The measured energy loss of high energy electrons in copper and lead

Abstract

The energy distributions of electrons of about 53, 75 and 93 MeV have been measured before and after passing through copper absorber of thickness up to 5.726 g/cm2 and lead absorbers of thickness up to 2.825 g/cm2. Earlier data for aluminum absorbers are reviewed. The electrons were accelerated by the LINAC of the Naval Postgraduate School. The most probable energy losses agree with the theory of Blunck and Westphal for all thicknesses; the half widths agree except for large thicknesses, where they are smaller than theoretical values for lead, in agreement for copper, and larger for aluminum. Large numbers of electrons of energy less than 30 MeV are observed in the distributions of transmitted electrons, particularly for thick absorbers and higher values of atomic number. These are apparently the result of multiple processes in the absorbers.