Observation of solar neutrons by means of high-altitude neutron monitors

Five minute data of neutron monitors of the stations Alma-Ata and Lomnitski Shtit were applied for exposure of cosmic ray variations coinciding by time with most powerful phenomena in solar flares. The statistical analysis reliably revealed that distribution of variations of moutainos neutron monitor counting rate during γ-burst essentially differs from variation distribution in preceding and following periods. Short-term increases of neutron monitor counting rate were observed in more than half of events, their beginning coincided on the average with the beginning of γ-burst. It is supposed that the observed increase is conditioned by E>300 MeV neutrons from solar flares. Thus, probably, relativistic neutrons (and, therefore, relativistic protons) are generated in most of powerful solar flares