Multi-functional research and development beamline at the Photon Factory: Application to two-beam experiments

We report the development and initial applications of the multi-functional research and development beamlines BL-11A and BL-11B at the Photon Factory, which are designed to enable simultaneous use of hard and soft x-rays. The two beamlines share a common bending-magnet source and deliver independently monochromatized hard- and soft-x-ray beams that can be focused onto the same sample position in a downstream experimental hutch, providing a versatile platform for two-beam experiments in which hard and soft x-rays can serve as pump and/or probe beams in various combinations. As proof-of-concept demonstrations, we performed probe-probe measurements of water electrolysis on a cobalt electrocatalyst and pump-probe measurements of x-ray-induced dissociation of a caged compound. In the probe-probe scheme, hard- and soft-x-ray absorption spectroscopy was carried out simultaneously to track correlated changes in the catalyst oxidation state and oxygen-related intermediates during the oxygen evolution reaction. In the pump-probe scheme, chemical changes in 2-iodosobenzoic acid induced by hard-x-ray excitation at the iodine L3 edge were monitored using soft-x-ray absorption spectroscopy at the oxygen K edge.