PROTON SPECTRA OF THE 4 REMARKABLE GLE IN THE 22ND SOLAR-CYCLE

The proton spectra of several large solar particle events in the 22nd solar cycle (namely for the enhancements on 29 September 1989, 19 Octo ber 1989, 24 May 1990 and 15 June 1991) were obtained within the wide energy range directly by experimental data without any advance model. The data from spacecraft measurements and the world network of neutron monitors have been used to analyse these events. All the obtained spe ctra indicate a similar behaviour in the low energy range but differ a t high energies > 1 GeV. The proposed method allows us to define the t imes of the maximum increase depending on the particle energy. The tim e-energy dependencies together with the proton flux profiles at differ ent energies and the obtained spectra might be used as a predictor for estimation of the radiation dose in the maximum of the event, as well as its behaviour. Copyright (C) 1996 Elsevier Science Ltd