DEMONSTRATION OF THE DWPF FLOWSHEET IN THE SRNL SHIELDED CELLS USING ARP PRODUCT SIMULANT AND SB4 TANK 40 SLUDGE SLURRY (open access)

DEMONSTRATION OF THE DWPF FLOWSHEET IN THE SRNL SHIELDED CELLS USING ARP PRODUCT SIMULANT AND SB4 TANK 40 SLUDGE SLURRY

The radioactive startup of two new SRS processing facilities, the Actinide Removal Process (ARP) and the Modular Caustic-Side-Solvent-Extraction Unit (MCU) will add two new waste streams to the Defense Waste Processing Facility (DWPF). The ARP will remove actinides from the 5.6 M salt solution resulting in a sludge-like product that is roughly half monosodium titanate (MST) insoluble solids and half sludge insoluble solids. The ARP product will be added to the Sludge Receipt and Adjustment Tank (SRAT) at boiling and dewatered prior to pulling a SRAT receipt sample. The cesium rich MCU stream will be added to the SRAT at boiling after both formic and nitric acid have been added and the SRAT contents concentrated to the appropriate endpoint. A concern was raised by an external hydrogen review panel that the actinide loaded MST could act as a catalyst for hydrogen generation (Mar 15, 2007 report, Recommendation 9). Hydrogen generation, and it's potential to form a flammable mixture in the off-gas, under SRAT and Slurry Mix Evaporator (SME) processing conditions has been a concern since the discovery that noble metals catalyze the decomposition of formic acid. Radiolysis of water also generates hydrogen, but the radiolysis rate is orders of magnitude …
Date: May 14, 2008
Creator: Lambert, D; John Pareizs, J; Bradley Pickenheim, B; Cj Bannochie, C; Michael Stone, M; Damon Click, D et al.
Object Type: Report
System: The UNT Digital Library
DESIGN OF THE DEMOSNTRATION BULK VITRIFICATION SYSTEM FOR THE SUPPLEMENTAL TREATMENT OF LOW ACTIVITY TANK WASTE AT HANFORD (open access)

DESIGN OF THE DEMOSNTRATION BULK VITRIFICATION SYSTEM FOR THE SUPPLEMENTAL TREATMENT OF LOW ACTIVITY TANK WASTE AT HANFORD

In June 2004, the Demonstration Bulk Vitrification System (DBVS) was initiated with the intent to design, construct, and operate a full-scale bulk vitrification pilot-plant to treat low-activity tank waste from Hanford Tank 241-S-109. The DBVS facility uses In-Container Vitrification{trademark} (ICV{trademark}) at the core of the treatment process. The basic process steps combine liquid low-activity waste (LAW) and glassformers; dry the mixture; and then vitrify the mixture in a batch feed-while-melt process in a refractory lined steel container. Off-gases are processed through a state-of-the-art air pollution control system including sintered-metal filtration, thermal oxidation, acid gas scrubbing, and high-efficiency particulate air (HEPA) and high-efficiency gas adsorber (HEGA) filtration. Testing has focused on development and validation of the waste dryer, ICV, and sintered-metal filters (SMFs) equipment, operations enhancements, and glass formulation. With a parallel testing and design process, testing has allowed improvements to the DBVS equipment configuration and operating methodology, since its original inception. Design improvements include optimization of refractory panels in the ICV, simplifying glassformer addition equipment, increasing the number of waste feed chutes to the ICV, and adding capability for remote clean-out of piping, In addition, the U.S. Department of Energy (DOE) has provided an independent review of the entire DBVS …
Date: February 14, 2008
Creator: JE, VAN BEEK
Object Type: Article
System: The UNT Digital Library
A High-Flux, Flexible Membrane with Parylene-encapsulated Carbon Nanotubes (open access)

A High-Flux, Flexible Membrane with Parylene-encapsulated Carbon Nanotubes

We present fabrication and characterization of a membrane based on carbon nanotubes (CNTs) and parylene. Carbon nanotubes have shown orders of magnitude enhancement in gas and water permeability compared to estimates generated by conventional theories [1, 2]. Large area membranes that exhibit flux enhancement characteristics of carbon nanotubes may provide an economical solution to a variety of technologies including water desalination [3] and gas sequestration [4]. We report a novel method of making carbon nanotube-based, robust membranes with large areas. A vertically aligned dense carbon nanotube array is infiltrated with parylene. Parylene polymer creates a pinhole free transparent film by exhibiting high surface conformity and excellent crevice penetration. Using this moisture-, chemical- and solvent-resistant polymer creates carbon nanotube membranes that promise to exhibit high stability and biocompatibility. CNT membranes are formed by releasing a free-standing film that consists of parylene-infiltrated CNTs, followed by CNT uncapping on both sides of the composite material. Thus fabricated membranes show flexibility and ductility due to the parylene matrix material, as well as high permeability attributed to embedded carbon nanotubes. These membranes have a potential for applications that may require high flux, flexibility and durability.
Date: March 14, 2008
Creator: Park, H. G.; In, J.; Kim, S.; Fornasiero, F.; Holt, J. K.; Grigoropoulos, C. P. et al.
Object Type: Article
System: The UNT Digital Library
Q1Report for CADWR Project: Desalination Using Carbon NAnotube Membranes (open access)

Q1Report for CADWR Project: Desalination Using Carbon NAnotube Membranes

In this research and development project, LLNL will leverage the process for fabrication of the membranes developed by our internally funded effort (LLNL Laboratory Directed Research and Development). LLNL will then employ chemical manipulations to modify charge at the ends of the nanotubes and make the membranes more selective to either positive or negative ions through a combination of size and charge selectivity. LLNL's goal is to demonstrate ion exclusion while preserving high permeabilities and low energy use. Success of this research and development project may warrant further developments in the fabrication of membranes.
Date: May 14, 2008
Creator: Bakajin, O
Object Type: Report
System: The UNT Digital Library
Zachary D. Barker: Final DHS HS-STEM Report (open access)

Zachary D. Barker: Final DHS HS-STEM Report

Working at Lawrence Livermore National Laboratory (LLNL) this summer has provided a very unique and special experience for me. I feel that the research opportunities given to me have allowed me to significantly benefit my research group, the laboratory, the Department of Homeland Security, and the Department of Energy. The researchers in the Single Particle Aerosol Mass Spectrometry (SPAMS) group were very welcoming and clearly wanted me to get the most out of my time in Livermore. I feel that my research partner, Veena Venkatachalam of MIT, and I have been extremely productive in meeting our research goals throughout this summer, and have learned much about working in research at a national laboratory such as Lawrence Livermore. I have learned much about the technical aspects of research while working at LLNL, however I have also gained important experience and insight into how research groups at national laboratories function. I believe that this internship has given me valuable knowledge and experience which will certainly help my transition to graduate study and a career in engineering. My work with Veena Venkatachalam in the SPAMS group this summer has focused on two major projects. Initially, we were tasked with an analysis of data …
Date: August 14, 2008
Creator: Barker, Z D
Object Type: Report
System: The UNT Digital Library
2006 Hanford Site Annual Illness and Injury Surveillance Report (open access)

2006 Hanford Site Annual Illness and Injury Surveillance Report

The U.S. Department of Energy’s (DOE) commitment to assuring the health and safety of its workers includes the conduct of illness and injury surveillance activities that provide an early warning system to detect health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence, occupational injuries and illnesses, and disabilities and deaths among current workers.
Date: May 14, 2008
Creator: United States. Department of Energy. Office of Health, Safety, and Security.
Object Type: Report
System: The UNT Digital Library
A Multi-Layer Phoswich Radioxenon Detection System (open access)

A Multi-Layer Phoswich Radioxenon Detection System

Laboratory radioactive sources were used to characterize the phoswich detector. The CaF{sub 2} scintillator has a low light-yield and slow decay time, thus produces very small signals due to low-energy gamma rays or X-rays. Therefore, detection of 30 keV X-rays (from the xenon radioisotopes) using this layer and discriminating its very small signals from electronic noise was a challenging task. Several solutions were considered and experimentally evaluated. We found that the best solution would be extending the fast triangular filter from 10 taps to 30 taps. This will extend the peaking time of this filter from 25 nsec to 75 nsec. The digital filter is implemented in FPGA on our DPP2.0 and is used to trigger the detection system. Functionality of the new filter in capturing and discriminating 30 keV X-rays was confirmed by using a {sup 133}Ba gamma-ray source. Development of the DPP GUI software has continued with the addition of two new panels to display histograms of beta/gamma and beta/x-ray coincidence events. This includes coincidence events from a single channel, as well as two-channel, coincidence event. A pileup rejection algorithm has been implemented in the FPGA code, and controls to adjust its sensitivity have been added to the …
Date: July 14, 2008
Creator: Hamby, David M.
Object Type: Report
System: The UNT Digital Library
Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to eta K gamma (open access)

Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to eta K gamma

The authors present measurements of the CP-violation parameters S and C for the radiative decay B{sup 0} {yields} {eta}K{sub S}{sup 0}{gamma}; for B {yields} {eta}K{gamma} they also measure the branching fractions and for B{sup +} {yields} {eta}K{sup +}{gamma} the time-integrated charge asymmetry {Alpha}{sub ch}. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 465 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation. The results are S = -0.18{sub -0.46}{sup +0.49} {+-} 0.12, C = -0.32{sub -0.39}{sup +0.40} {+-} 0.07, {Beta}(B{sup 0} {yields} {eta}K{sup 0}{gamma}) = (7.1{sub -2.0}{sup +2.1} {+-} 0.4) x 10{sup -6}, {Beta}(B{sup +} {yields} {eta}K{sup +}{gamma}) = (7.7 {+-} 1.0 {+-} 0.4) x 10{sup -6}, and {Alpha}{sub ch} = (-9.0{sub -9.8}{sup +10.4} {+-} 1.4) x 10{sup -2}. The first error quoted is statistical and the second systematic.
Date: May 14, 2008
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Molecular analysis of the gut microbiota of identical twins with Crohn's disease (open access)

Molecular analysis of the gut microbiota of identical twins with Crohn's disease

Increasing evidence suggests that a combination of host genetics and the composition of the gut microbiota are important for development of Crohn's disease (CD). Our aim was to study identical twins with CD to determine microbial factors independently of host genetics. Fecal samples were studied from 10 monozygotic twin pairs with CD (discordant n=6, concordant n=4) and 8 healthy twin pairs. DNA was extracted, 16S rRNA genes were PCR amplified and T-RFLP fingerprints generated using general bacterial and Bacteroides group specific primers. The microbial communities were also profiled based on their % G+C contents. Bacteroides 16S rRNA genes were cloned and sequenced from a subset of the samples. The bacterial diversity in each sample and similarity indices between samples were estimated based on the T-RFLP data using a combination of statistical approaches. Healthy individuals had a significantly higher bacterial diversity compared to individuals with CD. The fecal microbial communities were more similar between healthy twins than between twins with CD, especially when these were discordant for the disease. The microbial community profiles of individuals with ileal CD were significantly different from healthy individuals and those with colonic CD. Also, CD individuals had a lower relative abundance of B. uniformis and …
Date: March 14, 2008
Creator: Jansson, Janet; Dicksved, Johan; Halfvarson, Jonas; Rosenquist, Magnus; Jarnerot, Gunnar; Tysk, Curt et al.
Object Type: Article
System: The UNT Digital Library
Constraints on rhobar, etabar from B to K*pi (open access)

Constraints on rhobar, etabar from B to K*pi

A linear CKM relation, {bar {eta}} = tan {Phi}{sub 3/2}({bar p} - 0.24 {+-} 0.03), involving a 1{sigma} range for {Phi}{sub 3/2}, 20{sup o} < {Phi}{sub 3/2} < 115{sup o}, is obtained from B{sup 0} {yields} K*{pi} amplitudes measured recently in Dalitz plot analyses of B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} and B{sup 0}(t) {yields} K{sub S}{pi}{sup +}{pi}{sup -}. This relation is consistent within the large error on {Phi}{sub 3/2} with other CKM constraints which are unaffected by new b {yields} s{bar q}q operators. Sensitivity of the method to a new physics contribution in the {Delta}S = {Delta}I = 1 amplitude is discussed.
Date: January 14, 2008
Creator: Gronau, Michael; Pirjol, Dan; Soni, Amarjit & Zupan, Jure
Object Type: Report
System: The UNT Digital Library

Fuel Cell Bus Evaluation Results

Presentation on the results from the DOE fuel cell bus evaluation given at the Transportation Research Board's 87th annual meeting, January 14, 2008.
Date: January 14, 2008
Creator: Eudy, L.
Object Type: Presentation
System: The UNT Digital Library
Development of Improved Iron-Aluminide Filter Tubes and Elements (open access)

Development of Improved Iron-Aluminide Filter Tubes and Elements

The purpose of this Cooperative Research and Development Agreement (CRADA) was to explore and develop advanced manufacturing techniques to fabricate sintered iron-aluminide intermetallic porous bodies used for gas filtration so as to reduce production costs while maintaining or improving performance in advanced coal gasification and combustion systems. The use of a power turbine fired with coal-derived synthesis gas requires some form of gas cleaning in order to protect turbine and downstream components from degradation by erosion, corrosion, and/or deposition. Hot-gas filtration is one form of cleaning that offers the ability to remove particles from the gases produced by gasification processes without having to substantially cool and, possibly, reheat them before their introduction into the turbine. This technology depends critically on materials durability and reliability, which have been the subject of study for a number of years.
Date: January 14, 2008
Creator: Judkins, R. R.; Sutton, T. G.; Miller, C. J. & Tortorelli, P. F.
Object Type: Report
System: The UNT Digital Library
Flooding Experiments and Modeling for Improved Reactor Safety (open access)

Flooding Experiments and Modeling for Improved Reactor Safety

Countercurrent two-phase flow and “flooding” phenomena in light water reactor systems are being investigated experimentally and analytically to improve reactor safety of current and future reactors. The aspects that will be better clarified are the effects of condensation and tube inclination on flooding in large diameter tubes. The current project aims to improve the level of understanding of flooding mechanisms and to develop an analysis model for more accurate evaluations of flooding in the pressurizer surge line of a Pressurized Water Reactor (PWR). Interest in flooding has recently increased because Countercurrent Flow Limitation (CCFL) in the AP600 pressurizer surge line can affect the vessel refill rate following a small break LOCA and because analysis of hypothetical severe accidents with the current flooding models in reactor safety codes shows that these models represent the largest uncertainty in analysis of steam generator tube creep rupture. During a hypothetical station blackout without auxiliary feedwater recovery, should the hot leg become voided, the pressurizer liquid will drain to the hot leg and flooding may occur in the surge line. The flooding model heavily influences the pressurizer emptying rate and the potential for surge line structural failure due to overheating and creep rupture. The air-water …
Date: September 14, 2008
Creator: Solmos, M., Hogan, K.J., VIerow, K.
Object Type: Article
System: The UNT Digital Library
Theoretical Treatment of the Thermophysical Properties of Fluids Containing Chain-like Molecules (open access)

Theoretical Treatment of the Thermophysical Properties of Fluids Containing Chain-like Molecules

This research program was designed to enhance our understanding of the behavior of fluids and fluid mixtures containing chain-like molecules. The original objective was to explain and predict the experimentally observed thermophysical properties, including phase equilibria and dynamics, of systems containing long flexible molecules ranging in length from alkanes to polymers. Over the years the objectives were expanded to include the treatment of molecules that were not chain-like. Molecular dynamics and Monte Carlo computer simulations were used to investigate how variations in molecular size, shape and architecture influence the types of phase equilibria, thermodynamic properties, structure and surface interactions that are observed experimentally. The molecular insights and theories resulting from this program could eventually serve as the foundation upon which to build correlations of the properties of fluids that are both directly and indirectly related to the Nation’s energy resources including: petroleum, natural gas, and polymer solutions, melts, blends, and materials.
Date: November 14, 2008
Creator: Hall, Carol K.
Object Type: Report
System: The UNT Digital Library
Characterization of Intergranular Fission Gas Bubbles in U-MO Fuel. (open access)

Characterization of Intergranular Fission Gas Bubbles in U-MO Fuel.

This report can be divided into two parts: the first part, which is composed of sections 1, 2, and 3, is devoted to report the analyses of fission gas bubbles; the second part, which is in section 4, is allocated to describe the mechanistic model development. Swelling data of irradiated U-Mo alloy typically show that the kinetics of fission gas bubbles is composed of two different rates: lower initially and higher later. The transition corresponds to a burnup of {approx}0 at% U-235 (LEU) or a fission density of {approx}3 x 10{sup 21} fissions/cm{sup 3}. Scanning electron microscopy (SEM) shows that gas bubbles appear only on the grain boundaries in the pretransition regime. At intermediate burnup where the transition begins, gas bubbles are observed to spread into the intragranular regions. At high burnup, they are uniformly distributed throughout fuel. In highly irradiated U-Mo alloy fuel large-scale gas bubbles form on some fuel particle peripheries. In some cases, these bubbles appear to be interconnected and occupy the interface region between fuel and the aluminum matrix for dispersion fuel, and fuel and cladding for monolithic fuel, respectively. This is a potential performance limit for U-Mo alloy fuel. Microscopic characterization of the evolution of …
Date: April 14, 2008
Creator: Kim, Y. S.; Hofman, G.; Rest, J.; Shevlyakov, G. V.; Division, Nuclear Engineering & RIAR, SSCR
Object Type: Report
System: The UNT Digital Library
High-Level Control System in C#* (open access)

High-Level Control System in C#*

We have started upgrading the control room programs for the injector at the Advanced Light Source (ALS). We chose to program in C* exclusively on the .NET Framework to create EPICS client programs on Windows Vista PCs. This paper reports the status of this upgrade project.
Date: October 14, 2008
Creator: Nishimura, Hiroshi; Timossi, Chris; Portmann, Greg; Urashka, Michael.; Ikami, Craig & Beaudrow, M.
Object Type: Article
System: The UNT Digital Library
Accelerating Full Configuration Interaction Calculations for Nuclear Structure (open access)

Accelerating Full Configuration Interaction Calculations for Nuclear Structure

One of the emerging computational approaches in nuclear physics is the full configuration interaction (FCI) method for solving the many-body nuclear Hamiltonian in a sufficiently large single-particle basis space to obtain exact answers - either directly or by extrapolation. The lowest eigenvalues and correspondingeigenvectors for very large, sparse and unstructured nuclear Hamiltonian matrices are obtained and used to evaluate additional experimental quantities. These matrices pose a significant challenge to the design and implementation of efficient and scalable algorithms for obtaining solutions on massively parallel computer systems. In this paper, we describe the computational strategies employed in a state-of-the-art FCI code MFDn (Many Fermion Dynamics - nuclear) as well as techniques we recently developed to enhance the computational efficiency of MFDn. We will demonstrate the current capability of MFDn and report the latest performance improvement we have achieved. We will also outline our future research directions.
Date: April 14, 2008
Creator: Yang, Chao; Sternberg, Philip; Maris, Pieter; Ng, Esmond; Sosonkina, Masha; Le, Hung Viet et al.
Object Type: Article
System: The UNT Digital Library
Accelerating scientific discovery : 2007 annual report. (open access)

Accelerating scientific discovery : 2007 annual report.

As a gateway for scientific discovery, the Argonne Leadership Computing Facility (ALCF) works hand in hand with the world's best computational scientists to advance research in a diverse span of scientific domains, ranging from chemistry, applied mathematics, and materials science to engineering physics and life sciences. Sponsored by the U.S. Department of Energy's (DOE) Office of Science, researchers are using the IBM Blue Gene/L supercomputer at the ALCF to study and explore key scientific problems that underlie important challenges facing our society. For instance, a research team at the University of California-San Diego/ SDSC is studying the molecular basis of Parkinson's disease. The researchers plan to use the knowledge they gain to discover new drugs to treat the disease and to identify risk factors for other diseases that are equally prevalent. Likewise, scientists from Pratt & Whitney are using the Blue Gene to understand the complex processes within aircraft engines. Expanding our understanding of jet engine combustors is the secret to improved fuel efficiency and reduced emissions. Lessons learned from the scientific simulations of jet engine combustors have already led Pratt & Whitney to newer designs with unprecedented reductions in emissions, noise, and cost of ownership. ALCF staff members provide …
Date: November 14, 2008
Creator: Beckman, P.; Dave, P. & Drugan, C.
Object Type: Report
System: The UNT Digital Library
Final Scientific Report (open access)

Final Scientific Report

NanoDynamics Inc. has undertaken a study to develop and demonstrate an anode-supported solid oxide fuel cell capable of generating a minimum of 20 W per cell on hydrogen. The cell technology will also be assed for operation on renewable hydrocarbon-based fuels such as biomass gas, as well its applicability for larger-scale power production. The project was divided into five sub-tasks, the first of which was the development and refinement of the cell manufacturing processes of gel-casting and paste extrusion for the fabrication of planar and tubular anode supports. These methods exhibited high production yields with excellent reproducibility. Using a conventional YSZ-based cell as a performance benchmark, new materials-sets and cell configurations were developed. Three prototype configurations were implemented, the best generating an average of 10 W per cell, and exhibiting excellent potential for further development and scale-up. Using a variety of techniques such as modifying the materials-set, microstructure, and cell configuration, cells with an average power output of 22.7 W were demonstrated, 13.5% in excess of the 20 W project goal. Thermal cycling was performed on such cells, and it was found that over a regime of 150 cycles (approximately 300 h), the cell power increased by 1.8%. So-called “short-stacks” …
Date: January 14, 2008
Creator: Finnerty, Caine
Object Type: Report
System: The UNT Digital Library

Ethanol Production, Distribution, and Use: Discussions on Key Issues

From production to the environment, presentation discusses issues surrounding ethanol as a transportation fuel.
Date: May 14, 2008
Creator: Harrow, G.
Object Type: Presentation
System: The UNT Digital Library
Optical Switching in VO2 films by below-gap excitation (open access)

Optical Switching in VO2 films by below-gap excitation

We study the photo-induced insulator-metal transition in VO2, correlating threshold and dynamic evolution with excitation wavelength. In high-quality single crystal samples, we find that switching can only be induced with photon energies above the 670-meV gap. This contrasts with the case of polycrystalline films, where formation of the metallic state can also be triggered with photon energies as low as 180 meV, well below the bandgap. Perfection of this process may be conducive to novel schemes for optical switches, limiters and detectors, operating at room temperature in the mid-IR.
Date: March 14, 2008
Creator: Dipartimento di Fisica, Universita?di Brescia, Italy
Object Type: Article
System: The UNT Digital Library
Literature Review of Data on the Incremental Costs to Design and Build Low-Energy Buildings (open access)

Literature Review of Data on the Incremental Costs to Design and Build Low-Energy Buildings

This document summarizes findings from a literature review into the incremental costs associated with low-energy buildings. The goal of this work is to help establish as firm an analytical foundation as possible for the Building Technology Program's cost-effective net-zero energy goal in the year 2025.
Date: May 14, 2008
Creator: Hunt, W. D.
Object Type: Report
System: The UNT Digital Library
Analysis of the Argonne Distance Tabletop Exercise Method (open access)

Analysis of the Argonne Distance Tabletop Exercise Method

The purpose of this report is to summarize and evaluate the Argonne Distance Tabletop Exercise (DISTEX) method. DISTEX is intended to facilitate multi-organization, multi-objective tabletop emergency response exercises that permit players to participate from their own facility's incident command center. This report is based on experience during its first use during the FluNami 2007 exercise, which took place from September 19-October 17, 2007. FluNami 2007 exercised the response of local public health officials and hospitals to a hypothetical pandemic flu outbreak. The underlying purpose of the DISTEX method is to make tabletop exercising more effective and more convenient for playing organizations. It combines elements of traditional tabletop exercising, such as scenario discussions and scenario injects, with distance learning technologies. This distance-learning approach also allows playing organizations to include a broader range of staff in the exercise. An average of 81.25 persons participated in each weekly webcast session from all playing organizations combined. The DISTEX method required development of several components. The exercise objectives were based on the U.S. Department of Homeland Security's Target Capabilities List. The ten playing organizations included four public health departments and six hospitals in the Chicago area. An extent-of-play agreement identified the objectives applicable to each …
Date: February 14, 2008
Creator: Tanzman, E. A.; Nieves, L. A. & Sciences, Decision and Information
Object Type: Report
System: The UNT Digital Library
Decomposition of the Multistatic Response Matrix and Target Characterization (open access)

Decomposition of the Multistatic Response Matrix and Target Characterization

Decomposition of the time-reversal operator for an array, or equivalently the singular value decomposition of the multistatic response matrix, has been used to improve imaging and localization of targets in complicated media. Typically, each singular value is associated with one scatterer even though it has been shown in several cases that a single scatterer can generate several singular values. In this paper we review the analysis of the time-reversal operator (TRO), or equivalently the multistatic response matrix (MRM), of an array system and a small target. We begin with two-dimensional scattering from a small cylinder then show the results for a small non-spherical target in three dimensions. We show that the number and magnitudes of the singular values contain information about target composition, shape, and orientation.
Date: February 14, 2008
Creator: Chambers, D H
Object Type: Article
System: The UNT Digital Library