Reflectivity calibration of soft X-ray multilayer mirror in Beijing Synchrotron Radiation Facility

Beijing Synchrotron Radiation Facility(BSRF)-3W1B beam line was used to calibrate the reffectivint of some multilayer mirrors. The wavelength-scanning method is adopted to get the multilayer mirrors' reflectirity-energy curves. The reflectivity calibration curves of 21°-B4C/Si, 21°-B4C/Mo, 10°-Cr/Ti, 15°- B4C/W, 10°- B4C/W and 6.86°-B4C/W multilayer mirrors are given in the region of 50~1 500 eV. The values of experiment and calculation are compared and analyzed. The calibration curves agree well with the theoretical ones, and the uncertainty of calibration is mainly caused by photon energy uncertainty and calibrating angle uncertainty.