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The improved performance of third-generation light sources and the advent of next-generation synchrotron radiation facilities require the use of extremely precise monitoring of the main photon-beam parameters, such as position, absolute and relative intensity, and temporal structure. These parameters, and associated real-time feedbacks, are fundamental at the beamline control level and at the machine control level, to improve the stability of the photon beams and to provide bunch-to-bunch quantitative information. Fast response time, high radiation hardness and visible–blind response are main features of photon-beam monitors for VUV and X-ray synchrotron radiation beamlines; hence diamond-based detectors are outstanding candidates. Here, results are presented of an extensive measurement campaign aiming at optimizing the capabilities of diamond detectors to discern time structures below the 100 ps timescale. A custom-built device has been fabricated and tested at the Italian Synchrotron Radiation Laboratory Elettra in Trieste. The results obtained show that diamond is an excellent material for ultra-fast photon pulses with picosecond time resolution; finally the possibilities for application at free-electron laser sources are discussed.

In K-Edge Subtraction (KES) imaging the K-edge of a high-Z contrast medium is used to generate a differential image in which, in principle, only the contrast agent is visible, suppressing any background. A possible approach to KES imaging is by using polychromatic spectra and spectral X-ray photon counting detectors (XPCD). In this paper we present the development and validation of a simulation tool for KES imaging with spectral XPCD. In addition an analytical formula, based on theoretical considerations, is derived, that further supports the simulation results. The validation is made on experimental data obtained with an X-ray tube, an iodine-based contrast agent, and Pixirad-1/Pixie-III detection system.