Synchrotron Tests of a 3D Medipix2 X-Ray Detector

Three-dimensional (3D) photodiode detectors offer advantages over standard planar photodiodes in a range of applications, including X-ray detection for synchrotrons and medical imaging. The principal advantage of these sensors for X-ray imaging is their low charge sharing between adjacent pixels, which could improve spatial and spectral resolution. A ´double-sided´ 3D detector has been bonded to a Medipix2 single-photon-counting readout chip, and tested in a monochromatic X-ray beam at the Diamond synchrotron. Tests of the 3D detector´s response spectrum and its Line Spread Function have shown that it has substantially lower charge sharing than a standard planar Medipix2 sensor. Additionally, the 3D detector was used to image diffraction rings produced by a powdered silicon sample, demonstrating the detector´s use in a standard synchrotron experiment.