Japan's PF Launches Quantum Multi-Beam Experiments, Achieving Simultaneous Hard and Soft X-ray Measurements

The Photon Factory, a synchrotron radiation facility at the Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK) in Japan, has recently launched collaborative experiments on the development and research multi-purpose beamlines BL-11A and BL-11B, achieving simultaneous irradiation of the same sample with hard and soft X-rays at the same position. The research results will be published in the international academic journal *Review of Scientific Instruments*.

The Photon Factory uses electrons moving at near-light speed to generate high-brightness X-rays, known as synchrotron radiation, for studying material structures and properties. Among these, hard X-rays are better suited for observing the internal structure of materials, while soft X-rays are ideal for analyzing material surfaces and electronic states. Previously, at synchrotron radiation facilities, the two types of X-rays typically had to be used separately, making it difficult to conduct combined measurements on a sample at the same time and position.

The newly constructed BL-11A and BL-11B beamlines can extract hard and soft X-rays separately from the same light source and enable simultaneous dual-beam utilization at the experimental station. This technology makes "probe-probe measurements" and "pump-probe measurements" possible: the former allows simultaneous observation of different information from a sample using two types of X-rays, while the latter enables one type of X-ray to induce changes in the sample, with the other type tracking the change process.

In the first dual-beam experiments, the research team conducted in-situ observations of the electrolysis reaction of water, capturing changes in the catalyst state during repeated reactions and verifying the importance of simultaneous detection for studying dynamic reactions. The team also targeted a special organic molecular cage compound, using hard X-rays to induce its decomposition reaction and soft X-rays to track the reaction progress, demonstrating the effectiveness of the pump-probe measurement method.

The research team stated that BL-11A and BL-11B will serve as test platforms for dual-beam X-ray utilization research at synchrotron radiation facilities, promoting the validation and advancement of quantum multi-beam utilization technology. In the future, this method is expected to be applied to research fields such as catalytic reactions, battery materials, and the effects of radiation on materials and biomolecules.