An X-ray detector system for macromolecular crystallography based on a large area charge-coupled device (CCD)
sensor has been developed as part of a large research and development programme for advanced X-ray sensor
technology, funded by industry and the Particle Physics and Astronomy Research Council (PPARC) in the UK. The
prototype detector consists of two large area three-sides buttable charge-coupled devices (CCD 46-62 EEV), where
the single CCD area is 55.3mm41.5 mm. Overall detector imaging area is easily extendable to 85mm110 mm. The
detector consists of an optically coupled X-ray sensitive phosphor, skewed fibre-optic studs and CCDs. The
crystallographic measurement requirements at synchrotron sources are met through a high spatial resolution
(20481536 pixel array), high dynamic range (B105), a fast readout (B1 s), low noise (o10e) and much reduced
parallax error. Additionally, the prototype detector system has been optimised by increasingits efficiency at low X-ray
energies for use at conventional lab sources. The system design of the prototype detector is discussed and the proposed
method for crystallographic data processing is briefly outlined