A new set of resonances in the electron scattering spectrum of CO2

Abstract

Using an adapted photoelectron spectrometer a photoionisation source of electrons has been used in a transmission experiment to characterise a new set of resonances in the scattering of electrons by CO2 in the energy range 3.2-14.4 eV. Precise energy calibration is possible over a wide range of electron energies through the use of characteristic peaks in photoelectron spectra of N2 and CO2. A number of the resonances are shown to be Feshbach resonances and are associated with valence states of electronically excited CO2. Resonance lineshapes are accurately reproduced by the Fano theory.