Simulation of Accelerated Electron Beam Transport with a Fine Time Structure in Flare Loop Plasma

Abstract

This work discusses the results of the analysis of the pulsed time structure of X-ray radiation for the SOL1996-07-09T09:09:01, GOES X2.6-class flare recorded by CGRO/BATSE and the numerical simulation of the propagation of accelerated electrons in the plasma of a magnetic loop with a time structure at injection that reflects the structure of hard X-ray radiation. Initially, preliminary processing of the data series was carried out, and the spectral methods of Wavelet and Fourier transforms of X-ray series were then used in energy ranges: 22–56 keV and 56–105 keV. In the time series (22–56 keV and 56–105 keV), the time structures with a duration of ~0.1 to ~1 s are selected; their spectral power exceeds the red-noise level with a probability of 99%. The simulation of the thin time structure of the X-ray radiation of the accelerated electron beam was carried out on the basis of the solution of the kinetic equation for the given plasma parameter distributions and the magnetic field along the flare loop. It is shown that for plasma density values of less than ~10¹¹ cm^–3 in the loop top, the structure of hard X-ray radiation in the top does not reflect the millisecond structure of accelerated electrons. A fine structure of hard X-rays can occur in footpoints with a high plasma density (n₀ > 10¹¹ cm^–3), and more likely with a fairly soft electron spectrum (δ ~ 7) and/or with increasing angular anisotropy in the distribution of accelerated electrons at the time of their injection into the top of the magnetic loop.