X-ray polarization measurement of the Beamline 4B7 of Beijing synchrotron radiation facility using a PET crystal

An experimental method has been developed to measure the X-ray polarization of the Beamline 4B7 on Beijing Synchrotron Radiation Facility in the X-ray energy range 2100–5600 eV by using a PET crystal diagnostic system and rotating the system around the incident X-ray beam by 90°. The experimental results show that the measured X-ray polarization is more than 0.88 in the photon energy range 2100–3600 eV with maximum of 0.99 at 2707.3 eV, and quickly decreases to about 0.38 at 4719.2 eV with photon energy increasing from 3600 to 4719.2 eV, then it keeps almost constant as the photon energy increases further to 5600 eV.