Large surface X-ray pixel detector

A large surface semiconductor photon counting pixel detector is being built. As a first step, this detector is optimized for X-ray crystallography. The aim is to provide a high dynamic range (> [10.sup.9]), high counting rate ([10.sup.7] ph/s per pixel), and fast image readout (3 ms). A full custom chip has been produced and tested, and results are presented. Prototypes of 6 [cm.sup.2] containing pixels of 330 x 330 [micro][m.sup.2] have been built together with a full fast readout system. These prototypes have been tested in the D2am beam line at the ESRF synchrotron (Grenoble, France) for photon energies between 10 and 24 KeV. For photon energies above 10 keV, the signal is separable from the noise. We give results on the efficiency as a0 function of the photon rate and the effect of the threshold on the efficiency in the region between the pixels. Furthermore, to demonstrate the large dynamic range, we made diffraction images. Index Terms--Crystallography, detector, instrumentation, pixels, X-rays.