The Transmission of Electrons through Thin Metallic Foils

Abstract

Experimental studies have been made on the relative transmission of positrons and negatrons in the energy range 50-750 kev through aluminum and platinum windows of an end-window-type G-M counter. In qualitative agreement with the theoretical predictions that more scattering takes place in material having higher atomic number, a platinum foil having the same surface density as a corresponding aluminum foil shows lower relative transmission at any given energy even though the low energy cutoffs of the two windows are just about the same. Also in qualitative agreement with theory, a larger percentage of positrons than negatrons are transmitted at any given energy for the same platinum foil. Theoretical transmission curves, with an empirically determined constant, have been developed. These curves are in relatively good agreement with the experimental curves.