Radiation-Induced Low Energy Electron Emission from Metals

Low energy electron emission from several metals exposed to Co60 gamma rays, 10 MeV electrons, and 0.1 to 1.0 KeV electrons has been studied. The experiments described here, together with other reported results, indicate that for a given metal the emission of electrons with energies below 50 eV is proportional to the absorbed dose and is independent of the type and energy of the primary radiation. For the common metals the charge emitted per square centimeter per rad is found to be between 1.0 to 3.0 × 10-13 coulombs. It also appears that the magnitude of the emission induced by high energy radiations can be predicted from the secondary emission yields observed under low energy electron bombardment. Under certain assumptions it is shown that the data is consistent with an internal isotropic low energy electron distribution given by N(E)¿ E-3