Theory of Secondary Emission

The elementary theory of secondary electron emission developed by Salow, Bruining, Baroody, and others has been generalized and modified to incorporate recent measurements by Young of the range-energy relation and the dissipation of energy by slow electrons in solids. It is found that these modifications give considerably improved agreement between the theoretical and experimental "universal" reduced yield curves. However, for primary energies several times higher than that for which the yield has its maximum value, deviations occur; the reduced yield curve for metals appears to lie slightly above the theoretical curve, while that for MgO falls increasingly below. Similar results are found for Ge, but the agreement is better than for MgO.