The coefficient of absorption can be defined by the constant α in the exponential relation N=N0e-at. The precise physical interpretation of such an exponential law when applied to a beam of electrons moving through a metal plate of thickness "t" is not so simple as its mathematical expression would lead one to suppose. It may, however, lie interpreted if we assume that there exists no "scattering" or energy transformation as the beam of electrons passes through the metal. If α x is taken as that fraction of the number which is absorbed when the beam of electrons passes normally through a very thin screen of thickness x (cm), then for a plate of thickness t (cm), N=N0e-at, in which N0 is the intensity of the beam when it enters, and N that of the beam when it emerges from the slab of material in which the absorption has taken place.
Proceedings of the Iowa Academy of Science
©1918 Iowa Academy of Science, Inc.
Stuhlman, Otto Jr.
"On the Coefficient of Absorption of Photoelectrons in Silver and Platinum,"
Proceedings of the Iowa Academy of Science, 25(1), 61-65.
Available at: https://scholarworks.uni.edu/pias/vol25/iss1/10