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in creator/contributor: "Wang, P."

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Materials Performance in USC Steam

The proposed steam inlet temperature in the Advanced Ultra Supercritical (A-USC) steam turbine is high enough (760 °C) that traditional turbine casing and valve body materials such as ferritic/martensitic steels will not suffice due to temperature limitations of this class of materials. Cast versions of several traditionally wrought Ni-based superalloys were evaluated for use as casing or valve components for the next generation of industrial steam turbines. The full size castings are substanti… more

Date: May 1, 2010

Creator: Holcomb, G. R.; Wang, P.; Jablonski, P. D. & Hawk, J. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Development of soft x-ray tracer diagnostics for hohlraum experiments

The purpose of this report is to summarize work performed by the University of Wisconsin during fiscal year 1996 under the NLUF contract DE-FG-96SF21015. This contract involved the development of soft x-ray spectral diagnostics from tracer layers in hohlraum witness plates. This effort was originally intended to be focused on OMEGA experiments, but the experiments were changed to NOVA because initial indirect drive shots had not yet been performed on the OMEGA upgrade. Data were collected in a … more

Date: April 1, 1998

Creator: MacFarlane, J. J.; Cohen, D. H.; Wang, P.; Peterson, R. R. & Moses, G. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Probability based load criteria for the design of nuclear structures: a critical review of the state-of-the-art

Structures for nuclear power plant facilities must be designed to withstand safely and effectively all kinds of loads and load combinations that may be expected to occur during their lifetime. The traditional methods of structural design attempt to account for the inevitable variability in the loads, material strengths, in-service environments, and fabrication process, etc., through the use of safety factor, allowable stresses or load and resistance factors. These approaches may result in an un… more

Date: April 1, 1981

Creator: Shinozuka, M.; Ellingwood, B.R.; Wang, P.C.; Meyer, C.; Wen, Y.K.; Kao, S. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Parasitic mode losses versus signal sensitivity in beam position monitors

A beam position monitor (BPM) for a storage or damping ring may be subject to heating problems due to the parasitic mode (PM) losses, beam interception and synchrotron radiation interception. In addition, high PM losses can cause beam instabilities under some conditions. Recessing and/or masking the BPM may increase the PM losses in the process of solving the latter two problems. This paper presents three complementary methods for estimating the PM losses and for improving the design of a strip… more

Date: April 1, 1985

Creator: Denard, J. C.; Bane, K. L.; Bijleveld, J.; Hutton, A. M.; Pellegrin, J. L.; Rivkin, L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Initial application of a dual-sweep streak camera to the Duke storage ring OK-4 source

The visible and UV spontaneous emission radiation (SER) from the Duke OK-4 wiggler has been used with a Hamamatsu C5680 dual-sweep streak camera to characterize the stored electron beams. Particle beam energies of 270 and 500 MeV in the Duke storage ring were used in this initial application with the OK-4 adjusted to generate wavelengths from 500 nm to near 200 nm. The OK-4 magnetic system with its 68 periods provided a much stronger radiation source than a nearby bending magnet source point. S… more

Date: August 1, 1997

Creator: Lumpkin, A. H.; Yang, B. X.; Litvinenko, V.; Park, S.; Wang, P. & Wu, Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Modeling NIF Experimental Designs with Adaptive Mesh Refinement and Lagrangian Hydrodynamics

Incorporation of adaptive mesh refinement (AMR) into Lagrangian hydrodynamics algorithms allows for the creation of a highly powerful simulation tool effective for complex target designs with three-dimensional structure. We are developing an advanced modeling tool that includes AMR and traditional arbitrary Lagrangian-Eulerian (ALE) techniques. Our goal is the accurate prediction of vaporization, disintegration and fragmentation in National Ignition Facility (NIF) experimental target elements. … more

Date: August 31, 2005

Creator: Koniges, A E; Anderson, R W; Wang, P; Gunney, B N; Becker, R; Eder, D C et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Optimization of the Configuration of Pixilated Detectors Based on the Sgabbib-Nyquist Theory for the X-ray Spectroscopy of Hot Tokamak Plasmas

This paper describes an optimization of the detector configuration, based on the Shannon-Nyquist theory, for two major x-ray diagnostic systems on tokamaks and stellarators: x-ray imaging crystal spectrometers and x-ray pinhole cameras. Typically, the spectral data recorded with pixilated detectors are oversampled, meaning that the same spectral information could be obtained using fewer pixels. Using experimental data from Alcator C-Mod, we quantify the degree of oversampling and propose altern… more

Date: August 9, 2012

Creator: : E. Wang, P. Beiersdorfer, M. Bitter, L.F. Delgado-Apricio, K.W. Hill and N. Pablant

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Hierarchical Material Models for Fragmentation Modeling in NIF-ALE-AMR

Fragmentation is a fundamental process that naturally spans micro to macroscopic scales. Recent advances in algorithms, computer simulations, and hardware enable us to connect the continuum to microstructural regimes in a real simulation through a heterogeneous multiscale mathematical model. We apply this model to the problem of predicting how targets in the NIF chamber dismantle, so that optics and diagnostics can be protected from damage. The mechanics of the initial material fracture depend … more

Date: August 28, 2007

Creator: Fisher, A.; Masters, N.; Koniges, A.; Anderson, R.; Gunney, B.; Wang, P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Estimate for GLAST LAT Milky Way Dark Matter WIMP Line Sensitivity

The LAT Dark Matter and New Physics Working group has been developing approaches for the indirect astrophysical detection of annihilation of dark matter. Our work has assumed that a significant component of dark matter is a new type of Weakly Interacting Massive Particle (WIMP). The annihilation of two WIMPs usually results in the production of many high energy gamma rays (>1 GeV) that can be well measured in the GLAST LAT if present. There is also the possibility to observe {gamma} lines fr… more

Date: November 2, 2007

Creator: Edmonds, Y.; Baltz, E.; Bloom, E.; Cohen-Tanugi, J.; Godfrey, G.; Wai, L. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Spectroscopic diagnosis of foam z-pinch plasmas on SATURN

Solid and annular silicon aerogel and agar foams were shot on the accelerator SATURN to study plasma initiation, acceleration, and stagnation. SATURN delivers 7 MA with a 50 nsec rise time to these foam loads. We fielded several spectroscopic diagnostics to measure plasma parameters throughout the z-pinch discharge. A spatially resolved single frame time-gated EUV spectrometer measured the extent of plasma ablation off the surface foam. A time integrated crystal spectrometer showed that charact… more

Date: June 1996

Creator: Nash, T. J.; Derzon, M. S.; Allshouse, G.; Deeney, C.; Jobe, D.; McGurn, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Initial dual-sweep streak camera measurements on the Duke storage ring OK-4 UV/visible FEL

initial measurements at the Duke storage ring free electron laser (FEL) of both spontaneous emission radiation (SER) from the OK-4 and FEL radiation outcoupled from the oscillator cavity have been done with a dual-sweep streak camera. In the SER case, ANL`s Hamamatsu C5680 streak camera was used to characterize stored electron-beam bunch lengths versus rf gap voltage and single-bunch current. Electron-beam bunch lengths were observed in a range from 50 to 300 ps (FWHM). Particle beam energies o… more

Date: August 1, 1997

Creator: Lumpkin, A. H.; Yang, B. X.; Litvinenko, V.; Burnham, B.; Park, S.; Wang, P. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Novel Technique for Monitoring the Performance of the LAT Instrument on Board the GLAST Satellite

The Gamma-ray Large Area Space Telescope (GLAST) is an observatory designed to perform gamma-ray astronomy in the energy range 20 MeV to 300 GeV, with supporting measurements for gamma-ray bursts from 10 keV to 25 MeV. GLAST will be launched at the end of 2007, opening a new and important window on a wide variety of high energy astrophysical phenomena . The main instrument of GLAST is the Large Area Telescope (LAT), which provides break-through high-energy measurements using techniques typicall… more

Date: June 13, 2007

Creator: Paneque, D.; Borgland, A.; Bovier, A.; Bloom, E.; Edmonds, Y.; Funk, S. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Vacuum electron acceleration by an intense laser

Using 3D test particle simulations, the characteristics and essential conditions under which an electron, in a vacuum laser beam, can undergo a capture and acceleration scenario (CAS). When a{sub 0} {approx}> 100 the electron can be captured and violently accelerated to energies {approx}> 1 GeV, with an acceleration gradient {approx}> 10 GeV/cm, where a{sub 0} = eE{sub 0}/m{sub e}{omega}c is the normalized laser field amplitude. The physical mechanism behind the CAS is that diffraction of the f… more

Date: January 12, 2001

Creator: Wang, P. X.; Ho, Y. K.; Yuan, X. Q.; Kong, Q.; Sessler, A. M.; Esarey, E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Hierarchical Material Models for Fragmentation Modeling in NIF-ALE-AMR

Date: January 10, 2008

Creator: Fisher, A C; Masters, N D; Dixit, P; Benson, D J; Koniges, A E; Anderson, R W et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Subluminous phase velocity of a focused laser beam and vacuum laser acceleration

No Description Available.

Date: October 1, 2001

Creator: Ho, Y. K.; Yuan, X. Q.; Pang, J.; Cao, N.; Kong, Q.; Wang, P. X. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Carbon implanted in optical grade fused silica: annealing effects in reducing and oxidizing atmospheres

Carbon is implanted into fused silica with doses of 1, 3, 6, 10X10{sup 16} ions/cm{sup 2}. Infrared spectroscopy identified the formation of CO and CO{sub 2} molecules in the implanted glasses. Relations among concentrations of carbon dioxide, carbon monoxide, and carbon doses are established by the infrared measurements. Annealing under different atmospheres have dramatic effects on CO and CO{sub 2} concentrations.

Date: January 1, 1997

Creator: Tsung, Y.S.; Mu, R.; Ueda, A.; Henderson, D.O.; Wang, P.W.; White, C.W. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Analytical Investigation of Certain Aspects of LMFBR Subassembly-Failure Propagation

An analytical investigation of certain problems in the area of subassembly-to-subassembly failure propagation in LMFBR's is described. Existing analyses of the response of the adjacent subassembly duct to mechanical loads are reviewed and summarized, and major uncertainties are identified. Additional analyses of the response of the adjacent subassembly to certain thermal loads are presented in two parts. In the first part, the effect of an external heat flux on duct melting and thermal stresses… more

Date: February 1976

Creator: Marr, William W.; Wang, P. Y.; Misra, B.; Padilla, A. & Crawford, R. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Long term biosustainability in a high energy, low diversity crustal biome

Geochemical, microbiological, and molecular analyses of alkaline saline groundwater at 2.8 kilometers depth in Archaean metabasalt revealed a microbial biome dominated by a single phylotype affiliated with thermophilic sulfate reducers belonging to Firmicutes. These sulfate reducers were sustained by geologically produced sulfate and hydrogen at concentrations sufficient to maintain activities for millions of years with no apparent reliance on photosynthetically derived substrates.

Date: October 1, 2006

Creator: Lin, L-H.; Wang, P-L.; Rumble, D.; Lippmann-Pipke, J.; SherwoodLollar, B.; Boice, E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Characteristics of laser-driven electron acceleration invacuum

The interaction of free electrons with intense laser beamsin vacuum is studied using a 3D test particle simulation model thatsolves the relativistic Newton-Lorentz equations of motion inanalytically specified laser fields. Recently, a group of solutions wasfound for very intense laser fields that show interesting and unusualcharacteristics. In particular, it was found that an electron can becaptured within the high-intensity laser region, rather than expelledfrom it, and the captured electron c… more

Date: November 1, 2001

Creator: Wang, P. X.; Ho, Y. K.; Yuan, X. Q.; Kong, Q.; Sessler, A. M.; Esarey, E. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Development of X-ray tracer diagnostics for radiatively-driven ablator experiments [annual report FY1998]

This report covers fiscal year 1998 of our ongoing project to develop tracer X-ray spectroscopic diagnostics for hohlraum environments. This effort focused on an experimental campaign carried out at OMEGA on 25--27 August 1998. This phase of the project heavily emphasized experimental design, diagnostic development, and target fabrication, as well as building up numerical models for the experiments. The spectral diagnostic under development involves using two thin (few 1000 {angstrom}) mid-Z tr… more

Date: May 1999

Creator: MacFarlane, J. J.; Cohen, D. H.; Wang, P.; Moses, G. A.; Peterson, R. R.; Jaanimagi, P. A. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Branching Fraction for B0 -> pi- l+ nu and Determination of |Vub| in Upsilon(4S) -> B0 B0bar Events Tagged by B0bar -> D(*)+ l- nubar

We report preliminary results from a study of the charmless exclusive semileptonic decay B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu} based on the data collected at the {Upsilon}(4S) resonance using the BABAR detector at SLAC. The analysis uses events in which the signal B meson recoils against a B meson that has been reconstructed in a semileptonic decay {bar B}{sup 0} {yields} D{sup (*)+}{ell}{sup -}{bar {nu}}. We extract the total branching fraction {Beta}(B{sup 0} {yields} {pi}{sup -}{ell}… more

Date: June 29, 2005

Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of the B+- --> rho+- pi0 Branching Fraction and Direct CP Asymmetry

An improved measurement of the process B{sup {+-}} {yields} {rho}{sup {+-}}{pi}{sup 0} is presented. The data sample of 211 fb{sup -1} comprises 232 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. The yield and CP asymmetry are calculated using an extended maximum likelihood fitting method. The branching fraction and asymmetry are found to be {Beta}(B{sup {+-}} {yields} {rho}{sup {+-}}{pi}{sup 0}) = [10.0 {+-} 1.4 (Sta… more

Date: June 29, 2005

Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of the B0-bar Lifetime and the B0B0-bar Oscillation Frequency Using Partially Reconstructed B0-bar to D*+ l- nu-bar Decays

The authors present a simultaneous measurement of the {bar B}{sup 0} lifetime {tau}{sub B{sup 0}} and B{sup 0}{bar B}{sup 0} oscillation frequency {Delta}m{sub d}. We use a sample of about 50,000 partially reconstructed {bar B}{sup 0} {yields} D*{sup +}{ell}{sup -}{bar {nu}}{sub {ell}} decays identified with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at SLAC. The flavor of the other B meson in the event is determined from the charge of another high-momentum lepton.

Date: July 27, 2005

Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A Study of $e^+e^-\to p\bar{p}$ Using Initial StateRadiation with BaBar

The e{sup +}e{sup -} {yields} p{bar p} cross-section is determined over a range of p{bar p} masses, from threshold to 4.5 GeV/c{sup 2}, by studying the e{sup +}e{sup -} {yields} p{bar p}{gamma} process. The data set corresponds to an integrated luminosity of 232 fb{sup -1}, collected with the BABAR detector at the PEP-II storage ring, at an e{sup +}e{sup -} center-of-mass energy of 10.6 GeV. The mass dependence of the ratio of electric and magnetic form factors, |G{sub E}/G{sub M}|, is measured… more

Date: December 13, 2005

Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department