Collisions of Electrons with Hydrogen Atoms. I. Ionization

摘要: The cross section for ionization of the hydrogen atom on electron impact has been measured as a function energy. A modulated beam atoms and molecules in varying proportions, taken from furnace, is crossed by dc beam, positive ions formed are into mass spectrometer. By using such modulation techniques, distinguished much larger number collisions electrons with residual gas vacuum chamber. From study mass-spectrometer peak strengths temperature constant flow, ratio sections molecule directly determined. absolute atomic sections, determined multiplying this known molecular cross-checked taking relative atom. Complete agreement first Born approximation found only above about 250 ev. Deviations experiment theory at lower energies predicted qualitatively theory.