Molecular effects in K-shell ionization by charged particles

摘要

Measurements of atomic inner-shell ionization cross sections for low-Z elements are complicated by small fluoresence yeidls and becasue elements to dnot occur naturally in atomic form. These conditions favor the measurement of Auger-electron yeidls to determine vacancy formation and they require the use of molecular gas ltagets. Becuase molecular structure has little influence of the energy levels of inner shells it is expected to have little effect on K-shell ionization probabilities. On the other hand, Auger-eletron transitions involve molecular orbitals which introduce molecular effects in the spectra and could potentially influence yields. Variations in measured atomic K-shell ionization cross sections for different molecular targest have generally been found to be small (10-15