54 Matching Results

Search Results

Results: 1 - 24 next
open access

Photon Colliders

Description: A photon collider interaction region has the possibility of expanding the physics reach of a future TeV scale electron-positron collider. A survey of ongoing efforts to design the required lasers and optics to create a photon collider is presented in this paper.
Date: October 7, 2002
Creator: Gronberg, J.
Partner: UNT Libraries Government Documents Department
open access

Solid-State Heat-Capacity-Laser Review

Description: We describe our recent progress in the area of solid-state heat-capacity-lasers (SSHCL). In particular, we examine the physics of heat-capacity operation of a solid state laser and give the present technology status of our 10 kW flashlamp-pumped laser The current status of work leading to a diode-pumped Nd:GGG HCL is also described.
Date: May 7, 2002
Creator: Rotter, M D & Dane, C B
Partner: UNT Libraries Government Documents Department
open access

A Picosecond 14.7 nm X-Ray Laser for Probing Matter Undergoing Rapid Changes

Description: With laser-driven tabletop x-ray lasers now operating in the efficient saturation regime, the source characteristics of high photon flux, high monochromaticity, picosecond pulse duration, and coherence are well-matched to many applications involving the probing of matter undergoing rapid changes. We give an overview of recent experiments at the Lawrence Livermore National Laboratory (LLNL) Compact Multipulse Terawatt (COMET) laser using the picosecond 14.7 nm x-ray laser as a compact, ultrafast… more
Date: October 7, 2002
Creator: Dunn, J.; Smith, R. F.; Nilsen, J.; Nelson, A. J.; Van Buuren, T. W.; Moon, S. J. et al.
Partner: UNT Libraries Government Documents Department
open access

Holographic Protection of Chronology in Universes of the Godel Type

Description: We analyze the structure of supersymmetric Godel-like cosmological solutions of string theory. Just as the original four-dimensional Godel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on"phenomenological" aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Godel universes. We find that holography can serve as a chronol… more
Date: December 7, 2002
Creator: Boyda, Edward; Ganguli, Surya; Horava, Petr & Varadarajan, Uday
Partner: UNT Libraries Government Documents Department
open access

Photoionization of Sc2+ ions by synchrotron radiation: Highresolution measurements and absolute cross sections in the photon energyrange 23-68 eV

Description: Cross sections for photoionization of doubly-chargedscandium ions has been measured using a merged-beams technique. Resultsare compared with the time-reversed process ofphotorecombination.
Date: October 7, 2002
Creator: Schippers, Stefan E.; Müller, A.; Ricz, S.; Bannister, M. E.; Dunn, G. H.; Schlachter, A. S. et al.
Partner: UNT Libraries Government Documents Department
open access

Ammonia conversion and NOx formation in laminar coflowing nonpremixed methane-air flames

Description: This paper reports on a combined experimental and modeling investigation of NOx formation in nitrogen-diluted laminar methane diffusion flames seeded with ammonia. The methane-ammonia mixture is a surrogate for biomass fuels which contain significant fuel-bound nitrogen. The experiments use flue-gas sampling to measure the concentration of stable species in the exhaust gas, including NO, O2, CO, and CO2. The computations evolve a two-dimensional low Mach number model using a solution-adaptive p… more
Date: January 7, 2002
Creator: Sullivan, Neal; Jensen, Anker; Glarborg, Peter; Day, Marcus S.; Grcar, Joseph F.; Bell, John B. et al.
Partner: UNT Libraries Government Documents Department
open access

Determining size-specific emission factors for environmental tobacco smoke particles

Description: Because size is a major controlling factor for indoor airborne particle behavior, human particle exposure assessments will benefit from improved knowledge of size-specific particle emissions. We report a method of inferring size-specific mass emission factors for indoor sources that makes use of an indoor aerosol dynamics model, measured particle concentration time series data, and an optimization routine. This approach provides--in addition to estimates of the emissions size distribution and i… more
Date: July 7, 2002
Creator: Klepeis, Neil E.; Apte, Michael G.; Gundel, Lara A.; Sextro, Richard G. & Nazaroff, William W.
Partner: UNT Libraries Government Documents Department
open access

KTeV results: Re(e'/e) and rare decay results

Description: The KTeV physics program encompasses many goals including a precision measurement of the direct CP violation parameter Re({epsilon}{prime}/{epsilon}) in K{sub S,L} {yields} {pi}{pi} decays, and studies of rare neutral kaon decays. The KTeV detector collected data during the Fermilab fixed-target runs of 1996-97 and 1999. This article focuses on the precision measurement of the direct CP violation parameter Re({epsilon}{prime}/{epsilon}) using the 1996-97 data set. In addition, measurements of t… more
Date: October 7, 2002
Creator: Whitmore, Juliana
Partner: UNT Libraries Government Documents Department
open access

Computer-aided analysis of eddy current rotating probe data.

Description: Eddy current (EC) estimate of flaw size obtained from inservice inspection is often the primary means of assessing the structural integrity of steam generator tubes. Reliable prediction of failure pressure and leak rate in tubes with complex cracking requires more detailed information about the geometry and extent of degradation than is generally available from conventional bobbin coil examinations. High-resolution inspections with EC rotating probes are thus carried out on selected regions of … more
Date: March 7, 2002
Creator: Bakhtiari, S.; Park, J. Y.; Kupperman, D. S. & Shack, W. J.
Partner: UNT Libraries Government Documents Department
open access

Review of North American Neutrino Factory R and D

Description: We report here on the R and D program of the U.S. Neutrino Factory and Muon Collider Collaboration. Our effort includes work on targetry, muon ionization cooling, simulation work, and development of superconducting RF cavities. In addition, we are involved in the international effort toward a Muon Ionization Cooling Experiment (MICE). Recent activities in all these areas will be described.
Date: October 7, 2002
Creator: Zisman, Michael S. & Collaboration, Neutrino Factory and Muon Collider
Partner: UNT Libraries Government Documents Department
open access

Generating Composite Overlapping Grids on CAD Geometries

Description: We describe some algorithms and tools that have been developed to generate composite overlapping grids on geometries that have been defined with computer aided design (CAD) programs. This process consists of five main steps. Starting from a description of the surfaces defining the computational domain we (1) correct errors in the CAD representation, (2) determine topology of the patched-surface, (3) build a global triangulation of the surface, (4) construct structured surface and volume grids u… more
Date: February 7, 2002
Creator: Henshaw, W.D.
Partner: UNT Libraries Government Documents Department
open access

Recent Progress on the Standardized DOE Spent Nuclear Fuel Canister

Description: The Department of Energy (DOE) has developed a set of containers for the handling, interim storage, transportation, and disposal in the national repository of DOE spent nuclear fuel (SNF). This container design, referred to as the standardized DOE SNF canister or standardized canister, was developed by the Department's National Spent Nuclear Fuel Storage Program (NSNFP) working in conjunction with the Office of Civilian Radioactive Waste Management (OCRWM) and the DOE spent fuel sites. This can… more
Date: May 7, 2002
Creator: Morton, D.K.; Snow, S.D.; Rahl, T.E.; Hill, T.J. (INEEL) & Morissette, R.P. (Beckman and Associates, Inc.)
Partner: UNT Libraries Government Documents Department
open access

Determining worst-case fatigue thresholds for grain-bridging ceramics

Description: A method for determining worst-case cyclic fatigue thresholds in grain-bridging ceramics by quantifying the role of bridging is demonstrated for a model alumina. Crack-growth properties for both long and short (< 2 mm) cracks emanating from machined notches (root radii, (rho) {approx}; 15 - 150 (mu)m) were investigated. When compared as a function of the applied stress-intensity range (delta K), growth rates (da/dN) were far higher and fatigue thresholds (Delta)KTH were markedly lower with s… more
Date: October 7, 2002
Creator: Kruzic, J. J.; Yuan, R.; Canon, R. M. & Ritchie, R. O.
Partner: UNT Libraries Government Documents Department
open access

CDF Status and B Physics Prospects

Description: With extensive upgrades to the detector and electronics, CDF has started collecting data with Run II of the Tevatron. The enhanced silicon coverage and the use of silicon based tracks in the trigger, make CDF well suited for a broad program of B hadron measurements. We present the current status of the experiment and prospects for measurements in Run II.
Date: October 7, 2002
Creator: Miller, J. Stephen
Partner: UNT Libraries Government Documents Department
open access

Proposal for Qualification of Gas-Generating Radioactive Payloads for Transportation within a Type B Package

Description: Characterization data describing radioactive materials (RAM) in storage are likely those associated with the processes that produced the materials or with the mission for which they were produced. Along with impurity data, often absent or unknown as a result of post-processing storage environment is moisture content. Radiolysis of moisture may lead to a hydrogen flammability hazard within a closed volume such as a storage can or a transportation package. This paper offers a practical means of q… more
Date: June 7, 2002
Creator: Houghtaling, T.K.
Partner: UNT Libraries Government Documents Department
open access

HIGH ENERGY NUCLEAR INTERACTIONS AND QCD : AN INTRODUCTION.

Description: The goal of these lectures, oriented towards the students just entering the field, is to provide an elementary introduction to QCD and the physics of nuclear interactions at high energies. We first introduce the general structure of QCD and discuss its main properties. Then we proceed to Glauber multiple scattering theory which lays the foundation for the theoretical treatment of nuclear interactions at high energies. We introduce the concept of Gribov's inelastic shadowing, crucial for the und… more
Date: January 7, 2002
Creator: KHARZEEV,D.E. & RAUFEISEN,J.
Partner: UNT Libraries Government Documents Department
open access

B physics in Run II

Description: Run II at the Tevatron started on March 1, 2001 with a design instantaneous luminosity of 2 x 10{sup 32} cm{sup -2} s{sup -1}. The upgraded D0 detector is expected to collect 2 fb{sup -1} of data at {radical}s = 2.0 TeV in approximately 2 years. The D0 collaboration is planning to make measurements in a number of important areas of B physics, including sin(2{beta}), B{sub s} mixing, the {Lambda}{sub b} lifetime and rare B decays. In this note we describe the upgraded D0 detector and highlights … more
Date: October 7, 2002
Creator: Kuznetsov, Valentin E
Partner: UNT Libraries Government Documents Department
open access

Impact of design options on natural circulation performance of the AFR-300 advanced fast reactor.

Description: The AFR-300, Advanced Fast Reactor (300 Mwe), has been proposed as a Generation IV concept. It could also be used to dispose of surplus weapons grade plutonium or as an actinide burner for transmutation of high level radioactive waste. AFR-300 uses metallic fuel and sodium coolant. The design of AFR-300 takes account of the successful design and operation of EBR-II, but the AFR-300 design includes a number of advances such as an advanced fuel cycle, inspectability and improved economics. One si… more
Date: March 7, 2002
Creator: Dunn, F. D.
Partner: UNT Libraries Government Documents Department
open access

An Optimal Ion Exchange Design for Removal of Cesium from Hanford Waste

Description: Non-elutable crystalline silicotitanate (CST) ion-exchanger materials have been studied for removing cesium from a variety of radioactive wastes at several U.S. DOE sites over the last decade. For the current pretreatment facility design of the River Protection Project (RPP) Waste Treatment Plant (WTP) in Hanford, the removal of cesium from low activity waste (LAW) is achieved by ion-exchange technology based on SuperLig(R) 644 resin. However, due to concerns over potential radiological and che… more
Date: March 7, 2002
Creator: Hang, T.
Partner: UNT Libraries Government Documents Department
open access

Strain Gage Test Results of Band-Type Locking Rings for a Typical Drum Type Radioactive Material Package

Description: Band type closure rings are commonly used for securing the drum lid on radioactive material packages of lower weight classifications. Lid installation is achieved by placing the band around the perimeter of the lidded drum and tightening the single bolt in stages until a designated torque value is obtained. The band is subjected to heavy rapping with a soft hammer during installation to equilibrate the band strains around the drum perimeter. The study described here investigated the strain dist… more
Date: June 7, 2002
Creator: McKeel, C. A.
Partner: UNT Libraries Government Documents Department
open access

Dense ceramic membranes for hydrogen separation.

Description: We have developed cermet membranes that nongalvanically separate hydrogen from gas mixtures. The highest measured hydrogen flux was 20.0 cm{sup 3} (STP)/min-cm{sup 2} for an ANL-3a membrane at 900 C. For ANL-3 membranes with thickness of 40-500 {micro}m, hydrogen permeation is limited by the bulk diffusion of hydrogen through the metal phase. The effect of hydrogen partial pressure on permeation rate confirmed this conclusion, suggesting that higher permeation rates may be obtained by decreasin… more
Date: May 7, 2002
Creator: Balachandran, U.; Lee, T. H.; Wang, S.; Zhang, G. & Dorris, S. E.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen