Rigidity spectra of primary cosmic radiation

Abstract

The comparison of the cosmic-ray intensity measured with balloon-borne ion chambers at different atmospheric depths at stations in North America and in the U.S.S.R. for the period 1937-67 is presented. It is found that there is no difference in variations of cosmic-ray spectra in periods of increasing and decreasing solar activity in 1954-64. In 1937-40 the cosmic-ray spectra are found to be distinctly different, suggesting a slow change in the spectrum over periods greater than the 11-year cycle of solar activity.