Electron-Induced Showers in Copper

An experimental determination has been made of the radial and longitudinal distribution of energy produced in showers initiated by electrons of 118 Mev and 157 Mev in copper. A small crystal CsBr(Tl) coupled to a thin light pipe and photomultiplier was used as a probe. Graphs of the radial distributions are given from which, by numerical integration, transition curves are determined. Calculations are made for an approximately optimum design of scintillation crystal [e.g., NaI(Tl)] to capture a large fraction of the energy within a shower.