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Temperature and spectral investigation of bulk KDP below damage using 355 nm laser irradiation (open access)

Temperature and spectral investigation of bulk KDP below damage using 355 nm laser irradiation

A spectral and temperature investigation of fast-grown KDP crystals under high fluence, 355 nm laser irradiation is discussed. Pump-and-probe Raman spectroscopy indicate transient changes of the vibrational spectrum. Photothermal deflection experiments provide information on the temporal behavior of the temperature change. The presence of emission in the visible and NIR spectral regions is attributed to the presence of impurities and/or defects in the crystal.
Date: October 1, 1997
Creator: Demos, S. G., LLNL
System: The UNT Digital Library
Top quark results from D-Zero (open access)

Top quark results from D-Zero

This is a brief summary of D0's top quark measurements, including {sigma}{sub t{bar t}} and m{sub t} in the {ell} + jets and dilepton channels, {sigma}{sub t{bar t}} in the all jets channel, and the search for top disappearance via t {yields} bH{sup +}, H{sup +} {yields} {tau}{nu} or c{bar s}.
Date: November 1, 1997
Creator: Strovink, Mark
System: The UNT Digital Library
Bench-Scale Demonstration of Hot-Gas Desulfurization Technology (open access)

Bench-Scale Demonstration of Hot-Gas Desulfurization Technology

Prior to the current project, development of the DSRP was done in a laboratory setting, using synthetic gas mixtures to simulate the regeneration off-gas and coal gas feeds. The objective of the current work is to further the development of zinc titanate fluidized-bed desulfurization (ZTFBD) and the DSRP for hot-gas cleanup by testing with actual coal gas. The objectives of this project are to: (1) Develop and test an integrated, skid-mounted, bench-scale ZTFBD/DSRP reactor system with a slipstream of actual coal gas; (2) Test the bench-scale DSRP over an extended period with a slipstream of actual coal gas to quantify the degradation in performance, if any, caused by the trace contaminants present in coal gas (including heavy metals, chlorides, fluorides, and ammonia); (3) Expose the DSRP catalyst to actual coal gas for extended periods and then test its activity in a laboratory reactor to quantify the degradation in performance, if any, caused by static exposure to the trace contaminants in coal gas; (4) Design and fabricate a six-fold larger-scale DSRP reactor system for future slipstream testing; (5) Further develop the fluidized-bed DSRP to handle high concentrations (up to 14 percent) of SO{sub 2} that are likely to be encountered when …
Date: July 1, 1997
Creator: Portzer, Jeffrey W. & Gangwal, Santosh K.
System: The UNT Digital Library
Equation of State measurements of hydrogen isotopes on Nova (open access)

Equation of State measurements of hydrogen isotopes on Nova

High intensity lasers can be used to perform measurements of materials at extremely high pressures if certain experimental issues can be overcome. We have addressed those issues and used the Nova laser to shock-compress liquid deuterium and obtain measurements of density and pressure on the principal Hugoniot at pressures from 300 kbar to more than 2 Mbar. The data are compared with a number of equation of state models. The data indicate that the effect of molecular dissociation of the deuterium into a monatomic phase may have a significant impact on the equation of state near 1 Mbar.
Date: November 1, 1997
Creator: Collins, G. W., LLNL
System: The UNT Digital Library
Test on 2,000 photomultipliers for the CDF endplug calorimeter upgrade (open access)

Test on 2,000 photomultipliers for the CDF endplug calorimeter upgrade

A systematic test of various characteristics, such as gain, dark current, maximum peak current, stability and relative quantum efficiency, has been made to evaluate about 2,000 photomultiplier tubes for the upgraded CDF Endplug calorimeters. The phototubes are Hamamatsu R4125,19mm diameter with green-extended photocathode. In this report we discuss the distribution of the major characteristics measured and the failure mode. Comparisons between independent measurements made on some of the characteristics are used to evaluate the quality of the measurement itself.
Date: December 1, 1997
Creator: Fiori, I.
System: The UNT Digital Library
Evidence of critical scaling behavior during vapor phase synthesis of continuous filament composites (open access)

Evidence of critical scaling behavior during vapor phase synthesis of continuous filament composites

The authors present experimental measurements of the accessible pore fraction in ceramic matrix composites during consolidation by vapor phase infiltration. For two topologically distinct filament architectures, the accessible pore fraction decreased during consolidation with a power law decay and a critical scaling exponent of 0.41 (R{sup 2} = 0.97). A three-dimensional analysis of the percolating pores revealed that the structures became topologically equivalent and simply connected near the critical density.
Date: February 1, 1997
Creator: Kinney, J. H., LLNL
System: The UNT Digital Library
Comparative study of 137Cs transfer from soil to vegetation in the Marshall Islands (open access)

Comparative study of 137Cs transfer from soil to vegetation in the Marshall Islands

None
Date: October 1, 1997
Creator: Robison, W. I.; Conrado, C. L. & Hamilton, T. F.
System: The UNT Digital Library
An asymmetric muon-proton Collider: Luminosity Consideration (open access)

An asymmetric muon-proton Collider: Luminosity Consideration

An asymmetric muon-proton collider is proposed as an instrument for possible quark structure search. Energy of proton beam is supposed to be some 5-6 times of muon energy. Estimated luminosity of the collider with two rings--the Tevatron accelerator and {mu}-ring--is found to be of the order of 10{sup 33} s{sup -1} cm{sup -2}.
Date: April 1, 1997
Creator: Shiltsev, V. D.
System: The UNT Digital Library
Enhanced Control of Mercury and other HAP by Innovative Modifications to Wet FGD Processes (open access)

Enhanced Control of Mercury and other HAP by Innovative Modifications to Wet FGD Processes

The overall objective of this project was to learn more about controlling emissions of hazardous air pollutants (HAPs) from coal-fired power plants that are equipped with wet flue gas desulfurization (FGD) systems. The project was included by FETC as a Phase I project in its Mega-PRDA program. Phase I of this project focused on three research areas. These areas in order of priority were: (1) Catalytic oxidation of vapor-phase elemental mercury; (2) Enhanced particulate-phase HAPs removal by electrostatic charging of liquid droplets; and (3) Enhanced mercury removal by addition of additives to FGD process liquor. Mercury can exist in two forms in utility flue gas--as elemental mercury and as oxidized mercury (predominant form believed to be HgCl{sub 2}). Previous test results have shown that wet scrubbers effectively remove the oxidized mercury from the gas but are ineffective in removing elemental mercury. Recent improvements in mercury speciation techniques confirm this finding. Catalytic oxidation of vapor-phase elemental mercury is of interest in cases where a wet scrubber exists or is planned for SO{sub 2} control. If a low-cost process could be developed to oxidize all of the elemental mercury in the flue gas, then the maximum achievable mercury removal across the existing …
Date: July 1, 1997
Creator: Hargrove, O. W.; Carey, T. R.; Richardson, C. F.; Skarupa, R. C.; Meserole, F. B.; Rhudy, R. G. et al.
System: The UNT Digital Library
Clear Liquor Scrubbing with Anhydrite Production (open access)

Clear Liquor Scrubbing with Anhydrite Production

The objective of this project to develop an advanced flue gas desulfurization (FGD) process that has decreased capital and operating costs, higher SO{sub 2} removal efficiency, and better by-product solids quality than existing, commercially available technology. A clear liquor process (which uses a scrubbing liquid with no solids) will be used to accomplish this objective rather than a slurry liquor process (which contains solids). This clear liquor scrubbing (CLS) project is focused on three research areas: (1) Development of a clear liquor scrubbing process that uses a clear solution to remove SO{sub 2} from flue gas and can be operated under inhibited-oxidation conditions; (2) Development of an anhydrite process that converts precipitated calcium sulfite to anhydrous calcium sulfate (anhydrite); and (3) Development of an alkali/humidification process to remove HCl from flue gas upstream of the FGD system. The anhydrite process also can be retrofit into existing FGD systems to produce a valuable by-product as an alternative to gypsum. This fits well into another of FETC's PRDA objectives of developing an advanced byproduct recovery subsystem capable of transforming SO{sub 2} into a useable byproduct or high-volume valuable commodities of interest. This paper describes the proposed processes, outlines the test approach, and …
Date: July 1, 1997
Creator: Hargrove, O. W.; Carey, T. R.; Lowell, P. S.; Meserole, F. B.; Rhudy, R. G. & Feeley, Thomas J.
System: The UNT Digital Library
Searches for heavy exotic states at the Tevatron (open access)

Searches for heavy exotic states at the Tevatron

None
Date: December 1, 1997
Creator: Hoffman, Kara
System: The UNT Digital Library
Electronic structure and phase stability of Pu-Ga alloys (open access)

Electronic structure and phase stability of Pu-Ga alloys

Plutonium metal has six different crystallographic allotropes from room temperature until it melts just above 600 C. The room-temperature {alpha} phase is monoclinic with 32 atoms per unit cell, (an {alpha} phase with 16 atoms per cell also exists), which is the lowest-symmetry crystal structure known of any pure element. In fact, only the high-temperature {delta} (fcc) phase of Pu possesses one of the traditional close-packed structures. The low-symmetry and small lattice constants of the lowest-temperature phase of the light actinides can be used as an argument for f-bonding in these materials. The large volume increase in Pu in going from the {alpha} to the {delta} phase has been argued on phenomenological grounds to be the result of decreased f-bonding. In addition, XPS data have been obtained for both the {alpha} and the {delta} phases. Both sets of data show the presence of a peak below the Fermi level (EF). This peak is 2.0 eV wide in the {alpha} phase and 3.0 eV wide in the {delta} phase. The XPS intensity calculations (for the two phases) which treat the f-electrons as bonding states agree with the measurements of the {alpha} phase spectra, but not with those of the {delta} phase. …
Date: March 1, 1997
Creator: Gonis, A., LLNL
System: The UNT Digital Library
Nondestructive Evaluation of Ceramic Candle Filters Using Vibration Response (open access)

Nondestructive Evaluation of Ceramic Candle Filters Using Vibration Response

This study aims at the development of an effective nondestructive evaluation technique to predict the remaining useful life of a ceramic candle filter during a power plant's annual maintenance shutdown. The objective of the present on-going study is to establish the vibration signatures of ceramic candle filters at varying degradation levels due to different operating hours, and to study the various factors involving the establishment of the signatures.
Date: July 1, 1997
Creator: Chen, Roger H. L.; Kiriakidis, Alejandro C. & Peng, Steve W.
System: The UNT Digital Library
Laminar burn rates of gun propellants measured in the high-pressure strand burner (open access)

Laminar burn rates of gun propellants measured in the high-pressure strand burner

The pressure dependence of the laminar burn rate of gun propellants plays a role in the design and behavior of high-performance guns. We have begun a program to investigate the effects of processing variables on the laminar burn rates, using our high-pressure strand burner to measure these rates at pressures exceeding 700 MPa. We have burned JA2 and M43 propellant samples, provided by Dr. Arpad Juhasz, ARL, from propellant lots previously used in round-robin tests. Our results at room temperature are in accord with other measurements. In addition, we present results measured for propellant that has been preheated to 50 C before burning. We used our thermochemical equilibrium code, CHEETAH, to help interpret the simultaneous pressure and temperature measurements taken during the testing, and show examples of its use. It has been modified to provide performance measures and equations of state for the products that are familiar to the gun-propellant community users of BLAKE.
Date: October 1, 1997
Creator: Reaugh, J. E., LLNL
System: The UNT Digital Library
Size effect and detonation front curvature (open access)

Size effect and detonation front curvature

Heat flow in a cylinder with internal heating is used as a basis for deriving a simple theory of detonation front curvature, leading to the prediction of quadratic curve shapes. A thermal conductivity of 50 MW/mm{sup 2} is found for TATB samples.
Date: July 1, 1997
Creator: Souers, P. C., LLNL
System: The UNT Digital Library
Hot-Gas Desulfurization with Sulfur Recovery (open access)

Hot-Gas Desulfurization with Sulfur Recovery

The objective of this study is to develop a second generation HGD process that regenerates the sulfided sorbent directly to elemental sulfur using SO{sub 2}, with minimal consumption of coal gas. The goal is to have better overall economics than DSRP when integrated with the overall IGCC system.
Date: July 1, 1997
Creator: Portzer, Jeffrey W.; Damle, Ashok S. & Gangwal, Santosh K.
System: The UNT Digital Library
Use of in-process EDM truing to generate complex contours on metal-bond, superabrasive grinding wheels for precision grinding structural ceramics (open access)

Use of in-process EDM truing to generate complex contours on metal-bond, superabrasive grinding wheels for precision grinding structural ceramics

This paper presents recent work performed at Lawrence Livermore National Laboratory to develop cost-effective, versatile and robust manufacturing methods for grinding precision features in structural ceramics using metal-bond, superabrasive grinding wheels. The developed processes include utilizing specialized, on-machine hardware to generate precision profiles onto grinding wheels using electrical-discharge machining (EDM) and a contoured rotating electrode. The production grinding processes are described, which were developed and used to grind various precision details into a host of structural ceramics such as Al{sub 2}O{sub 3}, Si{sub 3}N{sub 4}, and BeO. The methodologies, hardware and results of both creep-feed and cylindrical grinding are described. A discussion of imparted grinding damage and wheel wear is also presented.
Date: August 1, 1997
Creator: Piscotty, M. A., LLNL
System: The UNT Digital Library
Jet properties and QCD at high E{sub T} (open access)

Jet properties and QCD at high E{sub T}

None
Date: October 1, 1997
Creator: Flaugher, B.
System: The UNT Digital Library
Probing High Density Plasmas With Soft X-Ray Lasers (open access)

Probing High Density Plasmas With Soft X-Ray Lasers

None
Date: August 1, 1997
Creator: Celliers, P.; Barbee, T. W., Jr.; Cauble, R.; Da Silva, L. B.; Decker, C. D.; Kalantar, D. H. et al.
System: The UNT Digital Library
Integrated demonstration of molten salt oxidation with salt recycle for mixed waste treatment (open access)

Integrated demonstration of molten salt oxidation with salt recycle for mixed waste treatment

Molten Salt Oxidation (MSO) is a thermal, nonflame process that has the inherent capability of completely destroying organic constituents of mixed wastes, hazardous wastes, and energetic materials while retaining inorganic and radioactive constituents in the salt. For this reason, MSO is considered a promising alternative to incineration for the treatment of a variety of organic wastes. Lawrence Livermore National Laboratory (LLNL) has prepared a facility and constructed an integrated pilot-scale MSO treatment system in which tests and demonstrations are performed under carefully controlled (experimental) conditions. The system consists of a MSO processor with dedicated off-gas treatment, a salt recycle system, feed preparation equipment, and equipment for preparing ceramic final waste forms. This integrated system was designed and engineered based on laboratory experience with a smaller engineering-scale reactor unit and extensive laboratory development on salt recycle and final forms preparation. In this paper we present design and engineering details of the system and discuss its capabilities as well as preliminary process demonstration data. A primary purpose of these demonstrations is identification of the most suitable waste streams and waste types for MSO treatment.
Date: November 1, 1997
Creator: Hsu, P.C.
System: The UNT Digital Library
Supersymmetry searches at the Tevatron (open access)

Supersymmetry searches at the Tevatron

None
Date: December 1, 1997
Creator: Conway, John
System: The UNT Digital Library
Hard target penetrator explosive development optimization of fragment, blast and survivability properties of explosives for hard target applications (open access)

Hard target penetrator explosive development optimization of fragment, blast and survivability properties of explosives for hard target applications

Several new explosives have been developed for hard target and related applications. Materials having energy densities as high as 20 KJ/cc have been made. Mid-scale field trials have been carried out at Eglin Air Force Base. Fragmentation improvements 150% that of Tritonal have been attained.
Date: May 1, 1997
Creator: Simpson, R. L., LLNL
System: The UNT Digital Library
Supersymmetric lepton flavor violation at the NLC (open access)

Supersymmetric lepton flavor violation at the NLC

Supersymmetric theories generally have new flavor violation sources in the squark and slepton mass matrices. If significant lepton flavor violation exists, selectron and smuon should be nearly degenerate. This leads to the phenomenon of slepton oscillations, which is analogous to neutrino oscillations, if sleptons are produced at the Next Linear Collider. The direct slepton production at the Next Linear Collider provides a much more powerful probe of lepton flavor violation than the current bounds from rare processes, such as {mu} {yields} e{gamma}.
Date: April 1, 1997
Creator: Cheng, Hsin-Chia
System: The UNT Digital Library
Introduction of section II and overview of dose reconstruction: lessons learned from studies in the U.S. (open access)

Introduction of section II and overview of dose reconstruction: lessons learned from studies in the U.S.

The purpose of this presentation is to provide an overview of dose reconstruction with an emphasis on the lessons learned from work in the United States. Several major dose reconstructions have been undertaken in the United States, particularly in reference to Department of Energy (DOE) facilities. Some of these activities have now been completed and these are indicated in the upper part of Table 2. The first major activity took place at the Nevada Test Site (NTS),where researchers have considered several different specific populations. The activities began with an analysis of hypothetical individuals, which was followed by an analysis of the collective dose to all exposed individuals within the surrounding region. Later, the University of Utah undertook some specific epidemiologic studies and calculated doses to specific individuals. The Hanford Environmental Dose Reconstruction Study has completed its results for hypothetical individuals. The Hanford researchers did not report collective dose. Long-Term Radiation Contamination in Chelyabinsk, Russia
Date: January 1, 1997
Creator: Anspaugh, L. R, LLNL
System: The UNT Digital Library