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18th U.S. Department of Energy Low-Level Radioactive Waste Management Conference. Program (open access)

18th U.S. Department of Energy Low-Level Radioactive Waste Management Conference. Program

This conference explored the latest developments in low-level radioactive waste management through presentations from professionals in both the public and the private sectors and special guests. The conference included two continuing education seminars, a workshop, exhibits, and a tour of Envirocare of Utah, Inc., one of America's three commercial low-level radioactive waste depositories.
Date: May 20, 1997
Creator: unknown
System: The UNT Digital Library
1972-1997, Twenty-five years of energy and environmental history : lessons learned. (open access)

1972-1997, Twenty-five years of energy and environmental history : lessons learned.

Given the events of the past 25 years concerning energy and environmental issues and our reaction to them, what lessons can we learn? First, the individual American consumer wants and expects energy to be a stable commodity with low prices and easy availability. As evidenced by the heated debate over increasing the federal gasoline tax by $.05 per gallon (which would still leave Americans paying only one-third of what Europeans pay for gasoline), increases in energy prices elicit very strong public and political opposition. As further evidence, it has been argued that the general public support of the Gulf War was due, in part, to a recognition of the need to maintain a stable source of cheap oil from the region. The American public wants to maintain the benefits of cheap and abundant energy and expects its political leaders to make it happen. A second lesson is that if constraints on the energy supply do occur (e.g., the OPEC-imposed oil embargo) ardor environmental impacts from energy use do appear to be significant (e.g., SO{sub 2} and CO{sub 2} emissions), the preference is for a technology fix rather than a behavioral change. This is evidenced by our reliance on moving low-sulfur …
Date: December 17, 1997
Creator: Drucker, H.
System: The UNT Digital Library
1997 DOE technical standards program workshop: Proceedings (open access)

1997 DOE technical standards program workshop: Proceedings

The Department of Energy held its annual Technical Standards Program Workshop on July 8--10, 1997, at the Loews L`Enfant Plaza Hotel in Washington, DC. The workshop focused on aspects of implementation of the National Technology Transfer and Advancement Act of 1995 [Public Law (PL) 104-113] and the related revision (still pending) to OMB Circular A119 (OMB A119), Federal Participation in the Development and Use of Voluntary Standards. It also addressed DOE`s efforts in transitioning to a standards-based operating culture, and, through this transition, to change from a developer of internal technical standards to a customer of external technical standards. The workshop was designed to provide a forum to better understand how the new law is affecting Department activities. Panel topics such as ``Public Law 104-113 and Its Influence on Federal Agency Standards Activities`` and ``Update on Global Standards Issues`` provided insight on both the internal and external effects of the new law. Keynote speaker Richard Meier of Meadowbrook International (and formerly the Deputy Assistant US Trade Representative) addressed the subject of international trade balance statistics. He pointed out that increases in US export figures do not necessarily indicate increases in employment. Rather, increased employment results from product growth. Mr Meier …
Date: October 1, 1997
Creator: unknown
System: The UNT Digital Library
1997 Gordon Research Conference on Molecular Electronic Spectroscopy. Final Progress Report (open access)

1997 Gordon Research Conference on Molecular Electronic Spectroscopy. Final Progress Report

None
Date: September 5, 1997
Creator: unknown
System: The UNT Digital Library
1997 international Sherwood fusion theory conference (open access)

1997 international Sherwood fusion theory conference

Papers presented during the conference are indexed separately.
Date: May 1, 1997
Creator: unknown
System: The UNT Digital Library
31305: Tevatron searches for compositeness (open access)

31305: Tevatron searches for compositeness

Tevatron experiments have recently set or improved limits on quark and lepton compositeness. Included here are results from {radical}s = 1.8 TeV p{anti p} collider experiments D0 and CDF and from fixed target neutrino experiment CCFR, who report limits on quark-quark, quark-lepton, and quark-neutrino compositeness, respectively.
Date: November 1, 1997
Creator: Gallas, E. & Collaborations, E740 and E741
System: The UNT Digital Library
36Cl/Cl ratios in geothermal systems: preliminary measurements from the Coso Field (open access)

36Cl/Cl ratios in geothermal systems: preliminary measurements from the Coso Field

The {sub 36}Cl/Cl isotopic composition of chlorine in geothermal systems can be a useful diagnostic tool in characterizing hydrologic structure, in determining the origins and age of waters within the systems, and in differentiating the sources of chlorine (and other solutes) in the thermal waters. The {sub 36}Cl/Cl values for several geothermal water samples and reservoir host rock samples from the Coso, California geothermal field have been measured for these purposes. The results indicate that most of the chlorine is not derived from the dominant granitoid that host the geothermal system. If the chlorine was originally input into the Coso subsurface through meteoric recharge, that input occurred at least 1-1.25 million years ago. The results suggest that the thermal waters could be connate waters derived from sedimentary formations, presumably underlying and adjacent top the granitic rocks, which have recently migrated into the host rocks. Alternatively, most of the chlorine but not the water, may have recently input into the system from magmatic sources. In either case, the results indicate that most of the chlorine in the thermal waters has existed within the granitoid host rocks for no more than about 100,00-200,00 years. this residence time for the chlorine is similar …
Date: July 1, 1997
Creator: Nimz, G.J.; Moore, J.N. & Kasameyer, P.W.
System: The UNT Digital Library
3D electromagnetic inversion for environmental site characterization (open access)

3D electromagnetic inversion for environmental site characterization

A 3-D non-linear electromagnetic inversion scheme has been developed to produce images of subsurface conductivity structure from electromagnetic geophysical data. The solution is obtained by successive linearized model updates where full forward modeling is employed at each iteration to compute model sensitivities and predicted data. Regularization is applied to the problem to provide stability. Because the inverse part of the problem requires the solution of 10`s to 100`s of thousands of unknowns, and because each inverse iteration requires many forward models to be computed, the code has been implemented on massively parallel computer platforms. The use of the inversion code to image environmental sites is demonstrated on a data set collected with the Apex Parametrics {open_quote}MaxMin I-8S{close_quote} over a section of stacked barrels and metal filled boxes at the Idaho National Laboratory`s {open_quote}Cold Test Pit{close_quote}. The MaxMin is a loop-loop frequency domain system which operates from 440 Hz up to 56 kHz using various coil separations; for this survey coil separations of 15, 30 and 60 feet were employed. The out-of phase data are shown to be of very good quality while the in-phase are rather noisy due to slight mispositioning errors, which cause improper cancellation of the primary free …
Date: April 1, 1997
Creator: Alumbaugh, D.L. & Newman, G.A.
System: The UNT Digital Library
3D Electromagnetic inversion using conjugate gradients (open access)

3D Electromagnetic inversion using conjugate gradients

In large scale 3D EM inverse problems it may not be possible to directly invert a full least-squares system matrix involving model sensitivity elements. Thus iterative methods must be employed. For the inverse problem, we favor either a linear or non-linear (NL) CG scheme, depending on the application. In a NL CG scheme, the gradient of the objective function is required at each relaxation step along with a univariate line search needed to determine the optimum model update. Solution examples based on both approaches will be presented.
Date: June 1, 1997
Creator: Newman, G.A. & Alumbaugh, D.L.
System: The UNT Digital Library
3D electromagnetic modeling using staggered finite differences (open access)

3D electromagnetic modeling using staggered finite differences

The method of finite differences has been employed to solve a variety of 3D electromagnetic (EM) forward problems arising in geophysical applications. Specific sources considered include dipolar and magnetotelluric (MT) field excitation in the frequency domain. In the forward problem, the EM fields are simulated using a vector Helmholtz equation for the electric field, which are approximated using finite differences on a staggered grid. To obtain the fields, a complex-symmetric matrix system of equations is assembled and iteratively solved using the quasi minimum method (QMR) method. Perfectly matched layer (PML) absorbing boundary conditions are included in the solution and are necessary to accurately simulate fields in propagation regime (frequencies > 10 MHZ). For frequencies approaching the static limit (< 10 KHz), the solution also includes a static-divergence correction, which is necessary to accurately simulate MT source fields and can be used to accelerate convergence for the dipolar source problem.
Date: June 1, 1997
Creator: Newman, G.A. & Alumbaugh, D.L.
System: The UNT Digital Library
3D particle simulations of space-charge-dominated beams in HIF accelerator experiments (open access)

3D particle simulations of space-charge-dominated beams in HIF accelerator experiments

The development of a high current, heavy-ion beam for inertial confinement fusion requires a detailed understanding of the behavior of the beam, including effects of the large self-fields. This necessity makes particle-in-cell (PIC) simulation the appropriate tool, and for this reason, the three-dimensional PIC/accelerator code WARP3d is being developed. WARP3d has been used extensively to study the creation and propagation of ion beams both to support experiments and for the understanding of basic beam physics. An overview of the structure of the code is presented along with a discussion of features that make the code an effective tool in the understanding of space-charge dominated beam behavior. A number of applications where WARP3d has played an important role is discussed, emphasizing the need of three-dimensional, first principles simulations. Results and comparisons with experiment are presented.
Date: May 1, 1997
Creator: Grote, D. P.; Friedman, A.; Lund, S. M. & Haber, I.
System: The UNT Digital Library
3D seismic imaging on massively parallel computers (open access)

3D seismic imaging on massively parallel computers

The ability to image complex geologies such as salt domes in the Gulf of Mexico and thrusts in mountainous regions is a key to reducing the risk and cost associated with oil and gas exploration. Imaging these structures, however, is computationally expensive. Datasets can be terabytes in size, and the processing time required for the multiple iterations needed to produce a velocity model can take months, even with the massively parallel computers available today. Some algorithms, such as 3D, finite-difference, prestack, depth migration remain beyond the capacity of production seismic processing. Massively parallel processors (MPPs) and algorithms research are the tools that will enable this project to provide new seismic processing capabilities to the oil and gas industry. The goals of this work are to (1) develop finite-difference algorithms for 3D, prestack, depth migration; (2) develop efficient computational approaches for seismic imaging and for processing terabyte datasets on massively parallel computers; and (3) develop a modular, portable, seismic imaging code.
Date: February 1, 1997
Creator: Womble, D. E.; Ober, C. C. & Oldfield, R.
System: The UNT Digital Library
A 3He{sup +}{sup +} RFQ accelerator for the production of PET isotopes (open access)

A 3He{sup +}{sup +} RFQ accelerator for the production of PET isotopes

Project status of the 3He{sup +}{sup +} 10.5 MeV RFQ Linear Accelerator for the production of PET isotopes will be presented. The accelerator design was begun in September of 1995 with a goal of completion and delivery of the accelerator to BRF in Shreveport, Louisiana by the summer of 1997. The design effort and construction is concentrated in Lab G on the Fermilab campus. Some of the high lights include a 25 mA peak current 3He` ion source, four RFQ accelerating stages that are powered by surplus Fermilab linac RF stations, a gas jet charge doubler, and a novel 540 degree bending Medium Energy Beam Transport (MEBT). The machine is designed to operate at 360 Hz repetition rate with a 2.5% duty cycle. The average beam current is expected to be 150-300 micro amperes electrical, 75- 150 micro amperes particle current.
Date: May 1, 1997
Creator: Pasquinelli, R.J. & Collaboration, E887
System: The UNT Digital Library
Ab initio calculation of tight-binding parameters (open access)

Ab initio calculation of tight-binding parameters

We calculate ab initio values of tight-binding parameters for the f- electron metal Ce and various phases of Si, from local-density functional one-electron Hamiltonian and overlap matrix elements. Our approach allows us to unambiguously test the validity of the common minimal basis and two-center approximations as well as to determine the degree of transferability of both nonorthogonal and orthogonal hopping parameters in the cases considered.
Date: December 1, 1997
Creator: McMahan, A. K. & Klepeis, J. E.
System: The UNT Digital Library
Ab-initio calculations of density of states for Ti-oxide (open access)

Ab-initio calculations of density of states for Ti-oxide

Electron energy-loss spectroscopy has been shown to be a powerful tool to determine the chemistry and the electronic structure at grain boundaries by analyzing the energy loss near edge structure (ELNES). This paper describes the ability of ab-initio density of state calculations to perform detailed quantitative analysis at interfaces.
Date: April 1, 1997
Creator: Duscher, G.; Koestlmeier, S. & Elsaesser, C.
System: The UNT Digital Library
ABCC/RERF: Commemorating the First 50 Years and Looking to the Future [Symposium program] (open access)

ABCC/RERF: Commemorating the First 50 Years and Looking to the Future [Symposium program]

In 1946, President Harry Truman, in a document currently on display at the entrance to this auditorium, approved a directive to the National Academy of Sciences-National Research Council (NAS-NRC) to initiate a long-term investigation of the health effects associated with exposure to radiation from the atomic bombs. With funding provided by the Atomic Energy Commission, now the Department of Energy, NAS-NRC established the Atomic Bomb Casualty Commission (ABCC) in March 1947. The government of Japan through the Japanese National Institute of Health, became a partner in that endeavor in 1948. In 1975, the Radiation Effects Research Foundation (RERF) was established and assumed the responsibilities of ABCC. This symposium commemorates 50 years of ABCC/RERF. It is dedicated to the many survivors and their families without whose cooperation we would not have learned as much as we have about the effects of radiation. It is also dedicated to the thousands of employees of RERF and scientists around the world who have contributed through the years to the analysis and interpretation of the information emerging from this unique study.
Date: June 13, 1997
Creator: unknown
System: The UNT Digital Library
Aberration analysis calculations for synchrotron radiation beamline design (open access)

Aberration analysis calculations for synchrotron radiation beamline design

The application of ray deviation calculations based on aberration coefficients for a single optical surface for the design of beamline optical systems is reviewed. A systematic development is presented which allows insight into which aberration may be causing the rays to deviate from perfect focus. A new development allowing analytical calculation of line shape is presented.
Date: September 1, 1997
Creator: McKinney, W.R.; Howells, M. & Padmore, H.A.
System: The UNT Digital Library
Absolute equation of state measurements of shocked liquid deuterium up to 200 GPa (2 Mbar) (open access)

Absolute equation of state measurements of shocked liquid deuterium up to 200 GPa (2 Mbar)

We present results of the first measurements of density, shock speed and particle speed in compressed liquid deuterium at pressures in excess in 1 Mbar. We have performed equation of state (EOS) measurements on the principal Hugoniot of liquid deuterium from 0.2 to 2 Mbar. We employ high-resolution radiography to simultaneously measure the compression of the sample. We are also attempting to measure the color temperature of the shocked D2. Key to this effort is the development and implementation of interferometric methods in order to carefully characterized the profile and steadiness of the shock and the level of preheat in the samples. These experiments allow us to differentiate between the accepted EOS model for D2 and a new model which included the effects of molecular dissociation on the EOS.
Date: June 10, 1997
Creator: Budil, K. S.; Da Silva, L. B. & Celliers, P.
System: The UNT Digital Library
Absorptance measurements of transmissive optical components by the surface thermal lensing technique (open access)

Absorptance measurements of transmissive optical components by the surface thermal lensing technique

The surface thermal lensing technique (STL) successfully resolved and measured the absorptance of transmissive optical components: near- normal angle-of-incidence anti-reflectors and beam splatters. The STL system uses an Ar ion laser to pump the components at 514.5 mn. The absorptance-induced surface deformation diffracts the HeNe probe beam into a photo-detector. The signal intensity was calibrated with a sample of known absorptance. The optical components were designed to function in a copper vapor laser (CVL) transport system, and were previously tested for absorptance with a high power CVL system at 511 rtm. To assure proper absorptance data from the STL system, the pump laser power densities were set at the operational level of the coatings, absorptance time trends were monitored, and absorptance area scans were made. Both types of transmissive optics are more stable than the CVL high reflectors that were measured in another study. Parameter studies based on Fresnel diffraction theory were also performed to optimize experimental condition. The STL system was assessed to have 10 ppb sensitivity for absorption measurement given 2 W of pump power.
Date: September 24, 1997
Creator: Chow, R.; Taylor, J. R.; Wu, Z. L.; Han, Y. & Tian, L. Y.
System: The UNT Digital Library
AC magnetic field losses in BSCCO-2223 superconducting tapes (open access)

AC magnetic field losses in BSCCO-2223 superconducting tapes

The AC magnetic losses at power frequencies (60 Hz) were investigated for mono- and multifilament Ag-sheathed (Bi, Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} (BSCCO-2223) tapes with similar transport critical current (I{sub c}) values at 77 K. The multifilament sample exhibited higher losses than the monofilament under the same conditions. Loss peaks are discussed in terms of intergranular, intragranular and eddy current losses. Because of BSCCO`s anisotropy, field orientation has a large effect on the magnitude of these peaks, even at relatively small angles. Losses for fields applied parallel to the c-axis of the textured BSCCO grains are larger by more than one order of magnitude than those applied perpendicular.
Date: September 1, 1997
Creator: Lelovic, M.; Mench, S. & Deis, T.
System: The UNT Digital Library
Acccelerator Physics Issues of a Very Large Hadron Collider (open access)

Acccelerator Physics Issues of a Very Large Hadron Collider

A Very Large Hadron Collider (VLHC) was proposed for the post-LHC future. This paper gives a quick survey of a number of accelerator physics issues based on the information obtained from a parameter spreadsheet SSP. The main technical challenges to build such a machine appear to be: the large number of events per crossing (in hundreds), enormous beam stored energy (equivalent to tens tons of TNT), ground motion (which is particularly harmful when the synchrotron frequency is in the sub-Hertz range), small dynamic aperture (due to long filling time), fast growth of the resistive wall instability (in a fraction of one turn), low threshold of the single bunch transverse instability (due to big machine size), strong synchrotron radiation (at a level close to the LEP) and short radiation damage lifetime, etc. Possible solutions to some of these problems will also be discussed.
Date: June 1, 1997
Creator: Chou, W.
System: The UNT Digital Library
Acceleration and collision of ultra-high energy particles using crystal channels (open access)

Acceleration and collision of ultra-high energy particles using crystal channels

We assume that, independent of any near-term discoveries, the continuing goal of experimental high-energy physics (HEP) will be to achieve ultra-high center-of-mass energies early in the next century. To progress to these energies in such a brief span of time will require a radical change in accelerator and collider technology. We review some of our recent theoretical work on high-gradient acceleration of charged particles along crystal channels and the possibility of colliding them in these same strong-focusing atomic channels. An improved understanding of energy and emittance limitations in natural crystal accelerators leads to the suggestion that specially manufactured nano-accelerators may someday enable us to accelerate particles beyond 10{sup 8} eV with emittances limited only by the uncertainty principle of quantum mechanics.
Date: April 1, 1997
Creator: Chen, P. & Noble, R.J.
System: The UNT Digital Library
An accelerator controls network designed for reliability and flexibility (open access)

An accelerator controls network designed for reliability and flexibility

The APS accelerator control system is a typical modern system based on the standard control system model, which consists of operator interfaces to a network and computer-controlled interfaces to hardware. The network provides a generalized communication path between the host computers, operator workstations, input/output crates, and other hardware that comprise the control system. The network is an integral part of all modern control systems and network performance will determine many characteristics of a control system. This paper describes the methods used to provide redundancy for various network system components as well as methods used to provide comprehensive monitoring of this network. The effect of archiving tens of thousands of data points on a regular basis and the effect on the controls network will be discussed. Metrics are provided on the performance of the system under various conditions.
Date: December 2, 1997
Creator: McDowell, W. P. & Sidorowicz, K. V.
System: The UNT Digital Library
Accelerator-driven destruction of long-lived radioactive waste and energy production (open access)

Accelerator-driven destruction of long-lived radioactive waste and energy production

Nuclear waste management involves many issues. ATW is an option that can assist a repository by enhancing its capability and thereby assist nuclear waste management. Technology advances and the recent release of liquid metal coolant information from Russia has had an enormous impact on the viability of an ATW system. It now appears economic with many repository enhancing attributes. In time, an ATW option added to present repository activities will provide the public with a nuclear fuel cycle that is acceptable from economic and environmental points of view.
Date: December 31, 1997
Creator: Schriber, S. O.
System: The UNT Digital Library