A novel measurement approach for near-edge x-ray absorption fine structure: Continuous 2 π angular rotation of linear polarization

A new technical method is developed for soft X-ray spectroscopy of near-edge x-ray absorption fine structure (NEXAFS). The measurement is performed with continuously rotating linearly polarized light over 2$\pi$, generated by a segmented undulator. A demonstration of the rotational NEXAFS experiment was successfully made with a 2D film, showing detailed polarization-dependence in intensity of the molecular orbitals. The present approach provides varieties of technical opportunities that are compatible with the state-of-the-art experiments in nano-space and under the $operando$ condition.