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in subjects: "Luminescence"

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Advanced amorphous materials for photovoltaic conversion. Annual report, October 1, 1978-September 30, 1979

The objectives of this project are twofold: (1) to investigate new amorphous semiconductor (a-SC) materials, in which recombination centers are passivated, using plasma deposition techniques; and (2) to characterize the optoelectronic properties pertaining to both majority-carrier and minority-carrier transport in as-deposited films and in devices. The electronic properties of plasma-deposited a-Si:H alloys were studied as functions of oxygen and nitrogen impurities. Over a wide range of proces… more

Date: January 1, 1980

Creator: Griffith, R. W.; Kampas, F. J.; Vanier, P. E. & Hirsch, M. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Recent studies on radiation induced F-center and colloid particle formation in synthetic NaCl and natural rock salt

Radiation induced F-center and Na metal colloid formation have been studied, at temperatures between 100 and 350/sup 0/C, in melt growth synthetic NaCl crystals and natural rock salt samples, using equipment for making optical measurements during 1 to 3 MeV electron irradiation. In both types of NaCl the damage formation kinetics are qualitatively similar. However, there are large quantitative differences which depend on irradiation temperature, dose rate, total dose, inherent strain, strain ap… more

Date: January 1, 1982

Creator: Levy, P. W.; Loman, J. M.; Swyler, K. J. & Dougherty, D. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Resonance-fluorescence kinetic study of oxygen atom + hydrocarbon reactions, V: O(/sup 3/P) + Neopentane (415-922K)

Absolute values of the rate constants for the reaction of O(/sup 3/P) with neo-C/sub 5/H/sub 12/ were determined directly with the use of the complementary techniques: flash photolysis (FP) and discharge flow (DF). The O-atoms were monitored via resonance fluorescence (RF) in both systems, allowing experiments to be carried out at very low (0). Secondary reactions were averted in this way, and the rate data thus obtained were stoichiometry-free. The DF-RF experiments were performed over the tem… more

Date: January 1, 1982

Creator: Michael, J. V.; Keil, D. G. & Klemm, R. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Kinetic modelling of krypton fluoride laser systems

A kinetic model has been developed for the KrF* rare gas halide laser system, specifically for electron-beam pumped mixtures of krypton, fluorine, and either helium or argon. The excitation produced in the laser gas by the e-beam was calculated numerically using an algorithm checked by comparing the predicted ionization yields in the pure rare gases with their experimental values. The excitation of the laser media by multi-kilovolt x-rays was also modeled and shown to be similar to that produce… more

Date: November 1, 1983

Creator: Jancaitis, K.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Progress Report on Neutron Radiography

BS> The potential advantages of neutron radiography as an inspection method are discussed along with a historical review and discussions of neutron sources and detectors. The results of the current investigation of neutron-image detectors are discussed in regard to photographic speed, relative neutron-gamma response, and resolution comparisons. Two neutron-image detecting methods are discussed. In one, the direct-exposure method, both the converter screens and the film are exposed to the neutro… more

Date: February 1, 1962

Creator: Berger, H. & McGonnagle, W.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Fundamental combustion and diagnostics research at Sandia. Progress report, April-June 1980

The combustion research emphasizes basic research into fundamental problems associated with combustion. The overall program addresses detailed chemistry of combustion, fundamental processes associated with laminar and turbulent flames, development of research techniques specifically applicable to combustion environments, and operation of the user-oriented Combustion Research Facility. The first section of this report contains activities in Combustion Research, the second section contains activi… more

Date: September 1, 1980

Creator: Gusinow, M.A. (ed.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Luminescence from defects and impurity centers in yttrium oxide

High-purity (99.999%) Y{sub 2}O{sub 3} powder is used as a starting material for fabricating high-temperature superconductors (HTS), and is frequently found as an unreacted second phase in the final product. We have found that as-received Y{sub 2}O{sub 3} contains Tb{sup 3+} paramagnetic impurity ions as determined by TSL and emission-spectra measurements. Deep luminescence traps (presumably Tb{sup 4+} ions) are formed in Y{sub 2}O{sub 3} when it is exposed to {gamma}-rays, x rays, or fluoresce… more

Date: January 1, 1989

Creator: Jahan, M.S.; Cooke, D.W.; Bennett, B.L.; Hults, W.L.; Maez, M.A.; Ott, K.C. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Fluorescence-pumped photolytic gas laser system for a commercial laser fusion power plant

The first results are given for the conceptual design of a short-wavelength gas laser system suitable for use as a driver (high average power ignition source) for a commercial laser fusion power plant. A comparison of projected overall system efficiencies of photolytically excited oxygen, sulfur, selenium and iodine lasers is described, using a unique windowless laser cavity geometry which will allow scaling of single amplifier modules to 125 kJ per aperture for 1 ns pulses. On the basis of hig… more

Date: July 14, 1977

Creator: Monsler, M.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Energy transfer and utilization in biological systems. Final report, September 1, 1967--September 15, 1976. [Fluorescence studies of photosynthesis]

In fluorescence studies of the photosynthetic process it was shown that the photosynthetic rate and light loss via chlorophyll fluorescence are strictly complementary. The exciplex state of matter responsible for most photochemistry was discovered and a wide variety of information about the state gained from studies of indole exciplexes. In addition to the nature of the bonding, degree of stability and general excited state behavior of indole exciplexes, their ability to lose electrons in a hig… more

Date: March 1, 1978

Creator: Lumry, R.W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Light-induced electron transfer vs. energy transfer in molecular thin-film systems

Quenching of fluoranthene (FA) singlets by tetrabromo-o-benzoquinone (TBBQ) and N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) was studied both in xylene solutions and in spin-cast polystyrene (PS) films. Emphasis was placed on time-resolved fluorescence transients resulting from pulsed excitation. Linear Stern-Volmer plots were obtained for quenching in solution and gave diffusion-controlled rate constants, of 1.45 x 10/sup 10/ M/sup -1/ sec/sup -1/ and 1.53 x 10/sup 10/ M/sup -1/ sec/sup -1/… more

Date: January 1, 1980

Creator: Renschler, C. L. & Faulkner, L. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Synchronous detection of laser-induced fluorescence

Many toxic or carcinogenic organic molecules have large absorption and fluorescence emission cross sections and can thus be detected by laser-induced fluorescence (LIF) in liquid samples at parts-per-billion levels or better. The technique of synchronous detection of laser-induced fluorescence (SDLIF) provides a way to distinguish between the fluorescence from a toxic molecule and the fluorescence from a background substance. This is done by synchronously scanning the laser excitation and fluor… more

Date: January 1, 1982

Creator: Quigley, G.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A 2-D imaging heat-flux gauge

This report describes a new leadless two-dimensional imaging optical heat-flux gauge. The gauge is made by depositing arrays of thermorgraphic-phosphor (TP) spots onto the faces of a polymethylpentene is insulator. In the first section of the report, we describe several gauge configurations and their prototype realizations. A satisfactory configuration is an array of right triangles on each face that overlay to form squares when the gauge is viewed normal to the surface. The next section of the… more

Date: July 1, 1991

Creator: Noel, B.W.; Borella, H.M. (Los Alamos National Lab., NM (United States)); Beshears, D.L.; Sartory, W.K.; Tobin, K.W.; Williams, R.K. (Oak Ridge National Lab., TN (United States)) et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Time-Dependent Study of Radiation Trapping by Time-Delayed Two-Photon Absorption

The transport of resonance radiation through an optically thick vapor of Sr atoms is studied. A pulsed dye laser tuned to the 461 nm resonance line excites a narrow (approx. 60 ..mu..m diam) column of Sr atoms along the axis of a cylindrical oven containing Sr vapor and Ar buffer gas. After a delay of less than or equal to 80 ns, a second dye laser excites the atom from the first excited state (5s5p) to a higher excited state (5s7s). The fluorescence from this latter transition is monitored as … more

Date: October 1, 1983

Creator: Molander, W.; Belsley, M.; Streater, A. & Burnett, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Proposed method for remote thermometry in turbine engines. [Eu-doped yttrium oxide]

The method uses laser-induced fluorescence from a pulsed uv laser to excite a rare-earth-oxide phosphor bonded in a thin layer to the surface to be measured. The luminescent decay times of certain lines are temperature-dependent. Initial results indicate that at least one phosphor, europium-doped yttrium oxide, is usable to 950/sup 0/C. (DLC)

Date: January 1, 1985

Creator: Noel, B. W.; Cates, M. R.; Allison, S. W.; Borella, H. M.; Franks, L. A. & Marshall, B. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Miners-Iron test of optical fibers

An experiment is described in which a number of optical fibers will be exposed to nuclear radiation in the Miners-Iron event at the Nevada Test Site. Two polymer clad silicon fibers and a borosilicate clad fiber will experience a dose of several Mrads, while a second set will experience about 0.1 Mrad. Attenuation and luninescence experiments are planned. Optic fibers will also be used for cables. (FS)

Date: January 1, 1980

Creator: HEckman, R.C.; Allen, J.W.; Dolce, S.R.; Hohlfelder, J.J. & Machin, E.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Narrow-band, near-uv, high-repetition-rate laser-induced fluorescence system for use as an edge diagnostic in fusion machines

A laser system for impurity diagnostics in the edge region of fusion devices is described, representing a substantial advance in repetition rate and capacity for velocity distribution measurements. A single mode cw dye laser with scan capability of 30 GHz in 100 msec is amplified by 3 fast flow dye cells, pumped by a high repetition rate excimer laser (60 mJ/pulse at 130 Hz at 308 rm). Average power during the 8 ns pulses of about 0.8 MW for amplified narrowband output at 604 rm, and 80 kW afte… more

Date: January 1, 1983

Creator: Young, C. E.; Gruen, D. M.; Pellin, M. J. & Calaway, W. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Luminescence from metals and insulators

The term luminescence is normally applied to light emission that is not explainable by the mechanisms discussed by the other speakers in this meeting. Specifically, it is not transition radiation, surface plasmon radiation, or bremsstrahlung. One normally thinks of luminescence as arising from one-electron transitions within a medium. This talk consists of an overview of luminescence from condensed matter under irradiation by either energetic particles or photons. The author begins with organic… more

Date: January 1, 1985

Creator: Crawford, O.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Conservation potential of compact fluorescent lamps in India and Brazil

We evaluate the conservation potential of compact fluorescent lamps (CFLs) for managing the rapidly increasing electrical energy and peak demand in India and Brazil. Using very conservative assumptions, we find that the cost of conserved energy using 16 W CFLs is 4 and 6 times less than the long range marginal cost of electricity for the two countries. The cost of avoided peak installed capacity is 6 and 9.5 times less than the cost of new installed capacity for India and Brazil. The analysis i… more

Date: July 1, 1989

Creator: Gadgil, A.; Martino Jannuzzi, G. de (Lawrence Berkeley Lab., CA (USA) & Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Fluorescence dynamics and cross relaxation of 4+ curium in cerium tetrafluoride

Fluorescence from Cm{sup 4+} has been observed for the first time. The dynamics of its emitting 5f state have been probed using time- and frequency-resolved laser-induced fluorescence. Nonexponential fluorescence decays were found from Cm{sub 0.001}Ce{sub 0.999}F{sub 4} and Cm{sub 0.05}Ce{sub 0.95}F{sub 4} at temperatures from 4.2 K to 300 K. A simple cross-relaxation model was found to fit the excited f-state dynamics of the Cm{sub 0.001}Ce{sub 0.999}F{sub 4} sample at low excitation intensity… more

Date: January 1, 1989

Creator: Liu, G.K. & Beitz, J.V.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Picosecond studies of temperature and solvent effects on the fluorescence from coumarin 102 and acridine

Hydrogen bonding characteristics of acridine and coumarin 102 are studied in different solutions. Coumarin 102 upon excitation forms a complex in alcoholic solutions, whereas excited acridine relaxes in aprotic and protic solvents by a process involving an activation energy.

Date: January 1, 1980

Creator: Shapiro, S.L. & Winn, K.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Determination of somatic mutations in human erythrocytes by cytometry

Flow cytometric assays of human erythrocytes labeled with monoclonal antibodies specific for glycophorin A were used to enumerate variant cells that appear in peripheral blood as a result of somatic gene-loss mutations in erythrocyte precursor cells. The assay was performed on erythrocytes from 10 oncology patients who had received at least one treatment from radiation or mutagenic chemotherapy at least 3 weeks before being assayed. The patients were suffering from many different malignancies (… more

Date: June 21, 1985

Creator: Jensen, R.H.; Langlois, R.G. & Bigbee, W.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Influence of propagation on off-resonant molecular excitation

The proposal of Makarov, Cantrell, and Louisell regarding stimulated inelastic resonance fluorescence (SIRF) is shown to not accurately represent the effects of propagation on off-resonant excitation of two-level model molecular absorbers.

Date: January 1, 1980

Creator: Eberly, J. H.; Konopnicki, M. J. & Shore, B. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Development and application of photosensitive device systems to studies of biological and organic materials

This report describes progress as of the third year of a 3-year DoE grant for 1/1/92 to 12/31/92. Because this is the last year of a 3- year grant cycle, this report will summarize progress over the entire 3-year period. The overall goals of the grant are to develop novel instrumentation and techniques for the performance of biological and materials research, and especially for the development of x-ray detectors suitable for use at storage ring sources. Research progress has been excellent and … more

Date: May 15, 1992

Creator: Gruner, S. M. & Reynolds, G. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Rare gas halide lasers for fusion. Final technical report, 1 March 1979-29 February 1980

In an effort to reliably extend the understanding of KrF* lasers, we collected specific, detailed experimental data and carried out theoretical calculations to explore and document those issues we identified as likely to be important in the short pulse operating regime. These included the effects of: (1) fuel burnup, (2) electron quenching, (3) gain/absorption at high current densities, (4) photoionization, (5) accessibility of the lying levels of KrF by laser flux, (6) temperature on fluoresce… more

Date: April 1, 1980

Creator: Duzy, C.; Hsia, J.; Hyman, H.; Jacob, J.; Klimek, D.; Parks, J. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department