Single, double, and triple Auger processes in C$^{1+}$ for attosecond spectroscopy

Abstract

We predict that attosecond spectroscopy could be used to observe time delay for electron emission {in the C$^{1+}$ ion} from a few step processes {that include electron impact excitation}. The results reveal that the photon energy corresponding to the excitation to the $1s 2s^{2} 2p^{2} \, ^{2}D_{1.5}$ level from the ground one has to be used to study the emission of the electrons produced with the largest probability from a few step processes. Double and triple Auger processes are investigated in the C$^{1+}$ ion as a sequence of single Auger transition with subsequent ionization by the Auger electron. Single- and two-step processes describe the double Auger transition while the triple Auger transition arises from two- and three-step processes. Fairly good agreement with experimental values for cross sections demonstrates that inner shell excitation by photon leads to subsequential emission of the electrons in the double and triple Auger processes.