Data Quality Comparison Between the PILATUS-6MF and ADSC Q315

Users have been collecting data on the PILATUS-6MF during the latter half of February.  Systematic comparisons and anecdotal evidence show a marked improvement over the ADSC Q315, especially at higher resolution and/or weak diffraction.   At higher resolution where weak diffraction spots were lost due to background noise on the ADSC Q315, the almost noise-less PILATUS-6MF allows recovery of these diffraction spots.  Weak diffraction spot recovery can occur in flux-limited or anisotropic crystals.  It will also be possible to use less incident dose to obtain reasonable data.

Fig. 1 A) Diffraction image of thaumatin taken using Q315. B) Diffraction image of thaumatin taken using PILATUS.  Both images are of the same crystal, at the orientation, and exposed to x-rays under similar conditions.

Survey Tracker

Due to the speed at which images are collected by the PILATUS-6MF, it is no longer possible to see each image as it comes off the detector.  To compensate, a survey tracker has been implemented in the control software of both beamlines.  The survey tracker takes a snapshot of every looped crystal and stores a bitmap of the image with the diffraction images.  A table allows the user to select a filename and see both crystal snapshot and diffraction image on the screen.  The table will also display RAPD-calculated statistics about chosen image.  Finally, the entire table can be exported as a space-delimited file and saved for future reference or converted to an Excel spreadsheet.