Publications

Aug, 2026

Journal

Full spectrum modeling of in situ gamma-ray detector measurements with a focus on precipitation-induced transients

Gamma-ray detectors that are deployed outdoors experience increased event rates during precipitation due to the attendant increase in Rn-222 progeny at ground level. The increased radiation due to these decay products (Pb-214 and Bi-214) has been studied for many decades in applications such as atmospheric science and radiation protection. For those applications radon prog…

Jan, 2026

ORNL Report

SAS4D Final Report

Jan, 2026

ORNL Report

PROACTIVE Focus Area 4: Structured Decision Metrics Analysis Final Report

Jan, 2026

Journal

Interpolation of computed gamma-ray detector response functions

Gamma-ray spectra measured by traditional detectors contain features that result from a combination of the effects of detector materials/geometry, the incident gamma-ray energy, and the angle of entry. The features, such as the full-energy photopeak, Compton continuum, annihilation peak, and escape peaks, are governed by simple relationships depending on incident energy an…

Dec, 2025

ORNL Report

PROACTIVE Capability Systems Overview Storyboard: Phase 1

May, 2025

ORNL Report

PROACTIVE FA4: Progress Update 2024

Sep, 2024

Journal

Tracking the location of a road-constrained radioactive source with a network of detectors

Data collected from a network of detectors and analyzed together has the opportunity to provide a more complete picture than when the data from each individual detector are analyzed independently. However, even with a dense array of detectors, the network data will not provide a complete picture and constraints will need to be added to the model in order to maximize the us…

May, 2024

ORNL Report

Threat Sources for Creating Synthetic Urban Search Data

Equivalent point source energy emission distributions were computed for various threat sources for use in simulating the detector responses for urban search scenarios. The sources include standard isotopic sources used in detector testing, medical and industrial sources occasionally encountered in urban searches, and several types of special nuclear materials. Most of the…

Dec, 2023

Conference Paper

Understanding and quantifying the systematic effects of clutter within a radiation detection scene

Because of low signal-to-noise ratios, the main difficultly in real-world detection scenarios is distinguishing between benign sources and potentially-threatening radioactive materials. The variability in observed signal during a radiation detection search operation can be contributed to the stochastic nature of the underlying physics and the systematic errors inherent to…

Dec, 2023

ORNL Report

Modeling Urban Scenarios & Experiments: Fort Indiantown Gap Data Collections Summary and Analysis

Dec, 2023

ORNL Report

Drone-assisted measurements for improved dispersion modeling FY18 Status Update

Dispersion analysis modeling from stack releases has historically relied heavily on either simplified assumptions that were developed from correlating historical smoke stack experiments, or from complex wind field modeling programs. The advent of drone assisted measurement technology and small portable sensors offers a tremendous opportunity to quantify and scale the asses…

Dec, 2023

ORNL Report

Modeling Urban Scenarios & Experiments (MUSE) Final Report

ABSTRACT Detection of radiological/nuclear threats in urban areas is difficult due to the relatively short range of radiation compared to the size of the search area and the ever-present background radiation. Detectors and detection algorithms are typically designed, evaluated and optimized using experimental determinations, usually in semi-controlled areas where backgroun…