Synchronous scanning of undulator gap and monochromator for XAFS measurement in soft X-ray region

Synchronous scanning of the undulator gap and a monochromator was done to obtain smooth profiles of incident x-rays that are suitable for XAFS measurements. By changing the gap from 150 mm (B=0.12 T) to 140 mm (B=0.15 T) with the use of the 3rd to 11th harmonic peaks, soft x-rays with energy from 200 eV to1200 eV were obtained. The smooth profile of the incident x-rays provided high-quality measurement of XANES and EXAFS spectra in the soft x-ray region. Issues that would improve the synchronous scanning system are discussed.