A Virtual Frisch-Grid Geometry-Based CZT Gamma Detector for In-Field Radioisotope Identification

Piotr Maj; Giovanni Pinaroli; Aleksey Bolotnikov; Gabriella A. Carini; Grzegorz W. Deptuch; Dominik S. Gorni; Sven Herrmann; Donald Pinelli; Joseph Pinz; Antonio Verderosa

arXiv · 2507.15177

A Virtual Frisch-Grid Geometry-Based CZT Gamma Detector for In-Field Radioisotope Identification

Piotr Maj·Giovanni Pinaroli·Aleksey Bolotnikov·Gabriella A. Carini·Grzegorz W. Deptuch·Dominik S. Gorni·Sven Herrmann·Donald Pinelli·Joseph Pinz·Antonio Verderosa

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Abstract

We present a Virtual Frisch-Grid geometry-based CZT gamma detector developed for identifying different radioisotopes over an energy range from single keV up to 2 MeV, and useful for efficient characterization of CZT crystals. The detector is built with a 3 x 3 matrix of CZT crystals, each measuring approximately 6 mm x 6 mm x 15 mm. The charge generated within the sensor's active volume is read out via an anode connected directly to the AVG3_Dev integrated circuit. A current signal induced by charge drift is collected on side pads of the crystals, enabling reconstruction of a 3D interaction position. This paper discusses the design, development, and performance of the standalone, mobile detector system, which integrates the AVG3_Dev readout IC developed at Brookhaven National Laboratory, high-speed FPGA-based with per-channel digital signal processing, and embedded system capabilities. The device is compact, battery-powered, and supports wireless data streaming, making it suitable for field operations towards radioisotope identification.

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Piotr Maj, Giovanni Pinaroli, Aleksey Bolotnikov, Gabriella A. Carini, Grzegorz W. Deptuch, Dominik S. Gorni, Sven Herrmann, Donald Pinelli, Joseph Pinz, Antonio Verderosa. 2025-07-21. A Virtual Frisch-Grid Geometry-Based CZT Gamma Detector for In-Field Radioisotope Identification. https://arxiv.org/abs/2507.15177

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