Transmission and secondary electron emission of 20–50 keV electrons through aluminium foils

Abstract

Experimental data and Monte Carlo results of 20–50 keV electron penetration through thin aluminium foils are presented. Transmission ratios as well as energy characteristics of secondary electrons are measured for 3–20 µm thick foils. Implications of these results for the requirements of a radioisotope micro-power sources energy conversion device are analyzed. It is shown that for a given foil thickness, there is a discrete peak in the low energy secondary electron emission. In addition, it is noted that the conversion factor for high energy primaries to low energy secondaries is less than one.