Abstract

Abstract The galactic cosmic ray proton and helium spectra have been measured with a balloon-borne superconducting magnetic spectrometer over the energy range from 200 MeV nucl−1 to 100 GeV nucl−1 during the 1987 solar minimum between the 21st and 22nd solar cycle. The absolute fluxes were approximately equal to the highest fluxes observed at the previous solar minimum in 1977. Above 10 GV the observed spectra are represented by a power law in rigidity with spectral indices of 2.74± 0.02 for protons and 2.68 ± 0.03 for helium. The data are consistent with rigidity power law interstellar spectra modulated with the solar modulation parameter φ = 500 MV.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.