Auger electrons associated with stopped π interactions in nuclear emulsions

Abstract

This study was undertaken in order to determine with more precision, by means of increased statistics, the frequency of Auger electrons from π--mesons interactions in nuclear emulsion. The energy distribution of Auger electrons from the light and heavy elements of the nuclear emulsion was obtained. A stack of 36 (2 × 4) in. 600 Μm G-5 nuclear emulsion was exposed to the π- beam of the cyclotron at the University of Chicago. The pion flux was 4.104π‘s per cm per minute and after traveling 1.5 cm of emulsion 95% of the π--mesons stopped within a strip 2 cm long. There were observed 5 498 π--meson interactions, out of which 950 had 1 092 Auger electrons associated with them. Of the 950 Auger bearing events, 863 were due to π--meson interactions with the heavy elements of the nuclear emulsion, and the remaining 87 were due to the absorption of the π--meson by the light elements of the nuclear emulsion. The frequency of events having one or more Auger electrons was observed to be 0.173 or 950/5 498. The observed energy spectrum of the Auger electrons from the heavy and light elements of the nuclear emulsion was found to agree, within the experimental errors, with the energy spectrum calculated by Eisenberg. It is also observed that 92% of all Auger electrons originate from heavy nuclei and 8% from light nuclei.