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SNAP sky background at the north ecliptic pole

Description: I summarize the extant direct and indirect data on the sky background SNAP will see at the North Ecliptic Pole over the wavelength range 0.4 < {lambda} < 1.7 {micro}m. At the spatial resolution of SNAP the sky background due to stars and galaxies is resolved, so the only source considered is zodiacal light. Several models are explored to provide interpolation in wavelength between the broadband data from HST and COBE observations. I believe the input data are now established well enough t… more
Date: July 1, 2002
Creator: Aldering, Greg
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Resistive Wall Instability in the NLC Main Damping Rings

Description: We study transverse coupled-bunch instabilities driven by the resistive-wall impedance in the NLC Main Damping Rings. We compare the growth rates of the different modes predicted by a simple theory using a simplified lattice model with the results of a detailed simulation that includes variation of the beta functions and the actual fill structure of the machine. We find that the results of the analytical calculations are in reasonable agreement with the simulations. We include a simple model of… more
Date: July 1, 2004
Creator: Wolski, Andrzej
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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GLIMM'S METHOD FOR GAS DYNAMICS

Description: We investigate Glimm's method, a method for constructing approximate solutions to systems of hyperbolic conservation laws in one space variable by sampling explicit wave solutions. It is extended to several space variables by operator splitting. We consider two functional problems. 1) We propose a highly accurate form of the sampling procedure, in one space variable, based on the van der Corput sampling sequence. We test the improved sampling procedure numerically in the case of inviscid c… more
Date: July 1, 1980
Creator: Colella, Phillip
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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CARBON AND DEUTERIUM NUCLEAR MAGNETIC RESONANCE IN SOLIDS

Description: In Chapter I we present the results on a study of cross polarization dynamics, between protons and carbon-13 in adamantane, by the direct observation of the dilute, carbon-13, spins. These dynamics are an important consideration in the efficiency of proton enhancement double-resonance techniques and they also provide good experimental models for statistical theories of cross relaxation. In order to test these theories we present a comparison of the experimental and theoretical proton dipolar fl… more
Date: July 1, 1976
Creator: Shattuck, Thomas Wayne
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Neutrino Factory and Muon Collider Collaboration R and D Program

Description: The Neutrino Factory and Muon Collider Collaboration (MC) comprises some 140 scientists and engineers located at U.S. National Laboratories and Universities, and at a number of non-U.S. research institutions. In the past year, the MC R and D program has shifted its focus mainly toward the design issues related to the development of a Neutrino Factory based on a muon storage ring. In this paper the status of the various R and D activities is described, and future plans are outlined.
Date: July 1, 2000
Creator: Zisman, M. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High p<sub partial> inclusive charged hadron distributions in Au+Au collisions at square root(s<sub NN>) = 130 Gev at RHIC

Description: This thesis reports the measurement of the inclusive charged particle (h{sup +} + h{sup -}) p{perpendicular} spectra for 1.7 < p{perpendicular} < 6 GeV/c at midrapidity (|{eta}| < 0.5) as a function of various centrality classes in Au+Au collisions at {radical}s{sub NN} = 130 GeV. Hadron suppression is observed relative to both scaled NN and peripheral Au+Au reference data, possibly indicating non-Abelian radiative energy loss in a hot, dense medium.
Date: July 1, 2003
Creator: Choi, Bum
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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THE COVALENT BINDING OF ENANTIOMERIC BENZO [A] PYRENE DIOL EPOXIDES TO DOUBLE STRANDED DNA IS STEREOSELECTIVE

Description: Reaction of optically pure (+) and (-) 7{beta},8{alpha}-dihydroxy-9{alpha},10{alpha}-epoxy-7,8,9.10-tetrahydrobenzo[a]pyrene with DNA in vitro yielded diastereomeric covalent adducts with the exocyclic amino groups of deoxyguanosine and deoxyadenosine. The ratio of two deoxyguanosine diastereomers derived by reacting the (+) and (-) hydrocarbons with native calf thymus and double stranded 0X174 DNA was 20:1 while reaction of the enantiomers with heat denatured calf thymus and single stranded 0X… more
Date: July 1, 1978
Creator: Meehan, T. & Straub, K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Baryon stopping and charged particle production from lead-lead collisions at 158 GeV per nucleon

Description: Net proton (proton minus antiproton) and negative charge hadron spectra (h-) from central Pb+Pb collisions at 158 GeV per nucleon at the CERN Super Proton Synchrotron were measured and compared to spectra from central collisions of the lighter S+S system. Net baryon distributions were derived from those of net protons and net lambdas. Stopping, or rapidity shift with respect to the beam, of net protons and net baryons increase with system size. The mean transverse momentum &60;pT&62; of… more
Date: July 1, 1999
Creator: Toy, Milton Y.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

Improvements to the image processing of HST NICMOS observationswith multiple readouts

Description: We report on improvements made to the standard NICMOS processing pipeline. The calculation of the uncertainties on the signal accumulation rate has been modified to include the statistical correlations between the consecutive readouts. In order to correct a problem with the existing cosmic ray rejection algorithm, we have developed and implemented a joint fit procedure, where the accumulating signal is fit as linear functions of time with the same rate both before and after the cosmic ray (CR) … more
Date: July 1, 2005
Creator: Fadeyev, Vitaliy; Aldering, Gregory & Perlmutter, Saul
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Target space supersymmetric sigma model techniques

Description: We briefly review the covariant formulation of the Green-Schwarz superstring by Berkovits, and describe how a detailed tree-level and one-loop analysis of this model leads, for the first time, to a derivation of the low-energy effective action of the heterotic superstring while keeping target-space supersymmetry manifest. The resulting low-energy theory is old-minimal supergravity coupled to tensor multiplet. The dilaton is part of the compensator multiplet.
Date: July 1, 1996
Creator: de Boer, Jan & Skenderis, Kostas
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Towards attosecond X-ray pulses from the FEL

Description: The ability to study ultrafast phenomena has been recently advanced by the demonstrated production and measurement of a single, 650-attosecond (10{sup 18} sec), VUV x-ray pulse[1] and, latter, a 250-attosecond pulse[2]. The next frontier is a production of the x-ray pulses with shorter wavelengths and in a broader spectral range. Several techniques for a generation of an isolated, attosecond duration, short-wavelength x-ray pulse based upon the ponderomotive laser acceleration [3], SASE and har… more
Date: July 1, 2004
Creator: Zholents, Alexander A. & Fawley, William M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Models of Scherk-Schwarz Symmetry Breaking in 5D: Classification and Calculability

Description: The form of the most general orbifold breaking of gauge, global and supersymmetries with a single extra dimension is given. In certain theories the Higgs boson mass is ultraviolet finite due to an unbroken local supersymmetry, which is explicitly exhibited. We construct: a 1 parameter SU(3) \times SU(2) \times U(1) theory with 1 bulk Higgs hypermultiplet, a 2 parameter SU(3) \times SU(2) \times U(1) theory with 2 bulk Higgs hypermultiplets, and a 2 parameter SU(5) \to SU(3) \times SU(2) \times … more
Date: July 1, 2001
Creator: Barbieri, Riccardo; Hall, Lawrence J. & Nomura, Yasunori
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

COMPARISONS OF CODED APERTURE IMAGING USING VARIOUS APERTURES AND DECODING METHODS

Description: The utility of coded aperture imaging of radioisotope distributions in Nuclear Medicine is in its ability to give depth information about a three dimensional source. We have calculated imaging with Fresnel zone plate and multiple pinhole apertures to produce coded shadows and reconstruction of these shadows using correlation, Fresnel diffraction, and Fourier transform deconvolution. Comparisons of the coded apertures and decoding methods are made by evaluating their point response functions bot… more
Date: July 1, 1976
Creator: Chang, L.-T.; Macdonald, B. & Perez-Mendez, V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A Detailed Study of FDIRC Prototype with Waveform Digitizing Electronics in Cosmic Ray Telescope Using 3D Tracks.

Description: We present a detailed study of a novel Cherenkov imaging detector called the Focusing DIRC (FDIRC) with waveform digitizing electronics. In this test study, the FDIRC prototype has been instrumented with seven Hamamatsu H-8500 MaPMTs. Waveforms from ~450 pixels are digitized with waveform sampling electronics based on the BLAB2 ASIC, operating at a sampling speed of ~2.5 GSa/s. The FDIRC prototype was tested in a large cosmic ray telescope (CRT) providing 3D muon tracks with ~1.5 mrad angular r… more
Date: July 1, 2012
Creator: Nishimura, K
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

IMAGES, IMAGES, IMAGES

Description: The role of images of information (charts, diagrams, maps, and symbols) for effective presentation of facts and concepts is expanding dramatically because of advances in computer graphics technology, increasingly hetero-lingual, hetero-cultural world target populations of information providers, the urgent need to convey more efficiently vast amounts of information, the broadening population of (non-expert) computer users, the decrease of available time for reading texts and for decision making,… more
Date: July 1, 1980
Creator: Marcus, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Summary Report of Working Group 6: Laser-Plasma Acceleration

Description: A summary is given of presentations and discussions in theLaser-Plasma Acceleration Working Group at the 2006 Advanced AcceleratorConcepts Workshop. Presentation highlights include: widespreadobservation of quasi-monoenergetic electrons; good agreement betweenmeasured and simulated beam properties; the first demonstration oflaser-plasma acceleration up to 1 GeV; single-shot visualization of laserwakefield structure; new methods for measuring<100 fs electronbunches; and new methods for "machinin… more
Date: July 1, 2006
Creator: Leemans, Wim P.; Downer, Michael & Siders, Craig
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Plasma Channel Beam Conditioner for a Free Electron Laser

Description: By "conditioning" an electron beam, through establishing acorrelation between transverse action and energy within the beam, theperformance of free electron lasers (FELs) can be dramatically improved.Under certain conditions, the FEL can perform as if the transverseemittances of the beam were substantially lower than the actual values.After a brief review of the benefits of beam conditioning, we present amethod to generate this correlation through the use of a plasma channel.The strong transvers… more
Date: July 1, 2007
Creator: Penn, G.; Sessler, A. M. & Wurtele, J. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electromagnetic wave scattering from magnetic fluctuations in tokamaks

Description: Cross sections are calculated for electromagnetic wave scattering and mode transformation from magnetic and density fluctuations in the vicinity of the principal electron cutoffs and resonances in a homogeneous plasma. For the special case of scattering perpendicular to the magnetic field, density fluctuations scatter ordinary to ordinary and extraordinary to extraordinary modes -- but cannot transform these modes. On the other hand, magnetic fluctuations perpendicular to the field can transfor… more
Date: July 1, 1991
Creator: Vahala, L. (Old Dominion Univ., Norfolk, VA (United States). Dept. of Electrical and Computer Engineering); Vahala, G. (College of William and Mary, Williamsburg, VA (United States). Dept. of Physics) & Bretz, N. (Princeton Univ., NJ (United States). Plasma Physics Lab.)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Gross shell structure of moments of inertia

Description: Average yrast moments of inertia at high spins, where the pairing correlations are expected to be largely absent, were found to deviate from the rigid-body values. This indicates that shell effects contribute to the moment of inertia. We discuss the gross dependence of moments of inertia and shell energies on the neutron number in terms of the semiclassical periodic orbit theory. We show that the ground-state shell energies, nuclear deformations and deviations from rigid-body moments of inertia… more
Date: July 1, 2002
Creator: Deleplanque, M. A.; Frauendorf, S.; Pashkevich, V. V.; Chu, S. Y. & Unzhakova, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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