Resource Type

Ab initio molecular orbital calculations of molten salt vapor complexes using Gaussian-2 theory: LiAlF[sub 4] and NaAlF[sub 4] (open access)

Ab initio molecular orbital calculations of molten salt vapor complexes using Gaussian-2 theory: LiAlF[sub 4] and NaAlF[sub 4]

The structures and energies of the molten salt vapor complexes LiAlF[sub 4] and NaAlF[sub 4] are studied using new high level ab initio molecular orbital methods. The structures are determined using Moller-Plesset perturbation theory to second-order and the total energies are determined using a recently introduced modification of Gaussian-2 (G2) theory. The total energies are used to determine relative energies of the corner-, edge-, and face-bridged structures and accurate reaction energies. The results are compared to previous theoretical and experimental studies.
Date: January 1, 1993
Creator: Curtiss, L.A.
System: The UNT Digital Library
Abort interlock diagnostic for protection of APS vacuum chamber (open access)

Abort interlock diagnostic for protection of APS vacuum chamber

The Advanced Photon Source (APS) vacuum system has been designed to be passively safe from bending magnet radiation heating at positron beam currents up to 30 mA. Above this value, certain components may be damaged from vertical beam missteering, although work is proceeding to raise the safe current threshold. Because of this, a system for preventing the misalignment of high power density beams is required. This report details a system for protection from dipole radiation only. Work on a system for ID radiation is continuing.
Date: January 1, 1993
Creator: Decker, G.
System: The UNT Digital Library
Abstracts of papers thirty-fourth ORNL/DOE conference on analytical chemistry in energy technology (open access)

Abstracts of papers thirty-fourth ORNL/DOE conference on analytical chemistry in energy technology

Less than 100 abstracts are included.
Date: 1993
Creator: unknown
System: The UNT Digital Library
Accelerator and Beam Transport Design Information (open access)

Accelerator and Beam Transport Design Information

This report contains viewgraphs on accelerator design and physics.
Date: January 1, 1993
Creator: Lawrence, George
System: The UNT Digital Library
Acceptance criteria for corroded carbon steel piping containing weld defects (open access)

Acceptance criteria for corroded carbon steel piping containing weld defects

Acceptance criteria for corroded low temperature, low pressure carbon steel piping containing weld defects is presented along with a typical application of these criteria. They are intended to preclude gross rupture or rapidly propagating failure due to uniform wall thinning, local wall thinning, pitting corrosion and weld defects. The minimum allowable uniform wail thickness is based on the code-of-record allowable stress and fracture criteria. Weld defects are postulated as potential sites for fracture initiation. CEGB/R6 failure assessment diagram is used as the fracture criteria to determine the minimum allowable wall thickness. Design of a large portion of the low temperature, low pressure piping is dominated by axial stresses. Existing local wall thinning acceptance criteria address high pressure piping where hoop stress dominates the design. The existing criteria is over conservative, in some cases, when used on low pressure piping. Local wall thinning criteria is developed to limit the axial stress on the locally thinned section, based on a reduced average thickness. Limits on pit density are also developed to provide acceptance criteria for pitted piping.
Date: January 1, 1993
Creator: Mertz, G. E.; Lam, P. S. & Awadalla, N. G.
System: The UNT Digital Library
ACHRO: A program to help design achromatic bends (open access)

ACHRO: A program to help design achromatic bends

ACHRO is a very simple 2000-line. FORTRAN code that provides help for the designer of the achromatic bend. Given a beam momentum, the program calculates the required drift lengths and dipole parameters which it will apply to any one of several different types of achromats. The types of achromats that the code helps to design include the Enge dual-270,'' the Brown 2-dipole, the Leboutet 3-dipole, and the Enge 4-dipole, as well as the periodic systems which can be designed to any order in symmetric, nonsymmetric and stair-step varieties. Given the dimensions into which a bend must fit, ACHRO will calculate the geometrical parameters in an X-Y plane for a single or multiple achromat, and for achromatic S-bend'' configurations where possible. ACHRO makes it very easy to optimize a bend with respect to drift lengths and magnet parameters by allowing the user to change parameter values and see the resulting calculation. Used in conjunction with a beam-transport code, ACHRO makes it possible for a designer to consider various types of achromatic bends in the same beamline layout in order to compare important bend characteristics such as dispersion, Isochronicity, sensitivity, geometric and chromatic aberrations, aperture requirements, space for diagnostics, etc., all of …
Date: January 1, 1993
Creator: Rusthoi, D.
System: The UNT Digital Library
Adaptive Transfer Function Networks (open access)

Adaptive Transfer Function Networks

Real-time pattern classification and time-series forecasting applications continue to drive artificial neural network (ANN) technology. As ANNs increase in complexity, the throughput of digital computer simulations decreases. A novel ANN, the Adaptive Transfer Function Network (ATF-Net), directly addresses the issue of throughput. ATF-Nets are global mapping equations generated by the superposition of ensembles of neurodes having arbitrary continuous functions receiving encoded input data. ATF-Nets may be implemented on parallel digital computers. An example is presented which illustrates a four-fold increase in computational throughput.
Date: January 1, 1993
Creator: Goulding, J.R. (Los Alamos National Lab., NM (United States) Portland State Univ., OR (United States). Dept. of Electrical Engineering)
System: The UNT Digital Library
An adaptive weighted diamond differencing method for three-dimensional, XYZ geometry (open access)

An adaptive weighted diamond differencing method for three-dimensional, XYZ geometry

About sixteen years ago, Bengt Carlson introduced a method for discretizing the neutral particle transport equation to achieve a positive solution while at the same time retaining much of the accuracy of the diamond differencing method. About six years later Russian researchers applied this work to their problems and extended it somewhat to enhance the flexibility of the method to incorporate monotonic properties of the solution. This latter work came to the attention of US researchers in late 1991 where it verified much of Carlson's conclusions in theory and in test problems. This method, called the adaptive weighted diamond (AWDD) method, is based upon a weighted diamond discretization of the transport equation with the weights chosen from a diamond difference prediction of the solution so as to correct it for positively and monotonicity. This work re-examines the method and extends it to three-dimensional XYZ geometry and demonstrates its potential for solving such problems accurately while achieving a much smoother solution than diamond with set-to-zero fixup and is as effective as the theta-weighted fixup method 3 while theoretically and operationally more satisfying.
Date: January 1, 1993
Creator: Alcouffe, R.E.
System: The UNT Digital Library
Addressing the insider threat (open access)

Addressing the insider threat

Computers have come to play a major role in the processing of information vital to our national security. As we grow more dependent on computers, we also become more vulnerable to their misuse. Misuse may be accidental, or may occur deliberately for purposes of personal gain, espionage, terrorism, or revenge. While it is difficult to obtain exact statistics on computer misuse, clearly it is growing. It is also clear that insiders -- authorized system users -- are responsible for most of this increase. Unfortunately, their insider status gives them a greater potential for harm This paper takes an asset-based approach to the insider threat. We begin by characterizing the insider and the threat posed by variously motivated insiders. Next, we characterize the asset of concern: computerized information of strategic or economic value. We discuss four general ways in which computerized information is vulnerable to adversary action by the insider: disclosure, violation of integrity, denial of service, and unauthorized use of resources. We then look at three general remedies for these vulnerabilities. The first is formality of operations, such as training, personnel screening, and configuration management. The second is the institution of automated safeguards, such as single-use passwords, encryption, and biometric …
Date: January 1, 1993
Creator: Hochberg, J. G.; Jackson, K. A.; McClary, J. F. & Simmonds, D. D.
System: The UNT Digital Library
ADLIB: A simple database framework for beamline codes (open access)

ADLIB: A simple database framework for beamline codes

There are many well developed codes available for beamline design and analysis. A significant fraction of each of these codes is devoted to processing its own unique input language for describing the problem. None of these large, complex, and powerful codes does everything. Adding a new bit of specialized physics can be a difficult task whose successful completion makes the code even larger and more complex. This paper describes an attempt to move in the opposite direction, toward a family of small, simple, single purpose physics and utility modules, linked by an open, portable, public domain database framework. These small specialized physics codes begin with the beamline parameters already loaded in the database, and accessible via the handful of subroutines that constitute ADLIB. Such codes are easier to write, and inherently organized in a manner suitable for incorporation in model based control system algorithms. Examples include programs for analyzing beamline misalignment sensitivities, for simulating and fitting beam steering data, and for translating among MARYLIE, TRANSPORT, and TRACE3D formats.
Date: January 1, 1993
Creator: Mottershead, C.T.
System: The UNT Digital Library
Advanced computers and simulation (open access)

Advanced computers and simulation

Accelerator physicists today have access to computers that are far more powerful than those available just 10 years ago. In the early 1980's, desktop workstations performed less one million floating point operations per second (Mflops), and the realized performance of vector supercomputers was at best a few hundred Mflops. Today vector processing is available on the desktop, providing researchers with performance approaching 100 Mflops at a price that is measured in thousands of dollars. Furthermore, advances in Massively Parallel Processors (MPP) have made performance of over 10 gigaflops a reality, and around mid-decade MPPs are expected to be capable of teraflops performance. Along with advances in MPP hardware, researchers have also made significant progress in developing algorithms and software for MPPS. These changes have had, and will continue to have, a significant impact on the work of computational accelerator physicists. Now, instead of running particle simulations with just a few thousand particles, we can perform desktop simulations with tens of thousands of simulation particles, and calculations with well over 1 million particles are being performed on MPPs. In the area of computational electromagnetics, simulations that used to be performed only on vector supercomputers now run in several hours on desktop …
Date: January 1, 1993
Creator: Ryne, R.D.
System: The UNT Digital Library
Advanced control system for the Integral Fast Reactor fuel pin processor (open access)

Advanced control system for the Integral Fast Reactor fuel pin processor

A computerized control system has been developed for the remotely-operated fuel pin processor used in the Integral Fast Reactor Program, Fuel Cycle Facility (FCF). The pin processor remotely shears cast EBR- reactor fuel pins to length, inspects them for diameter, straightness, length, and weight, and then inserts acceptable pins into new sodium-loaded stainless-steel fuel element jackets. Two main components comprise the control system: (1) a programmable logic controller (PLC), together with various input/output modules and associated relay ladder-logic associated computer software. The PLC system controls the remote operation of the machine as directed by the OCS, and also monitors the machine operation to make operational data available to the OCS. The OCS allows operator control of the machine, provides nearly real-time viewing of the operational data, allows on-line changes of machine operational parameters, and records the collected data for each acceptable pin on a central data archiving computer. The two main components of the control system provide the operator with various levels of control ranging from manual operation to completely automatic operation by means of a graphic touch screen interface.
Date: January 1, 1993
Creator: Lau, L. D.; Randall, P. F.; Benedict, R. W. & Levinskas, D.
System: The UNT Digital Library
Advanced oxidation and reduction processes: Closed-loop applications for mixed waste (open access)

Advanced oxidation and reduction processes: Closed-loop applications for mixed waste

At Los Alamos we are engaged in applying innovative oxidation and reduction technologies to the destruction of hazardous organics. Non thermal plasmas and relativistic electron-beams both involve the generation of free radicals and are applicable to a wide variety of mixed waste as closed-loop designs can be easily engineered. Silent discharge plasmas (SDP), long used for the generation of ozone, have been demonstrated in the laboratory to be effective in destroying hazardous organic compounds and offer an altemative to existing post-incineration and off-gas treatments. SDP generates very energetic electrons which efficiently create reactive free radicals, without adding the enthalpy associated with very high gas temperatures. A SDP cell has been used as a second stage to a LANL designed, packed-bed reactor (PBR) and has demonstrated DREs as high as 99.9999% for a variety of combustible liquid and gas-based waste streams containing scintillation fluids, nitrates, PCB surrogates, and both chlorinated and fluorinated solvents. Radiolytic treatment of waste using electron-beams and/or bremsstrahlung can be applied to a wide range of waste media (liquids, sludges, and solids). The efficacy and economy of these systems has been demonstrated for aqueous waste through both laboratory and pilot scale studies. We win present recent experimental and …
Date: January 1, 1993
Creator: Coogan, J. J.; Tennant, R. A.; Rosocha, L. A. & Wantuck, P. J.
System: The UNT Digital Library
Advanced power systems featuring a closely coupled catalytic gasification carbonate fuel cell plant (open access)

Advanced power systems featuring a closely coupled catalytic gasification carbonate fuel cell plant

Pursuing the key national goal of clean and efficient uulization of the abundant domestic coal resources for power generation, a study was conducted with DOE/METC support to evaluate the potential of integrated gasification/carbonate fuel cell power generation systems. By closely coupling the fuel cell with the operation of a catalytic gasifier, the advantages of both the catalytic gasification and the high efficiency fuel cell complement each other, resulting in a power plant system with unsurpassed efficiencies approaching 55% (HHV). Low temperature catalytic gasification producing a high methane fuel gas offers the potential for high gas efficiencies by operating with minimal or no combustion. Heat required for gasification is provided by combination of recycle from the fuel cell and exothermic methanation and shift reactions. Air can be supplemented if required. In combination with internally reforming carbonate fuel cells, low temperature catalytic gasification can achieve very attractive system efficiencies while producing extremely low emissions compared to conventional plants utilizing coal. Three system configurations based on recoverable and disposable gasification catalysts were studied. Experimental tests were conducted to evaluate these gasification catalysts. The recoverable catalyst studied was potassium carbonate, and the disposable catalysts were calcium in the form of limestone and iron in …
Date: January 1, 1993
Creator: Steinfeld, G. & Wilson, W.G.
System: The UNT Digital Library
Advanced Test Reactor probabilistic risk assessment (open access)

Advanced Test Reactor probabilistic risk assessment

This report discusses Level 1 probabilistic risk assessment (PRA) incorporating a full-scope external events analysis which has been completed for the Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory.
Date: January 1, 1993
Creator: Atkinson, S. A.; Eide, S .A.; Khericha, S. T. & Thatcher, T. A.
System: The UNT Digital Library
Advanced Test Reactor probabilistic risk assessment (open access)

Advanced Test Reactor probabilistic risk assessment

This report discusses Level 1 probabilistic risk assessment (PRA) incorporating a full-scope external events analysis which has been completed for the Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory.
Date: January 1, 1993
Creator: Atkinson, S. A.; Eide, S. A.; Khericha, S. T. & Thatcher, T. A.
System: The UNT Digital Library
Advanced Turbine Systems scoping and feasibility studies (open access)

Advanced Turbine Systems scoping and feasibility studies

The objective of the Advanced Turbine Systems (ATS) study was to investigate innovative natural gas fired cycle developments to determine the feasibility of achieving 60% (LHV) efficiency within a 10-year time frame. The potential ATS was to be environmentally superior, cost competitive and adaptable to coal-derived fuels. The National Energy Strategy (NES) calls for a balanced program of greater energy efficiency, use of alternative fuels, and the environmentally responsible development of all US energy resources> Consistent with the NES, a Department of Energy (DOE) program has been created to develop Advanced Turbine Systems. The objective of this 10-year program is to develop natural gas fired base load power plants that will have cycle efficiencies greater than 60% (LHV), be environmentally superior to current technology, and also be cost competitive.
Date: January 1, 1993
Creator: Bannister, R. L.; Little, D. A.; Wiant, B. C. & Archer, D. H.
System: The UNT Digital Library
Advanced Turbine Systems scoping and feasibility studies (open access)

Advanced Turbine Systems scoping and feasibility studies

The objective of the Advanced Turbine Systems (ATS) study was to investigate innovative natural gas fired cycle developments to determine the feasibility of achieving 60% (LHV) efficiency within a 10-year time frame. The potential ATS was to be environmentally superior, cost competitive and adaptable to coal-derived fuels. The National Energy Strategy (NES) calls for a balanced program of greater energy efficiency, use of alternative fuels, and the environmentally responsible development of all US energy resources> Consistent with the NES, a Department of Energy (DOE) program has been created to develop Advanced Turbine Systems. The objective of this 10-year program is to develop natural gas fired base load power plants that will have cycle efficiencies greater than 60% (LHV), be environmentally superior to current technology, and also be cost competitive.
Date: January 1, 1993
Creator: Bannister, R. L.; Little, D. A.; Wiant, B. C. (Westinghouse Electric Corp., Orlando, FL (United States)) & Archer, D. H. (Carnegie-Mellon Univ., Pittsburgh, PA (United States))
System: The UNT Digital Library
Advances in low energy neutral atom imaging techniques (open access)

Advances in low energy neutral atom imaging techniques

Recently proposed low energy neutral atom (LENA) imaging techniques use a collisional process to convert the low energy neutrals into ions before detection. At low energies, collisional processes limit the angular resolution and conversion efficiencies of these devices. However, if the intense ultraviolet light background can be suppressed, direct LENA detection is possible. We present results from a series of experiments designed to develop a novel filtering structure based on free-standing transmission gratings. If the grating period is sufficiently small, free standing transmission gratings can be employed to substantially polarize ultraviolet (UV) light in the wavelength range 300 [Angstrom] to 1500 [Angstrom]. If a second grating is placed behind the first grating with its axis of polarization oriented at a right angle to the first's, a substantial attenuation of UV radiation is achievable. ne neutrals will pass through the remaining open area of two gratings and be detected without UV background complications. We have obtained nominal 2000 [Angstrom] period (1000 [Angstrom] bars with 1000 [Angstrom] slits) free standing, gold transmission gratings and measured their UV and atomic transmission characteristics. The geometric factor of a LENA imager based on this technology is comparable to that of other proposed LENA imagers. In …
Date: January 1, 1993
Creator: Scime, E. E.; Funsten, H. O.; McComas, D. J.; Moore, K.R. (Los Alamos National Lab., NM (United States)) & Gruntman, M. (University of Southern California, Los Angeles, CA (United States). Space Sciences Center)
System: The UNT Digital Library
The AGS New Fast Extracted Beam System orbit bump pulser (open access)

The AGS New Fast Extracted Beam System orbit bump pulser

The AGS New Fast Extracted Beam System (New FEB) is designed for RHIC injection and the g-2 experiment, performing single bunch multiple extraction at the prf of 20 to 100 Hz up to 12 times per AGS cycle. Capacitor-discharge pulsers are required to produce local orbit bumps at the fast kicker and ejector magnet locations. These pulsers have to deliver half-sine current pulses at 1 KA peak with a base width of 5 msec. The discharge voltage will require approximately 800V with a [plus minus]0.1% accuracy. Direct charging will require a charger too costly and difficult to build because of the high prf. An alternative charging system is being developed to take advantage of the 1.5 sec idle time between each group of pulses. The charger power supply ratings and regulation requirements are thus greatly reduced. The system analysis and results from a prototype will be presented.
Date: January 1, 1993
Creator: Chang, J. S. & Soukas, A. V.
System: The UNT Digital Library
Los Alamos experimental capabilities: Ancho Canyon high explosives and pulse power facilities (open access)

Los Alamos experimental capabilities: Ancho Canyon high explosives and pulse power facilities

This document outlines the Ancho Canyon testing facility comprehensive material characterization capabilities. These include the high explosive (HE) firing sites, a full complement of gun facilities, and variety of pulse power capacitor bank systems of various energies. The explosive fabrication capability at Los Alamos allows the design and testing of unique HE experimental assemblies. Depending on the hydrodynamic requirements, these explosive systems can vary widely in cost. Years of experience have enabled the development of a comprehensive set of diagnostics to monitor these experiments.
Date: January 1, 1993
Creator: Morris, C.E.
System: The UNT Digital Library
Los Alamos National Laboratory Associate Directorate for Physics and Life Sciences Quality Program (open access)

Los Alamos National Laboratory Associate Directorate for Physics and Life Sciences Quality Program

This report discusses the following on Los Alamos National Laboratory: laboratory mission with physics and life sciences goals; physics and life sciences quality requirements and guidance documents basis; process flow-down of documentation; line-organization internal and external assessments; laboratory management issues under development; and the quality assurance management plan.
Date: January 1, 1993
Creator: Mignardot, H.
System: The UNT Digital Library
The ALEXIS data processing package: An update (open access)

The ALEXIS data processing package: An update

The ALEXIS experiment (Array of Low Energy X-ray Imaging Sensors), is a mini-satellite containing six wide angle EUV/ultrasoft x-ray telescopes. Its purpose is to map out the sky in three narrow (5%) bandpasses around 66, 71, and 93 eV. The 66 and 71 eV bandpasses are centered on intense Fe emission lines which are characteristic of million-degree plasmas such as the one thought to produce the soft x-ray background. The 93 eV bandpass is not near any strong emission lines and is more sensitive to continuum sources. The mission will be launched on the Pegasus Air-Launched Vehicle in early 1993 into a 400-nautical-mile, high-inclination orbit and will be controlled entirely from a small ground station located at Los Alamos. The project is a collaborative effort between Los Alamos National Laboratory, Sandia National Laboratory, and the University of California-Berkeley Space Sciences Laboratory.
Date: January 1, 1993
Creator: Bloch, J.J.; Smith, B.W. & Edwards, B.C.
System: The UNT Digital Library
Algorithms for optimal redundancy allocation (open access)

Algorithms for optimal redundancy allocation

Heuristic and exact methods for solving the redundancy allocation problem are compared to an approach based on genetic algorithms. The various methods are applied to the bridge problem, which has been used as a benchmark in earlier work on optimization methods. Comparisons are presented in terms of the best configuration found by each method, and the computation effort which was necessary in order to find it.
Date: January 1, 1993
Creator: Vandenkieboom, J. & Youngblood, R.
System: The UNT Digital Library