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Coherent anti-Stokes Raman scattering in benzene and nitromethane shock-compressed to 10 GPa

Description: The frequency shifts of the ring-stretching mode of shock-compressed liquid benzene and the CN stretching mode of nitromethane have been measured using coherent anti-Stokes Raman scattering. Shock pressures up to 11 GPa were achieved using a two-stage light gas gun. The frequency shifted Raman signal was generated using single pulse Nd:YAG and broadband-type lasers. 16 refs., 3 figs.
Date: January 1, 1985
Creator: Schmidt, S.C.; Moore, D.S.; Shaner, J.W.; Shampine, D.L. & Holt, W.T.
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Partner: UNT Libraries Government Documents Department
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Preliminary report on fluid inclusions from halites in the Castile and lower Salado formations of the Delaware Basin, southeastern New Mexico. [Freezing-point depression]

Description: A suite of samples composed primarily of halite from the upper Castile and lower Salado Formations of the Permian Basin was selected from Waste Isolation Pilot Plant (WIPP) core for a reconnaissance study of fluid inclusions. Volume percent of these trapped fluids averaged 0.7% to 1%. Freezing-point depressions varied widely and appeared to be unrelated to fluid-inclusion type, to sedimentary facies, or to stratigraphic depth. However, because very low freezing points were usually associated wi… more
Date: September 1, 1985
Creator: Stein, C. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Raman Spectroscopy of Shocked Water

Description: We describe a new technique for recording spontaneous Raman spectra from molecules during the passage of strong shock waves. We have used this technique to study the OH-stretch band of liquid H/sub 2/O shocked to pressure up to 26 GPa and 1700 K. The shape of the band changes over the range 7.5-26 GPa, and is described well by a two-component mixture model, implying changes in the intermolecular coupling of shock compressed water molecules. We discuss the implications of the spectra on the mech… more
Date: August 1, 1985
Creator: Holmes, N. C.; Nellis, W. J.; Graham, W. B. & Walrafen, G. E.
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Partner: UNT Libraries Government Documents Department
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Raman activity in synchronously dividing bacteria

Description: Using a spectrometer equipped with an optical-multichannel analyzer as the detector (OMA), we have observed the Stokes laser-Raman spectra of metabolically active Escherichia coli and Bacillus megaterium from 100 - 2100 cm/sup -1/. After lengthy investigation, no Raman lines attributable to the metabolic process nor the cells themselves were found. Previous Raman spectra of active bacteria cannot be used to support nonlinear theories in biology. 34 refs., 9 figs.
Date: January 1, 1985
Creator: Layne, S. P.
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Partner: UNT Libraries Government Documents Department
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Laser spectroscopy of sputtered atoms

Description: The use of laser radiation to study the sputtering process is of relatively recent origin. Much has been learned from this work about the basic physics of the sputtering process itself through measurements of velocity and excited state distributions of sputtered atoms and the effects of adsorbates on substrate sputtering yields. Furthermore, the identification, characterization, and sensitive detection of sputtered atoms by laser spectroscopy has led to the development of in situ diagnostics fo… more
Date: January 1, 1985
Creator: Gruen, D. M.; Pellin, M. J.; Young, C. E. & Calaway, W. F.
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Partner: UNT Libraries Government Documents Department
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Coherent and spontaneous Raman spectroscopy in shocked and unshocked liquids

Description: Coherent and non-coherent Raman spectroscopy is being used to study the structure and energy transfer in molecular liquids at high pressures. Stimulated Raman scattering, coherent anti-Stokes Raman scattering, and Raman induced Kerr effect scattering measurements have been performed in liquid benzene and liquid nitromethane shocked to pressures up to 11 GPa. Frequency shifts were observed for the 992 cm/sup -1/ ring stretching mode of benzene and the 920 cm/sup -1/ CN stretching mode of nitrome… more
Date: January 1, 1985
Creator: Schmidt, S.C.; Moore, D.S.; Schiferl, D.; Chatelet, M.; Turner, T.P.; Shaner, J.W. et al.
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Partner: UNT Libraries Government Documents Department
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Static high pressure study of nitric oxide chemistry: proposed mechanism for nitric oxide detonation. [Shock initiated detonation]

Description: The chemistry of nitric oxide under static high pressure conditions has been studied using diamond anvil cells and spectroscopic methods. Pressurized samples warmed rapidly to room temperature undergo facile disproportionation to form N/sub 2/O, N/sub 2/O/sub 3/, N/sub 2/O/sub 4/, and NO/sup +/NO/sub 3//sup -/. Nitric oxide maintained at 80 K is observed to react at ca. 2.5 GPa to form, dominantly, N/sub 2/, O/sub 2/, and NO/sup +/NO/sub 3//sup -/. The complex chemistry of nitric oxide is best … more
Date: January 1, 1985
Creator: Swanson, B. I.; Agnew, S. F. & Greiner, N. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Time-resolved spectroscopy of plasma resonances in highly excited silicon and germanium

Description: The dynamics of the electron-hole plasma in silicon and germanium samples irradiated by 20 ps. 532 nm laser pulses has been investigated in the near infrared by the time-resolved picosecond optical spectroscopy. The experimental reflectivities and transmission are compared with the predictions of the thermal model for degenerate carrier distributions through the Drude formalism. Above a certain fluence, a significant deviation between measured and calculated values indicates a strong increase o… more
Date: January 1, 1985
Creator: Huang, C. Y.; Malvezzi, A. M.; Bloembergen, N. & Kurz, H.
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Partner: UNT Libraries Government Documents Department
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Vibrational energy transfer in benzene-argon collisions

Description: This paper reports the results of an extensive study of the internal energy-transfer processes that occur in benzene-argon collisions. We used laser-induced fluorescence and information theory for determining the energy-transfer rates between internal states of benzene in the ground electronic state. The use of information theory gives estimates for all of the vibrational energy transfer rates. These fit the experimental data reasonably well. However, some of the data do deviate from the inform… more
Date: January 1, 1985
Creator: Lyman, J. L.; Mueller, G.; Houston, P. L.; Piltch, M.; Schmid, W. E. & Kompa, K. L.
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Partner: UNT Libraries Government Documents Department
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Sensitive detection of tunable diode laser absorption by polarization rotation

Description: Results are presented demonstrating that diode laser absorption sensitivity can be increased by using the Faraday or Kerr effect to rotate the polarization of the source so that crossed polarizers can be used to reduce source noise. The Faraday effect is demonstrated using nitrous oxide in a magnetic field, and the Kerr effect is demonstrated using methyl fluoride in an electric field. Some description of how absorption in an external field causes polarization rotation is presented as well as s… more
Date: January 1, 1985
Creator: Loge, G.W.; Laguna, G.A. & Hartford, A.
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Partner: UNT Libraries Government Documents Department
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Recent advances in the study of nuclei off the line of stability

Description: The hyperfine structure and isotope shifts of /sup 189m,191m,193m/Tl have been measured by means of collinear fast-beam/laser spectroscopy. Deformations for the 9/2/sup -/ isomers are determined to be larger than for the 1/2/sup +/ ground state and increase with decreasing neutron number. Despite different deformations, rotational properties are nearly identical in /sup 185-199/Tl. Microscopic theory ascribes this to a systematic balance between changing deformation and neutron pairing. 8 refs.… more
Date: 1985
Creator: Carter, H. K.; Leander, G. A.; Bounds, J. A. & Bingham, C. R.
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Partner: UNT Libraries Government Documents Department
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First results from the UNISOR collinear laser facility

Description: The hyperfine structure and isotope shifts of /sup 189m, 191m, 193m, 193g/Tl have been measured by means of collinear fast-beam/laser spectroscopy. Deformations for the 9/2/sup -/ isomers are determined to be larger than for the 1/2/sup +/ ground state and increase with decreasing neutron number. Despite different deformations, rotational properties are nearly identical in /sup 185 to 199/Tl. Microscopic theory ascribes this to a systematic balance between changing deformation and neutron pairi… more
Date: 1985~
Creator: Carter, H. K.; Leander, G. A.; Bounds, J. A. & Bingham, C. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Laser-driven instabilities in long scalelength plasmas

Description: In this update lecture we focus on laser-driven instabilities in long scalelength underdense plasmas. Particular attention is given to some recent experiments on Raman scattering of intense laser light. Many important features are in accord with theoretical expectations. These features include a correlation of hot electron generation with Raman scattering, an increase in this scattering as the density scale length increases, and collisional suppression of the instability. Some challenging aspec… more
Date: July 31, 1985
Creator: Kruer, W.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Damage accumulation in ceramics during ion implantation

Description: The damage structures of ..cap alpha..-Al/sub 2/O/sub 3/ and ..cap alpha..-SiC were examined as functions of ion implantation parameters using Rutherford backscattering-channeling, analytical electron microscopy, and Raman spectroscopy. Low temperatures or high fluences of cations favor formation of the amorphous state. At 300/sup 0/K, mass of the bombarding species has only a small effect on residual damage, but certain ion species appear to stabilize the damage microstructure and increase the… more
Date: January 1, 1985
Creator: McHargue, C. J.; Farlow, G. C.; Begun, G. M.; Williams, J. M.; White, C. W.; Appleton, B. R. et al.
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Partner: UNT Libraries Government Documents Department
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High-resolution absorption spectrum of the 6/sup 1/S/sub 0/. -->. 6/sup 3/P/sub 1/ transition in mercury with a cw dye laser. Revision 1

Description: Using a stabilized single-frequency commercial dye laser and an external cavity doubling crystal, we have measured the isotope shifts of mercury for the 6/sup 1/S/sub 0/ ..-->.. 6/sup 3/P/sub 1/ transition with an accuracy of 4 MHz. We describe the method for generating single-frequency light at 2537 A and compare the results of our measurements of the isotope shifts with previous work. 4 refs., 1 fig., 1 tab.
Date: January 1, 1985
Creator: Crane, J. K.; Erbert, G. V.; Mostek, S. D.; Kerlin, R. C. & Paisner, J. A.
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Partner: UNT Libraries Government Documents Department
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Production of gallium atoms by excimer laser photolysis of trimethyl gallium

Description: The gas phase kinetics of group III elements such as gallium are important in possible chemically driven energy transfer lasers and in chemical vapor deposition processes in the electronics industry. Excimer laser photodissociation of volatile gallium compounds via multiple photon process provides, in principle, a convenient room temperature source of gallium atoms for study using laser photolysis-laser induced fluorescence techniques. In this paper, we report preliminary results of the multipl… more
Date: March 1, 1985
Creator: Baughcum, Steven L.; Oldenborg, Richard C.; Winn, Kenneth R. & Hof, Douglas E.
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Partner: UNT Libraries Government Documents Department
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Infrared generation and wave-mixing studies in cesium

Description: A Nd-YAG pumped dye laser and heat pipe has been used to investigate stimulated infrared production, wave mixing, and ionization in cesium vapor near the one-photon resonant 7P/sub 1/2,3/2/ fine structure states.
Date: January 1, 1985
Creator: Christian, W.; Stockdale, J. A. D.; Dodhy, A. & Compton, R. N.
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Partner: UNT Libraries Government Documents Department
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Preliminary performance and ICF target experiments with Nova

Description: In December 1984, the Nova facility fired all ten laser arms, converted the output 1.05 micron energy to 0.35 micron light, and focused the 0.35 micron light through a 4 mm pinhole in the ten-beam target chamber. Since that time, a two-beam target chamber has been added, the performance of the laser evaluated, and preparation has been made for target experiments. This paper summarizes the performance of Nova and describes progress and plans for target experiments.
Date: November 1, 1985
Creator: Drake, R. P.
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Partner: UNT Libraries Government Documents Department
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Rapid analysis of steels using laser-based techniques

Description: Based on the data obtained by this study, we conclude that laser-based techniques can be used to provide at least semi-quantitative information about the elemental composition of molten steel. Of the two techniques investigated here, the Sample-Only method appears preferable to the LIBS (laser-induced breakdown spectroscopy) method because of its superior analytical performance. In addition, the Sample-Only method would probably be easier to incorporate into a steel plant environment. However, … more
Date: January 1, 1985
Creator: Cremers, David Allen; Archuleta, Frederick Levi & Dilworth, Harold Caldwell
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Partner: UNT Libraries Government Documents Department
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Measurement of gas density and temperature profiles in UF/sub 6/ using laser induced fluorescence

Description: Laser induced fluorescence (LIF) can be used to determine the pressure and temperature of an UF/sub 6/ gas sample. An external pulsed laser is used to excite the gas and a multichannel fiber optics system simultaneously collects fluorescence signals emanating from a number of points in the gas. The signals are digitized and presented to a minicomputer for data reduction. Both fluorescence intensity and lifetime are used to deduce temperature and pressure. The LIF probe system is described. Anal… more
Date: January 1, 1985
Creator: Caldwell, Stephen E.; Gentry, Richard A.; White, Ralph W. & Allison, Steven W.
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Partner: UNT Libraries Government Documents Department
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Picosecond dynamics of reactions in the liquid phase: studies of iodine photodissociation and development of new laser techniques

Description: Iodine photodissociation and recombination was studied as a model for processes common to chemical reaction in the liquid phase. Picosecond transient absorption measurements from 1000 to 295 nm were used to monitor the dynamics in a variety of solvents. Most of the atoms which undergo geminate recombination were found to do so in less than or equal to 15 ps, in agreement with the results of existing molecular dynamics simulations. Vibrational relaxation times vary from approx.15 ps near the mid… more
Date: September 1, 1985
Creator: Berg, Mark Alan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Chlorine and bromine solar neutrino experiments

Description: The solar neutrino experiment based upon the neutrino capture reaction /sup 37/Cl (..nu.., e/sup -/) /sup 37/Ar has been in operation in the Homestake Gold Mine at Lead, South Dakota since 1967. The results of this experiment are well known, and have been reported most recently to the solar neutrino conference at Lead in 1984. We report here the latest results from this experiment. A radiochemical neutrino detector based upon the neutrino capture reaction /sup 81/Br (..nu.., e/sup -/) /sup 81/K… more
Date: January 1, 1985
Creator: Davis, R., Jr.; Cleveland, B. T. & Rowley, J. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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