Development of EM-CCD-based X-ray detector for synchrotron applications

Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online's data policy on reuse of materials please consult the policies page. We have developed and successfully demonstrated a high speed, low noise camera system for crystallography and X-ray imaging applications. By coupling an EM-CCD to a 3:1 fibre optic taper and a CsI(Tl) scintillator it was possible to detect hard X-rays. This novel approach to hard X-ray imaging takes advantage of the low equivalent readout noise performance at high pixel readout frequencies of EM-CCD detectors with the increase in imaging area that offered through the use of a fibre-optic taper. Compared to the industry state of the art, based on CCD camera systems, we were able to achieve a high frame-rate for a full-frame readout (50 ms) and a lower readout noise (<1 electron rms) across a range of X-ray energies (6 keV to 18 keV). Introduction: Many X-ray imaging detectors, from medical diagnosis to synchrotron research, use scintillator-coupled CCD detectors. However, CCD systems have performance limitations such as an increase in noise at higher readout speeds. Recently, we completed a lab-based, STFC-funded, concept study on a novel photon-counting detector [1][2]. The Electron-Multiplying (EM) CCD was designed for low light level imaging such as night-time surveillance and differs from the standard CCD through the addition of a "gain register" [3]. By multiplying the signal by thousands, the effective read noise of the device can be dramatically reduced, allowing operation at very high speeds with sub-electron read noise, offering high resolution centroiding and energy discrimination [4][5]. As part of an STFC-funded IPS grant in collaboration with e2v technologies, we have developed a high-speed (24 fps full-frame), large area X-ray detector module, using high-speed electronics provided by XCAM ltd [6]. This project aims to transfer this technology and expertise to applications in synchrotron research through the use of a proof-of-concept camera module. The main applications for this camera in synchrotron research are powder diffraction, macromolecular crystallography and larger area X-ray imaging. By coupling a fibre-optic taper to a larger EM-CCD, an increase in the area of the detector is possible over previous studies, with arrays possible for increased area [7]. In comparison to previous CCD-based systems, the expected performance of the module will give a faster readout speed (increasing beamline throughput), higher effective dynamic range …