On the Yield and Energy Distribution of Secondary Positive Ions from Metal Surfaces

Abstract

The kinetic energy distribution of secondary positive ions liberated from a solid metallic target of beryllium under bombardment by positive ions was measured in a mass spectrometer provided with an energy analyzer. In conformity with earlier investigations, it was found that an appreciable fraction of the ions was liberated with energies less than 5−10 ev, although some secondary ions of more than 200 ev were found. The distributions appeared to be at least partially Maxwellian in character. Although errors in measurement were large, there appeared to be little dependence of the yield of secondary ions on the mass of the bombarding ion.