MEASUREMENT OF LINEAR COUPLING RESONANCE IN RHIC. (open access)

MEASUREMENT OF LINEAR COUPLING RESONANCE IN RHIC.

Linear coupling is one of the factors that determine beam lifetime in RHIC. The traditional method of measuring the minimum tune separation requires a tune scan and can't be done parasitically or during the acceleration ramp. A new technique of using ac dipoles to measure linear coupling resonance has been developed at RHIC. This method measures the degree of coupling by comparing the amplitude of the horizontal coherent excitation with the amplitude of the vertical coherent excitation if the beam is excited by the vertical AC dipole and vice versa. One advantage of this method is that it can be done without changing tunes from the normal machine working points. In principle, this method can also localize the coupling source by mapping out the coupling driving terms throughout the ring. This is very useful for local decoupling the interaction regions in RHIC. A beam experiment of measuring linear coupling has been performed in RHIC during its 2003 run, and the analysis of the experimental data is discussed in this paper.
Date: May 12, 2002
Creator: BAI,M. PILAT,F. SATOGATA,T. TOMAS,R.
Object Type: Article
System: The UNT Digital Library
Barrier Foil Heating Simulations Using LASNEX (open access)

Barrier Foil Heating Simulations Using LASNEX

It is necessary to place a barrier foil in front of the X-ray converter target to prevent the backstreaming ions. This research note presents the simulations of foil heating using the latest EOS tables. LASNEX simulations are carried out using both DARHT-II and ETA-II beam parameters. Results for all the foils studied here, using the DARHT-II beam parameters, show that the integrated line density along the axis at the end of the 4th pulse remains essentially unchanged even if the foils are heated by beams with relatively small beam spot sizes. The temperature can reach up to 3000 C on graphite foil but can only reach several hundred degree Celsius on Mylar foil. Simulations also show that ETA-II beam can create a ''burn-through'' hole on all the foils except graphite and diamond foils, which may require pre-heat. The threshold beam spot size required for hole formation will be compared with LASNEX simulation for the purpose of code verification.
Date: March 12, 2002
Creator: Ho, D. D.-M.
Object Type: Report
System: The UNT Digital Library
Achieving High Dopant Concentrations in Si: First Principles Simulations (open access)

Achieving High Dopant Concentrations in Si: First Principles Simulations

In this paper we discuss methods to obtain high dopant concentrations during processing of Si devices. The possibility of increasing the solubility of B in Si by misfit stress is investigated. The enthalpy of B atoms is calculated, with and without stress, using density functional theory. A second approach, the trapping of excess dopant atoms during deposition of Si, is also considered. For this purpose, the enthalpies of several dopant species in sites near the surface are calculated.
Date: August 12, 2002
Creator: Centoni, S A; Sadigh, B; Caturla, M J; Gilmer, G H & Diaz de la Rubia, T
Object Type: Article
System: The UNT Digital Library
Settling Test Using Simulants to Evaluate Uranium Metal Distribution in K Basin Sludge (open access)

Settling Test Using Simulants to Evaluate Uranium Metal Distribution in K Basin Sludge

This report presents the results of a large-scale settling test conducted with a K Basin sludge simulant that included metallic tungsten/cobalt (W/Co) fragments (density {approx}14.5 g/cm3) as a surrogate for uranium metal (density 19 g/cm3). The objective of the testing was to gain insight into how uranium metal is likely to be distributed within the K Basin sludge loaded into the large-diameter containers (LDCs) that will be used for storage at T Plant. In the LDCs, uranium metal will react with water and generate heat and hydrogen gas. During loading, transportation, and storage operations, the uranium metal distribution in the LDCs will have an impact on the thermal stability. Approximately 50 m3 of K Basin sludge have accumulated during the storage of more than 2100 metric tons of N Reactor fuel elements in two water-filled concrete pools (K East and K West Basins) in the 100K Area of the Hanford Site.
Date: April 12, 2002
Creator: Schmidt, Andrew J. & Elmore, Monte R.
Object Type: Report
System: The UNT Digital Library
Large Aperture, High-Efficiency Multilayer Dielectric Reflection Gratings (open access)

Large Aperture, High-Efficiency Multilayer Dielectric Reflection Gratings

The authors have designed and fabricated a 355 x 150 mm multilayer dielectric diffraction grating, 1800 l/mm for 1030 nm light, that exhibits >99% diffraction efficiency and a diffracted wavefront flatness of <0.15 {lambda}. This grating is an enabling component of a 1 ps, high rep-rate machining laser currently in operation at LLNL.
Date: April 12, 2002
Creator: Britten, J A; Bryan, S J; Summers, L J; Nguyen, H T; Shore, B W & Lyngnes, O
Object Type: Article
System: The UNT Digital Library
Thermogravimetric Thin Aqueous Film Corrosion Studies of Alloy 22; Calcium Chloride Solutions at 150C and Atmospheric Pressure (open access)

Thermogravimetric Thin Aqueous Film Corrosion Studies of Alloy 22; Calcium Chloride Solutions at 150C and Atmospheric Pressure

The extent of reaction of alloy-22 with limited amounts of aqueous calcium chloride (CaCl{sub 2}) was investigated. Alloy-22 is a highly corrosion-resistant nickel-chromium-molybdenum-tungsten alloy. Specimens were polished to a mirror finish prior to aerosol salt deposition. An aqueous film was formed by deliquescence of deposited CaCl{sub 2} at 150 C and 22.5% relative humidity (RH). The reactant gas was a continuous flow of purified humidified laboratory air. The reaction progress as a function of time was continuously measured in-situ by a micro-balance. An initial weight gain due to deliquescence of the CaCl{sub 2} was observed. A steady weight loss was observed over the next 72 hours, after which no further weight change was observed. During this weight loss, white precipitates formed and the specimen's surface became visibly dry. The precipitate crystals were identified as Ca(OH){sub 2} by post-test Raman spectroscopy; however, energy dispersive X-ray spectroscopy indicated that there was a significant amount of chlorine contained in them.
Date: November 12, 2002
Creator: Hailey, P & Gdoowski, G
Object Type: Article
System: The UNT Digital Library
Shocked and Stressed, Metals Get Stronger (open access)

Shocked and Stressed, Metals Get Stronger

People who know their way around metalworking are no doubt familiar with peening--using a ball-peen hammer to pound a piece of metal into shape and strengthen it against fatigue failure. For the past 50 years, an industrialized equivalent has been shot peening, in which metal or ceramic beads as large as marbles or as small as salt and pepper grains pneumatically bombard a metal surface. Laser peening, a process based on a superior laser technology developed at Lawrence Livermore, replaces the hammer blows and streams of beads with short blasts of laser light. The end result is a piece of metal with significantly improved performance. Lawrence Livermore and Metal Improvement Company, Inc., won a coveted R and D 100 Award for their laser-peening process in 1998 (see S and TR, October 1998, pp. 12-13). Since that time, they've been developing uses for the technology with a number of industries, including automotive, medical, and aerospace. They've also developed an offshoot technique--laser peenmarking{trademark}--which provides a way to easily and clearly identify parts with a mark that is extremely difficult to counterfeit. Another outgrowth is a new peen-forming technology that allows complex contouring of problematic thick metal components such as the thick sections …
Date: March 12, 2002
Creator: Hackel, L
Object Type: Report
System: The UNT Digital Library
Mapping Phase Transformations in the Heat-Affected-Zone of Carbon Manganese Steel Welds using Spatially Resolved X-Ray Diffraction (open access)

Mapping Phase Transformations in the Heat-Affected-Zone of Carbon Manganese Steel Welds using Spatially Resolved X-Ray Diffraction

Spatially Resolved X-Ray Diffraction (SRXRD) was used to investigate phase transformations that occur in the heat affected zone (HAZ) of gas tungsten arc (GTA) welds in AISI 1005 carbon-manganese steel. In situ SRXRD experiments performed at the Stanford Synchrotron Radiation Laboratory (SSRL) probed the phases present in the HAZ during welding, and these real-time observations of the HAZ phases were used to construct a map of the phase transformations occurring in the HAZ. This map identified 5 principal phase regions between the liquid weld pool and the unaffected base metal. Regions of annealing, recrystallization, partial transformation and complete transformation to {alpha}-Fe, {gamma}-Fe, and {delta}-Fe phases were identified using SRXRD, and the experimental results were combined with a heat flow model of the weld and thermodynamic calculations to compare these results with the important phase transformation isotherms. From the resulting phase transformation map, the kinetics of phase transformations that occur under the highly non-isothermal heating and cooling cycles produced during welding of steels can be better understood and modeled.
Date: February 12, 2002
Creator: Elmer, J W; Wong, J; Ressler, T & Palmer, T A
Object Type: Article
System: The UNT Digital Library
Characterization of Vadose Zone Sediment: Uncontaminated RCRA Borehole Core Samples and Composite Samples (open access)

Characterization of Vadose Zone Sediment: Uncontaminated RCRA Borehole Core Samples and Composite Samples

The overall goal of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc. asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediment from within the S-SX Waste Management Area. This report is the first in a series of four reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from RCRA borehole bore samples and composite samples. Intact cores from two RCRA boreholes (299-W22-48 and 299-W22-50) near the SX Tank Farm and four, large-quantity grab samples from outcrop sediment on and off the Hanford Site were sampled to better understand the fate of contaminants in the vadose zone beneath underground storage tanks at the Hanford Site. Borehole and outcrop samples analyzed for this report are located outside the tank farms, and therefore may be considered standard or background samples from which to compare contaminated sediments within the tank farms themselves. This report presents our interpretation of the physical, chemical, and …
Date: February 12, 2002
Creator: Serne, R. Jeffrey; Bjornstad, Bruce N.; Schaef, Herbert T.; Williams, Bruce A.; Lanigan, David C.; Horton, Duane G. et al.
Object Type: Report
System: The UNT Digital Library
Evaluation of Cloud Parameterizations in a High Resolution Atmospheric General Circulation Model Using ARM Data (open access)

Evaluation of Cloud Parameterizations in a High Resolution Atmospheric General Circulation Model Using ARM Data

Typical state of the art atmospheric general circulation models used in climate change studies have horizontal resolution of approximately 300 km. As computing power increases, many climate modeling groups are working toward enhancing the resolution of global models. An important issue that arises when resolution of a model is changed is whether cloud and convective parameterizations, which were developed for use at coarser resolutions, will need to be reformulated or re-tuned. We propose to investigate this issue and specifically cloud statistics using ARM data. The data streams produced by highly instrumented sections of Cloud and Radiation Testbeds (CART) of ARM program will provide a significant aid in the evaluation of cloud and convection parameterization in high-resolution models. Recently, we have performed multiyear global-climate simulations at T170 and T239 resolutions, corresponding to grid cell sizes of 0.7{sup 0} and 0.5{sup 0} respectively, using the NCAR Community Climate Model. We have also a performed climate change simulation at T170. On the scales of a T42 grid cell (300 km) and larger, nearly all quantities we examined in T170 simulation agree better with observations in terms of spatial patterns than do results in a comparable simulation at T42. Increasing the resolution to T239 …
Date: April 12, 2002
Creator: Govindasamy, B & Duffy, P
Object Type: Report
System: The UNT Digital Library
Optimization of Hydroacoustic Deployments at John Day Dam (open access)

Optimization of Hydroacoustic Deployments at John Day Dam

This report describes short-term studies conducted in late November and early December 2001 to optimize hydroacoustic sampling techniques for John Day Dam before the 2002 fish passage efficiency (FPE) study. Knowledge gained in this study should significantly improve hydroacoustic sampling and the accuracy of estimates of fish passage at two locations that have presented problems in past studies. The spillway has been most problematic because many fish detected there were not entrained. Without correction, non-commitment of fish can result in multiple detections and overestimation of fish passage and FPE. Trash-rack-mounted, down-looking transducers for sampling unguided fish at a submerged traveling screen (STS) also have posed problems because the beam was aimed so far downstream that researchers had concerns about fish aspect and detectability. The deployments, aiming angles, and ping rates described here should eliminate all problems encountered in previous studies. This report describes hydroacoustic evaluations. The spill-bay deployment identified in this study should completely eliminate multiple detections of fish by limiting the sample volume for counting fish to the deep high-discharge volume adjacent to the gate. Results from testing of transducers deployed in a turbine intake with an STS suggest that, after testing in 2002, it may be possible to …
Date: November 12, 2002
Creator: Ploskey, Gene R.; Cook, Christopher B.; Titzler, P. Scott & Moursund, Russell A.
Object Type: Report
System: The UNT Digital Library
Connecting to the Internet Securely: Windows 2000 CIAC-2321 (open access)

Connecting to the Internet Securely: Windows 2000 CIAC-2321

As the threat to computer systems increases with the increasing use of computers as a tool in daily business activities, the need to securely configure those systems becomes more important. There are far too many intruders with access to the Internet and the skills and time to spend compromising systems to not spend the time necessary to securely configure a system. Hand-in-hand with the increased need for security are an increased number of items that need to be securely configured. Windows 2000 has about seven hundred security related policy settings, up from seventy two in Windows NT. While Windows 2000 systems are an extension of the Windows NT 4 architecture, there are considerable differences between these two systems, especially in terms of system and security administration. Operational policy, system security, and file security are other areas where Windows 2000 has expanded considerably beyond the domain model of Windows NT 4. The Windows NT 4 Domain model consists of domains of workstations that, with a single login, share resources and are administered together. The database of user settings and credentials resides in the domain server. Domains can trust other domains to expand the sharing of resources between users of multiple domains. …
Date: March 12, 2002
Creator: Orvis, W; Call, K & Dias, J
Object Type: Report
System: The UNT Digital Library
Gallery of Datacubes Obtained with the Livermore Imaging Fourier Transform Spectrometer (open access)

Gallery of Datacubes Obtained with the Livermore Imaging Fourier Transform Spectrometer

We have acquired spatial-spectral datacubes of astronomical objects using the Livermore visible-band imaging Fourier transform spectrometer at Apache Point Observatory. Each raw datacube contains hundreds of thousands of spectral interferograms. We present in-progress demonstrations of these observations.
Date: September 12, 2002
Creator: Wurtz, R.; Wishnow, E. H.; Blais-Ouellette, S.; Cook, K. H.; Holden, B. P.; Carr, D. J. et al.
Object Type: Article
System: The UNT Digital Library
A Computer Generated Reduced Iso-Octane Chemical Kinetic Mechanism Applied to Simulation of HCCI Combustion (open access)

A Computer Generated Reduced Iso-Octane Chemical Kinetic Mechanism Applied to Simulation of HCCI Combustion

This paper shows how a computer can systematically remove non-essential chemical reactions from a large chemical kinetic mechanism. The computer removes the reactions based upon a single solution using a detailed mechanism. The resulting reduced chemical mechanism produces similar numerical predictions significantly faster than predictions that use the detailed mechanism. Specifically, a reduced chemical kinetics mechanism for iso-octane has been derived from a detailed mechanism by eliminating unimportant reaction steps and species. The reduced mechanism has been developed for the specific purpose of fast and accurate prediction of ignition timing in an HCCI engine. The reduced mechanism contains 199 species and 383 reactions, while the detailed mechanism contains 859 species and 3606 reactions. Both mechanisms have been used in numerical simulation of HCCI combustion. The simulations show that the reduced mechanism predicts pressure traces and heat release with good accuracy, similar to the accuracy obtained with the detailed mechanism. As may be expected, emissions of hydrocarbon and carbon monoxide are not as well predicted with the reduced mechanism as with the detailed mechanism, since the reduced mechanism was targeted for predicting HCCI ignition and not HC and CO emissions. Considering that the reduced mechanism requires about 25 times less computational …
Date: August 12, 2002
Creator: Aceves, S. M.; Martinez-Frias, J.; Flowers, D.; Smith, J. R.; Dibble, R. & Chen, J. Y.
Object Type: Article
System: The UNT Digital Library
An Updated Point Design for Heavy Ion Fusion (open access)

An Updated Point Design for Heavy Ion Fusion

An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant.
Date: November 12, 2002
Creator: Meier, W. R.; Yu, S. S.; Abbott, R. P.; Barnard, J. J.; Brown, T.; Callahan, D. A. et al.
Object Type: Article
System: The UNT Digital Library
Characterization of Vadose Zone Sediment: Slant Borehole SX-108 in the S-SX Waste Management Area (open access)

Characterization of Vadose Zone Sediment: Slant Borehole SX-108 in the S-SX Waste Management Area

The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediment from within the S-SX Waste Management Area. This report is the fourth in a series of four reports to present the results of these analyses. Specifically, this fourth report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from the slant borehole installed beneath tank 241-SX-108 (or simply SX-108 slant borehole). This report also presents our interpretation of the data in the context of determining the appropriate lithologic model, the vertical extent of contamination, the migration potential of the contaminants that still reside in the vadose zone, and the correspondence of the contaminant distribution in the borehole sediment in relationship to groundwater plumes in the aquifer proximate and downgradient from the SX Tank Farm.
Date: February 12, 2002
Creator: Serne, R. Jeffrey; Last, George V.; Schaef, Herbert T.; Lanigan, David C.; Lindenmeier, Clark W.; Ainsworth, Calvin C. et al.
Object Type: Report
System: The UNT Digital Library
Portent of Heine's Reciprocal Square Root Identity (open access)

Portent of Heine's Reciprocal Square Root Identity

Precise efforts in theoretical astrophysics are needed to fully understand the mechanisms that govern the structure, stability, dynamics, formation, and evolution of differentially rotating stars. Direct computation of the physical attributes of a star can be facilitated by the use of highly compact azimuthal and separation angle Fourier formulations of the Green's functions for the linear partial differential equations of mathematical physics.
Date: October 12, 2002
Creator: Cohl, H S
Object Type: Article
System: The UNT Digital Library
The National Ignition Facility: Status and Plans for the Experimental Program (open access)

The National Ignition Facility: Status and Plans for the Experimental Program

The National Ignition Facility (NIF), currently under construction at the University of California's Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, 351-nm laser system and a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. NIF is being built by the National Nuclear Security Administration and when completed will be the world's largest laser experimental system, providing a national center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF's 192 energetic laser beams will compress fusion targets to conditions where they will ignite and burn, liberating more energy than required to initiate the fusion reactions. NIF experiments will allow the study of physical processes at temperatures approaching 100 million K and 100 billion times atmospheric pressure. These conditions exist naturally only in the interior of stars and in nuclear weapons explosions. In the course of designing the world's most energetic laser system, a number of significant technology breakthroughs have been achieved. NIF is now entering the first phases of its laser commissioning program. Low-energy preamplifier rod laser shots have been successfully propagated through the entire laser chain. Higher energy shots are planned through the end …
Date: November 12, 2002
Creator: Moses, E I
Object Type: Article
System: The UNT Digital Library
Characterization of Vadose Zone Sediment: Borehole 41-09-39 in the S-SX Waste Management Area (open access)

Characterization of Vadose Zone Sediment: Borehole 41-09-39 in the S-SX Waste Management Area

The geology under the SX Tank Farm forms the framework through which the contaminants move and provides the basis with which to interpret and extrapolate the physical and geochemical properties that control the migration and distribution of contaminants. Of particular interest are the interrelationships between the coarser and finer-grained facies and the degree of contrast in their physical and geochemical properties. The vertical distribution of cesium-137, based on borehole gamma logging and the laboratory analysis of the sediment at borehole 41-09-39, suggest that much of the tank fluid that leaked from tanks SX-108, SX-109, SX-111, and SX-112 traveled within the coarse-grained Hanford formation H1 unit that is found between 67 and 88 feet below ground surface (bgs) at borehole 41-09-39. It is difficult to differentiate the known moisture content relationship with particle size (finer-grained material retains higher moisture contents) from excess moisture from leaked fluid. Thus, moisture content distribution did not give us a clear indication of the vertical extent of the plume. However, moisture content does help identify intervals that have been impacted by drilling operations. The pH values are not nearly as high as would be expected for tank liquor completely saturating sediment. Therefore, it would appear that …
Date: February 12, 2002
Creator: Serne, R. Jeffrey; Last, George V.; Schaef, Herbert T.; Lanigan, David C.; Lindenmeier, Clark W.; Ainsworth, Calvin C. et al.
Object Type: Report
System: The UNT Digital Library
Vendor Capability for Low Thermal Expansion Mask Substrates for EUV Lithography (open access)

Vendor Capability for Low Thermal Expansion Mask Substrates for EUV Lithography

Development of manufacturing infrastructure is required to ensure a commercial source of mask substrates for the timely introduction of EUVL. Improvements to the low thermal expansion materials that compose the substrate have been made, but need to be scaled to production quantities. We have been evaluating three challenging substrate characteristics to determine the state of the infrastructure for the finishing of substrates. First, surface roughness is on track and little risk is associated with achieving the roughness requirement as an independent specification. Second, with new flatness-measuring equipment just coming on line, the vendors are poised for improvement toward the SEMI P37 flatness specification. Third, significant acceleration is needed in the reduction of defect levels on substrates. The lack of high-sensitivity defect metrology at the vendors' sites is limiting progress in developing substrates for EWL.
Date: April 12, 2002
Creator: Blaedel, K L; Taylor, J S; Hector, S D; Yan, P Y; Ramamoorthy, A & Brooker, P D
Object Type: Article
System: The UNT Digital Library
Characterization of Vadose Zone Sediment: Borehole 299-W23-19 [SX -115] in the S-SX Waste Management Area. (open access)

Characterization of Vadose Zone Sediment: Borehole 299-W23-19 [SX -115] in the S-SX Waste Management Area.

The Tank Farm Vadose Zone Project is led by CH2M HILL Hanford Group, Inc. Their goals include defining risks from past and future single-shell tank farm activities, identifying and evaluating the efficacy of interim measures, and collecting geo-technical information and data. The purpose of these activities is to support future decisions made by the U.S. Department of Energy regarding near-term operations, future waste retrieval, and final closure activities for the single-shell tank Waste Management Areas. To help in this effort, CH2M HILL contracted with scientists at Pacific Northwest National Laboratory to analyze sediment samples collected from borehole 299-W23-19. The conclusions reached from this study support specific mechanisms influencing subsurface migration of contaminants. The mechanisms are supported by the distributions of contaminants beneath tank farms. These observations will help DOE and CH2M HILL identify and implement viable remediation and closure activities.
Date: February 12, 2002
Creator: Serne, R. Jeffrey; Schaef, Herbert T.; Bjornstad, Bruce N.; Lanigan, David C.; Gee, Glendon W.; Lindenmeier, Clark W. et al.
Object Type: Report
System: The UNT Digital Library
Macroparticle simulation studies of a proton beam haloexperiment (open access)

Macroparticle simulation studies of a proton beam haloexperiment

We report macroparticle simulations for comparison withmeasured results from a proton beam-halo experiment in a 52-quadrupoleperiodic-focusing channel. An important issue is that the inputphase-space distribution is not experimentally known. Three differentinitial distributions with different shapes predict different beamprofiles in the transport system. Simulations have been fairly successfulin reproducing the core of the measured matched-beam profiles and thetrend of emittance growth as a function of mismatch factor, butunderestimate the growth rate of halo and emittance for mismatched beams.In this study, we find that knowledge of the Courant-Snyder parametersand emittances of the input beam is not sufficient for reliableprediction of the halo. Input distributions iwth greater population inthe tails produce larger rates of emittance growth, a result that isqualitatively consistent with the particle-core model of halo formationin mismatched beams.
Date: September 12, 2002
Creator: Qiang, J.; Colestock, P. L.; Gilpatrick, D.; Smith, H. V.; Wangler, T. P. & Schulze, M. E.
Object Type: Article
System: The UNT Digital Library
Evolution of parton fragmentation functions at finitetemperature (open access)

Evolution of parton fragmentation functions at finitetemperature

The first order correction to the parton fragmentation functions in a thermal medium is derived in the leading logarithmic approximation in the framework of thermal field theory. The medium-modified evolution equations of the parton fragmentation functions are also derived. It is shown that all infrared divergences, both linear and logarithmic, in the real processes are canceled among themselves and by corresponding virtual corrections. The evolution of the quark number and the energy loss (or gain) induced by the thermal medium are investigated.
Date: June 12, 2002
Creator: Osborne, Jonathan; Wang, Enke & Wang, Xin-Nian
Object Type: Article
System: The UNT Digital Library
High Pressure Back up Air Piping Pressure Test (open access)

High Pressure Back up Air Piping Pressure Test

None
Date: March 12, 2002
Creator: Rucinski, Russell A.
Object Type: Report
System: The UNT Digital Library