Molecular effects in carbon K-shell Auger-electron production by 0.6-2.0 MeV protons and extraction of an atomic cross section

Carbon K-shell Auger-electron production cross sections are reported for 0.6-2.0 MeV protons incident on CH4 (methane), C2H2 (acetylene), C2H4 (ethylene), C2H6 (ethane), n-C4H10 (normal butane), i-C4H10 (isobutane), C6H6 (benzene), CO (carbon monoxide), and CO2 (carbon dioxide). A constant-energy mode 450 parallel-plate electrostatic analyzer was used for detection of Auger electrons. The carbon KLL Auger-electron cross sections for all molecules were found to be lower than that found for CH4 by 9-23%. All carbon KLL Auger-electron data could be brought into agreement when corrected for the chemical shift of the carbon K-shell binding energy in molecules and for intramolecular scattering. KLL Auger-electron production cross sections are compared to first Born and ECPSSR theories and show good agreement with both after the chemical shift of the carbon K-shell binding energy in molecules and the effects of intramolecular scattering are considered. (orig.)