One‐ and two‐dimensional simulations of electron beam instability: Generation of electrostatic and electromagnetic 2f p waves

We have performed computer simulations of the self-consistent nonlinear evolution of electrostatic and electromagnetic 2f p waves excited by electron beams with electromagnetic particle code. In both one- and two-dimensional periodic systems an electrostatic 2f p wave is generated at twice the wave number of forward propagating Langmuir waves by wave-wave coupling. This wave grows with the forward propagating Langmuir wave in the nonlinear stage of the simulations. The electrostatic 2f p wave in the simulations is saturated at about -20 ∼ -30 dB of that of the Langmuir waves. It is larger than the value expected from observations in the terrestrial electron foreshock. The electromagnetic 2f p wave is only excited in two-dimensional systems. The magnitude of the electromagnetic 2f p wave is correlated with the backward propagating Langmuir wave, not with the electrostatic 2f p wave. This result suggests that the electromagnetic 2f p wave is excited by the wave-wave coupling of forward and backward propagating Langmuir waves. The typical power density estimated from a reasonable amplitude of Langmuir wave is of the same order or much weaker than the value typically observed around the electron foreshock.

[1]  R. Bingham,et al.  Excitation of electron acoustic waves near the electron plasma frequency and at twice the plasma frequency , 2000 .

[2]  P. Robinson,et al.  Thermal and driven stochastic growth of Langmuir waves in the solar wind and Earth's foreshock , 2000 .

[3]  H. Matsumoto,et al.  Statistical studies of plasma waves and backstreaming electrons in the terrestrial electron foreshock observed by Geotail , 2000 .

[4]  L. Yin,et al.  Plasma waves in the Earth's electron foreshock: 2. Simulations using time‐of‐flight electron distributions in a generalized Lorentzian plasma , 1998 .

[5]  L. Yin,et al.  Generation of electromagnetic fpe and 2fpe waves in the Earth's electron foreshock via linear mode conversion , 1998 .

[6]  G. Thejappa,et al.  Evidence for Strong and Weak Turbulence Processes in the Source Region of a Local Type III Radio Burst , 1998 .

[7]  P. Robinson,et al.  Arguments against modulational instabilities of Langmuir waves in Earth's foreshock , 1998 .

[8]  Yasumasa Kasaba.  Study of Radio Waves in Geospace via Spacecraft Observations and Numerical Simulations(衛星観測と計算機実験による地球周辺宇宙空間における電波に関する研究) , 1997 .

[9]  J. Bougeret,et al.  Early Wind observations of bow shock and foreshock waves , 1996 .

[10]  R. Stone,et al.  Theory of 2 omega(sub pe) radiation induced by the bow shock , 1994 .

[11]  C. T. Dum,et al.  Two‐dimensional simulation studies of the electron beam‐plasma instability , 1994 .

[12]  P. Robinson.  Clumpy Langmuir waves in type III radio sources , 1992 .

[13]  I. Cairns,et al.  Simulation of the nonlinear evolution of electron plasma waves , 1991 .

[14]  C. T. Dum,et al.  Nonlinear wave scattering and electron beam relaxation , 1991 .

[15]  C. T. Dum.  Simulation studies of plasma waves in the electron foreshock - The transition from reactive to kinetic instability , 1990 .

[16]  C. T. Dum.  Simulation studies of plasma waves in the electron foreshock: The generation of Langmuir waves by a gentle bump‐on‐tail electron distribution , 1990 .

[17]  K. Papadopoulos,et al.  Electromagnetic radiation from strong Langmuir turbulence , 1988 .

[18]  I. Cairns.  A semiquantitative theory for the 2ƒp radiation observed upstream from the Earth's bow shock , 1988 .

[19]  D. Melrose,et al.  A theory for the 2fp radiation upstream of the Earth's bow shock , 1985 .

[20]  Alexander J. Klimas,et al.  A mechanism for plasma waves at the Harmonics of the plasma frequency in the Electron Foreshock Boundary , 1983 .

[21]  J. Dawson,et al.  Electromagnetic radiation from beam-plasma instabilities , 1983 .