A Magnetic Cosmic-Ray Spectrograph with Counter Recording

Abstract

An instrument is described in which the momentum of single cosmic-ray particles is measured, the particles leaving the instrument in a sufficiently collimated beam for use in subsequent experiments. The `maximum detectable momentum' of the apparatus is about 3 × 1010 eV/c., almost all particles are collected within 10° of the zenith and in directions individually defined to ±1°, the output is about 400 particles/day, and the proportion of spurious records is of the order of, or less than, 0.1%.