Spin dependence in core-valence double photoionization of neon

We have studied core-valence double photoionization (DPI) of Ne leading to the 1s-12s-1S1,3 and 1s-12p-1P1,3 states of Ne2+ over a range of photon energy extending up to approximately 200 eV above the thresholds using a multielectron coincidence technique. Each DPI process is distinctly identified in the energy correlation between two photoelectrons. The ratios of singlet-to-triplet cross sections exhibit variation with photon energy, indicating a spin dependence in the DPI dynamics. The state-resolved DPI probabilities have been investigated by an incoherent sum of the knock-out (KO) and shake-off (SO) contributions, revealing a significant disparity in the dynamics of the KO mechanism between the DPI into the P1 and P3 states.