PNNL

Abstract

The authors constructed a prototype Time-Encoded Signature (TES) system, complete with automated detection algorithms, useful for the detection of point-like, gamma-ray sources in search applications where detectors observe large variability in background count rates beyond statistical (Poisson) noise. The person-carried TES instrument consists of two Cesium Iodide scintillators placed on opposite sides of a Tungsten shield. This geometry mitigates systematic background variation, and induces a unique signature upon encountering point-like sources. This manuscript focuses on the development of detection algorithms that both identify point-source signatures and are computationally simple. The latter constraint derives from the instrument’s mobile (and thus low power) operation. The authors evaluated algorithms on both simulated and field data. The results of this analysis demonstrate the ability to detect sources at a wide range of source-detector distances using computationally simple algorithms.