Dynamic monitoring system with double-wire BPM of the macromolecular crystallography beamline 1W2B at BSRF

The stability of the synchrotron radiation(SR) beam's position is essential to beam flux,and it will also directly affect the quality of the experiment data.It is therefore necessary to monitor the beam position in real-time during the whole experiment.The double-wire type BPM(beam position monitor) is normally used to scan the beam profile and it can also monitor the beam position in a fixed position.But this kind of monitoring demands a special beam distribution because when the beam greatly deviates from the original position,the double-wire BPM might face the threat of damage.By means of the dynamic real-time tracking mode,1W2B macromolecular beamline of BSRF(Beijing Synchrotron Radiation Facility) has solved the problems of the routine monitoring mode,such as beam distribution and the damage of the photosensitive wires,thus providing a basis for the study of beam stability.