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Brennan, James S.

Publications and source records attributed to Brennan, James S..

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Apparatus and methods for sample analysis with multi-gradient microfluidics

A device for analyzing biological samples comprises first, second, third, and fourth layers. The first layer comprises a sample chamber in which a sample is positioned. The second layer comprises first, second, and third channels. A third, porous layer is positioned between the first layer and the second layer. A fourth layer composed of a substantially liquid-impermeable material is positioned between the second layer and the third layer. The fourth layer includes first and second pass-through channels that are aligned with the first and second channel, respectively. Fluids that flow in the first and second channels pass through the pass-through channels and diffuse into the sample chamber, establishing a chemical concentration gradient therein. A gas in the sample chamber can diffuse through the third and fourth layers and interact with a fluid flowing in the third channel, establishing a gas concentration gradient in the sample chamber.

Kim, Peter Wonhee↗
DOE OSTI2017

Magnetic Induction Sensors for Detecting Anomalous Shielding of Radiological and Nuclear Materials: A Feasibility Study

This study examined a concept for improving the nation's ability to detect unauthorized transport of radiological and nuclear material that involves detecting not the radiological or nuclear material itself, but rather the anomalous presence of materials, such as lead and tungsten, typically used to shield such illicit materials from detection. Specifically, the project studied a potentially inexpensive, non-intrusive, and fast method of detecting anomalous shielding: use of magnetic induction sensors to measure currents induced in conductors by a driver coil. The first phase of this work, documented in this report, identified the signatures of materials of interest, assessed the usefulness of measured signatures for discrimination between materials, and then benchmarked models and calculations. The next task involved assessing the strength of these signatures when the materials of interest were enclosed within other materials, such as aluminum and steel, of various thicknesses. A final task mimicked a real-world scenario by testing the ability to detect material signatures of interest at a scale of a vehicle or cargo vessel against a cluttered backdrop, with and without the shielding of another material, such as aluminum or steel. This final task raised doubts regarding whether this detection scheme will be useful under real-world conditions.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

System Construction of the Stilbene Compact Neutron Scatter Camera

This report documents the construction of a stilbene-crystal-based compact neutron scatter camera. This system is essentially identical to the MINER (Mobile Imager of Neutrons for Emergency Responders) system previously built and deployed under DNN R&D funding,1 but with the liquid scintillator in the detection cells replaced by stilbene crystals. The availability of these two systems for side-by-side performance comparisons will enable us to unambiguously identify the performance enhancements provided by the stilbene crystals, which have only recently become commercially available in the large size required (3” diameter, 3” deep).

36 MATERIALS SCIENCE↗
DOE OSTI2016

A compact neutron scatter camera for field deployment

Here, we describe a very compact (0.9 m high, 0.4 m diameter, 40 kg) battery operable neutron scatter camera designed for field deployment. Unlike most other systems, the configuration of the sixteen liquid-scintillator detection cells are arranged to provide omnidirectional (4π) imaging with sensitivity comparable to a conventional two-plane system. Although designed primarily to operate as a neutron scatter camera for localizing energetic neutron sources, it also functions as a Compton camera for localizing gamma sources. In addition to describing the radionuclide source localization capabilities of this system, we demonstrate how it provides neutron spectra that can distinguish plutonium metal from plutonium oxide sources, in addition to the easier task of distinguishing AmBe from fission sources.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2014

A High-Sensitivity Fast Neutron Imager

A wide range of NSC (Neutron Scatter Camera) activities were conducted under this lifecycle plan. This document outlines the highlights of those activities, broadly characterized as system improvements, laboratory measurements, and deployments, and presents sample results in these areas. Additional information can be found in the documents that reside in WebPMIS.

47 OTHER INSTRUMENTATION↗
DOE OSTI2014

MINER - A Mobile Imager of Neutrons for Emergency Responders

We have developed a mobile fast neutron imaging platform to enhance the capabilities of emergency responders in the localization and characterization of special nuclear material. This mobile imager of neutrons for emergency responders (MINER) is based on the Neutron Scatter Camera, a large segmented imaging system that was optimized for large-area search applications. Due to the reduced size and power requirements of a man-portable system, MINER has been engineered to fit a much smaller form factor, and to be operated from either a battery or AC power. We chose a design that enabled omnidirectional (4π) imaging, with only a ~twofold decrease in sensitivity compared to the much larger neutron scatter cameras. The system was designed to optimize its performance for neutron imaging and spectroscopy, but it does also function as a Compton camera for gamma imaging. This document outlines the project activities, broadly characterized as system development, laboratory measurements, and deployments, and presents sample results in these areas. Additional information can be found in the documents that reside in WebPMIS.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗