Solar protons, alpha particles, and heavy nuclei in November 1960

Abstract

Energy spectra of solar protons and α particles were measured in the event following the November 12, 1960, flare. The ratio of the abundance of protons to the abundance of α particles above the same rigidity was found to be 2. Spectra of protons, α particles, and medium nuclei were measured after the November 15, 1960, flare. The proton spectrum showed that the magnetic cutoff existing at Minneapolis until approximately 10 hours after the flare had a value of about 0.7 bv but was not sharp. The ratio of the abundance of the various nucleonic components above the same rigidity was found to be p : α : CNO = 100:100:1. The abundance of electrons of rigidity greater than 0.7 bv was found to be less than 2 per cent of the abundance of protons. A model is suggested by which it would be expected that the ratios of protons to α particles and protons to medium nuclei would change considerably between solar events, but the ratio of α particles to medium nuclei would remain constant.