Neutron monitor yield function for solar neutrons: A new computation

A new yield function of a standard neutron monitor 6NM64 for solar neutrons is presented and tabulated in the attached lookup tables. It corresponds to a wide range of altitudes of the neutron monitor locations and angles of incidence for neutrons entering the Earth’s atmosphere. The computations were made by Monte Carlo using the GEANT4-based PLANETOCOSMICS tool. The yield function was validated against the measured data for solar neutron events of 3 June 1982 and 24 May 1990, and good agreement was found within a wide range of the altitudes of the neutron monitor location and angles of incidence of solar neutron arrival. The sensitivity of the world neutron monitor network for registration of solar neutron events was reassessed. The neutron monitor network is shown to be, in addition to other methods, a sensitive tool for monitoring of high-energy solar-flare neutrons with ≈95% probability to detect statistically significantly (> 5σ) a solar neutron event similar to that of 3 June 1982.