U7C beamline and XAFS station of National Synchrotron Radiation Laboratory

The XAFS station on beamline U7C of National Synchrotron Radiation Laboratory (NSRL) was completely constructed in December 1998. The source for XAFS station is from a 3-pole superconducting wiggler with magnetic field of 6 T inserted in the straight section of the storage ring. Using a Si(111) double crystal monochromator with a fixed slit, the X-ray intensity at the sample position is about 3 × 10⁹ photons/second at the energy of 8980 eV of Cu K-edge. The Keithley 6517 electrometers are used to record the electron charges that are produced in the ionization chambers. A high ratio of signal to noise has been obtained for the XAFS spectra of Cu, Ni and Fe foils. Furthermore, the XAFS spectrum of Cu foil in NSRL is in good agreement with that obtained in BSRF and KEK.