MODULAR CCD-BASED DETECTOR FOR CRYSTALLOGRAPHY AT SYNCHROTRON BEAMLINES. Alexander Stewart, Walter Phillips, Martin Stanton and Daniel O'Mara, Rosenstiel Basic Medical Sciences Research Center Brandeis University Waltham, MA 02254

The detector is assembled from an array of 4 modular units, each unit constructed from a fiberoptic taper (with a 4:1 demagnification factor) with a phosphor x-ray converter deposited on the large end of the taper and a CCD epoxy-bonded to the small end. Each of the 4 modules has an area of 100x100mm square imaged into 1000x1000 pixels. The 2000x2000-pixel detector image is readout in 1.6s at 16 bits and stored on disk. We describe the design of detector hardware, electronics and data-readout method, and calibration and data-collection software. We discuss detector performance in terms of the DQE, point response function, dynamic range, and XDCE, and discuss the advantages and limitations of this and similar CCD-based detectors. Results from data collected at several beamlines with a single module will be presented.