Study of primary cosmic ray alpha and proton energy spectra, geomagnetic cut-off energies and temporal variations

Abstract

A new detector is described employing both a Cherenkov counter and a scintillation counter for measuring the cosmic-ray charge and energy spectrum. Alpha and proton energy spectra, alpha cut-off energies, and temporal variation obtained during a series ef Skyhook balloon flights are discussed. Five of the Skyhook flights reached an altitude greater than 114,000 feet. The alpha integral and differential energy spectrum data are tabulated and plotted. The alpha differential spectrum has a maximum in the vicinity of 325 Mev/nucleon and decreases at lower energies. The calculated cut-off energy for alpha particles at 55 deg was found to be 330 Mev/nucleon, in agreement with the data of Fowler et al. (A.C.)