HB-Line Special Nuclear Material Campaigns: Model-Based Project Management (open access)

HB-Line Special Nuclear Material Campaigns: Model-Based Project Management

This study is to show how a model was used to enable management to better estimate production capabilities to ensure contract milestones/commitments are met, to cope with fast changing project baselines and project missions, to ensure the project will meet the negotiated throughput, and to eliminate unnecessary but costly design changes.
Date: March 24, 2004
Creator: Chang, Robert
Object Type: Article
System: The UNT Digital Library
Analytical Method for Measuring Total Protium and Total Deuterium in a Gas Mixture Containing H2, D2, and HD Via Gas Chromatography (open access)

Analytical Method for Measuring Total Protium and Total Deuterium in a Gas Mixture Containing H2, D2, and HD Via Gas Chromatography

A new analytical technique has been developed that measures both total protium (H) and deuterium (D) in a gas mixture containing H2, D2, and HD. This new analytical technique uses a micro gas chromatograph (GC) with two molecular sieve columns. One column uses D2 as the carrier gas and the other uses H2 as the carrier gas. Laboratory tests have shown that when used in this configuration the GC can measure both total protium and total deuterium, each with a sensitivity of less than 20 ppm. This new analytical technique was developed as a result of a request to provide instrumentation to measure the protium and deuterium concentrations at several process points during initial testing of the new hydrogen tritium thermal cycling absorption process columns.
Date: March 24, 2004
Creator: SESSIONS, HENRY
Object Type: Report
System: The UNT Digital Library
A simple way to characterize linear coupling in a storage ring (open access)

A simple way to characterize linear coupling in a storage ring

The techniques of normal form analysis, well known in the literature, can be used to provide a straightforward characterization of linear betatron dynamics in a coupled lattice. Here, we consider both the beam distribution and the betatron oscillations in a storage ring, assuming that the beam emittances and betatron actions respectively are provided as parameters. We find that the beta functions for uncoupled motion generalize in a simple way to the coupled case. Defined in the way that we propose, the beta functions remain well behaved (positive and finite) under all circumstances, and have essentially the same physical significance for the beam size and betatron oscillations as in the uncoupled case. We discuss a technique for making direct measurements of the ratio of the coupled lattice functions at different points in the lattice.
Date: March 24, 2004
Creator: Wolski, Andrzej
Object Type: Report
System: The UNT Digital Library
STELLA-II: DEMONSTRATION OF MONOENERGETIC LASER ACCELERATION. (open access)

STELLA-II: DEMONSTRATION OF MONOENERGETIC LASER ACCELERATION.

Monoenergetic laser acceleration of trapped microbunches has been demonstrated for the first time. An inverse free electron laser (IFEL) is used to create microbunches, which are then accelerated by a second IFEL using a tapered undulatos. An adjustable magnetic field chicane is located between the two IFELs and is used to control the phase of the microbunches with respect to the laser field in the second IFEL. The IFELs are driven by a single lases beam from a high peak power CO{sub 2} laser. During the experiment, the trapped portion of the microbunch electrons had an energy gain of >16% with an energy width of -0.86% (full width at half-maximum).
Date: March 24, 2004
Creator: KIMURA,W. D. BABZIEN,M. BEN-ZVI,I. GALLARDO,J. C. KUSCHE,K. P. POGORELSKY,I. V. SKARITKA,J. YAKIMENKO,V. ET AL.
Object Type: Article
System: The UNT Digital Library
Review of Practice for Deeply Embedded/Buried Npp Structures Subject to Seismic Loadings. (open access)

Review of Practice for Deeply Embedded/Buried Npp Structures Subject to Seismic Loadings.

Motivated by many design considerations, several conceptual designs for advanced reactors have proposed that the entire reactor building and a significant portion of the steam generator building will be either partially or completely embedded below grade. For the analysis of seismic events, the soil-structure interaction (SSI) effect and passive earth pressure for these types of deeply embedded structures will have a significant influence on the predicted seismic response. Sponsored by the US Nuclear Regulatory Commission (NRC), Brookhaven National Laboratory (BNL) is carrying out a research program to assess the significance of these proposed design features for advanced reactors, and to evaluate the existing analytical methods to determine their applicability and adequacy in capturing the seismic behavior of the proposed designs. This paper summarizes a literature review performed by BNL to determine the state of knowledge and practice for seismic analyses of deeply embedded and/or buried (DEB) nuclear containment type structures. Included in the paper is BNL's review of the open literature of existing standards, tests, and practices that have been used in the design and analysis of DEB structures. The paper also provides BNL's evaluation of available codes and guidelines with respect to seismic design practice of DEB structures. Based …
Date: March 24, 2004
Creator: Xu, J.; Hofmayer, C.; Miller, C. & Graves, H.
Object Type: Article
System: The UNT Digital Library
Characterization of Functionalized Self-Assembled Monolayers and Surface-Attached Interlocking Molecules Using Near-Edge X-ray Absorption Fine Structure Spectroscopy (open access)

Characterization of Functionalized Self-Assembled Monolayers and Surface-Attached Interlocking Molecules Using Near-Edge X-ray Absorption Fine Structure Spectroscopy

Quantitative knowledge of the fundamental structure and substrate binding, as well as the direct measurement of conformational changes, are essential to the development of self-assembled monolayers (SAMs) and surface-attached interlocking molecules, catenanes and rotaxanes. These monolayers are vital to development of nano-mechanical, molecular electronic, and biological/chemical sensor applications. This dissertation investigates properties of functionalized SAMs in sulfur-gold based adsorbed molecular monolayers using quantitative spectroscopic techniques including near-edge x-ray absorption fine structure spectroscopy (NEXAFS) and x-ray photoelectron spectroscopy (XPS). The stability of the gold-thiolate interface is addressed. A simple model SAM consisting of dodecanethiol adsorbed on Au(111) degrades significantly in less than 24 hours under ambient laboratory air. S 2p and O 1s XPS show the gold-bound thiolates oxidize to sulfinates and sulfonates. A reduction of organic material on the surface and a decrease in order are observed as the layer degrades. The effect of the carboxyl vs. carboxylate functionalization on SAM structure is investigated. Carboxyl-terminated layers consisting of long alkyl-chain thiols vs. thioctic acid with short, sterically separated, alkyl groups are compared and contrasted. NEXAFS shows a conformational change, or chemical switchability, with carboxyl groups tilted over and carboxylate endgroups more upright. Surface-attached loops and simple surface-attached rotaxanes are quantitatively …
Date: March 24, 2004
Creator: Willey, T & Willey, T
Object Type: Thesis or Dissertation
System: The UNT Digital Library
CONCEPTS FOR CAPACITIVELY RF-SHIELDED BELLOWS IN CRYOGENIC STRUCTURES. (open access)

CONCEPTS FOR CAPACITIVELY RF-SHIELDED BELLOWS IN CRYOGENIC STRUCTURES.

Bellows are frequently required in accelerators and colliders. Usually RF-shields with spring fingers are employed to screen the bellows. The lack of accessibility in cryogenic systems can be a problem and asks for alternate solutions to eliminate possible overheating, sparking, etc that occurred in intensive beams. This note addresses an alternate kind of RF shield, which uses capacitive contact instead of mechanical contact. The analysis, as well as numerical example of a superconducting cavity structure, shows that the capacitive RF shield satisfies the impedance requirements of both beam and HOMs. The capability of thermal isolation is also analyzed.
Date: March 24, 2004
Creator: ZHAO,Y. HAHN,H.
Object Type: Report
System: The UNT Digital Library
Design and Status of the Visa II Experiment. (open access)

Design and Status of the Visa II Experiment.

VISA II is the follow-up project to the successful Visible to Infrared SASE Amplifier (VISA) experiment at the Accelerator Test Facility (ATF) in Brookhaven National Lab (BNL). This paper will report the motivation for and status of the two main experiments associated with the VISA II program. One goal of VISA II is to perform an experimental study of the physics of a chirped beam SASE FEL at the upgraded facilities of the ATF. This requires a linearization of the transport line to preserve energy chirping of the electron beam at injection. The other planned project is a strong bunch compression experiment, where the electron bunch is compressed in the chicane, and the dispersive beamline transport, allowing studies of deep saturation.
Date: March 24, 2004
Creator: Andonian, G.
Object Type: Article
System: The UNT Digital Library
DNA Damage Quantitation by Alkaline Gel Electrophoresis. (open access)

DNA Damage Quantitation by Alkaline Gel Electrophoresis.

Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by …
Date: March 24, 2004
Creator: Sutherland, B. M.; Bennett, P. V. & Sutherland, J. C.
Object Type: Book
System: The UNT Digital Library
Defining and Testing the Influence of Servo System Response on Machine Tool Compliance (open access)

Defining and Testing the Influence of Servo System Response on Machine Tool Compliance

Compliance can be defined as the measurement of displacement per unit of force applied e.g. nano-meters per Newton (m/N). Compliance is the reciprocal of stiffness. High stiffness means low compliance and visa versa. It is an important factor in machine tool characteristics because it reflects the ability of the machine axis to maintain a desired position as it encounters a force or torque. Static compliance is a measurement made with a constant force applied e.g. the average depth of cut. Dynamic compliance is a measurement made as a function of frequency, e.g. a fast too servo (FTS) that applies a varying cutting force or load, interrupted cuts and external disturbances such as ground vibrations or air conditioning induced forces on the machine. Compliance can be defined for both a linear and rotary axis of a machine tool. However, to properly define compliance for a rotary axis, the axis must allow a commanded angular position. Note that this excludes velocity only axes. In this paper, several factors are discussed that affect compliance but emphasis is placed on how the machine servo system plays a key role in compliance at low to mid frequency regions. The paper discusses several techniques for measuring …
Date: March 24, 2004
Creator: Hopkins, D J
Object Type: Article
System: The UNT Digital Library
Practical SQE on a Large Multi-Disciplinary HPC Development Team (open access)

Practical SQE on a Large Multi-Disciplinary HPC Development Team

In this paper we will discuss several software engineering practices that have proven useful in a large multidisciplinary physics code development project at Lawrence Livermore National Laboratory. In the project discussed here, as with many large scale efforts in HPC scientific computing, we have had to balance the competing demands of being a stable ''production'' code that our user base can rely on with being a platform for research into new physics, models, and software architectures. Much of this has been learned through necessity and experience. Likewise, much of it has been learned through interactions with other similar projects and hearing of their successes, and tailoring their ideas to our own requirements. The ideas presented here are not meant to necessarily transfer to other environments with different needs. It is our belief that projects need to be given large latitude in defining their own software engineering process versus a prescribed a solution. However, the ideas presented here are hopefully high level and general enough that we hope other projects might find some inspiration and adopt similar methods if it is to their benefit, much as we have done through the years.
Date: March 24, 2004
Creator: Neely, J R
Object Type: Article
System: The UNT Digital Library
Electrical Discharge Machining Techniques for Evaluating the Effects of Tritium on Materials (open access)

Electrical Discharge Machining Techniques for Evaluating the Effects of Tritium on Materials

In this investigation, new ways to evaluate the long-term effects of tritium on the structural properties of components were developed. Electric discharge machining (EDM) techniques for cutting tensile and fracture toughness samples from the tritium-exposed regions of returned reservoirs were demonstrated. An existing electric discharge machine was used to cut sub-size tensile and fracture toughness samples from the inside walls of reservoir mock-ups. Tensile properties from the EDM tensile samples were similar to those measured using full-size samples cut from similar stock. Although the existing equipment could not be used for machining tritium-exposed hardware, off-the-shelf EDM units are available that could. With the right equipment and the required radiological controls in place, similar machining and testing techniques could be used to directly measure the effects of tritium on the properties of material cut from reservoir returns. Stress-strain property data from tritium-exposed reservoirs would improve finite-element modeling of reservoir performance because the data are representative of the true state of the reservoir material in the field. Tensile data from samples cut directly from reservoirs complement existing shelf storage and burst test data of the Life Storage Program and help answer questions about a specific reservoir's processing history and properties.
Date: March 24, 2004
Creator: IMRICH, KENNETH
Object Type: Report
System: The UNT Digital Library