scholarly journals Electron Cyclotron Harmonic Wave Instability by Loss Cone Distribution

2018 ◽  
Vol 123 (11) ◽  
pp. 9035-9044 ◽  
Author(s):  
Xu Liu ◽  
Lunjin Chen ◽  
Wenyao Gu ◽  
Xiao‐Jia Zhang
Keyword(s):  
Harmonic Wave ◽  
Electron Cyclotron ◽  
Wave Instability ◽  
Loss Cone ◽  
Cyclotron Harmonic

Electron-cyclotron maser theory for extraordinary Bernstein waves

1997 ◽  
Vol 58 (1) ◽  
pp. 171-191 ◽  
Author(s):  
A. J. WILLES ◽  
P. A. ROBINSON
Keyword(s):  
Electron Distribution ◽  
Electron Cyclotron ◽  
Loss Cone ◽  
Wave Growth ◽  
Electron Cyclotron Maser ◽  
Cyclotron Maser ◽  
Hybrid Frequency ◽  
Bernstein Waves ◽  
Bernstein Wave ◽  
Cyclotron Harmonic

Electron-cyclotron maser emission is investigated in the regime where wave growth in the electrostatic Bernstein modes dominates (ωp/Ωe>1.5). A semirelativistic growth rate is derived assuming that the wave dispersion is dominated by a cool background electron distribution and the instability is driven by a low-density hot loss-cone-like electron distribution. The properties of Bernstein wave growth are most strongly dependent on the relative temperatures of the hot and cool electron distributions. For Thot/Tcool[gsim ]10, the fastest growing Bernstein waves are produced at frequencies just below each cyclotron harmonic in Bernstein modes lying below the upper-hybrid frequency. For Thot/Tcool[lsim ]10, additional Bernstein modes above the upper-hybrid frequency are excited, with wave frequencies in each excited mode lying significantly above the corresponding cyclotron harmonic. The dependence of Bernstein wave growth on the relative hot and cool electron number densities and emission angle is also discussed.

Electron cyclotron harmonic wave acceleration

1987 ◽  
Vol 316 ◽  
pp. 462 ◽  
Author(s):  
H. Karimabadi ◽  
C. R. Menyuk ◽  
P. Sprangle ◽  
L. Vlahos
Keyword(s):  
Harmonic Wave ◽  
Electron Cyclotron ◽  
Cyclotron Harmonic

scholarly journals Quasi-steady, marginally unstable electron cyclotron harmonic wave amplitudes

2013 ◽  
Vol 118 (6) ◽  
pp. 3165-3172 ◽  
Author(s):  
Xiaojia Zhang ◽  
Vassilis Angelopoulos ◽  
Binbin Ni ◽  
Richard M. Thorne ◽  
Richard B. Horne
Keyword(s):  
Harmonic Wave ◽  
Electron Cyclotron ◽  
Cyclotron Harmonic

Lag-correlated rising tones of electron cyclotron harmonic and whistler-mode upper-band chorus waves

2021 ◽  
Author(s):  
Zhonglei Gao
Keyword(s):  
Electron Cyclotron ◽  
Hot Electrons ◽  
Time Lags ◽  
Discrete Elements ◽  
Loss Cone ◽  
Whistler Mode ◽  
Chorus Waves ◽  
Van Allen Probes ◽  
Gain Energy ◽  
Cyclotron Harmonic

<p>Electron cyclotron harmonic (ECH) and whistler-mode chorus waves can contribute significantly to the magnetospheric dynamics. In the frequency-time spectrogram, ECH usually appears as a series of harmonic structureless bands, while chorus often exhibits successive discrete elements. Here, we present surprising observations by Van Allen Probes of lag-correlated rising tones of ECH and upper-band chorus waves. The time lags of ECH elements with respect to chorus elements range from 0.05 to 0.28 s, negatively correlated with the chorus peak amplitudes. The ECH elements seemingly emerge only when the chorus elements are sufficiently intense (peak amplitude >3 mV/m), and their peak amplitudes are positively correlated. Our data and modeling suggest that upper-band chorus may promote the generation of ECH through rapidly precipitating the ~keV electrons near the loss cone. This phenomenon implies that ECH and chorus may not grow independently but competitively or collaboratively gain energy from hot electrons.</p>

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