A 430-μW Pulse Shape Discrimination System-on-Chip

• Published in: IEEE transactions on nuclear science 2024-07, Vol.71 (7), p.1409-1419
• Main Authors: Schmitz, Joseph A., Murray, Samuel J., Hoffman, Michael W., Balkir, Sina
• Format: Article
• Language: English
• Subjects: Delays; Detectors; Electric charge; Figure of merit; Gamma-ray spectroscopy; Metal oxides; multichannel analyzer (MCA); neutron detector; Neutrons; Performance measurement; Power consumption; Power management; Pulse amplitude; Pulse shape; pulse shape discrimination (PSD); Radiation; Radiation detectors; Semiconductor device measurement; Semiconductors; Shape; System on chip; system-on-chip (SoC); Topology
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2024.3382542

This article presents a single-chip, low-power electronic pulse processing solution that is capable of performing pulse shape discrimination (PSD) when paired with a \mathrm {Cs_{2}LiYCl_{6}{:}Ce} radiation detector. It integrates all analog and digital processing required for PSD, forming a complete system-on-chip (SoC) for this application. It uses an event-based analog front end (AFE) to substantially reduce power consumption compared with nonintegrated, continuous-sampling-based processing electronics, consuming only 430~\mu W when detecting radiation at 1 kcps, which is substantially less than the existing works. As a trade-off, the PSD figure-of-merit (FOM) is lower than that of higher powered systems. This makes it suitable for neutron and gamma detection applications where battery life and portability are key performance metrics. The presented chip contains analog channels capable of performing simultaneous PSD and pulse height analysis (PHA) for each detection, measuring the particle's energy and classifying it as a neutron or gamma locally on the SoC. The chip was fabricated on a 0.13- \mu m complementary metal-oxide-semiconductor (CMOS) technology, characterized using an AmBe source, and demonstrated a PSD FOM of 1.36.