K-shell photoionization of atomic anions
Final Report Abstract
Within the present project, considerable progress has been achieved in K-shell detachment of atomic anions. Experimental results have been obtained for multiple detachment of B– , C– , O– , F– and Si– ions at the photon-ion merged-beams setup PIPE which is a permanent end station at beamline P04 of the PETRA III synchrotron-light source in Hamburg. In addition to a much increased photon flux as compared to what was available previously, the PIPE setup has an extraordinary detection sensitivity for heavy charged reaction products that allows one to study detachment processes with extremely low cross sections in the (sbu-)kilobarn range. Examples are processes involving the simultaneous creation of two core-holes by a single photon as observed in the net triple detachment of F– and the net five-fold detachment of C– . Moreover, hitherto disregarded photodetachment resonances have been discovered, which exhibit a variety of line-shapes. The Si– study extends, for the first time, our knowledge about K-shell detachment of atomic anions to M-shell ions. All experimental results have stimulated corresponding theoretical investigations which are challenged by the high degree of correlation that is characteristic for the structure and dynamics of atomic anions. These theoretical investigations have elucidated the role of many-electron processes in inner-shell detachment and have arrived at a more realistic description of processes where one photon directly detaches two electrons and of the complex deexcitation cascades that evolve after the initial creation of a K-shell hole.
Publications
- Near-K-edge double and triple detachment of the F– negative ion: observation of direct two-electron ejection by a single photon, Phys. Rev. Lett. 120, 133202 (2018)
A. Müller, A. Borovik Jr., S. Bari, T. Buhr, K. Holste, M. Martins, A. Perry-Saßmannshausen, R. A. Phaneuf, S. Reinwardt, S. Ricz, K. Schubert, and S. Schippers
(See online at https://doi.org/10.1103/PhysRevLett.120.133202) - Multiple photodetachment of atomic anions via single and double core-hole creation, J. Phys. B 53, 192001 (2020)
S. Schippers, A. Perry-Sassmannshausen, T. Buhr, M. Martins, S. Fritzsche, and A. Müller
(See online at https://doi.org/10.1088/1361-6455/aba719) - Multiple photodetachment of carbon anions via single and double core-hole creation, Phys. Rev. Lett. 124, 083203 (2020)
A. Perry-Sassmannshausen, T. Buhr, A. Borovik Jr., M. Martins, S. Reinwardt, S. Ricz, S. O. Stock, F. Trinter, A. Müller, S. Fritzsche, and S. Schippers
(See online at https://doi.org/10.1103/physrevlett.124.083203) - Atomic cascade computations, Symmetry 13, 520 (2021)
S. Fritzsche, P. Palmeri, and S. Schippers
(See online at https://doi.org/10.3390/sym13030520) - Multiple photodetachment of silicon anions via K-shell excitation and ionization, Phys. Rev. A 104, 053107 (2021)
A. Perry-Sassmannshausen, T. Buhr, M. Martins, S. Reinwardt, F. Trinter, A. Müller, S. Fritzsche, and S. Schippers
(See online at https://doi.org/10.1103/PhysRevA.104.053107)
