High energy primary electron

It is expected that the observation of electrons with energy above 1000 GeV will give some information on the origin of cosmic ray and the acceleration region. In this report, the observation of high energy primary electrons with emulsion chambers is discussed. Since the intensity of incidence of high energy electrons is very small, and the discrimination of electron events from proton events by electronic circuits is difficult, the use of emulsion chambers for the observation is practical. As the results of observation, seven events caused by the electrons above 1000 GeV were detected. The observed electron spectrum is presented. The intensity of electrons decreases rapidly with energy. The experimental data were compared with the calculated values based on the diffusion model of propagation in the galactic space. (Kato, T.)