부산대학교 도서관

Resonant Auger (RA) decay spectra of carbon 1s excited CH3Cl molecules are recorded with angular resolution using linearly polarized synchrotron radiation. The selected photon energies corresponding to the C 1s→8a1 core to lowest unoccupied molecular orbital and C 1s→4sa1, 4pe, and 4pa1 core to Rydberg excitations of methyl chloride are used and electrons in the binding energy range of 11-37 eV are detected. The vibrationally unresolved RA electron angular distributions, recorded for participator Auger transitions populating the X, A, B, and C states of the CH3Cl+ ion, exhibit strong variations across the selected electronic resonances. These observations are interpreted with the help of ab initio electronic structure and dynamics calculations, which account for electronic-state interference between the direct and different resonant ionization pathways. For spectator transitions, the theory predicts almost isotropic angular distributions with moderate changes of β parameters around zero, which is in agreement with the experimental observations.