Abstract
Experimental cross sections for $m$-fold photodetachment ($m=3-6$) of silicon anions via $K$-shell excitation and ionization were measured in the photon-energy range of 1830-1900 eV using the photon-ion merged-beams technique at a synchrotron light source. All cross sections exhibit a threshold behavior that is masked by pre-threshold resonances associated with the excitation of a $1s$ electron to higher, either partly occupied or unoccupied atomic subshells. Results from multi-configuration Dirac-Fock (MCDF) calculations agree with the experimentally derived cross sections for photo-absorption if small energy shifts are applied to the calculated resonance positions and detachment thresholds. Moreover, a systematic approach is applied for modeling the deexcitation cascades that set in after the initial creation of a $K$-shell hole. The resulting product charge-state distributions compare well with the measured ones for direct $K$-shell detachment but less well for resonant $K$-shell excitation. The present results are potentially useful for identifying silicon anions in cold plasmas such as interstellar gas clouds.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.