Characterization of a Small-Scale Prototype Detector With Wide Dynamic Range for Time-Resolved High-Energy X-Ray Applications

We present characterization measurements of a fast-framing, wide-dynamic-range x-ray area detector intended for high-energy applications (≥2-keV photons). The MM-PAD-2.1 combines an integrating pixel front-end with a charge-removal mechanism to extend the maximum measurable signal to > 10⁷ 20-keV ph/pixel/frame. The charge-removal mechanism is dead-time-less (i.e., incoming signal continues to be integrated by the front-end while charge removal is taking place) up to an incoming photon rate of > 10⁹ 20-keV ph/pix/s. A $16 \times 16$ pixel prototype was fabricated and characterized using both laboratory and synchrotron x-ray sources, allowing for measurements from single-photon to high-flux conditions. High-flux measurements show linear performance up to ~10¹⁰ ph/s in a spot spanning approximately $2 \times 1.5$ pixels (FWHM). The onset of temporary radiation damage in the detector was observed during these measurements, manifesting as failure of the digital readout from the detector. These effects were seen to reverse after annealing at 30 °C for several hours.