Abstract
A "specific yield" function SA(E,x) is defined which gives the production rate of disintegration neutrons at atmospheric depth x arising from a unit flux of vertically incident cosmic-ray primaries of atomic weight A and energy-per-nucleon E. The functions are obtained by comparing the latitude variations for the primary particle fluxes with the latitude variations for neutron production at various depths in the atmosphere. For atmospheric depths between at least 200 and 600 g/cm2, it is found that the specific yields increase rapidly with energy up to about 4-Bev/nucleon and then become insensitive to energy up to at least 12.7-Bev/nucleon. It is also shown that this insensitivity probably extends up to considerably larger energies. The theoretical implications of these results are qualitatively discussed.