COSMIC-RAY EXPERIMENTS WITH A PROTON VELOCITY SELECTOR

Abstract

Experiments with a selector of slow heavy cosmic-ray particles are described. The pressure coefficient of protons at sea level in the momentum region 700 to 1100 Mev./c is found to be 0.64 ± 0.08% per mb. Points are obtained on the differential momentum spectrum of protons at sea level between 650 and 1250 Mev./c, in agreement with the results of Mylroi and Wilson. This spectrum is discussed in connection with the experiments of Filthüth between 200 and 900 Mev./c.