UFERI - Ultra-Fast Energy Resolved Imager for next generation synchrotron experiments

Abstract

A new single photon-counting ASIC prototype called UFERI (Ultra-Fast Energy Resolved Imager) with a matrix of 42×42 pixels of 75 μm pitch is developed by the Detector Group of the SOLEIL synchrotron and the Microelectronics Group from AGH University of Krakow, in preparation for the upcoming upgrade of the SOLEIL synchrotron to a fourth-generation facility. The detector is dedicated to pseudo-Laue diffraction applications in intense, pink beams at photon energies between 5 to 30 keV. With its three thresholds and very small offset spread from pixel to pixel of about 1.1 mV, UFERI can discriminate three energy levels while its short dead time ensures a high count rate capability of up to 6 Mcounts/s/pix (10% count rate loss). To keep both, a low noise and a high count rate operation, a front-end amplifier’s feedback capacitor discharge technique is implemented on-chip, enabling high-speed chip operation with an Equivalent Noise Charge (ENC) of 86 e-rms. The UFERI chip can operate with detector signals of both polarities (holes and electrons) and consumes 42 μW/pixel. In this publication, we present a description of the ASIC’s architecture as well as characterisation results. The energy calibration, threshold dispersion, gain spread, as well as noise and count rate performance of the UFERI prototype are presented.