Abstract
The problem of particle acceleration in collapsing magnetic traps in the solar corona has been solved by taking into account the particle scattering and braking in the high-temperature plasma of solar flares. The Coulomb collisions are shown to be weak in traps with lifetimes t l < 10 s and strong for t l > 100 s. In the approximation of strong collisions, collapsing magnetic traps are capable of confining up to 20% of the injected particles in the corona for a long time. In the collisionless approximation, this value exceeds 90%. The question about the observational manifestations of collisions is examined. For collision times comparable to t l , the electron spectrumat energies above 10 keV is shown to be a double-power-law one. Such spectra were found by the RHESSI satellite in flares.
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Original Russian Text © S.A. Bogachev, B.V. Somov, 2009, published in Pis’ma v Astronomicheskiĭ Zhurnal, 2009, Vol. 35, No. 1, pp. 63–75.
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Bogachev, S.A., Somov, B.V. Effect of Coulomb collisions on the particle acceleration in collapsing magnetic traps. Astron. Lett. 35, 57–69 (2009). https://doi.org/10.1134/S1063773709010071
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DOI: https://doi.org/10.1134/S1063773709010071