Čerenkov Counter Measurement of Multiply Charged Cosmic Rays

Measurements have been made on the charge spectrum of cosmic rays at geomagnetic latitude 41°. The value 88±8 particles/${\mathrm{m}}^2$ sec sterad was found for the primary alpha-particle flux. For the flux of nuclei with $6<~Z<~8$ the value 7.4±1.7 particles/${\mathrm{m}}^2$ sec sterad was found, and for the $Z>~9$ flux, the value 4±2. It is most probable that all of the Li, Be, B nuclei observed were secondary. The experiment sets an upper limit 0.25 on the abundance of primary Li, Be, B relative to the medium elements ($6<~Z<~10$).