Theoretical and numerical studies are presented of the amplitude modulation of electron-acoustic waves (EAWs) propagating in space plasmas whose constituents are inertial cold electrons, Boltzmann distributed hot electrons, and stationary ions. Perturbations oblique to the carrier EAW propagation direction have been considered. The stability analysis, based on a nonlinear Schrödinger equation, ...

Electron plasma waves with amplitudes as high as 10 mV/m have been measured in the electron foreshock region of the earth's bow shock. It is shown that a population of stable suprathermal electrons of the type observed can produce the measured level of enhanced fluctuations without becoming unstable. The steady state wave level is given by the balancing between emission and absorption. The appa...

[1] During 124 high-speed-stream-driven storms from two solar cycles, a multispacecraft average of the 1.1–1.5 MeV electron flux measured at geosynchronous orbit is examined to study global dropouts of the flux. Solar wind and magnetospheric measurements are analyzed with a superposed epoch technique, with the superpositions triggered by storm-convection onset, by onset of the relativistic-elec...

The generation of an ultrashort relativistic electron bunch from a strong laser-plasma interaction have been studied by particle-in-cell simulations and observed experimentally. The electron beam was generated from the plasma created by focusing a Ti: sapphire 12 TW (tera watt) laser pulse at the edge of helium gas jet expanded into the vacuum from a pulsed supersonic nozzle. The laser pulse du...

Lower hybrid (LH) waves have the attractive property of damping strongly via electron Landau resonance on relatively fast tail electrons at (2.5−−3)× vte, where vte ≡ (2Te/me) is the electron thermal speed. Consequently these waves are well-suited to driving current in the plasma periphery where the electron temperature is lower, making LH current drive (LHCD) a promising technique for off-axis...

Based on particle-in-cell simulations, we propose to generate sub-nanosecond pulses of narrowband terahertz radiation with tens MW power using unique properties kiloampere relativistic (2 MeV) electron beams produced by linear induction accelerators. Due small emittance such beams, they can be focused into millimeter and sub-millimeter spots comparable in sizes the wavelength THz radiation. If ...

Waves propagating perpendicular to a magnetic field in a plasma consisting of electrons, positrons, and ions are studied theoretically and numerically. In a three component plasma, there appears a frequency domain in which the magnetosonic waves cannot propagate; thus, we have two separate modes below the electron cyclotron frequency. Their dispersion relations are discussed. Then, Korteweg–de ...

The isotropization process of a collisionless plasma with an electron temperature anisotropy along an external magnetic field (T e ‖ ≫ T e ⊥, ‖ and ⊥ with respect to the background magnetic field) and isotropic protons is investigated using a particle-in-cell (PIC) code. Restricting wave growth mainly parallel to the external magnetic field, the isotropization mechanism is identified to be the ...