The Design and Experimental Characterization of the SMART CCD-based Area X-ray Detectors. R.D. Durst, J.L. Chambers, Siemens Analytical X-ray Systems, Inc., 6300 Enterprise Lane, Madison, WI 53719, E.M. Westbrook, Structural Biology Center, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439

CCD-based area x-ray detectors offer a unique combination of high sensitivity, high count rate capability, fast frame read-out and ease of use which have led to their acceptance as the technology of choice for small molecule crystallography and also to increasing use in macromolecular crystallography. The characteristics of the ideal detector for x-ray crystallography and the real characteristics of CCD-based detectors, photon counting detectors and image plates are compared. The intrinsic limitations and trade offs in the design of CCD-based detectors in general and the SMART family of detectors (SMART 1K, SMART 2K, SMART 2x2 Mosaic) in particular are discussed and contrasted to the designs of other extant CCD-based detectors. Experimental measurements of the gain, dynamic range, noise, Detective Quantum Efficiency and spatial resolution are presented for each of the SMART detectors and it is shown that these detectors closely approximate their theoretically expected, ideal behavior.