Energy loss of high energy electrons in aluminum, copper, and lead

The energy distributions of electrons of about 54, 75, and 92 MeV were measured before and after passing through lead absorbers of 2 thicknesses ranging from 0.706 to 2.825 gm/cm , and through copper 2 and aluminum absorbers up to 5.726 gm/cm . The electrons were accelerated by the LINAC of the Naval Postgraduate School. A measurement to determine the optimum location of the absorber indicated that the separation between the scattering foil and absorber should not exceed 6 cm, if geometric difficulties are to be avoided. The most probable energy losses agree with the theory of Blunck and Westphal for all three materials and all thicknesses. The half-widths of the distri- 2 butions agree with theory up to thicknesses of about 2 gm/cm . For greater thicknesses the experimental half-widths of copper absorbers appear to agree with theory; the experimental half-widths of aluminum are greater than theoretical predictions; and those of lead are smaller than theory predicts.http://www.archive.org/details/energylossofhigh00deleMajor, United States ArmyApproved for public release; distribution is unlimited