Shape and Feshbach resonances in inner-shell photodetachment of negative ions

The photodetachment of small cluster systems is illustrated with the measurement and the calculation of K-shell photodetachment of size-selected B2− and B3− clusters. The experimental absolute photodetachment cross-sections exhibit bound resonances below threshold and two shape resonances above the K-shell threshold. Similar results were obtained for all of the cationic products observed, B+ and B2+ from B2−, as well as B+, B2+ and B3+ from B3−. The overall agreement between measured and calculated photodetachment cross-sections is very good.