Electron cyclotron harmonic resonances in highfrequency heating of the ionosphere
Abstract
Electron acceleration by upper hybrid waves under cyclotron harmonic resonance interaction is studied. Theory is formulated; the analytical solutions in the second and fourth harmonic cyclotron resonance cases are obtained, and in the third harmonic case, a first order differential equation governing the evolution of the electron energy is derived. The theory is applied for explaining the generation of artificial ionization layers observed in highfrequency (HF) ionospheric heating experiments. The upper hybrid waves are assumed to be excited parametrically by the Omode HF heating wave. As the decay mode is the lower hybrid wave, the excited upper hybrid waves have wavelengths ranging from 0.25 to 0.5 m, which are short enough to effectively incorporate the finite Larmour radius effect for the harmonic cyclotron resonance interactions as well as have a frequency bandwidth of about 20 kHz, which provides an altitude region of about 10 km for continuous harmonic cyclotron resonance interaction between electrons and descending waves in the slightly inhomogeneous geomagnetic field. The numerical results on electron acceleration show that electron fluxes with energies larger than 14 eV are generated in the three harmonic cases. These energetic electrons cause impact ionizations, which are descending to form artificial ionization layers atmore »
 Authors:
 Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, New York 11201 (United States)
 Publication Date:
 OSTI Identifier:
 22224194
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 9; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALTITUDE; ANALYTICAL SOLUTION; CYCLOTRON RESONANCE; DIFFERENTIAL EQUATIONS; ELECTROMAGNETIC RADIATION; EV RANGE; F REGION; GEOMAGNETIC FIELD; INTERACTIONS; KHZ RANGE; LAYERS; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; PLASMA WAVES; TAIL ELECTRONS
Citation Formats
Kuo, Spencer P. Electron cyclotron harmonic resonances in highfrequency heating of the ionosphere. United States: N. p., 2013.
Web. doi:10.1063/1.4822336.
Kuo, Spencer P. Electron cyclotron harmonic resonances in highfrequency heating of the ionosphere. United States. doi:10.1063/1.4822336.
Kuo, Spencer P. 2013.
"Electron cyclotron harmonic resonances in highfrequency heating of the ionosphere". United States.
doi:10.1063/1.4822336.
@article{osti_22224194,
title = {Electron cyclotron harmonic resonances in highfrequency heating of the ionosphere},
author = {Kuo, Spencer P.},
abstractNote = {Electron acceleration by upper hybrid waves under cyclotron harmonic resonance interaction is studied. Theory is formulated; the analytical solutions in the second and fourth harmonic cyclotron resonance cases are obtained, and in the third harmonic case, a first order differential equation governing the evolution of the electron energy is derived. The theory is applied for explaining the generation of artificial ionization layers observed in highfrequency (HF) ionospheric heating experiments. The upper hybrid waves are assumed to be excited parametrically by the Omode HF heating wave. As the decay mode is the lower hybrid wave, the excited upper hybrid waves have wavelengths ranging from 0.25 to 0.5 m, which are short enough to effectively incorporate the finite Larmour radius effect for the harmonic cyclotron resonance interactions as well as have a frequency bandwidth of about 20 kHz, which provides an altitude region of about 10 km for continuous harmonic cyclotron resonance interaction between electrons and descending waves in the slightly inhomogeneous geomagnetic field. The numerical results on electron acceleration show that electron fluxes with energies larger than 14 eV are generated in the three harmonic cases. These energetic electrons cause impact ionizations, which are descending to form artificial ionization layers at the bottom of the ionospheric F region.},
doi = {10.1063/1.4822336},
journal = {Physics of Plasmas},
number = 9,
volume = 20,
place = {United States},
year = 2013,
month = 9
}

Ion cyclotron range of frequency heating of a deuteriumtritium plasma via the secondharmonic tritium cyclotron resonance
Experiments have been performed on the TFTR to study rf wave heating of a DT plasma by way of the secondharmonic tritium cyclotron resonance. The addition of tritium ions to a deuterium plasma allows for absorption of the rf waves at the tritium cyclotron harmonics and by electron damping of a mode converted ion Bernstein wave. Competing mechanisms include direct electron damping and damping at the fundamental cyclotron resonance of deuterium, {alpha} particles, and {sup 3}He ions. The contribution of each is estimated from a series of plasma discharges where various plasma parameters are varied. The majority of the rfmore »