Real time pulse pile-up recovery in a high throughput digital pulse processor

Detection and measurement of radiation is used extensively for non-invasive material characterization in a range of industries. However, many practical applications are frustrated by pulse pile-up within the detector. Pulse pile-up, which occurs when multiple radiation events arrive within the temporal resolving time of the detector, degrades the fidelity of subsequent material analysis. Traditional pulse processing techniques use fast digital filters and logic circuits to detect piled-up events and discard the corrupted data, however, this leads to substantial detector dead time. Consequently, there is considerable interest in more complex signal-processing algorithms to extend the performance of pulse processors and improve material characterization techniques. We present a technology for real-time decoding of pulse pile-up events. It is a model-based signal-processing algorithm able to accurately characterize the number, time-of-arrival and energy of all events in the detector output. Even in the presence of severe multi-pulse pile-up, the composite events are decoded and the energy and time-of-arrival recovered. The technology has been evaluated using a range of detectors, sources and count rates. An exceptional improvement over traditional pulse processing techniques is demonstrated. © 2011 American Institute of Physics.