HIGH-ENERGY PROTON HELIUM AND GAMMA-RAY OBSERVATIONS ON OSO-3

A report on preliminary results obtained from the analysis of the first 700 orbits of data obtained in the University of Rochester particle telescope, carried in the wheel section of OSO-III, is presented. The telescope is sensitive to high-energy γ-rays (threshold 50 MeV) and the nuclear component of the cosmic radiation. An upper limit of 3.2 × 10-4 γ/cm2secster. is set on the intensity of the diffuse primary γ-radiation, on the assumption it arises from the decay of π° mesons produced in nuclear interactions. An upper limit to the flux from the sun, on the same assumptions, is set at 5.5 × 10-5 γ/cm2 sec. The analysis of the charged particle data yields the integral rigidity spectra of proton and helium nuclei from 3 to 15 GV; the results indicate that the He spectrum is slightly steeper than the proton spectrum and that the ratio P/He increases slowly from a value of approximately 6 at 3 GV to 8 at 15 GV. © 1969 D. Reidel Publishing Company.