Micro-focusing System of the Taiwan Contract Beamline BL12XU at SPring-8 for IXS Experiments under High Pressure

The Taiwan Contract Beamline BL12XU at SPring-8 is designed for inelastic X-ray scattering (IXS) experiments. DCS is a powerful technique capable of probing the dynamic behavior and electronic structure of materials under high pressure. The state-of-the-arts technology to generate static high pressure up to mega-bar range uses diamond anvil cells (DAC). The allowed volume of the sample in DAC scales inversely with the pressure and is limited to the order of 1 x 10-3 mm3. In order to utilize such a device to explore the interesting phenomena under high pressure, we have designed a micro-focusing system using a set of KB mirrors, which is compatible with the existing optical system of BL12XU. Realistic ray-tracing results indicate that the system can achieve a focus of 10 μm x 5.3 μm(H x V) with a total efficiency of about 86%. The improved focus is expected to substantially enhance the experimental capability of BL12XU for high-pressure research