Beamline diagnostics for protein crystallography using synchrotron radiation

Beam diagnostics devices are described for the monitoring of all basic parameters relevant to protein data collection using synchrotron radiation. The parameters include the total power in the white beam, the positions and directions of the incident white and monochromatic beams, and the intensity, wavelength, and polarization in the incident monochromatic beam. Such devices have been installed on a doubly focusing wiggler beamline, BW6, at DORIS. They assure high quality in protein data collection despite fluctuations in the beam, facilitate rapid alignment of the entire beamline, and provide a basis for automatic realignment of the diffraction setup and the x‐ray optics.