High energy cosmic-ray electrons lose their energy by synchrotron and inverse Compton process during their propagation through the Galaxy. Then the electron spectrum brings us unique information about the sources and propagation of cosmic-rays. Many observations have been carried out since the first discovery of cosmic-ray electrons. Beyond 100GeV, however, only a few observations were successful to observe the absolute flux of electrons. The Emulsion Chamber observations in collaboration with the Washington University group were the most successful to observe the spectrum extending up to a few TeV region. Beyond 100GeV, the statistical accuracy of the observed data is still limited, and we tried to accumulate the data by improving the method of detection of electrons, particularly in a few hundred GeV regions. We report here the results based on new flight exposures of the chamber in 1996. The statistical accuracy of electron spectrum was much improved at several hundred GeV. In this paper, some characteristics of the emulsion chamber compared with counter instruments are summarized. The rejection power for the cosmic-ray protons are analyzed in some detail. The astrophysical significances of the primary electron spectrum are also discussed.
100GeV 以上の高エネルギーの宇宙線電子について
SA0167146.pdf
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