The Cosmic-Ray Intensity above the Atmosphere

In a series of flights of Aerobee and V-2 rockets at geomagnetic latitude $\lambda =41\mathrm{}$°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./${\mathrm{cm}}^2$/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.