The aim of this joint sub-micron soft x-ray spectroscopy beamline of the NSRRC and the MPI CPfS is (1) to utilize a wide range of synchrotron based spectroscopies to unravel the electronic structure of novel strongly correlated materials, and (2) to develop new synchrotron based spectroscopic methods suitable for the study of strongly correlated materials. In particular, we expect to obtain single-crystalline quality data from even powder samples by searching for grains which have dimensions larger than several μm. This in turn will give us worldwide a major advantage in the study and characterization of new materials.

The TPS 45A beamline uses an elliptically polarized undulator with a 46 mm magnet period that delivers photons over the energies of 280 - 1500 eV with linear (horizontal and vertical) and circular (left and right) polarizations. Its optical design adopts the concepts of the Dragon-type design with an advanced innovation of using a bendable vertical focusing mirror (VFM) and an active grating monochromator (AGM) that utilize the novel 25-actuator optical surface benders. This 25-actuator optical surface bender not only provides a higher-degree polynomial profile for eliminating the optical aberration, but also reduces the intrinsic slope error and the thermal deformation on the optical surface. This ensures a high photon throughput of the order of 2 x 10¹¹ photons/sec/0.01%BW and an ultra-high energy resolving power of the order of 25,000. Together with a set of Kirkpatrick-Baez mirror, i.e. vertical refocusing mirror (VRFM) and horizontal refocusing mirror (HRFM), the beam spot size at the sample position is in the order of 1 μm x 1 μm.