Physics of auroral phenomena : proceedings of the 39th annual seminar, Apatity, 29 February-4 March, 2016 / [ed. board: N. V. Semenova, A. G. Yahnin]. - Апатиты : Издательство Кольского научного центра РАН, 2016. - 167 с. : ил., табл.

Proton acceleration in the solarflare GOES 12 AR10720 the current sheet. The particles (ions and electrons) are accelerated along the singular X-type line. When the particle is deviated from X-line, it enters into the drift region and the acceleration is ceased. The efficiency of particle acceleration by the electric field E = -VxB/c, directed along a singular line of the magnetic field is known from results of laboratory experiments with a powerful pulsed discharge [12, 13], which were carried out in association with the problem of controlled thermonuclear fusion. To determine the spectrum of particles accelerated in the flare current sheet, the method of test particles [10] is used. The current sheet magnetic fields configuration is calculated in the three-dimensional MHD numerical simulation for Bastille flare (14.07.2000) [14]. It is shown that accelerated protons do have an exponential spectrum which at the magnetic reconnection velocity 2 x l0 7 cm/c coincides with the spectrum measured by a network of neutron monitors at the front of the proton flux of the western flare. Thus, the prompt component of particles accelerated in the flare current sheet comes to the Earth orbit in the first 10-20 minutes. It travels during time of flight without collisions. They can propagate free only along the magnetic lines of the spiral of Archimedes. Such magnetic field lines must to connect flare with the proton registrar located on the Earth's orbit. The time of protons arrival to the Earth increases, apparently, due to the beam instability [15]. The scattering by inhomogeneities leads to diffusion propagation along and across magnetic field lines. Independent and additional information about the flux of accelerated protons coming to the Earth can be obtained from measurements on the GOES spacecrafts located at geocentric orbit and recording streams protons in wide angle in three energy ranges (W> 10 MeV, W > 50 MeV. and W > 100 MeV) [16-19. 21]. Powerful complexes of proton events. The GOES measurements demonstrate powerful complexes of proton events caused by several proton flares, following each other at intervals of about a day. The powerful complex of proton events can be created by one active region or by several regions. During the 11 years of the solar activity period not more than two - three complexes of proton events are observed. Typical development of strong proton events that occurred over the active region AR10720 is shown in Fig. 1. Weak active region appeared at the eastern limb. Fluxes of protons were completely absent, and X-ray pulses were small. They are not exceeded the class B. At Sun rotation the northern and southern magnetic fluxes are started to increase, the active region intensifies, and the magnetic field configuration becomes more complicated. The source of the magnetic field of the north direction is shown by white and the black shows the south direction. January 15 2005 the several XI flares appear and one of them is followed by a proton event. Later, when the active region is passed on the western part of the solar disk, the large (X-type) flares arise. Some of them are accompanied by proton events. However, a large number of flares are produced by AR10720, and the superposition of several proton events does not allow comparing the proton events clearly with specific flares. For such comparison we used a single flare that occurred in the western of eastern parts of the solar disk. Figure 1. At the top - the solar flares caused by the region AR 10720; lower - proton fluxes, registered by the GOES device; the north and south magnetic fluxes; magnetograms. Proton events from western and eastern flares. Fig. 2 shows the typical single proton events accompanied by the flares appeared in the western (above) and eastern (below) part of solar disk. During the eleven-year cycle o f solar activity 10-15 proton events can be observed. Each proton event is appeared after a flare (usually class X or class M). However, not all large flares produce pulses of solar cosmic rays. Only about 30% of large flares are followed by the 61