|
Titel |
On ion gyro-harmonic structuring in the stimulated electromagnetic emission spectrum during second electron gyro-harmonic heating |
VerfasserIn |
A. Samimi, W. A. Scales, P. A. Bernhardt, S. J. Briczinski, C. A. Selcher, M. J. McCarrick |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 30, no. 11 ; Nr. 30, no. 11 (2012-11-26), S.1587-1594 |
Datensatznummer |
250017286
|
Publikation (Nr.) |
copernicus.org/angeo-30-1587-2012.pdf |
|
|
|
Zusammenfassung |
Recent observations show that, during ionospheric heating experiments at
frequencies near the second electron gyro-harmonic, discrete spectral lines
separated by harmonics of the ion-gyro frequency appear in the stimulated
electromagnetic emission (SEE) spectrum within 1 kHz of the pump frequency. In
addition to the ion gyro-harmonic structures, on occasion, a broadband
downshifted emission is observed simultaneously with these spectral lines.
Parametric decay of the pump field into upper hybrid/electron Bernstein
(UH/EB) and low-frequency ion Bernstein (IB) and oblique ion acoustic (IA)
modes is considered responsible for generation of these spectral features.
Guided by predictions of an analytical model, a two-dimensional
particle-in-cell (PIC) computational model is employed to study the nonlinear
processes during such heating experiments. The critical parameters that
affect the spectrum, such as whether discrete gyro-harmonic on broadband
structures is observed, include angle of the pump field relative to the
background magnetic field, pump field strength, and proximity of the pump
frequency to the gyro-harmonic. Significant electron heating along the
magnetic field is observed in the parameter regimes considered. |
|
|
Teil von |
|
|
|
|
|
|