Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1771603 | Astroparticle Physics | 2006 | 6 Pages |
Abstract
Solar energetic particles (SEPs) from large solar flares give important information about the physical process in the solar corona and the heliosphere. Several observations have indicated that solar protons could sometimes be accelerated to at least tens of GeV, even hundreds of GeV, in intense solar energetic process. We studied the solar proton differential energy spectra with energy range of 1-500Â MeV at several time intervals during Bastille Day event. It was shown that the spectra could be fitted by a power law function before flare and after flare the power law spectra still existed above 30Â MeV although spectra became softer with time. There was a spectral “knee” occurring at â¼30Â MeV. We constructed a solar proton differential spectrum from 30Â MeV to 3Â GeV at peak flux time 10:30 UT and fitted it in the same manner. On the basis of a supposition of having the same power law spectrum in higher energy, we calculated the solar proton integrated fluxes in energy range of from 500Â MeV to 20Â GeV and compared them with other results obtained from experimental, modelling and theoretical calculations in other big historic SEP events. A Monte Carlo simulation was carried out for a primary proton beam at the top of the atmosphere producing secondary muons on the ground. Based on the simulation, possibility of registering the solar energetic proton beams with energies over 20Â GeV was discussed.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
Ruiguang Wang, Jinxiu Wang,