New method for estimating the absolute flux and energy spectrum of solar cosmic rays based on neutron-monitor data

A new method is described for estimating the absolute flux of solar cosmic rays based on the data from a single neutron monitor. The method is capable of yielding the energy spectrum at the isotropic phase of a solar flare using the available data from the currently operable worldwide network of cosmic-ray stations. The method is based on the determination of the effective momentum or energy for which the particle flux derived from the neutron-monitor count rate is weakly sensitive to small variations in the exponent of the power-law spectrum. A comparison of the calculations with direct space-borne measurements and calculations by other authors based on the data from the neutron-monitor network shows their satisfactory agreement for the last ground-level enhancement of solar cosmic rays observed on December 13, 2006.