Source: http://knit.mao.kiev.ua/en/archive/2010/6/06
Timestamp: 2019-04-20 03:14:57+00:00

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The generation of the second harmonic during the development of the corresponding instability is investigated for the pure electron oblique Bernstein modes modified by taking into account Coulomb collisions and existence of the weak large-scale electric field in the post-flare loop. We propose to name such modes as quasibernsteinian ones. It is supposed that the main characteristics of magnetoactive plasma at the foot-points of the loop structures, which correspond to the “lower-middle” chromosphere of an active region (AR), are determined through the semiempirical model for the solar atmosphere of Fontenla‒Avrett‒ Loeser (FAL).
It is been demonstrated that the use of this model instead of the models of Machado‒Avrett‒Vernaz-za‒Noyes (MAVN) and Vernazza‒Avrett‒Loeser (VAL) used before leads to considerable changes of the instability threshold values of subdreicer electric field amplitudes and boundary values of the perturbation wavelength. Microwave emission in the centimetre-millimetre interval can appear under favourable conditions due to the coalescence of two quasibernsteinian harmonics with next formation of electromagnetic wave.
1. Aleksandrov A. F., Bogdankevich L. S., Rukhadze A. A. Principles of Plasma Electrodynamics, 424 p. (Vysshaya Shkola, Moscow, 1989) [in Russian].
2. Antonov A. V., Gerasimov Yu. M., Karelin Yu. V. Research of Parameters of Solar Flares at 3-mm Wavelengths. Radio Physics and Radio Astronomy, 13 (1), 15—25 (2008) [in Russian].
3. Bogod V. M., Garaimov V. I., Zheleznyakov V. V., Zlotnik E. Ya. Detection of a Cyclotron Line in the Radio Spectrum of a Solar Active Region and Its Interpretation. Astron. zhurn., 77 (4), 313—320 (2000) [in Russian].
4. Gelfreikh G. B., Tsap Yu. T., Kopylova Yu. G., et al. Variations of Microwave Emission from Solar Active Regions. Pis'ma v Astron. zhurn., 30 (7), 540—547 (2004) [in Russian].
5. Gopasyuk S. I. Structure and dynamics of the magnetic field in active regions on the Sun., Itogi nauki i tehniki, VINITI, Astronomy, 34, 7—77 (1987) [in Russian].
6. Zheleznyakov V. V. Electromagnetic waves in cosmic plasma. Generation and propagation, 432 p. (Nauka, Moscow, 1977) [in Russian].
7. Zaitsev V.V., Stepanov A.V., Tsap Yu.T. On the problems of physics of solar and stellar flares. Kinematika i Fizika Nebesnykh Tel, 10 (6), 3—31 (1994) [in Russian].
8. Kopylova Yu. G., Stepanov A. V., Tsap Yu. T. Radial Oscillations of Coronal Loops and Microwave Radiation from Solar Flares. Pis'ma v Astron. zhurn., 28 (11), 870—879 (2002) [in Russian].
9. Kryshtal' A. N., Gerasimenko S. V. On the sequence of the rise of plasma wave instabilities near the footpoints of solar arch structures at the early stages of a flare process. Kinematika i Fizika Nebesnykh Tel, 21 (5), 352—367 (2005) [in Russian].
10. Melnikov V. F., Fleishman G. D., Fu Q. J., Huang G.-L. Flare-Plasma Diagnostics from Millisecond Pulsations of the Solar Radio Emission. Astron. zhurn., 79 (6), 551—569 (2002) [in Russian].
11. Podgorny A. I., Podgorny I. M. Numerical Simulation of a Solar Flare Produced by the Emergence of New Magnetic Flux. Astron. zhurn., 78 (1), 71—77 (2001) [in Russian].
of the; GAO RAN, Pulkovo, St. Petersburg, July 2—7, 2007, 138—139 (St. Petersburg, 2007) [in Russian].
13. Chen F. F. Introduction to Plasma Physics, 398 p. (Mir, Moscow, 1987) [in Russian].
14. Yurovskii Yu. F. On mechanisms for modulating the radio emission of solar flares. Astron. zhurn., 74 (6), 347—360 (1997) [in Russian].
15. Antonov A. V., Bezuglaya G. V., Gerasimov Yu. V., Karelin Yu. V. Oscillation of radiotion of solar flares in 3mm range. MSMV’07 Symp. Proc., Kharkov, Ukraine, June 25—30, 2007, Vol. 2, 751—753 (Kharkov, 2007).
16. Aschwanden M. I. An evaluation of coronal heating models for active regions based on Yohkoh, SOHO and TRACE ob servations. Astrophys. J., 560, 1035— 1043 (2001).
17. Aurass H. Radio type IV burst fine structures and the dynamics of flare process. In: Solar Coronal Structures: Proc. 144-th IAU Colloq., Bratislava, Slovakia, 20—24 September 1993, Eds V. Rusin, P. Heinzel, I.-C.Vial, 251—256 (VEDA Publ. Company, Bratislava, 1993).
18. Brinca A. L., Dysthe K. B. Effect of longitudinal electric fields on electrostatic electron cyclotron waves. J. Plasma Phys., 29 (1), 35—40 (1983).
19. Farnik F., Savy K. Soft X-ray pre-flare emission studied in Yohkoh-SXT images. Solar Phys., 183 (1), 339—357 (1998).
20. Fontenla J. M., Avrett E. H., Loeser R. Energy balance in solar transition region. III. Helium emission in hydrostatic, constant-abundance models with diffusion. Astrophys. J., 406 (1), 327—336 (1993).
21. Foukal P., Hinata S. Electric fields in the solar atmosphere: a review. Solar Phys., 132 (1), 307—330 (1991).
22. Harra L. K., Matthews S. A., Culhane J. L. Nonthermal velocity evolution in the precursor phase of a solar flare. Astrophys. J., 549 (2), L245—L248 (2001).
23. Heyvaerts J., Priest E., Rust D. An emerging flux model for the solar flare phenomenon. Astrophys. J., 216 (1), 213—221 (1977).
24. Kryshtal A. N. Bernstein wave instability in a collisional plasma with a quasistatic electric field. J. Plasma Phys., 60 (3), 469—484 (1998).
25. Machado M. E., Avrett E. H., Vernazza J. E., Noyes R. W. Semiempirical models of chromospheric flare regions. Astrophys. J., 242 (1), 336—351 (1980).
26. Schmahl E. I., Webb D. K., Woodgate B., et al. Coronal manifestations of preflare activity. Energetic Phenomena on the Sun (“Impulsive Phase Transport”), Eds M.Kundu and B.Woodgate, NASA CP — 2439, L48—L78 (Washington, DC, 1986).
27. Solanki S. K. Small-scale solar magnetic fields: an overview. Space Sci. Rev., 63, 1—183 (1993).
28. Vernazza J. E., Avrett E. H., Loeser R. Structure of the solar chromosphere. III-Models of the EUV brightness components of the quiet-sun. Astrophys. J. Suppl. Ser., 45 (1), 635—725 (1981).
29. Willes A. J., Robinson P. A. Electron-cyclotron maser theory for noninteger radio emission frequencies in solar microwave spike bursts. Astrophys. J., 467 (1), 465—472 (1996).

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