An alternative to the plasma emission model: Particle-In-Cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts

Abstract

1.5D PIC, relativistic, fully electromagnetic (EM) simulations are used to model EM wave emission generation in the context of solar type III radio bursts. The model studies generation of EM waves by a super-thermal, hot beam of electrons injected into a plasma thread that contains uniform longitudinal magnetic field and a parabolic density gradient. In effect, a single magnetic line connecting Sun to earth is considered, for which several cases are studied. (i) We find that the physical system without a beam is stable and only low amplitude level EM drift waves (noise) are excited. (ii) The beam injection direction is controlled by setting either longitudinal or oblique electron initial drift speed, i.e. by setting the beam pitch angle. In the case of zero pitch angle, the beam excites only electrostatic, standing waves, oscillating at plasma frequency, in the beam injection spatial location, and only low level EM drift wave noise is also generated. (iii) In the case of oblique beam pitch angles, again electrostatic waves with same properties are excited. However, now the beam also generates EM waves with the properties commensurate to type III radio bursts. The latter is evidenced by the wavelet analysis of transverse electric field component, which shows that as the beam moves to the regions of lower density, frequency of the EM waves drops accordingly. (iv) When the density gradient is removed, electron beam with an oblique pitch angle still generates the EM radiation. However, in the latter case no frequency decrease is seen. Within the limitations of the model, the study presents the first attempt to produce simulated dynamical spectrum of type III radio bursts in fully kinetic plasma model. The latter is based on 1.5D non-zero pitch angle (non-gyrotropic) electron beam, that is an alternative to the plasma emission classical mechanism.

Physics of Plasmas, in press, May 2011 issue (final accepted version)

References in corpus (3)

• Nonlinear development of electron-beam-driven weak turbulence in an inhomogeneous plasma
• Dynamics of electron beams in the solar corona plasma with density fluctuations
• Vlasov-Maxwell, self-consistent electromagnetic wave emission simulations in the solar corona

Cited by in corpus (14)

• Emission of Type II Radio Bursts - Single-Beam versus Two-Beam Scenario
• Wave-particle interactions in non-uniform plasma and the interpretation of Hard X-ray spectra in solar flares
• Solar Physics with the Square Kilometre Array
• Langmuir Wave Electric Fields Induced by Electron Beams in the Heliosphere
• Coronal type III radio bursts and their X-ray flare and interplanetary type III counterparts
• Note on quantitatively correct simulations of the kinetic beam-plasma instability
• Stopping Frequency of Type III Solar Radio Bursts in Expanding Magnetic Flux Tubes
• Plasma radio emission from inhomogeneous collisional plasma of a flaring loop
• The effect of initial conditions on the electromagnetic radiation generation in type III solar radio bursts
• The effects of density inhomogeneities on the radio wave emission in electron beam plasmas
• The effect of electron beam pitch angle and density gradient on solar type III radio bursts
• Electron cyclotron maser emission mode coupling to the z-mode on a longitudinal density gradient in the context of solar type III bursts
• Plasma emission induced by ring-distributed energetic electrons in overdense plasmas
• Whistler wave generation by non-gyrotropic, relativistic, electron beams