A readout system for X-ray powder crystallography

A system for capturing and processing data, from radiation detectors, in th e field of X-ray crystallography has been developed. The system includes a custom-made mixed analog-digital 16-channel VLSI circuit in 50 mu m pitch. Each channel comprises a charge amplifier, a shaper, a comparator and a 21- bit counter. The circuit can be scaled in a daisy chain configuration. Data acquisition is performed with a custom made PCT card while the control sof tware is developed with Visual C + + under the MS Windows NT environment. P erformance of a fully operational system, in terms of electronic noise. sta tistical variations and data capture speed is presented. The noise level pe rmits counting of X-rays down to 8 keV while the counting capability is in excess of 200 kHz. The system is intended for X-ray crystallography with si licon detectors. (C) 2000 Elsevier Science B.V. All rights reserved.