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Spectra in the 60 )angstrom) to 345 )angstrom) wavelength region of elements injected into the PLT tokamak

Description: High resolution spectra of the elements Fe, Ni, Zn, Ge, Se, and Mo injected into the PLT tokamak were recorded by the 2-meter Schwob-Fraenkel soft X-ray multichannel spectrometer (SOXMOS). Spectra were recorded every 50 ms during the time before and after injection. The spectral lines of the injected element were very strong in the spectrum recorded immedately after injection, and the transition in the injected element were easily distinguished from the transitions in te intrinsic elements (C, … more
Date: March 1, 1988
Creator: Wouters, A.; Schwob, J.L.; Suckewer, S.; Seely, J.F.; Feldman, U. & Dave, J.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurements of 2s-2p transition energies in helium-like and lithium-like nickel

Description: The wavelength of the fine structure transition 1s2s /sup 3/S/sub 1/ - 1s2p /sup 3/P/sub 2/ in Ni XXVII has been measured using fast-ion spectroscopy. The transition energy is sensitive to relativistic and Lamb shift corrections in this high-Z two-electron system. Comparison is made with measurements in other high-Z ions and with recent theoretical calculations. A preliminary measurement of the 1s/sup 2/2s /sup 2/S/sub 1/2/ - 1s/sup 2/2p /sup 2/P/sub 1/2/ find structure transition in Ni XXVI is… more
Date: January 1, 1987
Creator: Zacarias, A.S.; Livingston, A.E.; Lu, Y.N.; Ward, R.F.; Berry, H.G. & Dunford, R.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Scattering of elastic waves by small surface-breaking or subsurface cracks in three dimensions

Description: The long-wavelength limit of elastic wave scattering by surface cracks in 3d is considered. It is shown that, if the crack is normal to the surface, the scattering can be described by two real parameters, one of which may be taken to be the crack size. The other therefore depends on shape, orientation, and burial depth. Many computed illustrations are given. It is concluded that the amount of information about cracks obtainable by low frequency elastic wave scattering is very limited.
Date: January 1, 1985
Creator: Visscher, W.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Phase and Amplitude Control of the Radio Frequency Wave in the Two-Beam Accelerator

Description: The sensitivity of the radio frequency (rf) wave generated by the free electron laser portion of a Two-Beam Accelerator (TBA) is analyzed, both analytically and numerically in a 'resonant particle' approximation. It is shown that the phase of the rf wave is strongly dependent upon errors in the wiggler strength and wavelength and upon the electron beam characteristics of energy and current. The resulting phase error is shown to be unacceptable for a TBA, given reasonable errors in various compo… more
Date: July 1, 1985
Creator: Kuenning, R. W. & Sessler, A. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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An Analysis of Recent Measurements of the Temperature of theCosmic Microwave Background Radiation

Description: This paper presents an analysis of the results of recent temperature measurements of the cosmic microwave background radiation (CMBR). The observations for wavelengths longer than 0.1 cm are well fit by a blackbody spectrum at 2.74 {+-} 0.02 K; however, including the new data of Matsumoto et al. (1987) the result is no longer consistent with a Planckian spectrum. The data are described by a Thomson-distortion parameter u = 0.021 {+-} 0.002 and temperature 2.823 {+-} 0.010 K at the 68% confidenc… more
Date: July 1, 1987
Creator: Smoot, G.; Levin, S.M.; Witebsky, C.; De Amici, G. & Rephaeli, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Free Electron Lasers

Description: The free electron laser (FEL) uses a high quality relativistic beam of electrons passing through a periodic magnetic field to amplify a copropagating optical wave (1-4). In an oscillator configuration, the light is stored between the mirrors of an open optical resonator as shown in Figure 1. In an amplifier configuration, the optical wave and an intense electron beam pass through the undulator field to achieve high gain. In either case, the electrons must overlap the optical mode for good coupl… more
Date: January 1, 1985
Creator: Colson, W. B. & Sessler, A. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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TRANSVERSE WAKEFIELD EFFECTS IN THE TWO-BEAM ACCELERATOR

Description: Transverse wakefield effects in the high-gradient accelerating structure of the Two-Beam Accelerator (TBA) [1-3] are analyzed theoretically using three different models. The first is a very simple two-particle model due to Wilson [4]; the second, due to Chao, Richter, and Yao [5], is for a beam with uniform charge distribution, constant betatron wavelength, and a linear wake approximation. Both of these models give analytic scaling laws. The third model has a Gaussian beam (represented by 11 su… more
Date: August 1, 1985
Creator: Selph, F. & Sessler, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Free-Electron Lasers

Description: We can now produce intense, coherent light at wavelengths where no conventional lasers exist. The recent successes of devices known as free-electron lasers mark a striking confluence of two conceptual developments that themselves are only a few decades old. The first of these, the laser, is a product of the fifties and sixties whose essential characteristics have made it a staple resource in almost every field of science and technology. In a practical sense, what defines a laser is its emission… more
Date: April 1, 1986
Creator: Sessler, A. M. & Vaughan, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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All-optical modulation in gallium arsenide integrated optical waveguides

Description: We have investigated all-optical modulators in gallium arsenide integrated optical waveguides; these modulators use electron-hole pair generation to alter the propagation characteristics of a guided light beam. 6 refs., 6 figs.
Date: January 27, 1988
Creator: McWright, G.; Ross, B.; Guthreau, W.; Lafaw, D.; Lowry, M. & Tindall, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High resolution krypton M/sub 4,5/ x-ray emission spectra

Description: High resolution M/sub 4,5/ (3d ..-->.. 4p) x-ray emission spectra from a krypton plasma were measured using a recently developed grazing-incidence reflection-grating monochromator/spectrometer with very high flux rates at extreme ultraviolet and soft x-ray wave lengths. The nominal resolving power of the instrument, E/..delta..E, is about 300 in this energy range (approx.80 eV). Three dipole-allowed 3d ..-->.. 4p emission lines were observed at 80.98 eV, 80.35 eV and 79.73 eV. A broad peak at a… more
Date: October 1, 1987
Creator: Perera, R.C.C.; Hettrick, M.C. & Lindle, D.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Fiber-optic technology review

Description: A history of fiber technology is presented. The advantages of fiber optics are discussed (bandwidth, cost, weight and size, nonmetallic construction and isolation). Some aspects of the disadvantages of fiber systems briefly discussed are fiber and cable availability, fiber components, radiation effects, receivers and transmitters, and material dispersion. Particular emphasis over the next several years will involve development of fibers and systems optimized for use at wavelengths near 1.3 ..mu… more
Date: January 1, 1980
Creator: Lyons, P. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Optical constants of solid methane

Description: Methane is the most abundant simple organic molecule in the outer solar system bodies. In addition to being a gaseous constituent of the atmospheres of the Jovian planets and Titan, it is present in the solid form as a constituent of icy surfaces such as those of Triton and Pluto, and as cloud condensate in the atmospheres of Titan, Uranus, and Neptune. It is expected in the liquid form as a constituent of the ocean of Titan. Cometary ices also contain solid methane. The optical constants for b… more
Date: January 1, 1989
Creator: Khare, B.N.; Thompson, W.R.; Sagan, C. (Cornell Univ., Ithaca, NY (USA). Lab. for Planetary Studies); Arakawa, E.T.; Bruel, C.; Judish, J.P. (Oak Ridge National Lab., TN (USA)) et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spectra over complex terrain

Description: Spectra have been measured over land downwind of a water surface, over hilltops and escarpments, and over rolling farmland. The following hypotheses can be used to explain the differences between these spectra. (1) For wavelengths short compared to the fetch over the new terrain, spectral densities are in equilibrium with the new terrain. (2) For wavelengths long compared to this fetch, spectral densities remain unchanged if the ground is horizontal. If the flow is over a steep hill, the low-fr… more
Date: January 1, 1981
Creator: Panofsky, H.A.; Larko, D.; Lipschutz, R. & Stone, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Wavelengths of the 3p-3d transitions of the Co- and Fe-like ions: The effects of electron correlation

Description: The experimental observations of the 3p/sup 6/ 3d/sup 9/ /sup 2/D - 3p/sup 5/ 3d/sup 10/ /sup 2/p transitions of the Co-like ions and 3p/sup 6/ 3d/sup 8/ /sup 3/F/sub 4/ - 3p/sup 5/ 3d/sup 9/ /sup 3/F/sub 3/ of the Fe-like ions have recently been extended to highly charged ions of heavy elements up to uranium (Z = 92). A comparison between the observed energies and calculated values from the Dirac-Fock model indicated persistent discrepancies of 3 to 4 eV for all ions. Systematic multiconfigura… more
Date: September 2, 1987
Creator: Chen, Mau Hsiung
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Time-resolved flourescence measurements of KrF emission produced by vacuum ultraviolet photolysis of KrF/sub 2/ mixtures

Description: Vacuum ultraviolet (VUV) light radiation was used to produce electronically excited KrF excimers (in D-, B- and C-states) by the photolysis of KrF/sub 2/ and F/sub 2//Kr mixtures at various excitation wavelengths. The excited KrF photoproduct quantum yield was measured over the excitation wavelength range of 120 to 200 nm, and a quantum efficiency of 0.45 was estimated at the peak absorption wavelength of 159 nm for KrF/sub 2/. The collision-free fluorescence lifetime of the B-X transition near… more
Date: January 1, 1989
Creator: Tiee, J.J.; Quick, C.R.; Hsu, A.H. & Hof, D.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Radiation-induced transient attenuation of optical fibers at 800 and 1300 nm

Description: Radiation-induced absorption in optical fibers has been a subject of considerable interest throughout the world. As availability and applications of fibers have evolved from ''first window'' systems operating near 850 nm to ''second window'' systems near 1300 nm, interest in wavelength dependence of radiation effects in optical fibers has similarly evolved. The present work summarizes second-window, radiation-induced transient absorption measurements in optical fibers for times shorter than 5 .… more
Date: January 1, 1987
Creator: Looney, L.D. & Lyons, P.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Doubly excited states in some light atoms

Description: We have identified a singlet transition in doubly excited helium: 2p/sup 2/ /sup 1/D - 2p3d /sup 1/D, at 3298 +- 2A with a full width of 54A or 0.061 +- 0.005 eV. This width is in good agreement with a previous measurement and theory for the width of the 2p/sup 2/ /sup 1/D/sub 2/ state. We have remeasured the decay rate of 1s/sup 2/2p/sup 2/P - 1s2p/sup 2/ /sup 2/P in Li I and find it is in good agreement with theory. Several transitions in doubly excited Li II have been identified in the 1000A… more
Date: January 1, 1981
Creator: Berry, H. G.; Brooks, R. L.; Hardis, J. E. & Ray, W. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Comparison of two approaches to linear collider design

Description: This paper reviews linear collider parameters. It aims at analyzing two specific design approachs - the ones for CLIC at CERN and for a TeV linear collider at SLAC - which appear to lead into remarkably different directions although they start from the same premises and try to respect the same boundary conditions. 19 refs.
Date: November 1, 1987
Creator: Schnell, W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Collective acceleration of protons by the plasma waves in a counterstreaming electron beam

Description: A novel advanced accelerator is proposed. The counterstreaming electron beam accelerator relies on the same physical mechanism as that of the plasma accelerator but replaces the stationary plasma in the plasma accelerator by a magnetized relativistic electron beam, drifting antiparallel to the driving source and the driven particles, as the wave supporting medium. The plasma wave in a counterstreaming electron beam can be excited either by a density-ramped driving electron beam or by properly b… more
Date: March 1, 1987
Creator: Yan, Y.T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Figure and finish of grazing incidence mirrors

Description: Great improvement has been made in the past several years in the quality of optical components used in synchrotron radiation (SR) beamlines. Most of this progress has been the result of vastly improved metrology techniques and instrumentation permitting rapid and accurate measurement of the surface finish and figure on grazing incidence optics. A significant theoretical effort has linked the actual performance of components used as x-ray wavelengths to their topological properties as measured b… more
Date: August 1, 1989
Creator: Takacs, P.Z. (Brookhaven National Lab., Upton, NY (USA)) & Church, E.L. (Picatinny Arsenal, Dover, NJ (USA). Army Armament Research, Development and Engineering Center)
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Optical properties of flyash

Description: The purpose of this task is to validate the whole approach adopted in this program. Specifically, this bench-scale experiment is intended to compare the measured optical/radiative properties of a dispersion of well characterized ash with those calculated on the basis of the known size/composition distribution using the correlation formulae relating the composition and complex refractive index resulting from measurements on bulk samples of synthetic slag. Considerable thought has been given to t… more
Date: July 1, 1989
Creator: Self, S.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Anti-reflection coatings applied by acid-leaching process. Final report

Description: The Magicote C process developed by S.M. Thompsen was evaluated for use in applying an antireflective coating to the cover plates of solar cell panels. The process uses a fluosilicic acid solution supersaturated with silica at elevated temperature to selectively attack the surface of soda-lime glass cover plates and alter the physical and chemical composition of a thin layer of glass. The altered glass layer constitutes an antireflective coating. The process produces coatings of excellent optic… more
Date: September 1, 1980
Creator: Pastirik, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Moderated-neutron pulse shapes

Description: The time dependence of the neutron pulse from hydrogeneous moderators is well known in the slowing down region. The full width at half maximum, ..delta..t/sub 50/, behaves as 2/..sqrt..E when time is measured in ..mu..s and energy in eV. The shape of the pulse throughout the slowing down region is a universal function of vt, phi(v,t) = (..sigma../sub s/vt)/sup 2/ exp (-..sigma../sub s/vt). In this equation, v is the neutron velocity, ..sigma../sub s/ the macroscopic cross section of the moderat… more
Date: January 1, 1982
Creator: Taylor, A. D.; Russell, G. J.; Meier, M. M. & Robinson, H.
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Partner: UNT Libraries Government Documents Department
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The roles of frequency and aperture in linac accelerator design

Description: Expressions for accelerating structure parameters, including those that determine the peak and average power inputs required to attain a given gradient, are given as functions of aperture to wavelength ratio for a 2..pi../3 mode disk-loaded guide. The value of the wavelength to aperture ratio varies over a large range, corresponding to group velocities that vary from nearly zero to nearly the speed of light. The parameters exhibit proper asymptotic behavior in both limits. These parameters are … more
Date: September 1, 1988
Creator: Farkas, Z. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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