Measurements of primary and atmospheric cosmic - ray spectra with the BESS-TeV spectrometer

Abstract Primary and atmospheric cosmic-ray spectra were precisely measured with the BESS-TeV spectrometer. The spectrometer was upgraded from BESS-98 to achieve seven times higher resolution in momentum measurement. We report absolute fluxes of primary protons and helium nuclei in the energy ranges, 1–540 GeV and 1–250 GeV/ n , respectively, and absolute flux of atmospheric muons in the momentum range 0.6–400 GeV/ c .