Characterisation of a single photon counting pixel detector

The Large Area Detector is a photon counting detector based on pixel readout ASICs with 64×64 arrays of 150 μm square pixels bump bonded to a 300 μm thick Si detector. It is designed for X-ray diffraction studies and is capable of up to 1 MHz count rate per pixel. A prototype has been tested at the synchrotron radiation source in Daresbury in a 19.5 keV X-ray beam. This paper focuses on the spatial resolution and noise performance. The calculation of modulation transfer functions leads to analytical formulae allowing the determination of the theoretical spatial resolution.