Modal study of refractive effects on x-ray laser coherence (open access)

Modal study of refractive effects on x-ray laser coherence

The role of smoothly varying transverse gain and refraction profiles on x-ray laser intensity and coherence is analyzed by modally expanding the electric field within the paraxial approximation. Comparison with a square transverse profile reveals that smooth-edged profiles lead to: (1) a greatly reduced number of guided modes, (2) the continued cancellation of local intensity from a loosely guided mode by resonant free modes, (3) and the absence of extraneous (or anomalous) free mode resonances. These generic spectral properties should enable a considerable simplification in analyzing and optimizing the coherence properties of laboratory soft x-ray lasers. 6 refs., 3 figs.
Date: April 5, 1991
Creator: Amendt, P.; London, R.A. (Lawrence Livermore National Lab., CA (USA)) & Strauss, M. (Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev)
Object Type: Article
System: The UNT Digital Library
In-Home Performance of Exempt Pellet Stoves in Medford, Oregon. (open access)

In-Home Performance of Exempt Pellet Stoves in Medford, Oregon.

Pellet stoves that are considered exempt'' operate at an air-to-fuel ratio in excess of 35:1. They therefore qualify for exemption from the emissions certification process. A primary goal of this project was to determine how a sample of such stoves, operated in homes, would perform compared to their certified cousins,'' which were evaluated the previous year. In-home performance data documenting emissions from exempt stoves and net delivered efficiencies was particularly desired. This project evaluated six pellet stoves representing three major brands in Medford, Oregon. There were three Breckwell model P24FS, one Horizon Eclipse, one Horizon Destiny, and one Earth Stove TP40. The stoves were monitored for four week-long intervals in January and February 1991, for a total of 24 tests. Evaluations were conducted for particulate, CO (carbon monoxide) and PAH (polycyclic aromatic hydrocarbon) emissions and net efficiency. Monitoring was conducted using the AWES (automated woodstove emissions sampler) sampling system. A new data logger, developed for this project, was used to control the AWES and record real time data. 22 refs., 17 figs., 6 tabs.
Date: July 5, 1991
Creator: Barnett, Stockton G. & Fields, Paula G.
Object Type: Report
System: The UNT Digital Library
Effects of doping on hybridization gapped materials (open access)

Effects of doping on hybridization gapped materials

Doping studies are presented on three materials exhibiting hybridization gaps: Ce{sub 3}Bi{sub 4}Pt{sub 3}, U{sub 3}Sb{sub 4}Pt{sub 3}, and CeRhSb. In the case of trivalent La, Y, or Lu substituting for Ce or U, there is a suppression of the low temperature gap and an increase in the electronic specific heat, {gamma}. In the case of tetravalent Th substitutions for U there is no change in {gamma} and in the case of tetravalent Zr substitution for Ce in CeRhSb, there is an enhanced semiconductor-like behavior in the electrical resistance. These results are discussed in the light of a simple model of hybridization gapped systems. 12 refs., 3 figs.
Date: June 5, 1991
Creator: Canfield, P. C.; Thompson, J. D.; Hundley, M. F.; Lacerda, A. & Fisk, Z.
Object Type: Article
System: The UNT Digital Library
Summary of the Exploratory Studies Facility Alternatives Study; Draft (open access)

Summary of the Exploratory Studies Facility Alternatives Study; Draft

This paper presents a summary of the conduct and findings of the Exploratory Studies Facility Alternatives Study (ESF-AS). The Exploratory Studies Facility (ESF) is being planned for use in the characterization of a site for a potential high-level nuclear waste repository at Yucca Mountain, NV. The purpose of the ESF-AS were to identify and rank order ESF-repository options and to improve understanding of the favorable or unfavorable features of the ESF design. The analysis resulted in the ranking of 34 options, in accordance with the extent to which each option could achieve the objectives. Additional findings regarding design features that were identified as key elements in an option`s ability to provide good overall performance are also discussed.
Date: December 5, 1991
Creator: Costin, L.S.; Dennis, A.W. & Stevens, A.L.
Object Type: Article
System: The UNT Digital Library
Cedar Project---Original goals and progress to date (open access)

Cedar Project---Original goals and progress to date

This report describes: Cedar System Hardware; Compiler and Software Issues on Memory Management; Operating Systems; Compilers; and Multiprocessor Performance on Algorithms and Applications.
Date: September 5, 1991
Creator: Cybenko, G.; Kuck, D.; Padua, D. & Gallopoulos, E.
Object Type: Report
System: The UNT Digital Library
Chloromethyl chlorosulfate as a voltage delay inhibitor in lithium cells (open access)

Chloromethyl chlorosulfate as a voltage delay inhibitor in lithium cells

Chloromethyl chlorosulfate (CMCS) is used as a passive film growth inhibitor in electrochemical cells to minimize voltage delay and low-voltage discharge. Film growth on lithium anodes is significantly diminished when CMCS is added to SOCl{sub 2} and SO{sub 2}Cl{sub 2} electrolytes of lithium batteries. The CMCS also has the effect of extending the shelf-life of Li/SOCl{sub 2} and Li/SO{sub 2}Cl{sub 2} batteries.
Date: April 5, 1991
Creator: Delnick, F. M.
Object Type: Patent
System: The UNT Digital Library
Mechanisms of defect production and atomic mixing in high energy displacement cascades: A molecular dynamics study (open access)

Mechanisms of defect production and atomic mixing in high energy displacement cascades: A molecular dynamics study

We have performed molecular dynamics computer simulation studies of displacement cascades in Cu at low temperature. For 25 keV recoils we observe the splitting of a cascade into subcascades and show that cascades in Cu may lead to the formation of vacancy and interstitial dislocation loops. We discuss a new mechanism of defect production based on the observation of interstitial prismatic dislocation loop punching from cascades at 10 K. We also show that below the subcascade threshold, atomic mixing in the cascade is recoil-energy dependent and obtain a mixing efficiency that scales as the square root of the primary recoil energy. 44 refs., 12 figs.
Date: June 5, 1991
Creator: Diaz de la Rubia, T. & Guinan, M.W.
Object Type: Article
System: The UNT Digital Library
The implementation of a standards based heterogeneous network (open access)

The implementation of a standards based heterogeneous network

Computer networks, supporting an organization's activities, are prevalent and very important to the organization's mission. Implementing a heterogenous organizational network allows the staff to select the computing environment that best supports their job requirements. This paper outlines the lessons learned implementing a heterogenous computer network based on networking standards such as TCP/IP and Ethernet. Such a network is a viable alternative to a proprietary, vendor supported network and can provide all the functionality customers expect in a computer network. 2 figs.
Date: August 5, 1991
Creator: Eldridge, John M. & Tolendino, Lawence F.
Object Type: Report
System: The UNT Digital Library
Fixing the Closed Orbits in the Debuncher (open access)

Fixing the Closed Orbits in the Debuncher

Without a large number of new trims the best way to fix the closed orbits in the debuncher is to move quads. There are some obvious features in the vertical orbit, Figure 1, that look like they are indeed orbit distortions. The horizontal orbit, Figure 2, also has some systematic features that can be removed by moving a small number of quads. It is likely that removing these orbit distortions will help in improving the aperture. In addition, the second order effects of such large offsets in the closed orbit, like changes in phase advance due to the sextapoles, could improve operations.
Date: April 5, 1991
Creator: Halling, Mike
Object Type: Report
System: The UNT Digital Library
Radioecological implications of the Par Pond drawdown (open access)

Radioecological implications of the Par Pond drawdown

The drawdown of the Par Pond reservoir created dramatic alterations in this formerly stable lentic ecosystem. In addition, the radiation environment at Par Pond has changed significantly because of the exposure of Cesium 137-contaminated sediments and the appearance of new transport pathways to the terrestrial environment. In response to this situation, SREL was asked to study the radioecological implications of the reservoir drawdown. This report contains the objectives, methods, and results of the SREL study.
Date: December 5, 1991
Creator: Hickey, H. & Whicker, F. W.
Object Type: Report
System: The UNT Digital Library
Exploratory coprocessing research (open access)

Exploratory coprocessing research

The objectives of this project were to (1) study the scope of the beneficial effects of hydrothermal pretreatment of coal on subsequent conversion, (2) identify and study the chemical or physical causes of this effect, and (3) attempt to elucidate the chemistry responsible for any coal-resid synergisms.
Date: September 5, 1991
Creator: Hirschon, A. S.; Tse, D. S.; Malhotra, R.; McMillen, D. F. & Ross, D. S.
Object Type: Report
System: The UNT Digital Library
Exploratory Coprocessing Research. Final Report, September 1988--June 1991 (open access)

Exploratory Coprocessing Research. Final Report, September 1988--June 1991

The objectives of this project were to (1) study the scope of the beneficial effects of hydrothermal pretreatment of coal on subsequent conversion, (2) identify and study the chemical or physical causes of this effect, and (3) attempt to elucidate the chemistry responsible for any coal-resid synergisms.
Date: September 5, 1991
Creator: Hirschon, Albert S.; Tse, Doris S.; Malhotra, Ripudaman; McMillen, Donald F. & Ross, David S.
Object Type: Report
System: The UNT Digital Library
Coal Reserves Data Base report. Final report on the Demonstrated Reserve Base (DRB) of coal in Wyoming (open access)

Coal Reserves Data Base report. Final report on the Demonstrated Reserve Base (DRB) of coal in Wyoming

The Coal Reserves Data Base (CRDB) Program is a cooperative data base development program sponsored by the Energy Information Administration (EIA). The objective of the CRDB Program is to involve knowledgeable coal resource authorities from the major coal-bearing regions in EIA`s effort to update the Nation`s coal reserves data. This report describes one of two prototype studies to update State-level reserve estimates. The CRDB data are intended for use in coal supply analyses and to support analyses of policy and legislative issues. They will be available to both Government and non-Government analysts. The data also will be part of the information used to supply United States energy data for international data bases and for inquiries from private industry and the public. (VC)
Date: December 5, 1991
Creator: Jones, R. W. & Glass, G. B.
Object Type: Report
System: The UNT Digital Library
Ductile-Brittle Transition Temperature testing of tungsten using the three-point bend test (open access)

Ductile-Brittle Transition Temperature testing of tungsten using the three-point bend test

Three-point bend tests were performed to determine the Ductile-Brittle Transition Temperatures (DBTTs) of forged and chemical vapor deposition (CVD) tungsten. Testing was performed under quasi-static conditions at temperatures between 23{degrees}C and 450{degrees}C using a forced-air environmental chamber. Load-displacement data from the three-point bend tests indicated that the constitutive behavior of the materials tested varied considerably. Finite element modeling of the three-point bend test was performed to investigate plastic strains induced in the samples during testing as a function of constitutive behavior. The modeling assumed plane stress conditions in the sample and simple bi-linear elastic-plastic constitutive behavior of the test material. The strains induced in the samples were found to be functions of both the yield stress and work hardening behavior of the materials. The use of the three-point bend test to determine DBTT, and the DBTTs reported for the test materials, are discussed relative to the modeling results. It is concluded that the three-point bend test has some utility in the determination of DBTTs if some caution is used in the selection of test parameters and fixture geometries. However, the three-point bed test does not provide a complete picture of the nature of the ductile-brittle transition. 12 refs., 9 figs.
Date: March 5, 1991
Creator: Lassila, D.H.; Magness, F. & Freeman, D.
Object Type: Report
System: The UNT Digital Library
Beam to Shell Temperature Differencees for the CC Cryostat (open access)

Beam to Shell Temperature Differencees for the CC Cryostat

This note documents the calculation of stresses resulting from temperature differences between the CC cryostat shell and the module array support beams, and the calculation of corresponding maximum allowable temperature differences to be monitored during the cooldown of the cryostat. A finite element model of a portion of the inner vessel shell was analyzed for a uniform temperature change. The shell was assumed to be completely restrained by the support beams. A maximum allowable temperature difference was determined based on limits on secondary stress ranges prescribed by the ASME Code (Section VID, Division 2). The maximum allowable difference between the cryostat shell and the support beams was found to vary from about 18K near room temperature to about 30K as the shell temperature approaches liquid argon temperature. The allowable values are tabulated below and plotted in Figure 1. The variation results from the decrease in the coefficient of thermal expansion of stainless steels at lower temperatures. As shown in the plot, the variation is roughly linear. Note that although the shell is assumed to be at the lower temperature in Fig. 1, the limitation on temperature difference will also apply during warmup, when the shell will likely be warmer than …
Date: February 5, 1991
Creator: Luther, R.
Object Type: Report
System: The UNT Digital Library
Estimating deposition velocity from atmospheric releases of iodine (open access)

Estimating deposition velocity from atmospheric releases of iodine

Deposition velocity is a parameter used in atmospheric transport models to specify the amount an atmospheric constituent transferred from the atmosphere to the surface of the earth. The material may deposit on the surface of soil, water, or vegetation. The deposition may be the result of rainfall or diffusion. A method for the calculation of deposition velocity based upon the decrease in deposition with distance from a point source is presented. The method does not require a knowledge of the time over which the deposition occurs or the concentration of the material in the atmosphere. However, the method does assume the deposition rate is proportional to the air concentration. The sensitivity to errors resulting from certain errors in the measurements and from violation of some of the assumptions of the model underlining the calculations are also to be discussed. The method has been used to estimate the deposition velocity of I-129. Two sets of I-129 deposition data at various distances from the center of SRS were used in the calculations. The results indicate that the deposition velocity is near a value of 0.2 cm/s. This is consistent with the processes that are known to control iodine deposition.
Date: February 5, 1991
Creator: Murphy, C. E. Jr.
Object Type: Report
System: The UNT Digital Library
Estimating deposition velocity from atmospheric releases of iodine (open access)

Estimating deposition velocity from atmospheric releases of iodine

Deposition velocity is a parameter used in atmospheric transport models to specify the amount an atmospheric constituent transferred from the atmosphere to the surface of the earth. The material may deposit on the surface of soil, water, or vegetation. The deposition may be the result of rainfall or diffusion. A method for the calculation of deposition velocity based upon the decrease in deposition with distance from a point source is presented. The method does not require a knowledge of the time over which the deposition occurs or the concentration of the material in the atmosphere. However, the method does assume the deposition rate is proportional to the air concentration. The sensitivity to errors resulting from certain errors in the measurements and from violation of some of the assumptions of the model underlining the calculations are also to be discussed. The method has been used to estimate the deposition velocity of I-129. Two sets of I-129 deposition data at various distances from the center of SRS were used in the calculations. The results indicate that the deposition velocity is near a value of 0.2 cm/s. This is consistent with the processes that are known to control iodine deposition.
Date: February 5, 1991
Creator: Murphy, C. E. Jr.
Object Type: Report
System: The UNT Digital Library
From bit-strings (part way) to quaternions (open access)

From bit-strings (part way) to quaternions

We present work in progress on constructing rotations and boosts from bit strings, and a mapping of bit-strings onto integer quaternion coordinates.
Date: April 5, 1991
Creator: Noyes, H. Pierre
Object Type: Article
System: The UNT Digital Library
Reactor Operations Management Plan (open access)

Reactor Operations Management Plan

The K-Reactor last operated in April 1988. At that time, K-Reactor was one of three operating reactors at the Savannah River Site (SRS). Following an incident in P-Reactor in August 1988, it was decided to discontinue SRS reactor operation and conduct an extensive program to upgrade operating practices and plant hardware prior to restart of any of the reactors. The K-reactor was the first of three reactors scheduled to resume production. At the present time, it is the only reactor with planned restart. WSRC assumed management of SRS on April 1, 1989. WSRC established the Safety Basis for Restart and a listing of the actions planned to satisfy the Safety Basis. In consultation with DOE, it was determined that proper management of the restart activities would require a single plan that integrated the numerous activities. The plan was entitled the Reactor Operations Management Plan and is referred to simply as the ROMP. The initial version of ROMP was produced in July of 1989. Subsequent modifications led to Revision 3 which was approved by DOE in May, 1990. Other changes were made in a formal change process, resulting in the latest version, Revision 5, being issued in October, 1990. The ROMP …
Date: December 5, 1991
Creator: Rice, P.D.
Object Type: Article
System: The UNT Digital Library
Heavy fermions and other highly correlated electron systems (open access)

Heavy fermions and other highly correlated electron systems

In this paper I given a brief summary of the achievements grouped under three main headings, namely (1) heavy-fermion, mixed-valence and Kondo systems, (2) the n-channel Kondo problem and applications, and (3) one-dimensional conductors and antiferromagnets. The list of published papers and preprints is attached to the report, as well as a list of abstracts submitted to Conferences. All these papers are new in the sense that none of them was listed in the final technical report of grant DE-FG02-87ER45333.
Date: December 5, 1991
Creator: Schlottmann, P.
Object Type: Report
System: The UNT Digital Library
Heavy fermions and other highly correlated electron systems. Technical progress report, March 15, 1991--March 14, 1992 (open access)

Heavy fermions and other highly correlated electron systems. Technical progress report, March 15, 1991--March 14, 1992

In this paper I given a brief summary of the achievements grouped under three main headings, namely (1) heavy-fermion, mixed-valence and Kondo systems, (2) the n-channel Kondo problem and applications, and (3) one-dimensional conductors and antiferromagnets. The list of published papers and preprints is attached to the report, as well as a list of abstracts submitted to Conferences. All these papers are new in the sense that none of them was listed in the final technical report of grant DE-FG02-87ER45333.
Date: December 5, 1991
Creator: Schlottmann, P.
Object Type: Report
System: The UNT Digital Library
Warheads and Fissile Materials:Declarations and Counting (open access)

Warheads and Fissile Materials:Declarations and Counting

This paper reviews some of the issues about verifying the dismantlement of nuclear warheads and controlling nuclear materials in the context of arms control objectives. It is asserted that information about the stockpiles of nuclear warheads and materials is necessary to analyze the impacts and verification requirements of arms control measures including warhead dismantlement and fissile material controls. It is proposed that the US and the Soviets engage in a series of declarations about their stockpiles of nuclear weapons and materials. It is also asserted that currently it is more important to verify that warheads are retired to safe, secure facilities than to verify their dismantlement. It is proposed that production of new or rebuilt warheads be limited to less than the number retired each year. Verifying the number of new and rebuilt warheads deployed and the number retired avoids many of the difficulties in verifying dismantlement and material controls.
Date: November 5, 1991
Creator: Sutcliffe, W. G.
Object Type: Article
System: The UNT Digital Library
U.S. Department of Energy Geothermal Division Annual Operating Plan: 1991 (open access)

U.S. Department of Energy Geothermal Division Annual Operating Plan: 1991

This is an internal DOE Geothermal Program planning and control document. Many of these reports were issued only in draft form.
Date: June 5, 1991
Creator: United States. Department of Energy. Geothermal Division.
Object Type: Report
System: The UNT Digital Library
D-Zero Collider Detector Cryopump Design and Operation (open access)

D-Zero Collider Detector Cryopump Design and Operation

The vacuum pumping of the CC Cryostat was anticipated to be dominated by a water vapor load. The Engineering Note 270, extrapolating from earlier experience, predicts the removal of water vapor will be the dominant pumping load and take ca. 45 days to remove at the pumping speed planned. Part of the planned pumping capability was a homemade, liquid nitrogen temperature, water vapor cryopump. This note describes the design, fabrication and performance experiences of the Cryopump described in the D0 assembly drawing 3740.514-ME-294693.
Date: April 5, 1991
Creator: Wu, J. & Mulholland, G. T.
Object Type: Report
System: The UNT Digital Library