Rotation data collection for protein crytallography with time-variable incident intensity from synchrotron radiation sources

Time-variable incident intensity from synchrotron radiation sources may cause scaling errors in crystallographic data collection using integrative techniques as in rotation methods. This problem is avoided with a new technique which has been developed for computer-controlled film data collection with an Arndt-Wonacott camera. Effects of intensity fluctuations are automatically compensated by hardware on the basis of incident-beam monitoring with a small ionization chamber placed between collimator and crystal. (Auth.)