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.
Similar content being viewed by others
References
Bryant, D. A., Cline, T. L., Desai, U. D., and McDonald, F. B.: 1965,Astrophys. J. 141, 478.
Chupp, E. L., Forrest, D. J., Higbie, P. R., Suri, A. N., Tsai, C., and Dunphy, P. P.: 1973,Nature 241, 333.
Hudson, H. S.: 1979, in J. Arons, C. McKee, and C. Max (eds.),Particle Acceleration Mechanisms in Astrophysics, Amer. Inst. of Physics, New York, p. 115.
Kaplan, S. A., Pikel'ner, S. B., and Psytovich, V. N.: 1975,Plasma Physics of Solar Atmosphere 1977, Nat. Physics Reports, Moscow.
Lin, R. P.: 1974,Space Sci. Rev. 16, 189.
McClements, K., Su, J. J., Bingham, R., Dawson, J. M., and Spicer, D.: 1990,Solar Phys. 130, 229.
McDonald, F. B., Fichtel, C. E., and Fisk, L. A.: 1974, in F. B. McDonald and C. E. Fichtel (eds;),High Energy Particles and Quanta in Astrophysics, MIT Press, Cambridge, p. 212.
Ramaty, R., Kozlovsky, B., and Lingenfelter, R. E.: 1975,Space Sci. Rev. 18, 341.
Ramaty, R., Kozlovsky, B., and Lingenfelter, R. E.: 1979,Astrophys. J. Suppl. 40, 487.
Simnett, G. M.: 1971,Solar Phys. 20, 448.
Simnett, G. M.: 1986,Solar Phys. 106, 165.
Suri, A. N., Chupp, E. L., Forrest, D. J., and Reppin, C.: 1975,Solar Phys. 43, 414.
Syrovatskii, S. I.: 1981,Ann. Rev. Astron. Astrophys. 19, 163.
Tsytovich, V. N.: 1982,Physica Scripta T2/2, 562.1984,Proceedings of Course and Workshop on Plasma Astrophysics, Varenna, Italy ESA SP-20, 141, SukhumyESA SP-251, 217.
Tsytovich, V. N.: 1984,Soviet Phys. JETP 87, 1105.
Tsytovich, V. N.: 1987a,Soviet Phys. JETP 60, 631.
Tsytovich, V. N.: 1987b,Soviet Phys. JETP 66, 959.
Tsytovich, V. N.: 1987c,Soviet Phys. JETP 93, 1680.
Tsytovich, V. N.: 1988,Proceedings of Course and Workshop on Plasma Astrophysics, Varenna, Italy.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Tsytovich, V.N., Bingham, R., de Angelis, U. et al. Proton acceleration in flares and magnetohydrodynamic solar activity. Sol Phys 147, 329–335 (1993). https://doi.org/10.1007/BF00690722
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00690722