Evaporation of Zinc and Zinc Oxide under Electron Bombardment

By use of a mass spectrographic method, the rate of evaporation of zinc and zinc oxide is measured as a function of temperature both with and without electron bombardment of the surface being evaporated. In the case of zinc metal no increase of evaporation could be detected as resulting from bombardment whereas a definite increase was observed in the evaporation of zinc oxide. The enhancement of the evaporation rate of zinc oxide increases slowly at first and then rapidly with increasing temperature.