Abstract
The possibility of accelerated protons in solar flares having a sharp change in their spectral index is discussed. The analysis is based on the Tsytovich (1982, 1984, 1987a, b, c) acceleration model by MHD turbulence, which is shown to have different resonant conditions for non-relativistic and relativistic particles. The different resonant condition is shown to result in a sharp change in the accelerated proton spectral index, even in the absence of any peculiarity in the spectra of the MHD turbulence. Time scales for accelerated protons to relativistic energies are also derived, and shown to be consistent with observations. We also show that the threshold energy for electron acceleration by low frequency MHD turbulence is much greater than for proton acceleration. The turbulence therefore preferentially accelerates protons.
Original language | English |
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Pages (from-to) | 329-335 |
Number of pages | 7 |
Journal | Solar Physics |
Volume | 147 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 Oct 1993 |
Keywords
- accelerated protons
- solar flares
- spectral index
- resonance
- MHD turbulence
- electron acceleration
- proton acceleration