Coincidence Prompt Gamma-Ray Neutron Activation Analysis (open access)

Coincidence Prompt Gamma-Ray Neutron Activation Analysis

The normal prompt gamma-ray neutron activation analysis for either bulk or small beam samples inherently has a small signal-to-noise (S/N) ratio due primarily to the neutron source being present while the sample signal is being obtained. Coincidence counting offers the possibility of greatly reducing or eliminating the noise generated by the neutron source. The present report presents our results to date on implementing the coincidence counting PGNAA approach. We conclude that coincidence PGNAA yields: (1) a larger signal-to-noise (S/N) ratio, (2) more information (and therefore better accuracy) from essentially the same experiment when sophisticated coincidence electronics are used that can yield singles and coincidences simultaneously, and (3) a reduced (one or two orders of magnitude) signal from essentially the same experiment. In future work we will concentrate on: (1) modifying the existing CEARPGS Monte Carlo code to incorporate coincidence counting, (2) obtaining coincidence schemes for 18 or 20 of the common elements in coal and cement, and (3) optimizing the design of a PGNAA coincidence system for the bulk analysis of coal.
Date: November 10, 2002
Creator: Gardner, R. P.; Mayo, C. W.; Metwally, W. A.; Zhang, W.; Guo, W. & Shehata, A.
System: The UNT Digital Library
Expedited Removal Authority for VA Senior Executives (38 U.S.C. § 713): Selected Legal Issues (open access)

Expedited Removal Authority for VA Senior Executives (38 U.S.C. § 713): Selected Legal Issues

This report discusses selected legal issues relating to the authority for summary removal of individuals in senior executive positions at the Department of Veterans Affairs.
Date: November 10, 2015
Creator: Nicola, Thomas J.
System: The UNT Digital Library
FY2003 LDRD Final Annual Report Article: Pathogen Pathway Project (open access)

FY2003 LDRD Final Annual Report Article: Pathogen Pathway Project

Understanding virulence mechanisms of bacterial pathogens is vital to anticipating biological threats and to improving detectors, vaccines, and treatments. This project will characterize factors responsible for virulence of Yersinia pestis, the causative agent of plague and a biothreat agent, which has an inducible Type III secretion virulence mechanism also found in other animal, plant, and human pathogens. Our approach relies on genomic and proteomic characterization of Y. pestis in addition to a bioinformatic infrastructure. Scientific and technical capabilities developed in this project can be applied to other microbes of interest. This work will establish a significant new direction for biodefense at LLNL and expand our national and international scientific collaborations.
Date: November 10, 2003
Creator: Fitch, J P & McCutchen-Maloney, S L
System: The UNT Digital Library
System design description PFP thermal stabilization (open access)

System design description PFP thermal stabilization

The purpose of this document is to provide a system design description and design basis for the Plutonium Finishing P1ant (PFP) Thermal Stabilization project. The sources of material for this project are residues scraped from glovebox floors and materials already stored in vault storage that need further stabilizing to meet the 3013 storage requirements. Stabilizing this material will promote long term storage and reduced worker exposure. This document addresses: function design, equipment, and safety requirements for thermal stabilization of plutonium residues and oxides.
Date: November 10, 1998
Creator: RISENMAY, H.R.
System: The UNT Digital Library