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in subjects: "Polarization"

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Alignment and orientation in ion/endash/atom collisions

Recent progress in the theoretical study of alignment and orientation in atom-atom and ion-atom collisions at intermediate energies is reviewed. Recent systematic studies of the alignment and orientation of electronic charge cloud distributions of excited states resulting from such collisions clearly have provided more detailed information about the underlying collision dynamics. However, since accurate determination of these parameters is quite difficult, both theoretically and experimentally,… more

Date: January 1, 1987

Creator: Kimura, M. & Lane, N.F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ultraviolet imaging of hydrogen flames

We have assembled an ultraviolet-sensitive intensified camera for observing hydrogen combustion by imaging the OH, A/sup 2/..sigma.. - X/sup 2//Pi/ bandhead emissions near 309 nm. The camera consists of a quartz and CaF achromat lense-coupled to an ultraviolet image intensifier which is in turn fiber-coupled to a focus projection scan (FPS) vidicon. The emission band is selected with interference filters which serve to discriminate against background. The camera provides optical gain of 100 to … more

Date: January 1, 1988

Creator: Yates, G. J.; Wilke, M. & King, N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Some general properties of stimulated Raman propagation with pump depletion, transiency and dispersion

This note considers some of the properties of the Stokes pulse that grows from a specified seed pulse in the presence of a strong pump pulse as it propagates through a dispersive atomic vapor. We first present an generic dimensionless form for the coupled equations that govern the propagation of pump and Stokes fields or collinear plane-wave pulses. By treating the two fields we permit pump depletion. We include transient atomic response (as embodied in the Raman coherence), but neglect changes… more

Date: August 2, 1991

Creator: Shore, B. W.; Lowder, S. & Johnson, M. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Universal formula for the quasistatic second-order density perturbation by a cold magnetoplasma wave

Using the general expression for the ponderomotive Hamiltonian, the quasi-static quasi-neutral density change caused by the ponderomotive force of a cold magnetoplasma wave of arbitrary frequency and polarization is obtained. This formula agrees with and extends previous results for unmagnetized and magnetized plasma.

Date: December 16, 1977

Creator: Kaufman, A. N.; Cary, J. R. & Pereira, N. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental Determination of the Effective Nucleon-Nucleon Interaction for P-Nucleus Reactions at Intermediate Energies

A complete measurement of the polarization transfer observables has been made for the first time in the (p,p') reaction at intermediate energies. Measurements are reported for the /sup 12/C(p,p') /sup 12/C reaction to the 1/sup +/, T = 0(12.71 MeV) and 1/sup +/, T = 1(15.11 MeV) states at 500 MeV at laboratory scattering angles of 3.5/sup 0/, 5.5/sup 0/, 7.5/sup 0/, and 12.0/sup 0/. Linear combinations of these observables are shown to exhibit a very selective dependence on the isoscalar and is… more

Date: January 1, 1982

Creator: McClelland, J. B.; Aas, B. & Azizi, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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N and. delta. resonances: an experimental review

Experimental progress in N and ..delta.. resonances since the Oxford baryon conference is reviewed. The review concentrates on hadronic channels, and on developments of the last one or two years. The topics reviewed include the antiproton lifetime; the ..delta../sup + +/ magnetic moment; measurements of ..pi..N elastic and charge-exchange scattering in the ..delta.. region, the eta n threshold region, and the high-mass region; partial wave analyses of ..pi..N ..-->.. ..pi..N; measurements of tw… more

Date: July 1, 1980

Creator: Kelly, R.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Calculations of anti pp. -->. anti yy near threshold

The reactions anti pp ..-->.. anti yy will soon be studied near threshold at LEAR. Comparison of theoretical calculations with the measured differential cross sections, polarizations and spin correlations may help to determine the role of various meson exchange terms and the extent to which quark degrees of freedom are important. Calculations along these lines are in progress and are described briefly.

Date: January 1, 1982

Creator: Eisenstein, R. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Polarization spectroscopy of tokamak plasmas

Measurements of polarization of spectral lines emitted by tokamak plasmas provide information about the plasma internal magnetic field and the current density profile. The methods of polarization spectroscopy, as applied to the tokamak diagnostic, are reviewed with emphasis on the polarimetry of motional Stark effect in hydrogenic neutral beam emissions. 25 refs., 7 figs.

Date: September 1, 1991

Creator: Wroblewski, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Surface electrochemical control for fine coal and pyrite separation

Ongoing work includes the characterization of coal pyrites, the floatability evaluation typical US coal samples, the flotation behavior of coal pyrites, the electrochemical measurement of the surface properties of coal pyrites, and the characterization of species produced at pyrite surfaces.

Date: January 1, 1990

Creator: Hu, Weibai; Zhu, Ximeng; Bodily, D. M. & Wadsworth, M. E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Nuclear spin polarization of solid deuterium-tritium

It appears that parallel alignment of deuteron and triton magnetic moments increases the cross section of the nuclear reaction T(d,n) He/sup 4/ by 50%, thereby promising a laser driver of perhaps half the original energy. Both ''brute-force'' and dynamic nuclear polarization are considered, and the many potential problems of the latter are considered. High nuclear polarization by the dynamic technique requires a small nucleus-to-unpaired electron ratio, a long longitudinal nuclear relaxation ti… more

Date: January 1, 1985

Creator: Souers, P. C.; Fearon, E. M.; Mapoles, E. R.; Gaines, J. R.; Sater, J. D. & Fedders, P. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Theory of spin dependence at very high energies. [Review, S matrix]

The point of view taken is to introduce a number of topics for possible discussion during the course of this workshop. Some of the theoretical expectations for polarization phenomena are reviewed assuming that hadrons are composite. Polarization phenomena are considered from an S-matrix point of view.

Date: January 1, 1977

Creator: Thomas, G. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Research, development and demonstration of nickel-zinc batteries for electric vehicle propulsion. Annual report, 1979

Progress achieved under ANL Contract No. 31-109-38-4248 from 16 August 1978 to 16 August 1979 is reported. The first segment of the overall program, component development, consists of four basic tasks proceeding in parallel: nickel electrode development, zinc electrode development, separator development, and sealed cell development. Each of these tasks is reported herein on a self-contained basis. System engineering is the second major subdivision of the effort. It includes the design and testi… more

Date: June 1, 1980

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Technical Progress Report of the Indiana University High Energy Physics Group, December 1, 1979-November 30, 1980. [12/1/79-11/30/80]

Research programs during the current contract year are associated with major experiments conducted at SLAC, Fermilab, and CERN. The physics areas under study include an exploration of polarization phenomena in hadron processes, a study of low-p/sub t/ and high-p/sub t/ collisions utilizing the Multiparticle Spectrometer at Fermilab, studies of psi meson production in hadron interactions, and a high-resolution study of e/sup +/e- interactions at high energy at SLAC. The status of the various eff… more

Date: January 1, 1980

Creator: Brabson, B. B.; Crittenden, R. R.; Dzierba, A. R.; Heinz, R. M.; Martin, H. J.; Neal, H. A. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Acceleration using total internal reflection

This report considers the use of a dielectric slab undergoing total internal reflection as an accelerating structure for charged particle beams. We examine the functional dependence of the electromagnetic fields above the surface of the dielectric for polarized incident waves. We present an experimental arrangement for testing the performance of the method, using apparatus under construction for the Grating Acceleration experiment at Brookhaven National Laboratory. 13 refs., 4 figs., 2 tabs.

Date: June 7, 1991

Creator: Fernow, R.C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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One photon exchange processes and the calibration of polarization of high energy protons

Polarization phenomena in small momentum transfer high energy one-photon exchange processes in the reaction p + A ..-->.. X + A where A is a complex nucleus and X is anything are examined. It is shown that these polarizations can be related directly to photoproduction polarization effects in the reaction ..gamma.. + p ..-->.. X at low energies. Explicit formulae are written for polarization effects in the case where X ..-->.. ..pi../sup 0/ + p.

Date: January 1, 1978

Creator: Margolis, B. & Thomas, G. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Analysis of polarization properties of shallow metallic gratings by an extended Rayleigh-Fano Theory

Rayleigh-Fano theory has been extended for the purpose of calculating the polarization anomaly of a grating having shallow grooves and finite conductivity. Simple analytic formulas are derived for predicting the position and the appearance of the anomalies. Phenomenological explanations are given to the origin of the anomalies. The validity of our analysis is examined by comparing computed degree of polarization with experimental data obtained in the visible region for Al-, Ag-, and Au-coated b… more

Date: June 1, 1991

Creator: Koike, Masato (Lawrence Berkeley Lab., CA (United States)) & Namioka, Takeshi (Tohoku Univ., Sendai (Japan). Research Inst. for Scientific Measurements)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Galvanostatic polarization of zinc microanodes in KOH electrolytes

This report includes a critical review of the current literature on the anodic passivation of zinc electrodes, a description of supplementary experimental studies to extend the data to a low-current-density region and to provide a basis for evaluating conflicting results of published work, and a new interpretation of the anodic passivation mechanism. This work provides a starting point for understanding passivation phenomena in battery electrodes. The utilization of a zinc electrode in alkaline… more

Date: May 1, 1980

Creator: Liu, M. B.; Cook, G. M. & Yao, N. P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Optical Pumping for Intense Polarized Ion Sources

Laser optical pumping without buffer gas in dense (NL>10/sup 12/ atoms/cm/sup 2/) sodium vapor targets was investigated. The atomic polarization of the target was determined from the Faraday rotation angle of a second dye laser tuned midway between the sodium D-lines. Substantial polarizations were measured even though the pump laser bandwidth (approx. 1 MHz) was much smaller than the Doppler and hyperfine broadened sodium absorption line (approx. 3 GHz). Theoretical calculations based on rate … more

Date: January 1, 1982

Creator: Cornelius, W. D.; Taylor, D. J.; York, R. L. & Hinds, E. A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Neutron diffraction studies of thin film multilayer structures

The application of neutron diffraction methods to the study of the microscopic chemical and magnetic structures of thin film multilayers is reviewed. Multilayer diffraction phenomena are described in general and in particular for the case in which one of the materials of a bilayer is ferromagnetic and the neutron beam polarized. Recent neutron diffraction measurements performed on some interesting multilayer systems are discussed. 70 refs., 5 figs.

Date: January 1, 1985

Creator: Majkrzak, C.F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ferroelectric ceramics for dielectric power conversion. Annual report, March 1, 1979-April 30, 1980

Materials selected for study were those which could be expected to have useful Curie temperatures, resistivities, coercive fields, and Devonshire coefficients. Materials studied include PZT (lead-zirconia-titania system), Bi(Na,K)Ti/sub 2/O/sub 6/, rare earth titanoniobates, other tantalates and niobates, and thin films. Graphs are given for spontaneous polarization as a function of composition, temperature dependence of spontaneous polarization and coercive field for modified PSZT dielectrics,… more

Date: May 1, 1980

Creator: Payne, D. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Role of rotational degrees of freedom in heavy-ion collisions

The degrees of freedom affected by the angular momentum are identified. The relevance of the equilibrium fluctuations in a diffusive evolution of the system is discussed. The statistical limit is described and chosen as a reference for comparing with experiment. The rigid rotation regime is shown to be reached in a variety of reactions. The fragment spin alignment is measured from ..gamma..-ray multiplicities and anisotropies as well as from sequential fission angular distributions. Good agreem… more

Date: April 1, 1982

Creator: Moretto, Luciano G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Recent results on polarization phenomena

The topics relating to polarization phenomena discussed include the structure in certain pp spin observables with new results also presented and possibly indicating the existence of a dibaryon resonance, inclusive proton polarization, and pp elastic scattering at high energy. Some general features of the data are discussed. 23 references (JFP)

Date: January 1, 1977

Creator: Spinka, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fuel cells: applied research fuel cell materials and electrocatalysis. Annual report, January 1976--December 1976

Research is described on electrocatalysis of fuel cell reactions including the topics (1) mixed oxides as oxygen electrodes, (2) electrolyte effects on the oxygen reduction reaction, (3) anion effects on the oxygen reduction reaction, and (4) selection and evaluation of electrocatalysts for oxygen reduction in KHCO/sub 3//K/sub 2/CO/sub 3/ buffered electrolytes. Phosphoric acid fuel cell studies include inhibition of sintering of fuel cell catalyst particles: electrochemical methods for surface… more

Date: September 1, 1977

Creator: Srinivasan, S. & Isaacs, H. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Automatic voltage-imbalance detector

A device is described for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Date: May 20, 1981

Creator: Bobbett, R. E.; McCormick, J. B. & Kerwin, W. J.

Item Type: Patent

Partner: UNT Libraries Government Documents Department