Improvements on the quasifree absorption model for electron scattering

The quasifree nonempirical model proposed by Staszewka et al. in 1983 for the imaginary part of the electron scattering optical potential is revised, in order to improve its foundations, accuracy, and range of applicability. The importance of relativistic and many-body effects for heavy atoms is shown and some corrections proposed. A criterion for selecting the Δ parameter is discussed. The model is also shown to admit considerable simplifications without loss of accuracy. Calculated elastic (differential and integral) and inelastic cross sections for He to Xe noble gases and also for N₂, CO, and CO₂ molecules are compared to experimental values.