Electron Reflection from Cobalt, and Electron Waves

Abstract

MEASUREMENTS by a number of observers of the velocity distribution of the electrons leaving the surface of a metal under bombardment by a beam of electrons of known velocity, have shown that a part of the secondary electrons have the primary velocity, the rest having, in general, a lower velocity. No attempt appears to have been made to resolve the secondary emission into its two components when the secondary emission is studied as a function of the velocity of the primary electrons. This is a preliminary account of the results of such an experiment. Previous work (Davis, Proc. Nat. Aoad. Am., 14, p. 460; 1928) has shown that the total secondary emission from cobalt, when plotted against the primary velocity, exhibits a number of sharp maxima and minima extending over an unusually large range of voltages. This fact made it seem an ideal subject for the present type of investigation.