Triple differential cross section measurements for resonant double photoionization of Sr

The relative triple differential cross section for double photoionization has been measured at 25.26 and 25.14 eV in the region of the 4p --> 4d resonance in Sr for two different geometries, the first with a one-electron spectrometer aligned along the same direction as the principal E-vector direction of the synchrotron radiation, and the second with it aligned perpendicular to that direction. The results are different from those obtained in the corresponding case of Ca, particularly for the second geometry where there are indications that the resonance contains a substantial component with (3)p(o) symmetry in addition to the P-1(o) symmetry expected.