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On the Acceleration Processes in Solar Flares

Published online by Cambridge University Press:  14 August 2015

Z. Švestka*
Affiliation:
American Science and Engineering, Cambridge, Mass. 02139, U.S.A.∗

Abstract

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The paper summarizes what we know about the acceleration processes on the Sun. Four different instabilities are distinguished: (1) One with purely thermal consequences giving rise to the origin of any flare. (2) A non-thermal process at the flash phase of flares giving rise to ∼ 100 keV electrons and protons, manifested through hard X-ray and impulsive microwave bursts (current interruption?). (3) An instability giving rise to streams of electrons, without accelerating protons, manifested by type III bursts (tearing-mode instability?). When (2) and (3) are linked, flare associated electron events in space are often recorded. (4) Finally an explosive instability produces a shock wave which manifests itself as a type II burst. This instability leads to a second-step acceleration of particles preaccelerated in (2) and gives origin to >10 MeV protons and relativistic electrons (probably stochastic acceleration).

Type
Part 3: Solar Flares
Copyright
Copyright © Reidel 1975 

References

Chupp, E. L., Forrest, D. J., Higbie, P. R., Suri, A. N., Tsai, C., and Dunphy, P. P.: 1973, Nature 241, 333.CrossRefGoogle Scholar
De Jager, C.: 1969, in de Jager, C. and Švestka, Z. (eds.), Solar Flares and Space Research, p. 1.Google Scholar
De Jager, C. and Kundu, M. R.: 1963, Space Res. 3, 836.Google Scholar
Frost, K. J. and Dennis, B. R.: 1971, Astrophys. J. 165, 655.CrossRefGoogle Scholar
Kahler, S.: 1975, This volume, p. 211.CrossRefGoogle Scholar
Kane, S. R.: 1969, Astrophys. J. Letters 157, L139.CrossRefGoogle Scholar
Kane, S. R.: 1972, Solar Phys. 27, 174.CrossRefGoogle Scholar
Kane, S. R. and Anderson, K. A.: 1970, Astrophys. J. 162, 1003.CrossRefGoogle Scholar
Lin, R. P.: 1975, This volume, p. 385.CrossRefGoogle Scholar
McIntosh, P. S. and Donnelly, R. F.: 1972, Solar Phys. 23, 444.CrossRefGoogle Scholar
Rust, D. M. and Hegwer, R.: 1975, Solar Physics 40, 141.CrossRefGoogle Scholar
Sturrock, P. A.: 1968, in Kiepenheuer, K. O. (ed.), ‘Structure and Development of Solar Active Regions’, IAU Symp. 35, 471.Google Scholar
Švestka, Z.: 1970, Solar Phys. 13, 471.CrossRefGoogle Scholar
Švestka, Z.: 1974, Solar Flares, D. Reidel Publ. Co., Dordrecht, Holland (in press).Google Scholar
Švestka, Z. and Fritzová-Švestková, L.: 1974, Solar Phys. 36, 417.CrossRefGoogle Scholar
Švestka, Z. and Simon, P., (eds.): 1975, Catalog of Solar Particle Events, 1955–1969, D. Reidel Publ. Co., Dordrecht, Holland.Google Scholar
Švestka, Z., Castelli, J. P., Dizer, M., Dodson, H. W., McIntosh, P. S., and Urbarz, H.: 1974, Flares of 8 June, 1972, at 13h19m and 13h52m UT, CINOF Report, presented at the STP Symposium, Sao Paulo, June.Google Scholar
Takakura, T. and Kai, K.: 1966, Publ. Astron. Soc. Japan 18, 57.Google Scholar
Thomas, R.: 1975, This volume, p. 25.Google Scholar
Tindo, I. P., Ivanov, S. L., Mandelshtam, S. L., and Skurygin, A. I.: 1972, Solar Phys. 24, 429.CrossRefGoogle Scholar
Vedrenne, G.: 1975, This volume, p. 315.Google Scholar