The effect of reverse currents on the dynamics of nonthermal electron beams in solar flares and on their emitted X-ray bremsstrahlung

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view Abstract Citations (133) References (37) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The effect of reverse currents on the dynamics of nonthermal electron beams in solar flares and on their emitted X-ray bremsstrahlung Emslie, A. G. Abstract Recognizing the possible importance of reverse current ohmic energy losses from beams of electrons injected into the solar atmosphere during flares, we solve the equations governing the dynamics of such beams, taking into account energy and momentum losses of the beam particles by both collisional and ohmic heating processes. It is found that for injected fluxes compatible with hard X-ray burst observations of fairly large flares, the inclusion of ohmic terms results in a substantial modification of the variation of electron energy and pitch angle with depth in the target. The chromospheric energy deposition due to the beam, and X-ray bremsstrahlung emitted by the beam, are also evaluated for a variety of empirical flare model atmospheres, and it is found that, although both these quantities decrease as the injected electron flux increases, their ratio is insensitive to the parameters of the problem. Further, the emitted nonthermal X-ray flux is found to be bounded by a limiting value only marginally consistent with observations, thus suggesting that a significant portion of the X-ray flux is thermal in origin. The dependence of the results obtained on the model atmosphere used in the calculations is discussed. Publication: The Astrophysical Journal Pub Date: February 1980 DOI: 10.1086/157709 Bibcode: 1980ApJ...235.1055E Keywords: Bremsstrahlung; Electron Beams; Solar Atmosphere; Solar Flares; Solar Physics; Solar X-Rays; Atmospheric Models; Energy Spectra; X Ray Spectra; Solar Physics full text sources ADS |