008 16:47
Refereed?: Yes
Published?: Published
Last Modified: 26 Aug 2019 00:49
URI: https://eprints.lancs.ac.uk/id/eprint/9982

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