Electron acceleration during three-dimensional relaxation of an electron beam-return current plasma system in a magnetic field

Abstract

We investigate the effects of acceleration during non-linear electron-beam relaxation in magnetized plasma in the case of electron transport in solar flares. The evolution of electron distribution functions is computed using a three-dimensional particle-in-cell electromagnetic code. Analytical estimations under simplified assumptions are made to provide comparisons. We show that, during the non-linear evolution of the beam-plasma system, the accelerated electron population appears. We found that, although the electron beam loses its energy efficiently to the thermal plasma, a noticeable part of the electron population is accelerated. For model cases with initially monoenergetic beams in uniform plasma, we found that the amount of energy in the accelerated electrons above the injected beam-electron energy varies depending the plasma conditions and could be around 10-30% of the initial beam energy. This type of acceleration could be important for the interpretation of non-thermal electron populations in solar flares. Its neglect could lead to the over-estimation of accelerated electron numbers. The results emphasize that collective plasma effects should not be treated simply as an additional energy-loss mechanism, when hard X-ray emission in solar flares is interpreted, notably in the case of RHESSI data.

9 pages, 8 figures, accepted to Astronomy and Astrophysics

References in corpus (8)

• Implications of X-ray Observations for Electron Acceleration and Propagation in Solar Flares
• Deducing Electron Properties From Hard X-Ray Observations
• Production of Magnetic Turbulence by Cosmic Rays Drifting Upstream of Supernova Remnant Shocks
• Nonlinear development of electron-beam-driven weak turbulence in an inhomogeneous plasma
• Dynamics of electron beams in the solar corona plasma with density fluctuations
• Onsets and spectra of impulsive solar energetic electron events observed near the Earth
• Wave-particle interactions in non-uniform plasma and the interpretation of Hard X-ray spectra in solar flares
• Vlasov-Maxwell, self-consistent electromagnetic wave emission simulations in the solar corona

Cited by in corpus (9)

• A Unified Computational Model for Solar and Stellar Flares
• Density fluctuations and the acceleration of electrons by beam-generated Langmuir waves in the solar corona
• Langmuir Wave Electric Fields Induced by Electron Beams in the Heliosphere
• Modifications of thick-target model: re-acceleration of electron beams by static and stochastic electric fields
• Plasma radio emission from inhomogeneous collisional plasma of a flaring loop
• Role of Suprathermal Runaway Electrons Returning to the Acceleration Region in Solar Flares
• 3D particle-in-cell simulation of electron acceleration by Langmuir waves in an inhomogeneous plasma
• Effect of turbulent density-fluctuations on wave-particle interactions and solar flare X-ray spectra
• Bridging High-Density, Electron Beam Coronal Transport and Deep Chromospheric Heating in Stellar Flares