The Cosmic-Ray Intensity above the Atmosphere

Abstract
In a series of flights of Aerobee and V-2 rockets at geomagnetic latitude λ=41°N, single Geiger counters and Geiger counter telescopes have been employed to measure the total intensity of cosmic rays above the appreciable atmosphere. The directional intensity j, averaged over the upper hemisphere, is found to be 0.120±0.009/sec./cm2/steradian, constant from 55-km altitude to the highest altitude reached of 161 km. This result is an experimental upper limit to the primary intensity of charged particles at this latitude.