Active reset of digitized preamplifiers for ionizing-radiation sensors

In this paper, we propose a new add-on circuit structure that swiftly desaturates a digitized charge preamplifier for ionizing-radiation detectors when an energetic event occurs, or when a burst of piled up events puts it into saturation. The amplitude of the energetic event can even be reconstructed with a time-over-threshold (TOT) measurement of the fast-reset transient. With an analog-to-digital converter (ADC) range of 10 MeV, we were able to measure events of up to 100 MeV. The circuit is conceived for experiments where a spurious background of energetic particles and photons exists, such those with exotic beams in the new generation of nuclear-physics research facilities.