Sample records for harmful ultraviolet radiation

  1. Ultraviolet-B Radiation Harms Aquatic Life -Current Results http://www.currentresults.com/Water/Water-Pollution/ultraviolet.php 1 of 2 8/7/2007 1:45 PM

    E-Print Network [OSTI]

    Blaustein, Andrew R.

    Ultraviolet-B Radiation Harms Aquatic Life - Current Results http://www.currentresults.com/Water/Water-Pollution/ultraviolet.php 1 of 2 8/7/2007 1:45 PM Ultraviolet-B Radiation Harms Aquatic Life The first quantitative analysis of published studies on ultraviolet-B (UVB) radiation and water-borne life reveals that UVB causes widespread

  2. Ultraviolet-radiation-curable paints

    SciTech Connect (OSTI)

    Grosset, A M; Su, W F.A.; Vanderglas, E

    1981-09-30T23:59:59.000Z

    In product finishing lines, ultraviolet radiation curing of paints on prefabricated structures could be more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. Diffuse ultraviolet light can cure paints on three dimensional metal parts. In the uv curing process, the spectral output of radiation sources must complement the absorption spectra of pigments and photoactive agents. Photosensitive compounds, such as thioxanthones, can photoinitiate unsaturated resins, such as acrylated polyurethanes, by a free radical mechanism. Newly developed cationic photoinitiators, such as sulfonium or iodonium salts (the so-called onium salts) of complex metal halide anions, can be used in polymerization of epoxy paints by ultraviolet light radiation. One-coat enamels, topcoats, and primers have been developed which can be photoinitiated to produce hard, adherent films. This process has been tested in a laboratory scale unit by spray coating these materials on three-dimensional objects and passing them through a tunnel containing uv lamps.

  3. The Local Interstellar Ultraviolet Radiation Field

    E-Print Network [OSTI]

    Richard Conn Henry

    2002-01-03T23:59:59.000Z

    I have used the Hipparcos Input Catalog, together with Kurucz model stellar atmospheres, and information on the strength of the interstellar extinction, to create a model of the expected intensity and spectral distribution of the local interstellar ultraviolet radiation field, under various assumptions concerning the albedo a of the interstellar grains. (This ultraviolet radiation field is of particular interest because of the fact that ultraviolet radiation is capable of profoundly affecting the chemistry of the interstellar medium.) By comparing my models with the observations, I am able to conclude that the albedo a of the interstellar grains in the far ultraviolet is very low, perhaps a = 0.1. I also advance arguments that my present determination of this albedo is much more reliable than any of the many previous (and conflicting) ultraviolet interstellar grain albedo determinations. Beyond this, I show that the ultraviolet background radiation that is observed at high galactic latitudes must be extragalactic in origin, as it cannot be backscatter of the interstellar radiation field.

  4. Comparing Vacuum and Extreme Ultraviolet Radiation for Postionization of Laser Desorbed Neutrals from Bacterial Biofilms and Organic Fullerene

    E-Print Network [OSTI]

    Gaspera, Gerald L.

    2011-01-01T23:59:59.000Z

    Laboratory, USA Comparing Vacuum and Extreme Ultravioletradiation, extreme ultraviolet, vacuum ultravioletAbstract Vacuum and extreme ultraviolet radiation from 8 -

  5. Ultraviolet laser beam monitor using radiation responsive crystals

    DOE Patents [OSTI]

    McCann, Michael P. (Oliver Springs, TN); Chen, Chung H. (Knoxville, TN)

    1988-01-01T23:59:59.000Z

    An apparatus and method for monitoring an ultraviolet laser beam includes disposing in the path of an ultraviolet laser beam a substantially transparent crystal that will produce a color pattern in response to ultraviolet radiation. The crystal is exposed to the ultraviolet laser beam and a color pattern is produced within the crystal corresponding to the laser beam intensity distribution therein. The crystal is then exposed to visible light, and the color pattern is observed by means of the visible light to determine the characteristics of the laser beam that passed through crystal. In this manner, a perpendicular cross sectional intensity profile and a longitudinal intensity profile of the ultraviolet laser beam may be determined. The observation of the color pattern may be made with forward or back scattered light and may be made with the naked eye or with optical systems such as microscopes and television cameras.

  6. Measurement and analysis of near ultraviolet solar radiation

    SciTech Connect (OSTI)

    Mehos, M.S.; Pacheco, K.A.; Link, H.F.

    1991-12-01T23:59:59.000Z

    The photocatalytic detoxification of organic contaminants is currently being investigated by a number of laboratories, universities, and institutions throughout the world. The photocatalytic oxidation process requires that contaminants come in contact with a photocatalyst such as titanium dioxide, under illumination of ultraviolet (UV) radiation in order for the decomposition reaction to take place. Researches from the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories are currently investigating the use of solar energy as a means of driving this photocatalytic process. Measurements of direct-normal and global-horizontal ultraviolet (280--385 nm) and full-spectrum (280--4000 nm) solar radiation taken in Golden, Colorado over a one-year period are analyzed, and comparisons are made with data generated from a clear-sky solar radiation model (BRITE) currently in use for predicting the performance of solar detoxification processes. Analysis of the data indicates a ratio of global-horizontal ultraviolet to full-spectrum radiation of 4%--6% that is weakly dependent on air mass. Conversely, data for direct-normal ultraviolet radiation indicate a much large dependence on air mass, with a ratio of approximately 5% at low air mass to 1% at higher at masses. Results show excellent agreement between the measured data and clear-sky predictions for both the ultraviolet and the full-spectrum global-horizontal radiation. For the direct-normal components, however, the tendency is for the clear-sky model to underpredict the measured that. Averaged monthly ultraviolet radiation available for the detoxification process indicates that the global-horizontal component of the radiation exceeds the direct-normal component throughout the year. 9 refs., 7 figs.

  7. Lamp for generating high power ultraviolet radiation

    DOE Patents [OSTI]

    Morgan, Gary L. (Elkridge, MD); Potter, James M. (Los Alamos, NM)

    2001-01-01T23:59:59.000Z

    The apparatus is a gas filled ultraviolet generating lamp for use as a liquid purifier. The lamp is powred by high voltage AC, but has no metallic electrodes within or in contact with the gas enclosure which is constructed as two concentric quartz cylinders sealed together at their ends with the gas fill between the cylinders. Cooling liquid is pumped through the volume inside the inner quartz cylinder where an electrically conductive pipe spaced from the inner cylinder is used to supply the cooling liquid and act as the high voltage electrode. The gas enclosure is enclosed within but spaced from a metal housing which is connected to operate as the ground electrode of the circuit and through which the treated fluid flows. Thus, the electrical circuit is from the central pipe, and through the cooling liquid, the gas enclosure, the treated liquid on the outside of the outer quartz cylinder, and to the housing. The high voltage electrode is electrically isolated from the source of cooling liquid by a length of insulated hose which also supplies the cooling liquid.

  8. Ultraviolet radiation in the southern seas in early spring 1993

    SciTech Connect (OSTI)

    Wendler, G.; Quakenbush, T. [Univ. of Alaska, Fairbanks, AK (United States)

    1994-12-31T23:59:59.000Z

    The National Science Foundation research vessel Nathaniel B. Palmer carried out a cruise to Antarctica in early spring of 1993. It left Punta Arenas, Chile, close to the tip of South America on 11 August 1993. sailed south for 3 days to the tip of The Antarctic Peninsula, stopping at O`Higgens and Palmer Stations, and from there went southwest and into the Bellingshausen sea. On 10 September, it reached the most southerly position, 71{degrees}S, some distance north of the Thurston Island. From there, it went as far as 110{degrees}W before returning to Punta Arenas. The main purpose of the cruise was to investigate the snow- and sea-ice thickness, properties, and structures in this part of the southern oceans. It also allowed us to carry out continuous radiation measurements. We measured the following fluxes: global radiation (Eppley PSP), infrared incoming radiation (Eppley Pyrgeometer PIR), ultraviolet-A radiation (Eppley UV meter), ultraviolet-B radiation (Yankee Environmental Systems), and pitch and roll of the ship (Lucas Sensing Systems, Inc.). All instruments were sampled twice per second (Campbell Scientific, Model 21 X), and a notebook computer (ASI Patriot) stored 1-minute averages of the radiation data and 1-minute standard deviation of the ship`s pitch and roll. Visual observations of cloud cover were also recorded. 2 refs., 3 figs.

  9. Ambient Levels of Ultraviolet-B Radiation Cause Mortality in Juvenile Western Toads, Bufo boreas

    E-Print Network [OSTI]

    Blaustein, Andrew R.

    Ambient Levels of Ultraviolet-B Radiation Cause Mortality in Juvenile Western Toads, Bufo boreas industrial gases contribute to the depletion of the earth's protective ozone layer, resulting in increased amounts of cell damaging ultraviolet-B (UV-B) radiation reaching the surface of the earth. Recent

  10. Author's personal copy Effects of ultraviolet radiation on an intertidal trematode parasite: An assessment

    E-Print Network [OSTI]

    Poulin, Robert

    Author's personal copy Effects of ultraviolet radiation on an intertidal trematode parasite: An assessment of damage and protection A. Studer a, , V.M. Cubillos b,c , M.D. Lamare c , R. Poulin a , D ecosystems which experience high levels of ultraviolet radiation. Although these parasites mostly live within

  11. Tryptophan Cluster Protects Human ?D-Crystallin from Ultraviolet Radiation-Induced Photoaggregation

    E-Print Network [OSTI]

    Schafheimer, Steven Nathaniel

    Exposure to ultraviolet radiation (UVR) is a significant risk factor for age-related cataract, a disease of the human lens and the most prevalent cause of blindness in the world. Cataract pathology involves protein misfolding ...

  12. Solar ultraviolet-B radiation and vitamin D: a cross-sectional population-based

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Solar ultraviolet-B radiation and vitamin D: a cross-sectional population-based study using data,3* Abstract Background: Exposure to solar ultraviolet-B (UV-B) radiation is a major source of vitamin D3AUR 17326E125C4(7E3E3C7E>4(72B43.EE7D4" 7D4":BE27B725CE9393BE647 #12;RESEARCH ARTICLE Open Access Solar

  13. The Efficacy of Ultraviolet Radiation for Sterilizing Tools Used for Surgically Implanting Transmitters into Fish

    SciTech Connect (OSTI)

    Walker, Ricardo W.; Markillie, Lye Meng; Colotelo, Alison HA; Gay, Marybeth E.; Woodley, Christa M.; Brown, Richard S.

    2013-02-28T23:59:59.000Z

    Telemetry is frequently used to examine the behavior of fish, and the transmitters used are normally surgically implanted into the coelom of fish. Implantation requires the use of surgical tools such as scalpels, forceps, needle holders, and sutures. When several fish are implanted consecutively for large telemetry studies, it is common for surgical tools to be sterilized or, at minimum, disinfected between each use so that pathogens that may be present are not spread among fish. However, autoclaving tools can take a long period of time, and chemical sterilants or disinfectants can be harmful to both humans and fish and have varied effectiveness. Ultraviolet (UV) radiation is commonly used to disinfect water in aquaculture facilities. However, this technology has not been widely used to sterilize tools for surgical implantation of transmitters in fish. To determine its efficacy for this application, Pacific Northwest National Laboratory researchers used UV radiation to disinfect surgical tools (i.e., forceps, needle holder, stab scalpel, and suture) that were exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. These organisms included Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica. Surgical tools were exposed to the bacteria by dipping them into a confluent suspension of three varying concentrations (i.e., low, medium, high). After exposure to the bacterial culture, tools were placed into a mobile Millipore UV sterilization apparatus. The tools were then exposed for three different time periods—2, 5, or 15 min. S. parasitica, a water mold, was tested using an agar plate method and forceps-pinch method. UV light exposures of 5 and 15 min were effective at killing all four organisms. UV light was also effective at killing Geobacillus stearothermophilus, the organism used as a biological indicator to verify effectiveness of steam sterilizers. These techniques appear to provide a quick alternative disinfection technique for some surgical tools that is less harmful to both humans and fish while not producing chemical waste. However, we do not recommend using these methods with tools that have overlapping parts or other structures that cannot be directly exposed to UV light such as needle holders.

  14. Carbon contamination and oxidation of Au surfaces under extreme ultraviolet radiation: An x-ray photoelectron spectroscopy study

    E-Print Network [OSTI]

    Harilal, S. S.

    Carbon contamination and oxidation of Au surfaces under extreme ultraviolet radiation: An x 2012) Extreme ultraviolet (EUV) radiation-induced carbon contamination and oxidation of Au surfaces modification during EUV exposure. XPS analysis showed that total carbon contamination (C 1s peak

  15. Influences of atmospheric conditions and air mass on the ratio of ultraviolet to total solar radiation

    SciTech Connect (OSTI)

    Riordan, C.J.; Hulstrom, R.L.; Myers, D.R.

    1990-08-01T23:59:59.000Z

    The technology to detoxify hazardous wastes using ultraviolet (UV) solar radiation is being investigated by the DOE/SERI Solar Thermal Technology Program. One of the elements of the technology evaluation is the assessment and characterization of UV solar radiation resources available for detoxification processes. This report describes the major atmospheric variables that determine the amount of UV solar radiation at the earth's surface, and how the ratio of UV-to-total solar radiation varies with atmospheric conditions. These ratios are calculated from broadband and spectral solar radiation measurements acquired at SERI, and obtained from the literature on modeled and measured UV solar radiation. The following sections discuss the atmospheric effects on UV solar radiation and provide UV-to-total solar radiation ratios from published studies, as well as measured values from SERI's data. A summary and conclusions are also given.

  16. JOURNAL DE PHYSIQUE Colloque C4, supplkment au no 7 , Tome 39, Juillet 1978,page C4-221 STRATOSPHERIC POLLUTION RELATED ULTRAVIOLET RADIATION

    E-Print Network [OSTI]

    Boyer, Edmond

    -221 STRATOSPHERIC POLLUTION RELATED ULTRAVIOLET RADIATION PHENOMENA M. ACKERMAN Institut d'Abronomie Spatiale de aspects with recent examples. The new data obtained on the solar ultraviolet radiation since seven years are emphasized. 1. Introduction. - Solar ultraviolet radiation plays a fundamental role in the formation

  17. Tyrosine/Cysteine Cluster Sensitizing Human ?D-Crystallin to Ultraviolet Radiation-Induced Photoaggregation in Vitro

    E-Print Network [OSTI]

    Schafheimer, Steven Nathaniel

    Ultraviolet radiation (UVR) exposure is a major risk factor for age-related cataract, a protein-aggregation disease of the human lens often involving the major proteins of the lens, the crystallins. ?D-Crystallin (H?D-Crys) ...

  18. Stimulated emission of ultraviolet radiation by vapors of complex molecules

    SciTech Connect (OSTI)

    Barkova, L.A.; Gruzinskii, V.V.; Danilova, V.I.; Degtyarenko, K.M.; Kopylova, T.N.; Kuznetsov, A.L.

    1981-08-01T23:59:59.000Z

    Lasing was observed in vapors of new organic compounds: para-terphenyl, 2-phenylbenzoxazole, 2-(n-tolyl) benzoxazole, 2-(n-methoxyphenyl) benzoxazole, 2-(n-dimethylaminophenyl) benzoxazole, 2-biphenylbenzoxazole, 2-(..cap alpha..-naphthyl) benzoxazole, and also 1,4-di(n-phenylethynyl) benzole, and para-quaterphenyl pumped transversely by XeCl excimer laser radiation at lambda/sub p/ = 308 nm. The lasing bands without tuning covered the 330--370 nm range. The shortest-wavelength maximum (333.5 nm) was observed for 2-(n-methoxyphenyl) benzoxazole. An analysis was made of the lasing ability of the molecules.

  19. Laser Desorption Postionization Mass Spectrometry of Antibiotic-Treated Bacterial Biofilms using Tunable Vacuum Ultraviolet Radiation

    SciTech Connect (OSTI)

    Gasper, Gerald L.; Takahashi, Lynelle K.; Zhou, Jia; Ahmed, Musahid; Moore, Jerry F.; Hanley, Luke

    2010-08-04T23:59:59.000Z

    Laser desorption postionization mass spectrometry (LDPI-MS) with 8.0 ? 12.5 eV vacuum ultraviolet synchrotron radiation is used to single photon ionize antibiotics andextracellular neutrals that are laser desorbed both neat and from intact bacterial biofilms. Neat antibiotics are optimally detected using 10.5 eV LDPI-MS, but can be ionized using 8.0 eV radiation, in agreement with prior work using 7.87 eV LDPI-MS. Tunable vacuum ultraviolet radiation also postionizes laser desorbed neutrals of antibiotics and extracellular material from within intact bacterial biofilms. Different extracellular material is observed by LDPI-MS in response to rifampicin or trimethoprim antibiotic treatment. Once again, 10.5 eV LDPI-MS displays the optimum trade-off between improved sensitivity and minimum fragmentation. Higher energy photons at 12.5 eV produce significant parent ion signal, but fragment intensity and other low mass ions are also enhanced. No matrix is added to enhance desorption, which is performed at peak power densities insufficient to directly produce ions, thus allowing observation of true VUV postionization mass spectra of antibiotic treated biofilms.

  20. Ultraviolet-B radiation enhancement in dielectric barrier discharge based xenon chloride exciplex source by air

    SciTech Connect (OSTI)

    Gulati, P., E-mail: pgulati1512@gmail.com [CSIR-Central Electronics Engineering Research Institute (CSIR-CEERI), Pilani, Rajasthan-333031 (India); Department of Physics, Banasthali University, P.O. Banasthali Vidyapith, Rajasthan 304022 (India); Prakash, R.; Pal, U. N.; Kumar, M. [CSIR-Central Electronics Engineering Research Institute (CSIR-CEERI), Pilani, Rajasthan-333031 (India); Vyas, V. [Department of Physics, Banasthali University, P.O. Banasthali Vidyapith, Rajasthan 304022 (India)

    2014-07-07T23:59:59.000Z

    A single barrier dielectric barrier discharge tube of quartz with multi-strip Titanium-Gold (Ti-Au) coatings have been developed and utilized for ultraviolet-B (UV-B) radiation production peaking at wavelength 308?nm. The observed radiation at this wavelength has been examined for the mixtures of the Xenon together with chlorine and air admixtures. The gas mixture composition, chlorine gas content, total gas pressure, and air pressure dependency of the UV intensity, has been analyzed. It is found that the larger concentration of Cl{sub 2} deteriorates the performance of the developed source and around 2% Cl{sub 2} in this source produced optimum results. Furthermore, an addition of air in the xenon and chlorine working gas environment leads to achieve same intensity of UV-B light but at lower working gas pressure where significant amount of gas is air.

  1. Response of five tropical plant species to natural solar ultraviolet-B radiation

    SciTech Connect (OSTI)

    Searles, P.S.; Caldwell, M.M. (Utah State Univ., Logan, UT (United States)); Winter, K. (Smithsonian Tropical Research Institute, Balboa (Panama))

    1994-06-01T23:59:59.000Z

    The tropical latitudes currently receive high solar ultraviolet-B radiation (UV-B, 280-320 nm) even without ozone depletion. Thus, the influence of natural, present-day UV-B irradiance was examined for three native rainforest tree species and two economically important species on Barro Colorado Island, Panama (9[degrees] N). Solar UV-B radiation conditions were obtained using a UV-B excluding plastic film or a near-ambient UV-B transmitting film over potted plants in a small clearing. Significant differences were often exhibited as increased foliar UV-B absorbing compounds, increased leaf mass pre area, and reduced leaf blade length for plants receiving solar UV-B radiation. Plant height was typically reduced under solar UV-B, but some variation among species in response was seen. Biomass and photosystem II function were generally unaffected. The results provide evidence that tropical vegetation responds to the present level of Solar UV-B radiation. This suggests even a small increase in UV-B radiation with ozone depletion may have biological implications.

  2. Melanocytes can absorb ultraviolet radiation (UVR) and survive con-siderable genotoxic stress. The skin is the main barrier to the exter-

    E-Print Network [OSTI]

    Cai, Long

    to the appearance of skin and provide protection from damage by ultraviolet radiation. Pigmentation mutantsMelanocytes can absorb ultraviolet radiation (UVR) and survive con- siderable genotoxic stress. Thisreviewsummarizeshowpigmentationisregulatedatthemolecu- lar level and how the tanning response provides protection against dam- age and skin cancer. We

  3. Stability properties of Hawking radiation in the presence of ultraviolet violation of local Lorentz invariance

    E-Print Network [OSTI]

    Antonin Coutant

    2014-05-14T23:59:59.000Z

    In this thesis, we study several features of Hawking radiation in the presence of ultraviolet Lorentz violations. These violations are implemented by a modified dispersion relation that becomes nonlinear at short wavelengths. The motivations of this work arise on the one hand from the developing field of analog gravity, where we aim at measuring the Hawking effect in fluid flows that mimic black hole space-times, and on the other hand from the possibility that quantum gravity effects might be approximately modeled by a modified dispersion relation. We develop several studies on various aspects of the problem. First we obtain precise characterizations about the deviations from the Hawking result of black hole radiation, which are induced by dispersion. Second, we study the emergence, both in white hole flows or for massive fields, of a macroscopic standing wave, spontaneously produced from the Hawking effect, and known as `undulation'. Third, we describe in detail an instability named black hole laser, which arises in the presence of two horizons, where Hawking radiation is self-amplified and induces an exponentially growing in time emitted flux.

  4. Effects of PGF{sub 2{alpha}} on human melanocytes and regulation of the FP receptor by ultraviolet radiation

    SciTech Connect (OSTI)

    Scott, Glynis [Department of Dermatology, University of Rochester School of Medicine, Box 697, 601 Elmwood Avenue, Rochester, NY 14642 (United States)]. E-mail: Glynis_Scott@urmc.rochester.edu; Jacobs, Stacey [Department of Dermatology, University of Rochester School of Medicine, Box 697, 601 Elmwood Avenue, Rochester, NY 14642 (United States); Leopardi, Sonya [Department of Dermatology, University of Rochester School of Medicine, Box 697, 601 Elmwood Avenue, Rochester, NY 14642 (United States); Anthony, Frank A. [Schering-Plough HealthCare Products Inc., Memphis TN (United States); Learn, Doug [Charles River DDS, Argus Division, Horsham, PA (United States); Malaviya, Rama [University of Medicine and Dentistry, RWJMS, New Brunswick, NJ (United States); Pentland, Alice [Department of Dermatology, University of Rochester School of Medicine, Box 697, 601 Elmwood Avenue, Rochester, NY 14642 (United States)

    2005-04-01T23:59:59.000Z

    Prostaglandins are potent lipid hormones that activate multiple signaling pathways resulting in regulation of cellular growth, differentiation, and apoptosis. In the skin, prostaglandins are rapidly released by keratinocytes following ultraviolet radiation and are chronically present in inflammatory skin lesions. We have shown previously that melanocytes, which provide photoprotection to keratinocytes through the production of melanin, express several receptors for prostaglandins, including the PGE{sub 2} receptors EP{sub 1} and EP{sub 3} and the PGF{sub 2{alpha}} receptor FP, and that PGF{sub 2{alpha}} stimulates melanocyte dendricity. We now show that PGF{sub 2{alpha}} stimulates the activity and expression of tyrosinase, the rate-limiting enzyme in melanin synthesis. Analysis of FP receptor regulation showed that the FP receptor is regulated by ultraviolet radiation in melanocytes in vitro and in human skin in vivo. We also show that ultraviolet irradiation stimulates production of PGF{sub 2{alpha}} by melanocytes. These results show that PGF{sub 2{alpha}} binding to the FP receptor activates signals that stimulate a differentiated phenotype (dendricity and pigmentation) in melanocytes. The regulation of the FP receptor and the stimulation of production of PGF{sub 2{alpha}} in melanocytes in response to ultraviolet radiation suggest that PGF{sub 2{alpha}} could act as an autocrine factor for melanocyte differentiation.

  5. Resonantly enhanced method for generation of tunable, coherent vacuum ultraviolet radiation

    DOE Patents [OSTI]

    Glownia, James H. (Los Alamos, NM); Sander, Robert K. (Los Alamos, NM)

    1985-01-01T23:59:59.000Z

    Carbon Monoxide vapor is used to generate coherent, tunable vacuum ultraviolet radiation by third-harmonic generation using a single tunable dye laser. The presence of a nearby electronic level resonantly enhances the nonlinear susceptibility of this molecule allowing efficient generation of the vuv light at modest pump laser intensities, thereby reducing the importance of a six-photon multiple-photon ionization process which is also resonantly enhanced by the same electronic level but to higher order. By choosing the pump radiation wavelength to be of shorter wavelength than individual vibronic levels used to extend tunability stepwise from 154.4 to 124.6 nm, and the intensity to be low enough, multiple-photon ionization can be eliminated. Excitation spectra of the third-harmonic emission output exhibit shifts to shorter wavelength and broadening with increasing CO pressure due to phase matching effects. Increasing the carbon monoxide pressure, therefore, allows the substantial filling in of gaps arising from the stepwise tuning thereby providing almost continuous tunability over the quoted range of wavelength emitted.

  6. Resonantly enhanced method for generation of tunable, coherent vacuum-ultraviolet radiation

    DOE Patents [OSTI]

    Glownia, J.H.; Sander, R.K.

    1982-06-29T23:59:59.000Z

    Carbon Monoxide vapor is used to generate coherent, tunable vacuum ultraviolet radiation by third-harmonic generation using a single tunable dye laser. The presence of a nearby electronic level resonantly enhances the nonlinear susceptibility of this molecule allowing efficient generation of the vuv light at modest pump laser intensities, thereby reducing the importance of a six-photon multiple-photon ionization process which is also resonantly enhanced by the same electronic level but no higher order. By choosing the pump radiation wavelength to be of shorter wavelength than individual vibronic levels used to extend tunability stepwise from 154.4 to 124.6 nm, and the intensity to be low enough, multiple-photon ionization can be eliminated. Excitation spectra of the third-harmonic emission output exhibit shifts to shorter wavelength and broadening with increasing CO pressure due to phase matching effects. Increasing the carbon monoxide pressure, therefore, allows the substantial filling in of gaps arising from the stepwise tuning thereby providing almost continuous tunability over the quoted range of wavelength emitted.

  7. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED MELDING PROCESSES IN RELATION TO THE ARC CURRENT DENSITY A Thesis by ROBIN KENT DEVORE Submitted to the Graduate College of Texas A&M University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT...

  8. The effective spectral irradiance of ultra-violet radiations from inert-gas-shielded welding processes in relation to the ARC current density 

    E-Print Network [OSTI]

    DeVore, Robin Kent

    1973-01-01T23:59:59.000Z

    fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1973 Major Subject: Industrial Hygiene THE EFFECTIVE SPECTRAL IRRADIANCE OF ULTRAVIOLET RADIATIONS FROM INERT-GAS-SHIELDED WELDING PROCESSES IN RELATION TO THE ARC CURRENT... DENSITY A Thesis by ROBIN KENT DEVORE Approved as to style and content by: C alarm n of o itte Hea o partment e er Member December 1973 ABSTRACT The Effective Spectral Irradiance of Ultraviolet Radiations from Inert-Gas-Shielded Welding...

  9. Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

    SciTech Connect (OSTI)

    Hilbert, V.; Rödel, C.; Zastrau, U., E-mail: ulf.zastrau@uni-jena.de [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Döppner, T.; Ma, T. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Fletcher, L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Förster, E. [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Glenzer, S. H.; Lee, H. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Hartley, N. J. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Kazak, L.; Komar, D.; Skruszewicz, S. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

    2014-09-08T23:59:59.000Z

    A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5?nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

  10. Extreme-ultraviolet radiation transport in small scale length laser-produced tin plasmas

    E-Print Network [OSTI]

    Sequoia, Kevin Lamar Williams

    2009-01-01T23:59:59.000Z

    radiation heated sio2 aerogel plasma in "dog-bone" targetsspectra from Ti-doped aerogels. Journal of Quantitative

  11. Extreme-ultraviolet radiation transport in small scale length laser-produced tin plasmas

    E-Print Network [OSTI]

    Sequoia, Kevin Lamar Williams

    2009-01-01T23:59:59.000Z

    emissions from laser-produced tin plasmas. Proceedings ofRadiation from Laser- Produced Tin Plasmas. Physical Reviewspectra of xenon and tin discharges. Physical Review E,

  12. Polarization-dependent vacuum-ultraviolet reflectometry using elliptically polarized synchrotron radiation

    E-Print Network [OSTI]

    Boyer, Edmond

    (PTB) at the Berlin electron-storage ring BESSY II, a procedure has been developed to investigate sources. Using monochromatized synchro- tron radiation from the Berlin electron storage ring (BESSY) II to suppress the high portion of on-axis x-ray radiation of the BESSY II storage ring, which would induce

  13. Norathyriol Suppresses Skin Cancers Induced by Solar Ultraviolet Radiation by Targeting ERK Kinases

    SciTech Connect (OSTI)

    Li, Jixia; Malakhova, Margarita; Mottamal, Madhusoodanan; Reddy, Kanamata; Kurinov, Igor; Carper, Andria; Langfald, Alyssa; Oi, Naomi; Kim, Myoung Ok; Zhu, Feng; Sosa, Carlos P.; Zhou, Keyuan; Bode, Ann M.; Dong, Zigang (Cornell); (Guangdong); (UMM)

    2012-06-27T23:59:59.000Z

    Ultraviolet (UV) irradiation is the leading factor in the development of skin cancer, prompting great interest in chemopreventive agents for this disease. In this study, we report the discovery of norathyriol, a plant-derived chemopreventive compound identified through an in silico virtual screening of the Chinese Medicine Library. Norathyriol is a metabolite of mangiferin found in mango, Hypericum elegans, and Tripterospermum lanceolatum and is known to have anticancer activity. Mechanistic investigations determined that norathyriol acted as an inhibitor of extracellular signal-regulated kinase (ERK)1/2 activity to attenuate UVB-induced phosphorylation in mitogen-activated protein kinases signaling cascades. We confirmed the direct and specific binding of norathyriol with ERK2 through a cocrystal structural analysis. The xanthone moiety in norathyriol acted as an adenine mimetic to anchor the compound by hydrogen bonds to the hinge region of the protein ATP-binding site on ERK2. Norathyriol inhibited in vitro cell growth in mouse skin epidermal JB6 P+ cells at the level of G{sub 2}-M phase arrest. In mouse skin tumorigenesis assays, norathyriol significantly suppressed solar UV-induced skin carcinogenesis. Further analysis indicated that norathyriol mediates its chemopreventive activity by inhibiting the ERK-dependent activity of transcriptional factors AP-1 and NF-{kappa}B during UV-induced skin carcinogenesis. Taken together, our results identify norathyriol as a safe new chemopreventive agent that is highly effective against development of UV-induced skin cancer.

  14. The Morality of Collective Harm

    E-Print Network [OSTI]

    Nefsky, Julia

    2012-01-01T23:59:59.000Z

    Andreou, Chrisoula. “Environmental Damage and the Puzzle ofin. 39 Much environmental damage, and resulting harm tocould be defeated. Environmental damage, and resulting harm

  15. Quantifying the response of phytoplankton photosynthesis to ultraviolet radiation: Biological weighting functions

    E-Print Network [OSTI]

    , University of Zürich, Zollikerstr. 107, 8008 Zürich, Switzerland Key words: Lake Lucerne, Lake Cadagno radiation (UV) was assessed for phytoplankton assemblages in two Swiss lakes, pre-alpine Lake Lucerne compared to incubation of the same sample in L. Lucerne, consistent with increased UV sensitivity due

  16. An ultrashort pulse ultra-violet radiation undulator source driven by a laser plasma wakefield accelerator

    SciTech Connect (OSTI)

    Anania, M. P. [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); INFN, Laboratori Nazionali di Frascati, I-00044 Frascati (Italy); Brunetti, E.; Wiggins, S. M.; Grant, D. W.; Welsh, G. H.; Issac, R. C.; Cipiccia, S.; Shanks, R. P.; Manahan, G. G.; Aniculaesei, C.; Jaroszynski, D. A., E-mail: d.a.jaroszynski@strath.ac.uk [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Geer, S. B. van der; Loos, M. J. de [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands); Poole, M. W.; Shepherd, B. J. A.; Clarke, J. A. [ASTeC, STFC, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Gillespie, W. A. [SUPA, School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); MacLeod, A. M. [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee DD1 1HG (United Kingdom)

    2014-06-30T23:59:59.000Z

    Narrow band undulator radiation tuneable over the wavelength range of 150–260?nm has been produced by short electron bunches from a 2?mm long laser plasma wakefield accelerator based on a 20?TW femtosecond laser system. The number of photons measured is up to 9?×?10{sup 6} per shot for a 100 period undulator, with a mean peak brilliance of 1?×?10{sup 18} photons/s/mrad{sup 2}/mm{sup 2}/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120–130?MeV with the radiation pulse duration in the range of 50–100 fs.

  17. Direct photoetching of polymers using radiation of high energy density from a table-top extreme ultraviolet plasma source

    SciTech Connect (OSTI)

    Barkusky, Frank; Bayer, Armin; Peth, Christian; Mann, Klaus [Laser-Laboratorium-Goettingen e.V., Hans-Adolf-Krebs-Weg 1, D-37077 Goettingen (Germany)

    2009-01-01T23:59:59.000Z

    In order to perform material interaction studies with intense extreme ultraviolet (EUV) radiation, a Schwarzschild mirror objective coated with Mo/Si multilayers was adapted to a compact laser-driven EUV plasma source utilizing a solid Au target. By 10x demagnified imaging of the plasma a maximum pulse energy density of {approx}0.73 J/cm{sup 2} at a wavelength of 13.5 nm can be achieved in the image plane of the objective at a pulse duration of 8.8 ns. In this paper we present EUV photoetching rates measured for polymethyl methacrylate, polycarbonate, and polytetrafluoroethylene at various fluence levels. A linear dependence between etch depth and applied EUV pulse number could be observed without the necessity for any incubation pulses. By evaluating the slope of these data, etch rates were determined, revealing also a linear behavior for low fluences. A threshold energy density could not be observed. The slope of the linear etch regime as well as deviations from the linear trend at higher energy densities are discussed and compared to data known from deep UV laser ablation. Furthermore, the surface roughness of the structured polymers was measured by atomic force microscopy and compared to the nonirradiated polymer surface, indicating a rather smooth etch process (roughness increase of 20%-30%). The different shapes of the etch craters observed for the three polymers at high energy densities can be explained by the measured fluence dependence of the etch rates, having consequences for the proper use of polymer ablation for beam profiling of focused EUV radiation.

  18. Responses of the adult almond moth, (Ephestia cautella (Walker)) to intermittent near ultraviolet radiation stimuli

    E-Print Network [OSTI]

    Hollingsworth, Joe Pettus

    1961-01-01T23:59:59.000Z

    , but the light out- put also fluctuates in a similar manner when the lamp is operated from an alternating power souroe. Figure 3 shows the typical pattern of fluotuations in radiation output from an argon glow lamp when energiaed by conventional 60-cyols a... 3j2mycle of the energiaing voltage. Thus, the pulses shown are reourrent at the rats of 120 per second. insect attractants indicate that no consideration has been given to the possible influence of supply voltage frequency cn the attractive effi...

  19. Spectral dependencies of killing, mutation, and transformation in mammalian cells and their relevance to hazards caused by solar ultraviolet radiation

    SciTech Connect (OSTI)

    Suzuki, F.; Han, A.; Lankas, G.R.; Utsumi, H.; Elkind, M.M.

    1981-12-01T23:59:59.000Z

    Using germicidal lamps and Westinghouse sunlamps with and without filtration, the effectiveness of ultraviolet and near-ultraviolet light in inducing molecular and cellular changes was measured. Cell survival and the induction of resistance to 6-thioguanine or to ouabain were measured with V79 Chinese hamster cells, cell survival and neoplastic transformation were measured with C3H mouse 10 T 1/2 cells, and the induction of pyrimidine dimers containing thymine was measured in both cell lines. The short-wavelength cutoff of the sunlamp emission was shifted from approximately 290 nm (unfiltered) to approximately 300 and approximately 310 nm by appropriate filters. Although it was found that the efficiency with which all end points were induced progressively decreased as the short-wavelength cutoff was shifted to longer wavelengths, the rates of decrease differed appreciably. For example, doses of near-ultraviolet light longer than approximately 300 nm that were effective in mutating or in transforming cells were ineffective in killing them. In respect to pyrimidine dimer induction, several but not all cellular end points were induced by dose ratios of sunlamp light (short-wavelength cutoff, approximately 290 nm) to germicidal lamp light (254 nm) in fairly close accord with the doses required to produce equivalent proportions of dimers. However, for near-ultraviolet light having cutoffs at longer wavelengths, the biological action observed was appreciably greater than what would be predicted from the proportion of dimers induced. From the latter observation, it is inferred that increasing intensities of short-wavelength ultraviolet light, as would be expected from reductions in stratospheric ozone around the earth, would result in smaller increases in biological action, e.g., skin cancer, compared to current levels of action than would be predicted from an action spectrum completely corresponding to that of a pyrimidine dimer induction spectrum in DNA.

  20. Effect of ultraviolet radiation exposure on room-temperature hydrogen sensitivity of nanocrystalline doped tin oxide sensor incorporated into microelectromechanical systems device

    SciTech Connect (OSTI)

    Shukla, Satyajit; Agrawal, Rajnikant; Cho, Hyoung J.; Seal, Sudipta; Ludwig, Lawrence; Parish, Clyde [Advanced Materials Processing and Analysis Center (AMPAC) and Mechanical Materials Aerospace Engineering (MMAE) Department, Engineering 381, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816 (United States); National Aeronautics and Space Administration (NASA), John F. Kennedy Space Center, Kennedy Space Center (KSC), Florida 32899 (United States)

    2005-03-01T23:59:59.000Z

    The effect of ultraviolet (UV) radiation exposure on the room-temperature hydrogen (H{sub 2}) sensitivity of nanocrystalline indium oxide (In{sub 2}O{sub 3})-doped tin oxide (SnO{sub 2}) thin-film gas sensor is investigated in this article. The present sensor is incorporated into microelectromechanical systems device using sol-gel dip-coating technique. The present sensor exhibits a very high sensitivity, as high as 65 000-110 000, at room temperature, for 900 ppm of H{sub 2} under the dynamic test condition without UV exposure. The H{sub 2} sensitivity is, however, observed to reduce to 200 under UV radiation, which is contrary to the literature data, where an enhanced room-temperature gas sensitivity has been reported under UV radiation. The observed phenomenon is attributed to the reduced surface coverage by the chemisorbed oxygen ions under UV radiation, which is in consonance with the prediction of the constitutive equation, proposed recently by the authors, for the gas sensitivity of nanocrystalline semiconductor oxide thin-film sensors.

  1. NEW Fe IX LINE IDENTIFICATIONS USING SOLAR AND HELIOSPHERIC OBSERVATORY/SOLAR ULTRAVIOLET MEASUREMENT OF EMITTED RADIATION AND HINODE/EIS JOINT OBSERVATIONS OF THE QUIET SUN

    SciTech Connect (OSTI)

    Landi, E.; Young, P. R. [Naval Research Laboratory, Space Science Division, Washington, DC 20375 (United States)

    2009-12-20T23:59:59.000Z

    In this work, we study joint observations of Hinode/EUV Imaging Spectrometer (EIS) and Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation of Fe IX lines emitted by the same level of the high energy configuration 3s {sup 2}3p {sup 5}4p. The intensity ratios of these lines are dependent on atomic physics parameters only and not on the physical parameters of the emitting plasma, so that they are excellent tools to verify the relative intensity calibration of high-resolution spectrometers that work in the 170-200 A and 700-850 A wavelength ranges. We carry out extensive atomic physics calculations to improve the accuracy of the predicted intensity ratio, and compare the results with simultaneous EIS-SUMER observations of an off-disk quiet Sun region. We were able to identify two ultraviolet lines in the SUMER spectrum that are emitted by the same level that emits one bright line in the EIS wavelength range. Comparison between predicted and measured intensity ratios, wavelengths and energy separation of Fe IX levels confirms the identifications we make. Blending and calibration uncertainties are discussed. The results of this work are important for cross-calibrating EIS and SUMER, as well as future instrumentation.

  2. Effect of ultraviolet and x-ray radiation on the work function of TiO{sub 2} surfaces

    SciTech Connect (OSTI)

    Gutmann, S. [Department of Chemistry, University of South Florida, Tampa, Florida 33620 (United States); Wolak, M. A.; Beerbom, M. M.; Schlaf, R. [Department of Electrical Engineering, University of South Florida, Tampa, Florida 33620 (United States); Conrad, M. [Department of Mechanical Engineering, University of South Florida, Tampa, Florida 33620 (United States)

    2010-05-15T23:59:59.000Z

    The work functions of nanocrystalline anatase (TiO{sub 2}) thin films and a rutile single crystal were measured using photoemission spectroscopy (PES). The nanocrystalline titanium dioxide films were deposited in-vacuum using electrospray thin film deposition. A comparison between ultraviolet photoemission spectroscopy (UPS) and low intensity x-ray photoemission spectroscopy (LIXPS) work function measurements on these samples revealed a strong, immediate, and permanent work function reduction (>0.5 eV) caused by the UPS measurements. Furthermore, it was found that regular XPS measurements also reduce the work function after exposure times ranging from seconds to minutes. These effects are similar in magnitude to artifacts seen previously on indium tin oxide (ITO) substrates characterized with XPS and UPS, and are likely related to the formation of a surface dipole through the photochemical hydroxylation of oxygen vacancies present on the TiO{sub 2} surface.

  3. Radiation: Radiation Control (Indiana)

    Broader source: Energy.gov [DOE]

    It is the policy of the state to encourage the constructive uses of radiation and to control its harmful effects. This section contains regulations pertaining to the manufacture, use,...

  4. Generation of circularly polarized radiation from a compact plasma-based extreme ultraviolet light source for tabletop X-ray magnetic circular dichroism studies

    SciTech Connect (OSTI)

    Wilson, Daniel; Rudolf, Denis, E-mail: d.rudolf@fz-juelich.de; Juschkin, Larissa [RWTH Aachen University, Experimental Physics of EUV, Steinbachstraße 15, 52074 Aachen (Germany); Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-9), JARA-FIT, 52425 Jülich (Germany); Weier, Christian; Adam, Roman; Schneider, Claus M. [Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-6), JARA-FIT, 52425 Jülich (Germany); Winkler, Gerrit; Frömter, Robert [Institut für Angewandte Physik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg (Germany); Danylyuk, Serhiy [RWTH Aachen University, Chair for Technology of Optical Systems, JARA-FIT, Steinbachstraße 15, 52074 Aachen (Germany); Bergmann, Klaus [Fraunhofer Institute for Laser Technology, Steinbachstrasse 15, 52074 Aachen (Germany); Grützmacher, Detlev [Forschungszentrum Jülich GmbH, Peter Grünberg Institut (PGI-9), JARA-FIT, 52425 Jülich (Germany)

    2014-10-15T23:59:59.000Z

    Generation of circularly polarized light in the extreme ultraviolet (EUV) spectral region (about 25 eV–250 eV) is highly desirable for applications in spectroscopy and microscopy but very challenging to achieve in a small-scale laboratory. We present a compact apparatus for generation of linearly and circularly polarized EUV radiation from a gas-discharge plasma light source between 50 eV and 70 eV photon energy. In this spectral range, the 3p absorption edges of Fe (54 eV), Co (60 eV), and Ni (67 eV) offer a high magnetic contrast often employed for magneto-optical and electron spectroscopy as well as for magnetic imaging. We simulated and designed an instrument for generation of linearly and circularly polarized EUV radiation and performed polarimetric measurements of the degree of linear and circular polarization. Furthermore, we demonstrate first measurements of the X-ray magnetic circular dichroism at the Co 3p absorption edge with a plasma-based EUV light source. Our approach opens the door for laboratory-based, element-selective spectroscopy of magnetic materials and spectro-microscopy of ferromagnetic domains.

  5. High-resolution tangential absolute extreme ultraviolet arrays for radiated power density measurements on NSTX-U

    SciTech Connect (OSTI)

    Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; Kozub, T. A.; LeBlanc, B. P.; Stratton, B. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Faust, I. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Tritz, K. [The Johns Hopkins University, Baltimore, Maryland 21209 (United States)

    2014-11-15T23:59:59.000Z

    The radiated-power-density diagnostic on the equatorial midplane for the NSTX-U tokamak will be upgraded to measure the radial structure of the photon emissivity profile with an improved radial resolution. This diagnostic will enhance the characterization and studies of power balance, impurity transport, and MHD. The layout and response expected of the new system is shown for different plasma conditions and impurity concentrations. The effect of toroidal rotation driving poloidal asymmetries in the core radiation from high-Z impurities is also addressed.

  6. Solar Dynamics Observatory/ Extreme Ultraviolet Variability Experiment

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Solar Dynamics Observatory/ EVE Extreme Ultraviolet Variability Experiment Frequently Asked and model solar extreme ultraviolet irradiance variations due to solar flares, solar rotation, and solar and structure of the Sun. What is solar variability? Solar radiation varies on all time scales ranging from

  7. Method for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (Livermore, CA); Kubiak, Glenn D. (Livermore, CA)

    1999-01-01T23:59:59.000Z

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  8. Method for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (727 Clara St., Livermore, Alameda County, CA 94550); Kubiak, G. D. (475 Maple St., Livermore, Alameda County, CA 94550)

    2000-01-01T23:59:59.000Z

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  9. Photoresist composition for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E. (Alameda County, CA); Kubiak, G. D. (Alameda County, CA)

    1999-01-01T23:59:59.000Z

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods. A photoresist composition for extreme ultraviolet radiation of boron carbide polymers, hydrochlorocarbons and mixtures thereof.

  10. acanthopanax senticosus harms: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    value of y is needed at some point Weide, Bruce W. 11 Defenders of Wildlife Climate Change & Harmful Algal Blooms Harmful Algal Blooms CiteSeer Summary: Harmful algal blooms and...

  11. Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics

    E-Print Network [OSTI]

    Grigoriev, Igor

    2011-01-01T23:59:59.000Z

    Niche of harmful alga Aureococcus anophagefferens revealedc consensus. Harmful Algae 8:3–13. 2. Sunda WG, Graneli E,of the United States. Harmful Algae 8:39–53. 4. Smayda TJ (

  12. How plants beckon bacteria that do it harm | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    plants beckon bacteria that do it harm How plants beckon bacteria that do it harm Released: April 28, 2014 Work on microbial signaling offers better biofuels, human health...

  13. Inorganic volumetric light source excited by ultraviolet light

    DOE Patents [OSTI]

    Reed, S.; Walko, R.J.; Ashley, C.S.; Brinker, C.J.

    1994-04-26T23:59:59.000Z

    The invention relates to a composition for the volumetric generation of radiation. The composition comprises a porous substrate loaded with a component capable of emitting radiation upon interaction with an exciting radiation. Preferably, the composition is an aerogel substrate loaded with a component, e.g., a phosphor, capable of interacting with exciting radiation of a first energy, e.g., ultraviolet light, to produce radiation of a second energy, e.g., visible light. 4 figures.

  14. The Health Risks: Seafood Contamination, Harmful Algal

    E-Print Network [OSTI]

    health products from the sea. What is the central issue? Why should I care? How will OHH researchThe Health Risks: Seafood Contamination, Harmful Algal Blooms and Polluted Beaches Seafood associated public health costs. Announcing a New Interagency Report on Oceans and Human Health Research

  15. Method for generating extreme ultraviolet with mather-type plasma accelerators for use in Extreme Ultraviolet Lithography

    DOE Patents [OSTI]

    Hassanein, Ahmed (Bolingbrook, IL); Konkashbaev, Isak (Bolingbrook, IL)

    2006-10-03T23:59:59.000Z

    A device and method for generating extremely short-wave ultraviolet electromagnetic wave uses two intersecting plasma beams generated by two plasma accelerators. The intersection of the two plasma beams emits electromagnetic radiation and in particular radiation in the extreme ultraviolet wavelength. In the preferred orientation two axially aligned counter streaming plasmas collide to produce an intense source of electromagnetic radiation at the 13.5 nm wavelength. The Mather type plasma accelerators can utilize tin, or lithium covered electrodes. Tin, lithium or xenon can be used as the photon emitting gas source.

  16. Ultraviolet stimulation of hydrogen peroxide production using...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ultraviolet stimulation of hydrogen peroxide production using aminoindazole, diaminopyridine, and phenylenediamine solid polymer Ultraviolet stimulation of hydrogen peroxide...

  17. Influence of laser pulse duration on extreme ultraviolet and ion emission features from tin plasmas

    E-Print Network [OSTI]

    Harilal, S. S.

    Influence of laser pulse duration on extreme ultraviolet and ion emission features from tin plasmas ultraviolet (EUV) radiation from a laser pro- duced tin plasma has been studied extensively in recent years. The need for 13.5 nm wavelength and a regenerative target lead to the use of tin droplet targets.10 Hot tin

  18. Georgia Radiation Control Act (Georgia)

    Broader source: Energy.gov [DOE]

    The Georgia Radiation Control Act is designed to prevent any associated harmful effects upon the environment or the health and safety of the public through the institution and maintenance of a...

  19. accelerating harm reduction: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    users, notably children. Additionally for adults, some contents included in abnormal porn sites can do ordinary peoples mental health harm. In this paper, we propose an...

  20. The O iv and S iv intercombination lines in the ultraviolet spectra of astrophysical sources

    E-Print Network [OSTI]

    , obtained with the Solar Ultraviolet Measurements of the Emitted Radiation (sumer) instrument on the Solar/09/2002; 9:46; p.1 #12; 2 Keenan et al. line ratios and observational data. For example, Cook et al. (1995

  1. IN HARM'S WAY: Lack Of Federal Coal Ash

    E-Print Network [OSTI]

    Short, Daniel

    IN HARM'S WAY: Lack Of Federal Coal Ash Regulations Endangers Americans And Their Environment 2010 Thirty-nine New Damage Cases of Contamination from Improperly Disposed Coal Combustion Waste, Editor and Contributing Author #12;IN HARM'S WAY: Lack of Federal Coal Ash Regulations Endangers

  2. Global Dynamics of Zooplankton and Harmful Algae in Flowing Habitats

    E-Print Network [OSTI]

    Hsu, Sze-Bi

    Global Dynamics of Zooplankton and Harmful Algae in Flowing Habitats Sze-Bi Hsu Feng-Bin Wang Xiao from the dynamics of harmful algae and zooplankton in flowing- water habitats where a main channel. For the system modeling the dynamics of algae and their toxin that contains little limiting nutrient, we

  3. Portugal's Budget Austerity May Do More Harm Than Good

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    Portugal's Budget Austerity May Do More Harm Than Good July 02, 2013 4:00 AM by LAUREN FRAYER severe budget austerity does more harm than good. LAUREN FRAYER, BYLINE: Of all the bailed-out countries. Portuguese Finance Minister Vitor Gaspar took it even further - doubling budget cuts and tax hikes. Last year

  4. Method and apparatus for producing durationally short ultraviolet or X-ray laser pulses

    DOE Patents [OSTI]

    MacGowan, Brian J. (Livermore, CA); Matthews, Dennis L. (El Granada, CA); Trebes, James E. (Livermore, CA)

    1988-01-01T23:59:59.000Z

    A method and apparatus is disclosed for producing ultraviolet or X-ray laser pulses of short duration (32). An ultraviolet or X-ray laser pulse of long duration (12) is progressively refracted, across the surface of an opaque barrier (28), by a streaming plasma (22) that is produced by illuminating a solid target (16, 18) with a pulse of conventional line focused high power laser radiation (20). The short pulse of ultraviolet or X-ray laser radiation (32), which may be amplified to high power (40, 42), is separated out by passage through a slit aperture (30) in the opaque barrier (28).

  5. Method and apparatus for producing durationally short ultraviolet or x-ray laser pulses

    DOE Patents [OSTI]

    MacGowan, B.J.; Matthews, D.L.; Trebes, J.E.

    1987-05-05T23:59:59.000Z

    A method and apparatus is disclosed for producing ultraviolet or x- ray laser pulses of short duration. An ultraviolet or x-ray laser pulse of long duration is progressively refracted, across the surface of an opaque barrier, by a streaming plasma that is produced by illuminating a solid target with a pulse of conventional line focused high power laser radiation. The short pulse of ultraviolet or x-ray laser radiation, which may be amplified to high power, is separated out by passage through a slit aperture in the opaque barrier.

  6. Ultraviolet | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin TransitionProgram |FrankUltrafastHydrogen andPortalUltraviolet

  7. aerosol radiative effects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    space-borne sensors use information from the ultraviolet (UV) to the visible and thermal infrared Christopher, Sundar A. 25 Black carbon radiative heating effects on cloud...

  8. ENVIRONMENTAL REMEDIAL ACTION – ARE WE DOING MORE HARM THAN GOOD?

    E-Print Network [OSTI]

    Bruce W. Church

    The International Commission on Radiological Protection (ICRP) (1) has stated that interventions i.e., remedial actions should do more good than harm. This paper examines completed cleanup projects to answer the question posed in the title. Various researchers have published that toxins in the environment only cause a small percentage of cancers i.e., 1-3 percent (2,3). Estimates of hypothetical fatal cancers are inflated because primarily it is assumed that people will change their living habits and move onto or near uncontrolled waste sites. An occupancy factor of 100 % is used and by using large populations exposed to miniscule levels of radiation (4) unreal levels of fatal cancers are predicted. What we observe are technically indefensible numbers of cancers being calculated for these hypothetical people. This and other maximizing assumptions inflate the risk. The inflated risk, along with very conservative criteria, drives the removal of large volumes of soil and debris. An unintended consequence of these costly well-intentioned (5) remedial actions is the real fatalities and injuries that occur to workers doing the construction and to members of the public through transportation activities. Even though some analysis include the estimates of worker risk, there is little or no discussion which highlights the fact that real risk is being traded for hypothetical risk. This paper is an attempt to review this situation and through cited literature and case studies, come to a better understanding of what if any good is really being done. Maybe it is time to consider this transfer of risk from hypothetical victims to the real victims in remedial action decision-making.

  9. Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics

    E-Print Network [OSTI]

    Bertrand, Erin Marie

    Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking, because the ...

  10. Molecular insights into the niche of harmful brown tides

    E-Print Network [OSTI]

    Wurch, Louie L. (Louie Lorne)

    2011-01-01T23:59:59.000Z

    Recurrent brown tide blooms caused by the harmful alga Alureococcus anophagefferens have decimated coastal ecosystems and shellfisheries along the Eastern U.S and South Africa. The exact mechanisms controlling bloom ...

  11. Re-evaluation of SO2 release of the 15 June 1991 Pinatubo eruption using ultraviolet and infrared satellite sensors

    E-Print Network [OSTI]

    Rose, William I.

    Re-evaluation of SO2 release of the 15 June 1991 Pinatubo eruption using ultraviolet and infrared Infrared Radiation Sounder/2) sensor, whose data sets have a higher temporal resolution, are also analyzed ultraviolet and infrared satellite sensors, Geochem. Geophys. Geosyst., 5, Q04001, doi:10.1029/ 2003GC000654

  12. 620 OPTICS LETTERS / Vol. 29, No. 6 / March 15, 2004 Damage to extreme-ultraviolet Sc Si multilayer mirrors

    E-Print Network [OSTI]

    Rocca, Jorge J.

    620 OPTICS LETTERS / Vol. 29, No. 6 / March 15, 2004 Damage to extreme-ultraviolet Sc Si multilayer, Russia Received August 21, 2003 The damage threshold and damage mechanism of extreme-ultraviolet Sc Si multilayer mirror coatings are investigated with focused nanosecond pulses at 46.9-nm radiation from

  13. Extreme ultraviolet lithography machine

    DOE Patents [OSTI]

    Tichenor, Daniel A. (Castro Valley, CA); Kubiak, Glenn D. (Livermore, CA); Haney, Steven J. (Tracy, CA); Sweeney, Donald W. (San Ramon, CA)

    2000-01-01T23:59:59.000Z

    An extreme ultraviolet lithography (EUVL) machine or system for producing integrated circuit (IC) components, such as transistors, formed on a substrate. The EUVL machine utilizes a laser plasma point source directed via an optical arrangement onto a mask or reticle which is reflected by a multiple mirror system onto the substrate or target. The EUVL machine operates in the 10-14 nm wavelength soft x-ray photon. Basically the EUV machine includes an evacuated source chamber, an evacuated main or project chamber interconnected by a transport tube arrangement, wherein a laser beam is directed into a plasma generator which produces an illumination beam which is directed by optics from the source chamber through the connecting tube, into the projection chamber, and onto the reticle or mask, from which a patterned beam is reflected by optics in a projection optics (PO) box mounted in the main or projection chamber onto the substrate. In one embodiment of a EUVL machine, nine optical components are utilized, with four of the optical components located in the PO box. The main or projection chamber includes vibration isolators for the PO box and a vibration isolator mounting for the substrate, with the main or projection chamber being mounted on a support structure and being isolated.

  14. Self-cleaning optic for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Klebanoff, Leonard E.; Stulen, Richard H.

    2003-12-16T23:59:59.000Z

    A multilayer reflective optic or mirror for lithographic applications, and particularly extreme ultraviolet (EUV) lithography, having a surface or "capping" layer which in combination with incident radiation and gaseous molecular species such as O.sub.2, H.sub.2, H.sub.2 O provides for continuous cleaning of carbon deposits from the optic surface. The metal capping layer is required to be oxidation resistant and capable of transmitting at least 90% of incident EUV radiation. Materials for the capping layer include Ru, Rh, Pd, Ir, Pt and Au and combinations thereof.

  15. Harms of Unintentional Leaks during Volume Targeted Pressure Support Ventilation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Harms of Unintentional Leaks during Volume Targeted Pressure Support Ventilation Sonia Khirani1 Background: Volume targeted pressure support ventilation (VT-PSV) is a hybrid mode increasingly used. The objective of the study was to determine the ability of home ventilators to maintain the preset minimal VT

  16. Rapid deterioration of metallic surfaces induced by intense ultraviolet radiation Dah-An Luh,1,2,* Kuan-Chun Liu,1 Cheng-Maw Cheng,2 and Ku-Ding Tsuei2

    E-Print Network [OSTI]

    Luh, Dah-An

    to collect data and allows tests of dynamic modifications of the system properties of small samples University, Taoyuan 32001, Taiwan 2National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan of the Shockley states during annealing and cooling was also discovered. These observations seem to favor

  17. Eutrophication and harmful algal blooms: A scientific consensus J. Heisler a,3

    E-Print Network [OSTI]

    Cochlan, William P.

    Eutrophication and harmful algal blooms: A scientific consensus J. Heisler a,3 , P.M. Glibert b between water quality and eutrophication and the occurrence of harmful algal blooms (HABs). This meeting in revised form 21 January 2008 Accepted 1 August 2008 Keywords: Eutrophication Harmful algal blooms HABs

  18. Ultraviolet imaging of hydrogen flames

    SciTech Connect (OSTI)

    Yates, G.J.; Wilke, M.; King, N.

    1988-01-01T23:59:59.000Z

    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 1000 and is capable of being shuttered at nanosecond speeds and of being framed at over 600 frames per second. We present data from observations of test flames in air at standard RS-170 video rates with varying background conditions. Enhanced images using background subtraction are presented. Finally, we discuss the use of polarizaton effects to further discrimination against sky background. This work began as a feasibility study to investigate ultraviolet technology to detect hydrogen fires for the NASA space program. 6 refs., 7 figs, 2 tabs.

  19. Radiation and Uranium Resources Exposure Control (South Dakota)

    Broader source: Energy.gov [DOE]

    The public policy of South Dakota is to encourage the constructive uses of radiation, the proper development of uranium resources, and the control of any associated harmful effects. The disposal of...

  20. The effects of selected wavelengths and energy levels of ultraviolet irradiation on the endopeptidase and hemolytic activity of Aeromonas proteolytica

    E-Print Network [OSTI]

    Lovett, David Franklin

    1972-01-01T23:59:59.000Z

    irradiation of the radiosensitive B strain of Escherichia cali induced, at a high frequency, a radiation resistance strain, which she designated as B/r. Six years later Clark (2) found that this B/r strain was not only more resistant to ultraviolet...THE EFFECTS OF SELECTED WAVELENGTHS AND ENERGY LEVELS OF ULTRAVIOLET IRRADIATION ON THE ENDOPEPTIDASE AND HEMOLYTIC ACTIVITY OF AEROMONAS PROTEOLYTICA A Thesis by DAVID FRANKLIN LOVETT Submitted to the Graduate College of Texas ASM...

  1. MoRu/Be multilayers for extreme ultraviolet applications

    DOE Patents [OSTI]

    Bajt, Sasa C. (Livermore, CA); Wall, Mark A. (Stockton, CA)

    2001-01-01T23:59:59.000Z

    High reflectance, low intrinsic roughness and low stress multilayer systems for extreme ultraviolet (EUV) lithography comprise amorphous layers MoRu and crystalline Be layers. Reflectance greater than 70% has been demonstrated for MoRu/Be multilayers with 50 bilayer pairs. Optical throughput of MoRu/Be multilayers can be 30-40% higher than that of Mo/Be multilayer coatings. The throughput can be improved using a diffusion barrier to make sharper interfaces. A capping layer on the top surface of the multilayer improves the long-term reflectance and EUV radiation stability of the multilayer by forming a very thin native oxide that is water resistant.

  2. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    SciTech Connect (OSTI)

    Shin, Joong-Won, E-mail: jshin@govst.edu [Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States) [Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States); Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States); Bernstein, Elliot R., E-mail: erb@lamar.colostate.edu [Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States)

    2014-01-28T23:59:59.000Z

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5{sup ?}-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results.

  3. Ultraviolet divergences and supersymmetric theories

    SciTech Connect (OSTI)

    Sagnotti, A.

    1984-09-01T23:59:59.000Z

    This article is closely related to the one by Ferrara in these same Proceedings. It deals with what is perhaps the most fascinating property of supersymmetric theories, their improved ultraviolet behavior. My aim here is to present a survey of the state of the art as of August, 1984, and a somewhat more detailed discussion of the breakdown of the superspace power-counting beyond N = 2 superfields. A method is also described for simplifying divergence calculations that uses the locality of subtracted Feynman integrals. 74 references.

  4. Microgap ultra-violet detector

    DOE Patents [OSTI]

    Wuest, C.R.; Bionta, R.M.

    1994-09-20T23:59:59.000Z

    A microgap ultra-violet detector of photons with wavelengths less than 400 run (4,000 Angstroms) which comprises an anode and a cathode separated by a gas-filled gap and having an electric field placed across the gap is disclosed. Either the anode or the cathode is semi-transparent to UV light. Upon a UV photon striking the cathode an electron is expelled and accelerated across the gap by the electric field causing interactions with other electrons to create an electron avalanche which contacts the anode. The electron avalanche is detected and converted to an output pulse. 2 figs.

  5. Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics

    SciTech Connect (OSTI)

    Gobler, C J; Grigoriev, I V; Berry, D L; Dyhrman, S T; Wilhelm, S W; Salamov, A; Lobanov, A V; Zhang, Y; Collier, J L; Wurch, L L; Kustka, A B; Dill, B D; Shah, M; VerBerkomes, N C; Kuo, A; Terry, A; Pangilinan, J; Lindquist, E A; Lucas, S; Paulsen, I; Hattenrath-Lehmann, T K; Talmage, S; Walker, E A; Koch, F; Burson, A M; Marcoval, M A; Tang, Y; LeCleir, G R; Coyne, K J; Berg, G M; Bertrand, E M; Saito, M A; Gladyshev, V N

    2011-03-02T23:59:59.000Z

    Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements demonstrated that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the first HAB genome (A. anophagefferens) and compared its gene complement to those of six competing phytoplankton species identified via metaproteomics. Using an ecogenomic approach, we specifically focused on the gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 mbp) and more genes involved in light harvesting, organic carbon and nitrogen utilization, and encoding selenium- and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus has facilitated the proliferation of this and potentially other HABs.

  6. Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics

    SciTech Connect (OSTI)

    Grigoriev, Igor; Gobler, Christopher; Salamov, Asaf; Kuo, Alan; Terry, Astrid; Pangillian, Jasmyn; Lindquist, Erika; Lucas, Susan; Berry, Dianna; Dyhrman, Sonya; Wilhelm, Steven; Lobanov, Alexei; Zhang, Yan; Collier, Jackie; Wurch, Louie; Kusta, Adam; Dill, Brian; Shsh, Manesh; VerBerkmoes, Nathan; Paulsen, Ian; Hattenrath-Lehmann, Theresa; Talmage, Stephanie; Walker, Elyse; Koch, Florian; Burson, Amanda; Marcoval, Maria; Tang, Yin-Zhong; LeCleir, Gary; Coyne, Kathyrn; Berg, Gry; Bertrand, Erin; Saito, Mak; Gladyshev, Vadim

    2011-02-18T23:59:59.000Z

    Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking, because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements showed that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the genome of A. anophagefferens and compared its gene complement with those of six competing phytoplankton species identified through metaproteomics. Using an ecogenomic approach, we specifically focused on gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 Mbp) and has more genes involved in light harvesting, organic carbon and nitrogen use, and encoding selenium- and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species, with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus, has facilitated the proliferation of this and potentially other HABs.

  7. A Combined Vacuum Ultraviolet Laser and Synchrotron Pulsed Field...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Vacuum Ultraviolet Laser and Synchrotron Pulsed Field Ionization Study of BCl. A Combined Vacuum Ultraviolet Laser and Synchrotron Pulsed Field Ionization Study of BCl. Abstract:...

  8. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: A modular vacuum ultraviolet source

    SciTech Connect (OSTI)

    Sloan Roberts, F.; Anderson, Scott L. [Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112 (United States)] [Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112 (United States)

    2013-12-15T23:59:59.000Z

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a “soft” photoionization source for gas-phase mass spectrometry.

  9. Upgrade of absolute extreme ultraviolet diagnostic on J-TEXT

    SciTech Connect (OSTI)

    Zhang, X. L.; Cheng, Z. F., E-mail: chengfe@hust.edu.cn; Hou, S. Y.; Zhuang, G.; Luo, J. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-11-15T23:59:59.000Z

    The absolute extreme ultraviolet (AXUV) diagnostic system is used for radiation observation on J-TEXT tokamak [J. Zhang, G. Zhuang, Z. J. Wang, Y. H. Ding, X. Q. Zhang, and Y. J. Tang, Rev. Sci. Instrum. 81, 073509 (2010)]. The upgrade of the AXUV system is aimed to improve the spatial resolution and provide a three-dimensional image on J-TEXT. The new system consists of 12 AXUV arrays (4 AXUV16ELG arrays, 8 AXUV20ELG arrays). The spatial resolution in the cross-section is 21 mm for the AXUV16ELG arrays and 17 mm for the AXUV20ELG arrays. The pre-amplifier is also upgraded for a higher signal to noise ratio. By upgrading the AXUV imaging system, a more accurate observation on the radiation information is obtained.

  10. Method for plasma formation for extreme ultraviolet lithography-theta pinch

    DOE Patents [OSTI]

    Hassanein, Ahmed (Naperville, IL); Konkashbaev, Isak (Bolingbrook, IL); Rice, Bryan (Hillsboro, OR)

    2007-02-20T23:59:59.000Z

    A device and method for generating extremely short-wave ultraviolet electromagnetic wave, utilizing a theta pinch plasma generator to produce electromagnetic radiation in the range of 10 to 20 nm. The device comprises an axially aligned open-ended pinch chamber defining a plasma zone adapted to contain a plasma generating gas within the plasma zone; a means for generating a magnetic field radially outward of the open-ended pinch chamber to produce a discharge plasma from the plasma generating gas, thereby producing a electromagnetic wave in the extreme ultraviolet range; a collecting means in optical communication with the pinch chamber to collect the electromagnetic radiation; and focusing means in optical communication with the collecting means to concentrate the electromagnetic radiation.

  11. 9/2/08 9:42 AMRice professor: Granite countertops may cause you harm | Chron.com -Houston Chronicle Page 1 of 3http://www.chron.com/disp/story.mpl/moms/5908630.html

    E-Print Network [OSTI]

    Llope, William J.

    9/2/08 9:42 AMRice professor: Granite countertops may cause you harm | Chron.com - Houston Be wary of granite that glows Rice professor says countertops may be tainted with uranium By ALLAN TURNER. Some granite countertops, he says, contain high levels of uranium, which, by generating gamma radiation

  12. A simple transfer-optics system for an extreme-ultraviolet synchrotron beamline

    SciTech Connect (OSTI)

    Tarrio, C.; Grantham, S.; Vest, R.E.; Liu, K. [Electron and Optical Physics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8410 (United States)

    2005-04-01T23:59:59.000Z

    Radiometric experiments often require comparatively high intensities in the extreme ultraviolet, in the microwatt range. The monochromators that provide the high throughput needed for these experiments, though, do not always allow for end stations to be switched out easily. At the National Institute of Standards and Technology Synchrotron Ultraviolet Radiation Facility, the only beamline with sufficient extreme-ultraviolet power has a multi-ton endstation, which cannot be moved. We will describe a set of transfer optics that allow the photon beam to be collimated and deflected through a port on the downstream end of the large chamber. This allowed an absolute cryogenic radiometer to be attached, with the entrance cavity underfilled. We will describe ray-tracing results and offer preliminary results of the radiometer-based throughput of the system.

  13. SYNCHROTRON RADIATION SOURCES

    SciTech Connect (OSTI)

    HULBERT,S.L.; WILLIAMS,G.P.

    1998-07-01T23:59:59.000Z

    Synchrotron radiation is a very bright, broadband, polarized, pulsed source of light extending from the infrared to the x-ray region. It is an extremely important source of Vacuum Ultraviolet radiation. Brightness is defined as flux per unit area per unit solid angle and is normally a more important quantity than flux alone particularly in throughput limited applications which include those in which monochromators are used. It is well known from classical theory of electricity and magnetism that accelerating charges emit electromagnetic radiation. In the case of synchrotron radiation, relativistic electrons are accelerated in a circular orbit and emit electromagnetic radiation in a broad spectral range. The visible portion of this spectrum was first observed on April 24, 1947 at General Electric's Schenectady facility by Floyd Haber, a machinist working with the synchrotron team, although the first theoretical predictions were by Lienard in the latter part of the 1800's. An excellent early history with references was presented by Blewett and a history covering the development of the utilization of synchrotron radiation was presented by Hartman. Synchrotron radiation covers the entire electromagnetic spectrum from the infrared region through the visible, ultraviolet, and into the x-ray region up to energies of many 10's of kilovolts. If the charged particles are of low mass, such as electrons, and if they are traveling relativistically, the emitted radiation is very intense and highly collimated, with opening angles of the order of 1 milliradian. In electron storage rings there are three possible sources of synchrotron radiation; dipole (bending) magnets; wigglers, which act like a sequence of bending magnets with alternating polarities; and undulators, which are also multi-period alternating magnet systems but in which the beam deflections are small resulting in coherent interference of the emitted light.

  14. Onsite Wastewater Treatment Systems: Ultraviolet Light Disinfection

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    2008-10-02T23:59:59.000Z

    Some onsite wastewater treatment systems include a disinfection component. This publication explains how homeowners can disinfect wastewater with ultraviolet light, what the components of such a system are, what factors affect the performance of a...

  15. How Perceived Exposure to Environmental Harm Influences Environmental Behavior in Urban China

    E-Print Network [OSTI]

    Peterson, M. Nils

    Á Pro-environmental behavior INTRODUCTION Environmental degradation and the impact it has on society attitudes, perceived exposure to environmental harm tends to have more impact on individuals' environmentalREPORT How Perceived Exposure to Environmental Harm Influences Environmental Behavior in Urban

  16. 38Name ________________________________ Solar Proton Events can cause satellite damage and produce harmful radiation

    E-Print Network [OSTI]

    the solar panels 10% larger to they produce 4900 watts at launch. By the end of 2004, the power will have38Name ________________________________ Solar Proton Events can cause satellite damage and produce the SPEs between 1997 and 2004 with intensities greater than 300 pico-Flux Units (pFU). Study this table

  17. Vacuum-Ultraviolet (VUV) Photoionization of Small Methanol and Methanol-Water Clusters

    E-Print Network [OSTI]

    Kostko, Oleg

    2008-01-01T23:59:59.000Z

    Vacuum-ultraviolet (VUV) photoionization of small methanolwe report on the vacuum-ultraviolet (VUV) photoionization ofionization with tunable vacuum- ultraviolet synchrotron

  18. Vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters

    E-Print Network [OSTI]

    Ahmed, Musahid

    2008-01-01T23:59:59.000Z

    Physical Chemistry Vacuum-ultraviolet (VUV) photoionizationPhysical Chemistry Vacuum-ultraviolet (VUV) photoionizationwe report on the vacuum-ultraviolet (VUV) photoionization of

  19. Distinct Ultraviolet-Signaling Pathways in Bean Leaves. DNA Damage Is Associated with -1,3-Glucanase Gene

    E-Print Network [OSTI]

    Leubner, Gerhard

    Distinct Ultraviolet-Signaling Pathways in Bean Leaves. DNA Damage Is Associated with -1 (UV-B; 280­320 nm) radiation in primary leaves of French bean (Phaseolus vulgaris to the expression of bean class I Glu ( Glu I). In contrast to other proteins of the family of pathogenesis

  20. Ablation of solids using a femtosecond extreme ultraviolet free electron laser

    SciTech Connect (OSTI)

    Stojanovic, N.; Linde, D. von der; Sokolowski-Tinten, K.; Zastrau, U.; Perner, F.; Foerster, E.; Sobierajski, R.; Nietubyc, R.; Jurek, M.; Klinger, D.; Pelka, J.; Krzywinski, J.; Juha, L; Cihelka, J.; Velyhan, A.; Koptyaev, S.; Hajkova, V.; Chalupsky, J.; Kuba, J.; Tschentscher, T. [Institut fuer Experimentelle Physik, Universitaet Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg (Germany); Institut fuer Optik und Quantenelektronik, FSU Jena, 07743 Jena (Germany); Institute of Physics, PAS, Al. Lotnikov 32/46, 02-668 Warsaw (Poland); Institute of Physics, ASCR, 182 21 Prague (Czech Republic); Czech Technical University, 115 19 Prague (Czech Republic); Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22605 Hamburg (Germany)] (and others)

    2006-12-11T23:59:59.000Z

    The ablation of solids by high energy femtosecond pulses from an extreme ultraviolet (XUV) free electron laser has been investigated using picosecond optical imaging. The time-resolved measurements are supplemented by an analysis of the permanent structural surface modifications. Compared with femtosecond optical excitation, distinct differences in the material response are found which are attributed to the increased penetration depth of the XUV radiation and the absence of any absorption nonlinearities.

  1. Damage of multilayer optics with varying capping layers induced by focused extreme ultraviolet beam

    SciTech Connect (OSTI)

    Jody Corso, Alain; Nicolosi, Piergiorgio; Nardello, Marco; Guglielmina Pelizzo, Maria [National Research Council of Italy, Institute for Photonics and Nanotechnology, via Trasea 7, 35131 Padova (Italy) [National Research Council of Italy, Institute for Photonics and Nanotechnology, via Trasea 7, 35131 Padova (Italy); Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova (Italy); Zuppella, Paola [National Research Council of Italy, Institute for Photonics and Nanotechnology, via Trasea 7, 35131 Padova (Italy)] [National Research Council of Italy, Institute for Photonics and Nanotechnology, via Trasea 7, 35131 Padova (Italy); Barkusky, Frank [Laser-Laboratorium Goettingen e.V, Goettingen (Germany) [Laser-Laboratorium Goettingen e.V, Goettingen (Germany); KLA-Tencor, 5 Technology Dr., Milpitas, California 95035 (United States); Mann, Klaus; Mueller, Matthias [Laser-Laboratorium Goettingen e.V, Goettingen (Germany)] [Laser-Laboratorium Goettingen e.V, Goettingen (Germany)

    2013-05-28T23:59:59.000Z

    Extreme ultraviolet Mo/Si multilayers protected by capping layers of different materials were exposed to 13.5 nm plasma source radiation generated with a table-top laser to study the irradiation damage mechanism. Morphology of single-shot damaged areas has been analyzed by means of atomic force microscopy. Threshold fluences were evaluated for each type of sample in order to determine the capability of the capping layer to protect the structure underneath.

  2. Confirming Diagnosis of Hazardous and Harmful Alcohol Use Diagnostic accuracy of a computer assisted diagnostic system compared to conventional

    E-Print Network [OSTI]

    van Lambalgen, Michiel

    1 TITLE PAGE Confirming Diagnosis of Hazardous and Harmful Alcohol Use Diagnostic accuracy for alcoholism have good screening properties for detecting hazardous and harmful alcohol use (HHAU Test (BAT) for confirming the diagnosis of hazardous and harmful alcohol use. Design and Subjects BAT

  3. Confirming Diagnosis of Hazardous and Harmful Alcohol Use Diagnostic accuracy of a computer assisted diagnostic system compared to conventional

    E-Print Network [OSTI]

    van Lambalgen, Michiel

    1 TITLE PAGE Confirming Diagnosis of Hazardous and Harmful Alcohol Use Diagnostic accuracy for alcoholism have good screening properties for detecting hazardous and harmful alcohol use (HHAU Test (BAT) for confirming the diagnosis of hazardous and harmful alcohol use Design and Subjects BAT

  4. Threat of Bodily Harm Has Opposing Effects on Cognition Kesong Hu, Andrew Bauer, Srikanth Padmala, and Luiz Pessoa

    E-Print Network [OSTI]

    Pessoa, Luiz

    Emotion Threat of Bodily Harm Has Opposing Effects on Cognition Kesong Hu, Andrew Bauer, Srikanth., Bauer, A., Padmala, S., & Pessoa, L. (2011, June 27). Threat of Bodily Harm Has Opposing Effects on Cognition. Emotion. Advance online publication. doi: 10.1037/a0024345 #12;Threat of Bodily Harm Has Opposing

  5. Ultraviolet Limit of Open String Theory

    E-Print Network [OSTI]

    Shyamoli Chaudhuri

    2005-01-21T23:59:59.000Z

    We confirm the intuition that a string theory which is perturbatively infrared finite is automatically perturbatively ultraviolet finite. Our derivation based on the asymptotics of the Selberg trace formula for the Greens function on a Riemann surface holds for both open and closed string amplitudes and is independent of modular invariance and supersymmetry. The mass scale for the open strings stretched between Dbranes suggests a natural world-sheet ultraviolet regulator in the string path integral, preserving both T-duality and open-closed string world-sheet duality. Note added (Jan 2005): Comments and related references added.

  6. The Application of Ultraviolet Germicidal Technology in HVAC Systems

    E-Print Network [OSTI]

    Taylor, M. J.

    2000-01-01T23:59:59.000Z

    capability, which increases the operating costs of the equipment. Fortunately, IAQ degradation, foul odor, and increased expenses can be eliminated with the installation of the ultraviolet 'C' band (W-C) lamps. The ultraviolet germicidal lamps are designed...

  7. Why Plaintiffs Should Have to Prove Irreparable Harm in Copyright Preliminary Injunction Cases

    E-Print Network [OSTI]

    Samuelson, Pamela

    2009-01-01T23:59:59.000Z

    harm that might find support in Sony is applicable to a caseL.J. 829 (2008)(discussing Sony?s legacy for technologyand interesting than they might Sony, 450 U.S. at 451. Sony

  8. Deep Water Mixing Prevents Harmful Algal Bloom Formation: Implications for Managed Fisheries Refugia

    E-Print Network [OSTI]

    Hayden, Natanya Jeanne

    2012-10-19T23:59:59.000Z

    DEEP WATER MIXING PREVENTS HARMFUL ALGAL BLOOM FORMATION: IMPLICATIONS FOR MANAGED FISHERIES REFUGIA A Thesis by NATANYA JEANNE HAYDEN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... Refugia Copyright 2011 Natanya Jeanne Hayden DEEP WATER MIXING PREVENTS HARMFUL ALGAL BLOOM FORMATION: IMPLICATIONS FOR MANAGED FISHERIES REFUGIA A Thesis by NATANYA JEANNE HAYDEN Submitted to the Office of Graduate Studies of Texas A...

  9. Ultraviolet emissions from Gd3 + ions excited by energy transfer

    E-Print Network [OSTI]

    Cao, Wenwu

    Ultraviolet emissions from Gd3 + ions excited by energy transfer from Ho3 + ions Ying Yu October 2010 Accepted 28 October 2010 Available online 4 November 2010 Keywords: Ultraviolet emission Upconversion Energy transfer a b s t r a c t Ultraviolet (UV) upconversion (UC) emissions of Gd3+ ion were

  10. A passive measurement of dissociated atom densities in atmospheric pressure air discharge plasmas using vacuum ultraviolet self-absorption spectroscopy

    SciTech Connect (OSTI)

    Laity, George [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Applied Science and Technology Maturation Department, Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Fierro, Andrew; Dickens, James; Neuber, Andreas [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Frank, Klaus [Erlangen Centre for Astroparticle Physics, Department of Physics, Friedrich–Alexander University at Erlangen-Nürnberg, 91058 Erlangen (Germany)

    2014-03-28T23:59:59.000Z

    We demonstrate a method for determining the dissociation degree of atmospheric pressure air discharges by measuring the self-absorption characteristics of vacuum ultraviolet radiation from O and N atoms in the plasma. The atom densities are determined by modeling the amount of radiation trapping present in the discharge, without the use of typical optical absorption diagnostic techniques which require external sources of probing radiation into the experiment. For an 8.0?mm spark discharge between needle electrodes at atmospheric pressure, typical peak O atom densities of 8.5?×?10{sup 17}?cm{sup ?3} and peak N atom densities of 9.9?×?10{sup 17}?cm{sup ?3} are observed within the first ?1.0?mm of plasma near the anode tip by analyzing the OI and NI transitions in the 130.0–132.0?nm band of the vacuum ultraviolet spectrum.

  11. Microwave-driven ultraviolet light sources

    SciTech Connect (OSTI)

    Manos, Dennis M. (Williamsburg, VA); Diggs, Jessie (Norfolk, VA); Ametepe, Joseph D. (Roanoke, VA)

    2002-01-29T23:59:59.000Z

    A microwave-driven ultraviolet (UV) light source is provided. The light source comprises an over-moded microwave cavity having at least one discharge bulb disposed within the microwave cavity. At least one magnetron probe is coupled directly to the microwave cavity.

  12. Environmental radiation detection via thermoluminescence

    DOE Patents [OSTI]

    Miller, S.D.

    1993-03-23T23:59:59.000Z

    The method and apparatus of the present invention relate to cryogenically cooling a thermoluminescent material, exposing it to a low level of radiation (less than about 1 R) while it is at the cooled temperature, warming the thermoluminescent material to room temperature'' and counting the photons emitted during heating. Sufficient sensitivity is achieved without exposing the thermoluminescent material to ultraviolet light thereby simplifying the measurements.

  13. Environmental radiation detection via thermoluminescence

    DOE Patents [OSTI]

    Miller, Steven D. (Richland, WA)

    1993-01-01T23:59:59.000Z

    The method and apparatus of the present invention relate to cryogenically cooling a thermoluminescent material, exposing it to a low level of radiation (less than about 1 R) while it is at the cooled temperature, warming the thermoluminescent material to "room temperature", and counting the photons emitted during heating. Sufficient sensitivity is achieved without exposing the thermoluminescent material to ultraviolet light thereby simplifying the measurements.

  14. Differential tolerance of UV radiation between Chaoborus species and role

    E-Print Network [OSTI]

    Sommaruga, Ruben

    Differential tolerance of UV radiation between Chaoborus species and role of photoprotective that this genus is highly sensitive to solar ultraviolet radiation (UVR). Here, we first tested the UV sensi. obscuripes is associated with the presence of photo- protective compounds. Populations of UV

  15. Viability of Cladosporium herbarum spores under 157 nm laser and vacuum ultraviolet irradiation, low temperature (10 K) and vacuum

    SciTech Connect (OSTI)

    Sarantopoulou, E., E-mail: esarant@eie.gr; Stefi, A.; Kollia, Z.; Palles, D.; Cefalas, A. C. [National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute, 48 Vassileos Constantinou Avenue, Athens 11635 (Greece); Petrou, P. S.; Bourkoula, A.; Koukouvinos, G.; Kakabakos, S. [N.C.S.R. “Demokritos”, Institute for Nuclear and Radiological Sciences, Energy, Technology and Safety, Patriarchou Gregoriou Str. Aghia Paraskevi, Athens 15310 (Greece); Velentzas, A. D. [University of Athens, Faculty of Biology, Department of Cell Biology and Biophysics, Athens 15784 (Greece)

    2014-09-14T23:59:59.000Z

    Ultraviolet photons can damage microorganisms, which rarely survive prolonged irradiation. In addition to the need for intact DNA, cell viability is directly linked to the functionality of the cell wall and membrane. In this work, Cladosporium herbarum spore monolayers exhibit high viability (7%) when exposed to 157 nm laser irradiation (412 kJm?²) or vacuum-ultraviolet irradiation (110–180 nm) under standard pressure and temperature in a nitrogen atmosphere. Spore viability can be determined by atomic-force microscopy, nano-indentation, mass, ?-Raman and attenuated reflectance Fourier-transform far-infrared spectroscopies and DNA electrophoresis. Vacuum ultraviolet photons cause molecular damage to the cell wall, but radiation resistance in spores arises from the activation of a photon-triggered signaling reaction, expressed via the exudation of intracellular substances, which, in combination with the low penetration depth of vacuum-ultraviolet photons, shields DNA from radiation. Resistance to phototoxicity under standard conditions was assessed, as was resistance to additional environmental stresses, including exposure in a vacuum, under different rates of change of pressure during pumping time and low (10 K) temperatures. Vacuum conditions were far more destructive to spores than vacuum-ultraviolet irradiation, and UV-B photons were two orders of magnitude more damaging than vacuum-ultraviolet photons. The viability of irradiated spores was also enhanced at 10 K. This work, in addition to contributing to the photonic control of the viability of microorganisms exposed under extreme conditions, including decontamination of biological warfare agents, outlines the basis for identifying bio-signaling in vivo using physical methodologies.

  16. Source of coherent short wavelength radiation

    DOE Patents [OSTI]

    Villa, Francesco (Alameda, CA)

    1990-01-01T23:59:59.000Z

    An apparatus for producing coherent radiation ranging from X-rays to the far ultraviolet (i.e., 1 Kev to 10 eV) utilizing the Compton scattering effect. A photon beam from a laser is scattered on a high energy electron bunch from a pulse power linac. The short wavelength radiation produced by such scattering has sufficient intensity and spatial coherence for use in high resolution applications such as microscopy.

  17. Water clarity, maternal behavior, and physiology combine to eliminate UV radiation risk to

    E-Print Network [OSTI]

    Palen, Wendy J.

    Water clarity, maternal behavior, and physiology combine to eliminate UV radiation risk for review November 10, 2009) Increasing UV-B radiation (UV-B; 290­320 nm) due to stratospheric across natural landscapes. amphibian declines | ultraviolet radiation | risk analysis | dissolved organic

  18. Efficient compact watt-level deep-ultraviolet laser generated from a multi-kHz Q-switched diode-pumped

    E-Print Network [OSTI]

    Kung, Andy

    W of 213 nm radiation were generated from a fundamental power of 7 W of 1064 nm light at 5 kHz. The overall-4018(02)01669-3 #12;the resonance condition increases the UV pulse duration. As a result, the peak power density 2002; accepted 10 June 2002 Abstract Stable high-power operation in the deep ultraviolet is achieved

  19. Harmful algal blooms and eutrophication: Examining linkages from selected coastal regions of the United States

    E-Print Network [OSTI]

    Townsend, David W.

    Harmful algal blooms and eutrophication: Examining linkages from selected coastal regions of cultural eutrophication linked to the pressures of increasing human population including animal and plant on some aspects of the relationship between eutrophication and HABs (Heisler et al., 2008), recognizing

  20. Best Practices: Energy Savings Efficient energy use reduces Colorado State's total energy demand, decreases harmful

    E-Print Network [OSTI]

    Best Practices: Energy Savings Efficient energy use reduces Colorado State's total energy demand, decreases harmful emissions, and minimizes the cost of providing energy to the campus. As a result of energy conservation initiatives that have been implemented over the past 20 years, growth in the average demand per

  1. Changes in Acoustic Impedance of Marine Sediment Covered with Liquid Henning Harms, Wlner Matuschek, Volker Mellert

    E-Print Network [OSTI]

    Vormann, Matthias

    ) with different densities and sound speeds as a function of grazing angle. The measurements clearly show of the liqui~, TABLE1, Sound speed and density of the chemicals wed in the experiments. substance lChanges in Acoustic Impedance of Marine Sediment Covered with Liquid Pollutants Henning Harms

  2. Graphene defect formation by extreme ultraviolet generated photoelectrons

    SciTech Connect (OSTI)

    Gao, A., E-mail: a.gao@utwente.nl; Lee, C. J.; Bijkerk, F. [FOM-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands and XUV Optics Group, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede (Netherlands)

    2014-08-07T23:59:59.000Z

    We have studied the effect of photoelectrons on defect formation in graphene during extreme ultraviolet (EUV) irradiation. Assuming the major role of these low energy electrons, we have mimicked the process by using low energy primary electrons. Graphene is irradiated by an electron beam with energy lower than 80?eV. After e-beam irradiation, it is found that the D peak, I(D), appears in the Raman spectrum, indicating defect formation in graphene. The evolution of I(D)/I(G) follows the amorphization trajectory with increasing irradiation dose, indicating that graphene goes through a transformation from microcrystalline to nanocrystalline and then further to amorphous carbon. Further, irradiation of graphene with increased water partial pressure does not significantly change the Raman spectra, which suggests that, in the extremely low energy range, e-beam induced chemical reactions between residual water and graphene are not the dominant mechanism driving defect formation in graphene. Single layer graphene, partially suspended over holes was irradiated with EUV radiation. By comparing with the Raman results from e-beam irradiation, it is concluded that the photoelectrons, especially those from the valence band, contribute to defect formation in graphene during irradiation.

  3. The determination of regionalised wind roses for the UK, for use with the HARM acid depositional model.

    E-Print Network [OSTI]

    Metcalfe Dr. Claire Jarvis & Dr. Jim Nicholson #12;Abstract- The Hull acid rain (HARM) depositional model of Geography) is not permitted. #12;1 INTRODUCTION The Hull acid rain (HARM) Lagrangian receptor depositional, 2002, p1 & 6). Other acid rain models that use the Lagrangian receptor technique such as the original

  4. ULTRAVIOLET EXTINCTION AT HIGH GALACTIC LATITUDES

    SciTech Connect (OSTI)

    Peek, J. E. G.; Schiminovich, David, E-mail: jegpeek@gmail.com [Department of Astronomy, Columbia University, New York, NY (United States)

    2013-07-01T23:59:59.000Z

    In order to study the properties and effects of high Galactic latitude dust, we present an analysis of 373,303 galaxies selected from the Galaxy Evolution Explorer All-Sky Survey and Wide-field Infrared Explorer All-Sky Data Release. By examining the variation in aggregate ultraviolet colors and number density of these galaxies, we measure the extinction curve at high latitude. We additionally consider a population of spectroscopically selected galaxies from the Sloan Digital Sky Survey to measure extinction in the optical. We find that dust at high latitude is neither quantitatively nor qualitatively consistent with standard reddening laws. Extinction in the FUV and NUV is {approx}10% and {approx}35% higher than expected, with significant variation across the sky. We find that no single R{sub V} parameter fits both the optical and ultraviolet extinction at high latitude, and that while both show detectable variation across the sky, these variations are not related. We propose that the overall trends we detect likely stem from an increase in very small silicate grains in the interstellar medium.

  5. THORIUM-BASED MIRRORS IN THE EXTREME ULTRAVIOLET Nicole Farnsworth

    E-Print Network [OSTI]

    Hart, Gus

    THORIUM-BASED MIRRORS IN THE EXTREME ULTRAVIOLET by Nicole Farnsworth Submitted to Brigham Young Ultraviolet and Thorium-based Mirrors . . . 1 1.2 Project Background the Optical Constants of Thorium Oxide 34 3.1 Reflectance and Transmittance Measurements

  6. Potential of Ozone Formation by the Smog Mechanism to shield the surface of the Early Earth from UV radiation?

    E-Print Network [OSTI]

    John Lee Grenfell; Barbara Stracke; Beate Patzer; Ruth Titz; Heike Rauer

    2006-09-08T23:59:59.000Z

    We propose that the photochemical smog mechanism produced substantial ozone (O3) in the troposphere during the Proterozoic, which contributed to ultraviolet (UV) radiation shielding hence favoured the establishment of life. The smog mechanism is well-established and is associated with pollution hazes which sometimes cover modern cities. The mechanism proceeds via the oxidation of volatile organic compounds (VOCs) such as methane (CH4) in the presence of UV radiation and nitrogen oxides (NOx). It would have been particularly favoured during the Proterozoic given the high levels of CH4 (up to 1000 ppm) recently suggested. Proterozoic UV levels on the surface of the Earth were generally higher compared with today, which would also have favoured the mechanism. On the other hand, Proterozoic O2 required in the final step of the smog mechanism to form O3 was less abundant compared with present times. Further, results are sensitive to Proterozoic NOx concentrations, which are challenging to predict, since they depend on uncertain quantities such as NOx source emissions and OH concentrations. We review NOx sources during the Proterozoic and apply a photochemical box model having methane oxidation with NOx, HOx and Ox chemistry to estimate the O3 production from the smog mechanism. Runs suggest the smog mechanism during the Proterozoic can produce about double present day ozone columns for NOx levels of 1.53 10-9 by volume mixing ratio, which was attainable according to our NOx source analysis, with 1 per-cent present atmospheric levels (PALs) of O2. Clearly, forming ozone in the troposphere is a trade-off for survivability. On the one hand harmful UV is blocked, but on the other hand ozone is a respiratory irratant, which becomes fatal at concentrations exceeding about 1 ppmv.

  7. Cluster beam targets for laser plasma extreme ultraviolet and soft x-ray sources

    DOE Patents [OSTI]

    Kublak, G.D.; Richardson, M.C.

    1996-11-19T23:59:59.000Z

    Method and apparatus for producing extreme ultraviolet (EUV) and soft x-ray radiation from an ultra-low debris plasma source are disclosed. Targets are produced by the free jet expansion of various gases through a temperature controlled nozzle to form molecular clusters. These target clusters are subsequently irradiated with commercially available lasers of moderate intensity (10{sup 11}--10{sup 12} watts/cm{sup 2}) to produce a plasma radiating in the region of 0.5 to 100 nanometers. By appropriate adjustment of the experimental conditions the laser focus can be moved 10--30 mm from the nozzle thereby eliminating debris produced by plasma erosion of the nozzle. 5 figs.

  8. Controlled doping of graphene using ultraviolet irradiation

    SciTech Connect (OSTI)

    Luo Zhengtang [Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong); Pinto, Nicholas J.; Davila, Yarely [Department of Physics and Electronics, University of Puerto Rico at Humacao, Humacao, 00792 (Puerto Rico); Charlie Johnson, A. T. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396 (United States)

    2012-06-18T23:59:59.000Z

    The electronic properties of graphene are tunable via doping, making it attractive in low dimensional organic electronics. Common methods of doping graphene, however, adversely affect charge mobility and degrade device performance. We demonstrate a facile shadow mask technique of defining electrodes on graphene grown by chemical vapor deposition (CVD) thereby eliminating the use of detrimental chemicals needed in the corresponding lithographic process. Further, we report on the controlled, effective, and reversible doping of graphene via ultraviolet (UV) irradiation with minimal impact on charge mobility. The change in charge concentration saturates at {approx}2 Multiplication-Sign 10{sup 12} cm{sup -2} and the quantum yield is {approx}10{sup -5} e/photon upon initial UV exposure. This simple and controlled strategy opens the possibility of doping wafer-size CVD graphene for diverse applications.

  9. Quantitative imaging of living cells by deep ultraviolet microscopy

    E-Print Network [OSTI]

    Zeskind, Benjamin J

    2006-01-01T23:59:59.000Z

    Developments in light microscopy over the past three centuries have opened new windows into cell structure and function, yet many questions remain unanswered by current imaging approaches. Deep ultraviolet microscopy ...

  10. 2013 R&D 100 Award: 'SHIELD' protects NIF optics from harmful pulses

    ScienceCinema (OSTI)

    Chou, Jason

    2014-07-22T23:59:59.000Z

    In the past, it took as long as 12 hours to manually screen 48 critical checkpoints at the National Ignition Facility (NIF) for harmful laser pulses. The screening equipment had to be moved from point to point throughout a facility the size of three football fields. Now with a new technology, called Laser SHIELD (Screening at High-throughput to Identify Energetic Laser Distortion), and with the push of a button, the screening can be done in less than one second. Proper screening of pulses is critical for the operation of high-energy lasers to ensure that the laser does not exceed safe operating conditions for optics. The energetic beams of light are so powerful that, when left uncontrolled, they can shatter the extremely valuable glass inside the laser. If a harmful pulse is found, immediate adjustments can be made in order to protect the optics for the facility. Laser SHIELD is a custom-designed high-throughput screening system built from low-cost and commercially available components found in the telecommunications industry. Its all-fiber design makes it amenable to the unique needs of high-energy laser facilities, including routing to intricate pick-off locations, immunity to electromagnetic interference and low-loss transport (up to several kilometers). The technology offers several important benefits for NIF. First, the facility is able to fire more shots in less time-an efficiency that saves the facility millions of dollars each year. Second, high-energy lasers are more flexible to wavelength changes requested by target physicists. Third, by identifying harmful pulses before they damage the laser's optics, the facility potentially saves hundreds of thousands of dollars in maintenance costs each year.

  11. 2013 R&D 100 Award: 'SHIELD' protects NIF optics from harmful pulses

    SciTech Connect (OSTI)

    Chou, Jason

    2014-04-03T23:59:59.000Z

    In the past, it took as long as 12 hours to manually screen 48 critical checkpoints at the National Ignition Facility (NIF) for harmful laser pulses. The screening equipment had to be moved from point to point throughout a facility the size of three football fields. Now with a new technology, called Laser SHIELD (Screening at High-throughput to Identify Energetic Laser Distortion), and with the push of a button, the screening can be done in less than one second. Proper screening of pulses is critical for the operation of high-energy lasers to ensure that the laser does not exceed safe operating conditions for optics. The energetic beams of light are so powerful that, when left uncontrolled, they can shatter the extremely valuable glass inside the laser. If a harmful pulse is found, immediate adjustments can be made in order to protect the optics for the facility. Laser SHIELD is a custom-designed high-throughput screening system built from low-cost and commercially available components found in the telecommunications industry. Its all-fiber design makes it amenable to the unique needs of high-energy laser facilities, including routing to intricate pick-off locations, immunity to electromagnetic interference and low-loss transport (up to several kilometers). The technology offers several important benefits for NIF. First, the facility is able to fire more shots in less time-an efficiency that saves the facility millions of dollars each year. Second, high-energy lasers are more flexible to wavelength changes requested by target physicists. Third, by identifying harmful pulses before they damage the laser's optics, the facility potentially saves hundreds of thousands of dollars in maintenance costs each year.

  12. Reflective masks for extreme ultraviolet lithography

    SciTech Connect (OSTI)

    Nguyen, Khanh Bao

    1994-05-01T23:59:59.000Z

    Extreme ultraviolet lithographic masks are made by patterning multilayer reflective coatings with high normal incidence reflectivity. Masks can be patterned by depositing a patterned absorber layer above the coating or by etching the pattern directly into the coating itself. Electromagnetic simulations showed that absorber-overlayer masks have superior imaging characteristics over etched masks (less sensitive to incident angles and pattern profiles). In an EUVL absorber overlayer mask, defects can occur in the mask substrate, reflective coating, and absorber pattern. Electromagnetic simulations showed that substrate defects cause the most severe image degradation. A printability study of substrate defects for absorber overlayer masks showed that printability of 25 nm high substrate defects are comparable to defects in optical lithography. Simulations also indicated that the manner in which the defects are covered by multilayer reflective coatings can affect printability. Coverage profiles that result in large lateral spreading of defect geometries amplify the printability of the defects by increasing their effective sizes. Coverage profiles of Mo/Si coatings deposited above defects were studied by atomic force microscopy and TEM. Results showed that lateral spread of defect geometry is proportional to height. Undercut at defect also increases the lateral spread. Reductions in defect heights were observed for 0.15 {mu}m wide defect lines. A long-term study of Mo/Si coating reflectivity revealed that Mo/Si coatings with Mo as the top layer suffer significant reductions in reflectivity over time due to oxidation.

  13. Intense ultraviolet perturbations on aquatic primary producers

    E-Print Network [OSTI]

    Guimarais, Mayrene; Horvath, Jorge

    2010-01-01T23:59:59.000Z

    During the last decade, the hypothesis that one or more biodiversity drops in the Phanerozoic eon, evident in the geological record, might have been caused by the most powerful kind of stellar explosion so far known (Gamma Ray Bursts) has been discussed in several works. These stellar explosions could have left an imprint in the biological evolution on Earth and in other habitable planets. In this work we calculate the short-term lethality that a GRB would produce in the aquatic primary producers on Earth. This effect on life appears as a result of ultraviolet (UV) re-transmission in the atmosphere of a fraction of the gamma energy, resulting in an intense UV flash capable of penetrating ~ tens of meters in the water column in the ocean. We focus on the action of the UV flash on phytoplankton, as they are the main contributors to global aquatic primary productivity. Our results suggest that the UV flash could cause an hemispheric reduction of phytoplankton biomass in the upper mixed layer of the World Ocean o...

  14. Vacuum-Ultraviolet (VUV) Photoionization of Small Methanol and Methanol-Water Clusters

    SciTech Connect (OSTI)

    Kostko, Oleg; Belau, Leonid; Wilson, Kevin R.; Ahmed, Musahid

    2008-04-24T23:59:59.000Z

    In this work, we report on the vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuum-ultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH+(n = 1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH n(H2O)H+ (n = 2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH+, (CH3OH)2+, (CH3OH)nH+ (n = 1-9), and (CH3OH)n(H2O)H+ (n = 2-9) as a function of photon energy. With an increasein the water content in the molecular beam, there is an enhancement of photoionization intensity for the methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.

  15. Extreme ultraviolet ionization of pure He nanodroplets: Mass-correlated photoelectron imaging, Penning ionization, and electron energy-loss spectra

    SciTech Connect (OSTI)

    Buchta, D.; Stienkemeier, F.; Mudrich, M. [Physikalisches Institut, Universität Freiburg, 79104 Freiburg (Germany)] [Physikalisches Institut, Universität Freiburg, 79104 Freiburg (Germany); Krishnan, S. R.; Moshammer, R. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany)] [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Brauer, N. B.; Drabbels, M. [Laboratoire de Chimie Physique Moléculaire, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland)] [Laboratoire de Chimie Physique Moléculaire, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland); O’Keeffe, P.; Coreno, M. [CNR Istituto di Metodologie Inorganiche e dei Plasmi, CP10, 00016 Monterotondo Scalo (Italy)] [CNR Istituto di Metodologie Inorganiche e dei Plasmi, CP10, 00016 Monterotondo Scalo (Italy); Devetta, M. [CIMAINA and Dipartimento di Fisica, Università di Milano, 20133 Milano (Italy)] [CIMAINA and Dipartimento di Fisica, Università di Milano, 20133 Milano (Italy); Di Fraia, M. [Department of Physics, University of Trieste, 34128 Trieste (Italy)] [Department of Physics, University of Trieste, 34128 Trieste (Italy); Callegari, C.; Richter, R.; Prince, K. C. [Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste (Italy)] [Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste (Italy); Ullrich, J. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany) [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, D-38116 Braunschweig (Germany)

    2013-08-28T23:59:59.000Z

    The ionization dynamics of pure He nanodroplets irradiated by Extreme ultraviolet radiation is studied using Velocity-Map Imaging PhotoElectron-PhotoIon COincidence spectroscopy. We present photoelectron energy spectra and angular distributions measured in coincidence with the most abundant ions He{sup +}, He{sub 2}{sup +}, and He{sub 3}{sup +}. Surprisingly, below the autoionization threshold of He droplets, we find indications for multiple excitation and subsequent ionization of the droplets by a Penning-like process. At high photon energies we observe inelastic collisions of photoelectrons with the surrounding He atoms in the droplets.

  16. Finite element simulation for ultraviolet excimer laser processing of patterned Si/SiGe/Si(100) heterostructures

    SciTech Connect (OSTI)

    Conde, J. C.; Chiussi, S.; Gontad, F.; Gonzalez, P. [Dpto. Fisica Aplicada, University of Vigo, E-36310 Vigo (Spain); Martin, E. [Dpto. Mecanica, Maquinas, Motores Termicos y Fluidos, University of Vigo, E-36310 Vigo (Spain); Serra, C. [CACTI, University of Vigo, E-36310 Vigo (Spain)

    2010-07-05T23:59:59.000Z

    Ultraviolet (UV) Excimer laser assisted processing is an alternative strategy for producing patterned silicon germanium heterostructures. We numerically analyzed the effects caused by pulsed 193 Excimer laser radiation impinging on patterned amorphous hydrogenated silicon (a-Si:H) and germanium (a-Ge:H) bilayers deposited on a crystalline silicon substrate [Si(100)]. The proposed two dimensional axisymmetric numerical model allowed us to estimate the temperature and concentration gradients caused by the laser induced rapid melting and solidification processes. Energy density dependence of maximum melting depth and melting time evolution as well as three dimensional temperature and element distribution have been simulated and compared with experimentally obtained results.

  17. Repair of localized defects in multilayer-coated reticle blanks for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Stearns, Daniel G. (Los Altos, CA); Sweeney, Donald W. (San Ramon, CA); Mirkarimi, Paul B. (Sunol, CA)

    2004-11-23T23:59:59.000Z

    A method is provided for repairing defects in a multilayer coating layered onto a reticle blank used in an extreme ultraviolet lithography (EUVL) system. Using high lateral spatial resolution, energy is deposited in the multilayer coating in the vicinity of the defect. This can be accomplished using a focused electron beam, focused ion beam or a focused electromagnetic radiation. The absorbed energy will cause a structural modification of the film, producing a localized change in the film thickness. The change in film thickness can be controlled with sub-nanometer accuracy by adjusting the energy dose. The lateral spatial resolution of the thickness modification is controlled by the localization of the energy deposition. The film thickness is adjusted locally to correct the perturbation of the reflected field. For example, when the structural modification is a localized film contraction, the repair of a defect consists of flattening a mound or spreading out the sides of a depression.

  18. Danger radiations

    ScienceCinema (OSTI)

    None

    2011-04-25T23:59:59.000Z

    Le conférencier Mons.Hofert parle des dangers et risques des radiations, le contrôle des zones et les précautions à prendre ( p.ex. film badge), comment mesurer les radiations etc.

  19. On-board Measurement of NO and NO2 using Non-dispersive Ultraviolet...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    board Measurement of NO and NO2 using Non-dispersive Ultraviolet (NDUV) Spectroscopy On-board Measurement of NO and NO2 using Non-dispersive Ultraviolet (NDUV) Spectroscopy...

  20. Electron and proton aurora observed spectroscopically in the far ultraviolet

    E-Print Network [OSTI]

    Lummerzheim, Dirk

    Electron and proton aurora observed spectroscopically in the far ultraviolet M. Galand,1 D the location of the electron and proton aurorae is discussed. The estimation of the particle characteristics aurora. Because protons and electrons do not interact in the same way with the atmosphere, our study

  1. Time resolved ultraviolet absorption spectroscopy of pulsed fluorocarbon plasmas

    E-Print Network [OSTI]

    Gleason, Karen K.

    Time resolved ultraviolet absorption spectroscopy of pulsed fluorocarbon plasmas Brett A. Cruden.1063/1.1334936 I. INTRODUCTION The study of fluorocarbon plasmas is of great interest for their applications in silicon dioxide etching.1,2 Recently, at- tention has been paid to using fluorocarbon plasmas to pro- duce

  2. Increased European biofuel cultivation could harm human health1 by James Morgan for www.scienceomega.com2

    E-Print Network [OSTI]

    South Bohemia, University of

    Increased European biofuel cultivation could harm human health1 by James Morgan for www that the large-scale production of biofuels in4 Europe could result in increased human mortality and crop losses that many biofuel plant species, including poplar and willow, release more isoprene ­ an6 ozone precursor

  3. Guidance Document Fume hoods are used when handling toxic or hazardous chemicals. Harmful gases, vapors and fumes

    E-Print Network [OSTI]

    Guidance Document FumeHoods Fume hoods are used when handling toxic or hazardous chemicals. Harmful the maximum safe mark (provided by Facilities Management during annual test) Use secondary containment (a hood without permission from EHS. Call EHS or Facilities Management if a hood is not functioning

  4. Comparison of surface vacuum ultraviolet emissions with resonance level number densities. I. Argon plasmas

    SciTech Connect (OSTI)

    Boffard, John B., E-mail: jboffard@wisc.edu; Lin, Chun C. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Culver, Cody [Materials Science Program, University of Wisconsin, Madison, WI 53706 (United States); Wang, Shicong; Wendt, Amy E. [Department of Electrical and Computer Engineering, University of Wisconsin, Madison, WI 53706 (United States); Radovanov, Svetlana; Persing, Harold [Varian Semiconductor Equipment, Applied Materials Inc., Gloucester, MA 01939 (United States)

    2014-03-15T23:59:59.000Z

    Vacuum ultraviolet (VUV) photons emitted from excited atomic states are ubiquitous in material processing plasmas. The highly energetic photons can induce surface damage by driving surface reactions, disordering surface regions, and affecting bonds in the bulk material. In argon plasmas, the VUV emissions are due to the decay of the 1s{sub 4} and 1s{sub 2} principal resonance levels with emission wavelengths of 104.8 and 106.7?nm, respectively. The authors have measured the number densities of atoms in the two resonance levels using both white light optical absorption spectroscopy and radiation-trapping induced changes in the 3p{sup 5}4p?3p{sup 5}4s branching fractions measured via visible/near-infrared optical emission spectroscopy in an argon inductively coupled plasma as a function of both pressure and power. An emission model that takes into account radiation trapping was used to calculate the VUV emission rate. The model results were compared to experimental measurements made with a National Institute of Standards and Technology-calibrated VUV photodiode. The photodiode and model results are in generally good accord and reveal a strong dependence on the neutral gas temperature.

  5. Interim report of the Advisory Committee on human radiation experiments

    SciTech Connect (OSTI)

    Not Available

    1994-10-21T23:59:59.000Z

    The Advisory Committee on Human Radiation Experiments was created by President Clinton to advise the Human Radiation Interagency Working Group on the ethical and scientific criteria applicable to human radiation experiments carried out or sponsored by the U.S. Government. The Committee seeks to answer several fundamental question: What ethics criteria should be used to evaluate human radiation experiments? What was the Federal Government`s role in human radiation experiments? What are the criteria for determining appropriate Federal responses where wrongs or harms have occurred? What lessons learned from studying past and present research standards and practices should be applied to the future? The Committee has been gathering vast amounts of information and working to render it orderly and accessible. In the next six months, the Committee will continue with the tasks of data gathering and organizing. The focus of the work, however, will be developing criteria for judging historical and contemporary experiments, policies, and procedures, as well as criteria for remedies that may be appropriate where harms or wrongs have ocurred. Based on findings, the Committee will make specific recommendations regarding policies for the future.

  6. Radiative Levitation in Hot Horizontal Branch Stars

    E-Print Network [OSTI]

    W. Landsman

    1999-06-08T23:59:59.000Z

    There is now considerable evidence that horizontal branch (HB) stars hotter than about 11,500 K experience an enormous enhancement of their photospheric iron abundance due to radiative levitation. In globular clusters, the photospheric iron abundance can reach values of [Fe/H] ~ +0.3, or up to two orders of magnitude higher than the cluster iron abundance. Model atmospheres which take into account the iron overabundance are needed for understanding the appearance of the HB in globular cluster color-magnitude diagrams (CMDs), for the derivation of accurate luminosities, gravities and masses, and for the ultraviolet spectral synthesis of old, metal-poor stellar populations.

  7. Method for detecting radiation dose utilizing thermoluminescent material

    DOE Patents [OSTI]

    Miller, S.D.; McDonald, J.C.; Eichner, F.N.; Durham, J.S.

    1992-08-04T23:59:59.000Z

    The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material and then optically stimulating the thermoluminescent material by exposure to light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light. 5 figs.

  8. Photo deposition of metal with far uv radiation

    SciTech Connect (OSTI)

    Blum, S.E.; Brown, K.H.

    1984-05-29T23:59:59.000Z

    A method for depositing a refractory metal onto a substrate is described wherein a carbonyl compound vapor of the metal in the vicinity of or on the substrate is photodecomposed by ultraviolet radiation of wavelengths less than 200 nm. This causes the release of atoms of the metal, which then condense onto the substrate. In an example, a tungsten layer is photodeposited by this method onto a GaAs semiconductor layer to form a Schottky barrier diode.

  9. Radiation detector

    DOE Patents [OSTI]

    Fultz, Brent T. (Berkeley, CA)

    1983-01-01T23:59:59.000Z

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  10. Radiation detector

    DOE Patents [OSTI]

    Fultz, B.T.

    1980-12-05T23:59:59.000Z

    Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  11. Single-crystalline aluminum film for ultraviolet plasmonic nanolasers

    E-Print Network [OSTI]

    Chou, Bo-Tsun; Wu, Yen-Mo; Chung, Yi-Chen; Hsueh, Wei-Jen; Lin, Shih-Wei; Lu, Tien-Chang; Lin, Tzy-Rong; Lin, Sheng-Di

    2015-01-01T23:59:59.000Z

    Plasmonic devices have advanced significantly in the past decade. Being one of the most intriguing devices, plamonic nanolasers plays an important role in biomedicine, chemical sensor, information technology, and optical integrated circuits. However, nanoscale plasmonic devices, particularly in ultraviolet regime, are extremely sensitive to metal and interface quality, which renders the development of ultraviolet plasmonics. Here, by addressing the material issues, we demonstrate a low threshold, high characteristic temperature metal-oxide-semiconductor ZnO nanolaser working at room temperature. The template for ZnO nanowires consists of a flat single-crystalline aluminum film grown by molecular beam epitaxy and an ultra-smooth Al2O3 spacer layer prepared by atomic layer deposition. By effectively reducing surface plasmon scattering loss and metal intrinsic absorption loss, the high-quality metal film and sharp interfaces between layers boost the device performance. Our work paves the way for future applicati...

  12. The response of certain stored products insects to various wavebands of electromagnetic radiation

    E-Print Network [OSTI]

    Stermer, Raymond Andrew

    1958-01-01T23:59:59.000Z

    ?Numbers refer to referenoee listed in the bibliography. attracted to' blaok light, ultraviolet. Inseot traps using eleotromag-, netio radiation are reooszzsn4ed by Tenhet and Bare as a survey tool to 6 reflect the degree of infestation in tobacoo... INSECTS TO VARIOUS WAVESANDS OP ELECTRONAGNETIC RADIATION INTRODUCTION Interest in the attraotion of inseots to fire and light dates baok to the dsye of primitive man. From early literature such as "the Sanskrit EKooh~~atiks attributed to King Sudraka...

  13. Importance of Biologically Active Aurora-like Ultraviolet Emission: Stochastic Irradiation of Earth and Mars by Flares and Explosions

    E-Print Network [OSTI]

    David S. Smith; John Scalo; J. Craig Wheeler

    2003-07-30T23:59:59.000Z

    (Abridged) We show that sizeable fractions of incident ionizing radiation from stochastic astrophysical sources can be redistributed to biologically and chemically important UV wavelengths, a significant fraction of which can reach the surface. This redistribution is mediated by secondary electrons, resulting from Compton scattering and X-ray photoabsorption, with energies low enough to excite atmospheric molecules and atoms, resulting in a rich aurora-like spectrum. We calculate the fraction of energy redistributed into biologically and chemically important wavelength regions for spectra characteristic of stellar flares and supernovae using a Monte-Carlo transport code written for this problem and then estimate the fraction of this energy that is transmitted from the atmospheric altitudes of redistribution to the surface for a few illustrative cases. Redistributed fractions are found to be of order 1%, even in the presence of an ozone shield. This result implies that planetary organisms will be subject to mutationally significant, if intermittent, fluences of UV-B and harder radiation even in the presence of a narrow-band UV shield like ozone. We also calculate the surficial transmitted fraction of ionizing radiation and redistributed ultraviolet radiation for two illustrative evolving Mars atmospheres whose initial surface pressures were 1 bar. Our results suggest that coding organisms on planets orbiting low-mass stars (and on the early Earth) may evolve very differently than on contemporary Earth, with diversity and evolutionary rate controlled by a stochastically varying mutation rate and frequent hypermutation episodes.

  14. Durable Corrosion and Ultraviolet-Resistant Silver Mirror

    DOE Patents [OSTI]

    Jorgensen, G. J.; Gee, R.

    2006-01-24T23:59:59.000Z

    A corrosion and ultra violet-resistant silver mirror for use in solar reflectors; the silver layer having a film-forming protective polymer bonded thereto, and a protective shield overlay comprising a transparent multipolymer film that incorporates a UV absorber. The corrosion and ultraviolet resistant silver mirror retains spectral hemispherical reflectance and high optical clarity throughout the UV and visible spectrum when used in solar reflectors.

  15. Magnetic fluorescent lamp having reduced ultraviolet self-absorption

    DOE Patents [OSTI]

    Berman, Samuel M. (San Francisco, CA); Richardson, Robert W. (Pelham, NY)

    1985-01-01T23:59:59.000Z

    The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly (10) is enhanced by providing means (30) for establishing a magnetic field with lines of force along the path of electron flow through the bulb (12) of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.

  16. 280 Los Alamos Science Number 23 1995 "Ethical Harm" and the

    E-Print Network [OSTI]

    Massey, Thomas N.

    Clinton appointed an Advisory Committee on Human Ra- diation Experiments. The Advisory Committee's assignment was to determine the ethical and scien- tific standards for the human radiation experiments of the re- search. Subsequent news articles de- scribed additional studies that had ex- posed human subjects

  17. A high galactic latitude survey of far ultraviolet excess objects

    SciTech Connect (OSTI)

    Bixler, J.V.

    1988-01-01T23:59:59.000Z

    Two closely related efforts in astrophysical instrumentation and observation are described with the objective of performing a high galactic latitude survey of faint objects in the far ultraviolet. The avenues of research possible with data obtained from space based ultraviolet surveys are discussed and a summary of past, present and planned instruments capable of such survey work presented. The Faust telescope, an eight degree field of view imaging instrument with peak sensitivity at 1700A, designed for survey work is described. An imaging, active readout detector and associated ground support equipment were designed, constructed, and calibrated to replace the original photographic detector. The present state of observational data relevant to determining the atmospheric parameters of subdwarf B and O stars, and their mid-Galactic plane density and scale height was reviewed. Theoretical explanations of their evolutionary status were proposed. The optical observations and spectral reductions performed on objects included in a catalog of far ultraviolet bright, high galactic latitude objects are described. These observations provide a sample of subdwarf O and B stars free of brightness and temperature selection effects. A model atmospheres analysis was performed on the subdwarf sample to determine the temperature, gravity and helium to hydrogen ratio of the individual objects. The results show a smooth distribution of objects on the gravity versus temperature diagram near the theoretical location of the extended horizontal branch.

  18. RADIATION SAFETY TRAINING MANUAL Radiation Safety Office

    E-Print Network [OSTI]

    Sibille, Etienne

    protection and the potential risks of ionizing radiation. Radiation Safety Office personnel provide.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 II. OVERVIEW OF REGULATIONS, PROTECTION STANDARDS, AND RADIATION SAFETY ORGANIZATION.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 V. BASIC RADIATION PROTECTION PRINCIPLES

  19. Radiation Safety

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection Radiation Protection Regulations: The Federal Regulation

  20. Extreme-ultraviolet radiation transport in small scale length laser-produced tin plasmas

    E-Print Network [OSTI]

    Sequoia, Kevin Lamar Williams

    2009-01-01T23:59:59.000Z

    Physics) by Kevin Lamar Williams Sequoia Committee inR. Tynan Copyright Kevin Lamar Williams Sequoia, 2009 AllDissertation of Kevin Lamar Williams Sequoia is approved,

  1. High-Order Harmonic Generation Yielding Tunable Extreme-Ultraviolet Radiation of High Spectral Purity

    E-Print Network [OSTI]

    harmonic photon. The universal cutoff in high-order har- monic generation (HHG) processes exists at Ip 3 (ponderomotive) energy of a quasifree electron quivering in the laser field in the neighborhood of the ionic core [9] and for resonance-enhanced wave mixing [10]. In contrast to these studies, in the nonperturbative

  2. Aquatic ecosystems: effects of solar ultraviolet radiation and interactions with other climatic change factors

    E-Print Network [OSTI]

    Worrest, Robert C.

    -water and terrestrial habitats.8 However, protection is not perfect, and UV-B can cause molecular damage to lipids in biomass productivity due to enhanced UV-B are relayed through all levels of the intricate food web

  3. Note: Calibration of EBT3 radiochromic film for measuring solar ultraviolet radiation

    SciTech Connect (OSTI)

    Chun, S. L. [Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong (Hong Kong); Yu, P. K. N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon Tong (Hong Kong)

    2014-10-15T23:59:59.000Z

    Solar (UVA + UVB) exposure was assessed using the Gafchromic EBT3 film. The coloration change was represented by the net reflective optical density (Net ROD). Through calibrations against a UV-tube lamp, operational relationships were obtained between Net ROD and the (UVA + UVB) exposures (in J?cm{sup ?2} or J?m{sup ?2}). The useful range was from ?0.2 to ?30 J?cm{sup ?2}. The uniformity of UV irradiation was crucial for an accurate calibration. For solar exposures ranging from 2 to 11 J?cm{sup ?2}, the predicted Net ROD agreed with the recorded values within 9%, while the predicted exposures agreed with the recorded values within 15%.

  4. Extreme-ultraviolet radiation transport in small scale length laser-produced tin plasmas

    E-Print Network [OSTI]

    Sequoia, Kevin Lamar Williams

    2009-01-01T23:59:59.000Z

    a planar target causes a “bowtie” in the mesh near the edgethe same space. When a bowtie occurs in h2d, the problemis in a planar geometry a bowtie will occur before the laser

  5. Determination of ionization energies of small silicon clusters with vacuum?ultraviolet (VUV) radiation

    E-Print Network [OSTI]

    Kostko, Oleg

    2010-01-01T23:59:59.000Z

    shown in Figure 2  and  tetramer silicon isomers  shown in the  cations.   The  tetramer  is  the  largest  cluster positively charged silicon tetramer is a rhombus with D 2h  

  6. Coherence properties of the radiation from FLASH

    E-Print Network [OSTI]

    Schneidmiller, E A

    2015-01-01T23:59:59.000Z

    FLASH is the first free electron laser user facility operating in the vacuum ultraviolet and soft x-ray wavelength range. Many user experiments require knowledge of the spatial and temporal coherence properties of the radiation. In this paper we present an analysis of the coherence properties of the radiation for the fundamental and for the higher odd frequency harmonics. We show that temporal and spatial coherence reach maximum close to the FEL saturation but may degrade significantly in the post-saturation regime. We also find that the pointing stability of short FEL pulses is limited due to the fact that non-azimuthal FEL eigenmodes are not sufficiently suppressed. We discuss possible ways for improving the degree of transverse coherence and the pointing stability.

  7. EU promises new biofuel rules won't harm the environment http://www.pr-inside.com/eu-promises-new-biofuel-rules-won-t-r385258.htm 1 of 2 1/16/2008 12:32 PM

    E-Print Network [OSTI]

    EU promises new biofuel rules won't harm the environment http://www.pr-inside.com/eu-promises-new-biofuel promises new biofuel rules won't harm the environment © AP 2008-01-14 16:21:49 - BRUSSELS, Belgium (AP) - The European Union promised Monday that its new push to promote biofuels will try to prevent harming

  8. Carbon contamination of extreme ultraviolet (EUV) mask and its effect on imaging

    E-Print Network [OSTI]

    Fan, Yu-Jen

    2009-01-01T23:59:59.000Z

    induced carbon contamination of extreme ultraviolet optics."potential LWR due to the contamination topography may be anet aI. , "Accelerated contamination testing of EUV masks."

  9. alpha-class extreme ultraviolet: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Vacuum Society. S0734-211X 00 02506-3 I. INTRODUCTION EUV lithography optics require 5 Solar Dynamics Observatory Extreme Ultraviolet Variability Experiment Geosciences Websites...

  10. Spectral Control of Emission from Tin Doped Targets for Extreme Ultraviolet Lithography

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    control of emissions from tin doped targets for extremearray (UTA) emission around 13.5 nm from solid density tinand tin doped foam targets. Extreme ultraviolet (EUV)

  11. Making Up Self Harmers: an investigation of the concept over time and from the perspective of two different self harm groups 

    E-Print Network [OSTI]

    Mattingley, Helena

    2009-11-26T23:59:59.000Z

    This thesis aims to illustrate the processes involves in ‘making up’ the human kind of self harmers. Psychiatric attempts at defining, explaining, and controlling self harm behaviours are shaped by the people who they diagnose as much as they shape...

  12. High Energy Neutrino Flashes from Far-Ultraviolet and X-ray Flares in Gamma-Ray Bursts

    E-Print Network [OSTI]

    Kohta Murase; Shigehiro Nagataki

    2006-08-07T23:59:59.000Z

    The recent observations of bright optical and x-ray flares by the Swift satellite suggest these are produced by the late activities of the central engine. We study the neutrino emission from far-ultraviolet and x-ray flares under the late internal shock model. We show that the efficiency of pion production in the highest energy is comparable to or higher than the unity, and the contribution from such neutrino flashes to a diffuse very high energy neutrino background can be larger than that of prompt bursts if the total baryonic energy input into flares is comparable to the radiated energy of prompt bursts. These signals may be detected by IceCube and are very important because they have possibilities to probe the nature of flares (the baryon loading, the photon field, the magnetic field and so on).

  13. Radiation receiver

    DOE Patents [OSTI]

    Hunt, A.J.

    1983-09-13T23:59:59.000Z

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles. 5 figs.

  14. Radiation receiver

    DOE Patents [OSTI]

    Hunt, Arlon J. (Oakland, CA)

    1983-01-01T23:59:59.000Z

    The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.

  15. Vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters

    SciTech Connect (OSTI)

    Ahmed, Musahid; Ahmed, Musahid; Wilson, Kevin R.; Belau, Leonid; Kostko, Oleg

    2008-05-12T23:59:59.000Z

    In this work we report on thevacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuumultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH + (n=1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH)n(H2O)H + (n=2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH +, (CH 3OH)2 +, (CH3OH)nH + (n=1-9), and (CH 3OH)n(H2O)H + (n=2-9 ) as a function of photon energy. With an increase in the water content in the molecular beam, there is an enhancement of photoionization intensity for methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.

  16. CITIUS: An infrared-extreme ultraviolet light source for fundamental and applied ultrafast science

    SciTech Connect (OSTI)

    Grazioli, C.; Gauthier, D.; Ivanov, R.; De Ninno, G. [Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica (Slovenia) [Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica (Slovenia); Elettra Sincrotrone Trieste, Trieste (Italy)] [Italy; Callegari, C.; Spezzani, C. [Elettra Sincrotrone Trieste, Trieste (Italy)] [Elettra Sincrotrone Trieste, Trieste (Italy); Ciavardini, A. [Sapienza University, Rome (Italy)] [Sapienza University, Rome (Italy); Coreno, M. [Elettra Sincrotrone Trieste, Trieste (Italy) [Elettra Sincrotrone Trieste, Trieste (Italy); Institute of Inorganic Methodologies and Plasmas (CNR-IMIP), Montelibretti, Roma (Italy); Frassetto, F.; Miotti, P.; Poletto, L. [Institute of Photonics and Nanotechnologies (CNR-IFN), Padova (Italy)] [Institute of Photonics and Nanotechnologies (CNR-IFN), Padova (Italy); Golob, D. [Kontrolni Sistemi d.o.o., Sežana (Slovenia)] [Kontrolni Sistemi d.o.o., Sežana (Slovenia); Kivimäki, A. [Institute of Materials Manufacturing (CNR-IOM), TASC Laboratory, Trieste (Italy)] [Institute of Materials Manufacturing (CNR-IOM), TASC Laboratory, Trieste (Italy); Mahieu, B. [Elettra Sincrotrone Trieste, Trieste (Italy) [Elettra Sincrotrone Trieste, Trieste (Italy); Service des Photons Atomes et Molécules, Commissariat à l'Energie Atomique, Centre d'Etudes de Saclay, Bâtiment 522, 91191 Gif-sur-Yvette (France); Bu?ar, B.; Merhar, M. [Laboratory of Mechanical Processing Technologies, University of Ljubljana, Ljubljana (Slovenia)] [Laboratory of Mechanical Processing Technologies, University of Ljubljana, Ljubljana (Slovenia); Polo, E. [Institute of Organic Synthesis and Photoreactivity (CNR-ISOF), Ferrara (Italy)] [Institute of Organic Synthesis and Photoreactivity (CNR-ISOF), Ferrara (Italy); Ressel, B. [Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica (Slovenia)] [Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica (Slovenia)

    2014-02-15T23:59:59.000Z

    We present the main features of CITIUS, a new light source for ultrafast science, generating tunable, intense, femtosecond pulses in the spectral range from infrared to extreme ultraviolet (XUV). The XUV pulses (about 10{sup 5}-10{sup 8} photons/pulse in the range 14-80 eV) are produced by laser-induced high-order harmonic generation in gas. This radiation is monochromatized by a time-preserving monochromator, also allowing one to work with high-resolution bandwidth selection. The tunable IR-UV pulses (10{sup 12}-10{sup 15} photons/pulse in the range 0.4-5.6 eV) are generated by an optical parametric amplifier, which is driven by a fraction of the same laser pulse that generates high order harmonics. The IR-UV and XUV pulses follow different optical paths and are eventually recombined on the sample for pump-probe experiments. We also present the results of two pump-probe experiments: with the first one, we fully characterized the temporal duration of harmonic pulses in the time-preserving configuration; with the second one, we demonstrated the possibility of using CITIUS for selective investigation of the ultra-fast dynamics of different elements in a magnetic compound.

  17. Gravitational Radiation

    E-Print Network [OSTI]

    Bernard F Schutz

    2000-03-16T23:59:59.000Z

    Gravity is one of the fundamental forces of Nature, and it is the dominant force in most astronomical systems. In common with all other phenomena, gravity must obey the principles of special relativity. In particular, gravitational forces must not be transmitted or communicated faster than light. This means that when the gravitational field of an object changes, the changes ripple outwards through space and take a finite time to reach other objects. These ripples are called gravitational radiation or gravitational waves. This article gives a brief introduction to the physics of gravitational radiation, including technical material suitable for non-specialist scientists.

  18. Gamma Ray Burst Constraints on Ultraviolet Lorentz Invariance Violation

    E-Print Network [OSTI]

    Tina Kahniashvili; Grigol Gogoberidze; Bharat Ratra

    2006-10-20T23:59:59.000Z

    We present a unified general formalism for ultraviolet Lorentz invariance violation (LV) testing through electromagnetic wave propagation, based on both dispersion and rotation measure data. This allows for a direct comparison of the efficacy of different data to constrain LV. As an example we study the signature of LV on the rotation of the polarization plane of $\\gamma$-rays from gamma ray bursts in a LV model. Here $\\gamma$-ray polarization data can provide a strong constraint on LV, 13 orders of magnitude more restrictive than a potential constraint from the rotation of the cosmic microwave background polarization proposed by Gamboa, L\\'{o}pez-Sarri\\'{o}n, and Polychronakos (2006).

  19. Broadband extreme ultraviolet probing of transient gratings in vanadium dioxide

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sistrunk, Emily; Grilj, Jakob; Jeong, Jaewoo; Samant, Mahesh G.; Gray, Alexander X.; Dürr, Hermann A.; Parkin, Stuart S. P.; Gühr, Markus

    2015-01-01T23:59:59.000Z

    Nonlinear spectroscopy in the extreme ultraviolet (EUV) and soft x-ray spectral range offers the opportunity for element selective probing of ultrafast dynamics using core-valence transitions (Mukamel et al., Acc. Chem. Res. 42, 553 (2009)). We demonstrate a step on this path showing core-valence sensitivity in transient grating spectroscopy with EUV probing. We study the optically induced insulator-to-metal transition (IMT) of a VO? film with EUV diffraction from the optically excited sample. The VO? exhibits a change in the 3p-3d resonance of V accompanied by an acoustic response. Due to the broadband probing we are able to separate the two features.

  20. The ultraviolet spectra of SO?¹? and SO?¹? near 2300 A 

    E-Print Network [OSTI]

    Kim, Sang Uk

    1966-01-01T23:59:59.000Z

    22 10 Isotope Shift of Bands in the 2300 S02 ~ 13 Vapor Pressure Curve of SO Correction Curve. A System of 24 33 INTRODUCTION SO has three absorption regions in the ultraviolet portion of its spectrum. They are located at 5900 ? 5400 A.... The emission spectrum lines of the iron arc were used as a 14 TABLE I CORRESPONDING PRESSURES AT DIFFERENT TEMPERATURES PLATL' NUMBER 3 Spectrograms Temperatures -100 C - 85'c - 70'0 - 65'c 50 C Pressures 22 mm 33 mm 43 mm 73 15 standard...

  1. Graphene/GaN diodes for ultraviolet and visible photodetectors

    SciTech Connect (OSTI)

    Lin, Fang; Chen, Shao-Wen; Meng, Jie; Tse, Geoffrey; Fu, Xue-Wen; Xu, Fu-Jun [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Shen, Bo; Liao, Zhi-Min, E-mail: liaozm@pku.edu.cn, E-mail: yudp@pku.edu.cn; Yu, Da-Peng, E-mail: liaozm@pku.edu.cn, E-mail: yudp@pku.edu.cn [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2014-08-18T23:59:59.000Z

    The Schottky diodes based on graphene/GaN interface are fabricated and demonstrated for the dual-wavelength photodetection of ultraviolet (UV) and green lights. The physical mechanisms of the photoelectric response of the diodes with different light wavelengths are different. For UV illumination, the photo-generated carriers lower the Schottky barrier and increase the photocurrent. For green light illumination, as the photon energy is smaller than the bandgap of GaN, the hot electrons excited in graphene via internal photoemission are responsible for the photoelectric response. Using graphene as a transparent electrode, the diodes show a ?mS photoresponse, providing an alternative route toward multi-wavelength photodetectors.

  2. Large area, surface discharge pumped, vacuum ultraviolet light source

    DOE Patents [OSTI]

    Sze, Robert C. (Santa Fe, NM); Quigley, Gerard P. (Los Alamos, NM)

    1996-01-01T23:59:59.000Z

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source. A contamination-free VUV light source having a 225 cm.sup.2 emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm.sup.2 at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing.

  3. Large area, surface discharge pumped, vacuum ultraviolet light source

    DOE Patents [OSTI]

    Sze, R.C.; Quigley, G.P.

    1996-12-17T23:59:59.000Z

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source is disclosed. A contamination-free VUV light source having a 225 cm{sup 2} emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm{sup 2} at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing. 3 figs.

  4. The ultraviolet spectra of SO?¹? and SO?¹? near 2300 A

    E-Print Network [OSTI]

    Kim, Sang Uk

    1966-01-01T23:59:59.000Z

    22 10 Isotope Shift of Bands in the 2300 S02 ~ 13 Vapor Pressure Curve of SO Correction Curve. A System of 24 33 INTRODUCTION SO has three absorption regions in the ultraviolet portion of its spectrum. They are located at 5900 ? 5400 A.... The emission spectrum lines of the iron arc were used as a 14 TABLE I CORRESPONDING PRESSURES AT DIFFERENT TEMPERATURES PLATL' NUMBER 3 Spectrograms Temperatures -100 C - 85'c - 70'0 - 65'c 50 C Pressures 22 mm 33 mm 43 mm 73 15 standard...

  5. Extreme Ultra-Violet Spectroscopy of the Flaring Solar Chromosphere

    E-Print Network [OSTI]

    Milligan, Ryan O

    2015-01-01T23:59:59.000Z

    The extreme ultraviolet portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include temperature and density sensitive line ratios, Doppler shifted emission lines and nonthermal broadening, abundance measurements, differential emission measure profiles, and continuum temperatures and energetics, among others. In this paper I shall review some of the advances made in recent years using these techniques, focusing primarily on studies that have utilized data from Hinode/EIS and SDO/EVE, while also providing some historical background and a summary of future spectroscopic instrumentation.

  6. Ultraviolet Absorber UV-770 Market | OpenEI Community

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin Baxin HydropowerTrinityTurnbullGlobalUbbinkUkrainianUltraviolet

  7. Radiation Protection Act (Pennsylvania)

    Broader source: Energy.gov [DOE]

    This Act combines the radiation safety provisions of The Atomic Energy Development and Radiation Control Act and the Environmental Radiation Protection Act, and empowers the Department of...

  8. Ultraviolet Free Electron Laser Facility preliminary design report

    SciTech Connect (OSTI)

    Ben-Zvi, I. [ed.

    1993-02-01T23:59:59.000Z

    This document, the Preliminary Design Report (PDR) for the Brookhaven Ultraviolet Free Electron Laser (UV FEL) facility, describes all the elements of a facility proposed to meet the needs of a research community which requires ultraviolet sources not currently available as laboratory based lasers. Further, for these experiments, the requisite properties are not extant in either the existing second or upcoming third generation synchrotron light sources. This document is the result of our effort at BNL to identify potential users, determine the requirements of their experiments, and to design a facility which can not only satisfy the existing need, but have adequate flexibility for possible future extensions as need dictates and as evolving technology allows. The PDR is comprised of three volumes. In this, the first volume, background for the development of the proposal is given, including descriptions of the UV FEL facility, and representative examples of the science it was designed to perform. Discussion of the limitations and potential directions for growth are also included. A detailed description of the facility design is then provided, which addresses the accelerator, optical, and experimental systems. Information regarding the conventional construction for the facility is contained in an addendum to volume one (IA).

  9. Table top nanopatterning with extreme ultraviolet laser illumination M.G. Capeluto c

    E-Print Network [OSTI]

    Rocca, Jorge J.

    Table top nanopatterning with extreme ultraviolet laser illumination M.G. Capeluto c , P. Wachulak practical table-top nanopatterning tools based on extreme ultraviolet lasers for nanotechnology applications. Ó 2007 Elsevier B.V. All rights reserved. Keywords: EUV lasers; Table top photolithography

  10. Hubble Space Telescope FOS Optical and Ultraviolet Spectroscopy of the Bow Shock HH 47A 1

    E-Print Network [OSTI]

    Hartigan, Patrick

    Hubble Space Telescope FOS Optical and Ultraviolet Spectroscopy of the Bow Shock HH 47A 1 Patrick Telescope of the HH 47A bow shock and Mach disk that cover the entire spectral range between 2220 Å¡ that the Fe II line broadening must exceed that expected from thermal motions. Excitation of ultraviolet Fe II

  11. Office of radiation and indoor air: Program description

    SciTech Connect (OSTI)

    Not Available

    1993-06-01T23:59:59.000Z

    The goal of the Environmental Protection Agency`s (EPA) Office of Radiation and Indoor Air is to protect the public and the environment from exposures to radiation and indoor air pollutants. The Office develops protection criteria, standards, and policies and works with other programs within EPA and other agencies to control radiation and indoor air pollution exposures; provides technical assistance to states through EPA`s regional offices and other agencies having radiation and indoor air protection programs; directs an environmental radiation monitoring program; responds to radiological emergencies; and evaluates and assesses the overall risk and impact of radiation and indoor air pollution. The Office is EPA`s lead office for intra- and interagency activities coordinated through the Committee for Indoor Air Quality. It coordinates with and assists the Office of Enforcement in enforcement activities where EPA has jurisdiction. The Office disseminates information and works with state and local governments, industry and professional groups, and citizens to promote actions to reduce exposures to harmful levels of radiation and indoor air pollutants.

  12. Standoff ultraviolet raman scattering detection of trace levels of explosives.

    SciTech Connect (OSTI)

    Kulp, Thomas J.; Bisson, Scott E.; Reichardt, Thomas A.

    2011-10-01T23:59:59.000Z

    Ultraviolet (UV) Raman scattering with a 244-nm laser is evaluated for standoff detection of explosive compounds. The measured Raman scattering albedo is incorporated into a performance model that focused on standoff detection of trace levels of explosives. This model shows that detection at {approx}100 m would likely require tens of seconds, discouraging application at such ranges, and prohibiting search-mode detection, while leaving open the possibility of short-range point-and-stare detection. UV Raman spectra are also acquired for a number of anticipated background surfaces: tile, concrete, aluminum, cloth, and two different car paints (black and silver). While these spectra contained features in the same spectral range as those for TNT, we do not observe any spectra similar to that of TNT.

  13. Method for the protection of extreme ultraviolet lithography optics

    DOE Patents [OSTI]

    Grunow, Philip A.; Clift, Wayne M.; Klebanoff, Leonard E.

    2010-06-22T23:59:59.000Z

    A coating for the protection of optical surfaces exposed to a high energy erosive plasma. A gas that can be decomposed by the high energy plasma, such as the xenon plasma used for extreme ultraviolet lithography (EUVL), is injected into the EUVL machine. The decomposition products coat the optical surfaces with a protective coating maintained at less than about 100 .ANG. thick by periodic injections of the gas. Gases that can be used include hydrocarbon gases, particularly methane, PH.sub.3 and H.sub.2S. The use of PH.sub.3 and H.sub.2S is particularly advantageous since films of the plasma-induced decomposition products S and P cannot grow to greater than 10 .ANG. thick in a vacuum atmosphere such as found in an EUVL machine.

  14. Ultrafast Extreme Ultraviolet Induced Isomerization of Acetylene Cations

    SciTech Connect (OSTI)

    Jiang, Y. H.; Kurka, M.; Kuehnel, K. U.; Schroeter, C. D.; Moshammer, R. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Rudenko, A.; Foucar, L. [Max-Planck Advanced Study Group at CFEL, 22607 Hamburg (Germany); Herrwerth, O.; Lezius, M.; Kling, M. F. [Max-Planck-Institut fuer Quantenoptik, 85748 Garching (Germany); Tilborg, J. van; Belkacem, A. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Ueda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 980-8577 Sendai (Japan); Duesterer, S.; Treusch, R. [DESY, 22607 Hamburg (Germany); Ullrich, J. [Max-Planck-Institut fuer Kernphysik, 69117 Heidelberg (Germany); Max-Planck Advanced Study Group at CFEL, 22607 Hamburg (Germany)

    2010-12-31T23:59:59.000Z

    Ultrafast isomerization of acetylene cations ([HC=CH]{sup +}) in the low-lying excited A{sup 2}{Sigma}{sub g}{sup +} state, populated by the absorption of extreme ultraviolet (XUV) photons (38 eV), has been observed at the Free Electron Laser in Hamburg, (FLASH). Recording coincident fragments C{sup +}+CH{sub 2}{sup +} as a function of time between XUV-pump and -probe pulses, generated by a split-mirror device, we find an isomerization time of 52{+-}15 fs in a kinetic energy release (KER) window of 5.8

  15. Ultrafast Extreme Ultraviolet Induced Isomerization of Acetylene Cations

    SciTech Connect (OSTI)

    Jiang, Y.; Rudenko, Artem; Herrwerth, O.; Foucar, L.; Kurka, M.; Kuhnel, K.; Lezius, M.; Kling, Matthias; van Tilborg, Jeroen; Belkacem, Ali; Ueda, K.; Dusterer, S.; Treusch, R.; Schroter, Claus-Dieter; Moshammer, Robbert; Ullrich, Joachim

    2011-06-17T23:59:59.000Z

    Ultrafast isomerization of acetylene cations ([HC = CH]{sup +}) in the low-lying excited A{sup 2}{Sigma}{sub g}{sup +} state, populated by the absorption of extreme ultraviolet (XUV) photons (38 eV), has been observed at the Free Electron Laser in Hamburg, (FLASH). Recording coincident fragments C{sup +} + CH{sub 2}{sup +} as a function of time between XUV-pump and -probe pulses, generated by a split-mirror device, we find an isomerization time of 52 {+-} 15 fs in a kinetic energy release (KER) window of 5.8 < KER < 8 eV, providing clear evidence for the existence of a fast, nonradiative decay channel.

  16. Strong Ultraviolet Pulse From a Newborn Type Ia Supernova

    E-Print Network [OSTI]

    Cao, Yi; Howell, D Andrew; Gal-Yam, Avishay; Kasliwal, Mansi M; Valenti, Stefano; Johansson, J; Amanullah, R; Goobar, A; Sollerman, J; Taddia, F; Horesh, Assaf; Sagiv, Ilan; Cenko, S Bradley; Nugent, Peter E; Arcavi, Iair; Surace, Jason; Wo?niak, P R; Moody, Daniela I; Rebbapragada, Umaa D; Bue, Brian D; Gehrels, Neil

    2015-01-01T23:59:59.000Z

    Type Ia supernovae are destructive explosions of carbon oxygen white dwarfs. Although they are used empirically to measure cosmological distances, the nature of their progenitors remains mysterious, One of the leading progenitor models, called the single degenerate channel, hypothesizes that a white dwarf accretes matter from a companion star and the resulting increase in its central pressure and temperature ignites thermonuclear explosion. Here we report observations of strong but declining ultraviolet emission from a Type Ia supernova within four days of its explosion. This emission is consistent with theoretical expectations of collision between material ejected by the supernova and a companion star, and therefore provides evidence that some Type Ia supernovae arise from the single degenerate channel.

  17. Laser plasma formation assisted by ultraviolet pre-ionization

    SciTech Connect (OSTI)

    Yalin, Azer P., E-mail: ayalin@engr.colostate.edu; Dumitrache, Ciprian [Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Wilvert, Nick [Sandia Laboratory, Albuquerque, New Mexico 87123 (United States); Joshi, Sachin [Cummins Inc., Columbus, Indiana 47201 (United States); Shneider, Mikhail N. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

    2014-10-15T23:59:59.000Z

    We present experimental and modeling studies of air pre-ionization using ultraviolet (UV) laser pulses and its effect on laser breakdown of an overlapped near-infrared (NIR) pulse. Experimental studies are conducted with a 266?nm beam (fourth harmonic of Nd:YAG) for UV pre-ionization and an overlapped 1064?nm NIR beam (fundamental of Nd:YAG), both having pulse duration of ?10?ns. Results show that the UV beam produces a pre-ionized volume which assists in breakdown of the NIR beam, leading to reduction in NIR breakdown threshold by factor of >2. Numerical modeling is performed to examine the ionization and breakdown of both beams. The modeled breakdown threshold of the NIR, including assist by pre-ionization, is in reasonable agreement with the experimental results.

  18. Extreme ultraviolet mask substrate surface roughness effects on lithography patterning

    SciTech Connect (OSTI)

    George, Simi; Naulleau, Patrick; Salmassi, Farhad; Mochi, Iacopo; Gullikson, Eric; Goldberg, Kenneth; Anderson, Erik

    2010-06-21T23:59:59.000Z

    In extreme ultraviolet lithography exposure systems, mask substrate roughness induced scatter contributes to LER at the image plane. In this paper, the impact of mask substrate roughness on image plane speckle is explicitly evaluated. A programmed roughness mask was used to study the correlation between mask roughness metrics and wafer plane aerial image inspection. We find that the roughness measurements by top surface topography profile do not provide complete information on the scatter related speckle that leads to LER at the image plane. We suggest at wavelength characterization by imaging and/or scatter measurements into different frequencies as an alternative for a more comprehensive metrology of the mask substrate/multilayer roughness effects.

  19. Ultraviolet photoluminescence from Gd-implanted AlN epilayers

    SciTech Connect (OSTI)

    Zavada, J. M.; Nepal, N.; Lin, J. Y.; Jiang, H. X.; Brown, E.; Hoemmerich, U.; Hite, J.; Thaler, G. T.; Abernathy, C. R.; Pearton, S. J.; Gwilliam, R. [U.S. Army Research Office, Durham, North Carolina 27709 (United States); Department of Physics, Kansas State University, Manhattan, Kansas 66506-2601 (United States); Department of Physics, Hampton University, Hampton, Virginia 23668 (United States); Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Surrey Ion Beam Center, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2006-10-09T23:59:59.000Z

    Deep ultraviolet emission from gadolinium (Gd)-implanted AlN thin films has been observed using photoluminescence (PL) spectroscopy. The AlN epilayers were ion implanted with Gd to a total dose of {approx}6x10{sup 14} cm{sup -2}. Using the output at 197 nm from a quadrupled Ti:sapphire laser, narrow PL emission was observed at 318 nm, characteristic of the trivalent Gd ion. A broader emission band, also centered at 318 nm, was measured with excitation at 263 nm. The PL emission intensity decreased by less than a factor of 3 over the sample temperature range of 10-300 K and decay transients were of the order of nanoseconds.

  20. Ultraviolet Resonant Raman Enhancements in the Detection of Explosives

    SciTech Connect (OSTI)

    Short, B J; Carter, J C; Gunter, D; Hovland, P; Jagode, H; Karavanic, K; Marin, G; Mellor-Crummey, J; Moore, S; Norris, B; Oliker, L; Olschanowsky, C; Roth, P C; Schulz, M; Shende, S; Snavely, A; Spear, W

    2009-06-03T23:59:59.000Z

    Raman-based spectroscopy is potentially militarily useful for standoff detection of high explosives. Normal (non-resonance) and resonance Raman spectroscopies are both light scattering techniques that use a laser to measure the vibrational spectrum of a sample. In resonance Raman, the laser is tuned to match the wavelength of a strong electronic absorbance in the molecule of interest, whereas, in normal Raman the laser is not tuned to any strong electronic absorbance bands. The selection of appropriate excitation wavelengths in resonance Raman can result in a dramatic increase in the Raman scattering efficiency of select band(s) associated with the electronic transition. Other than the excitation wavelength, however, resonance Raman is performed experimentally the same as normal Raman. In these studies, normal and resonance Raman spectral signatures of select solid high explosive (HE) samples and explosive precursors were collected at 785 nm, 244 nm and 229 nm. Solutions of PETN, TNT, and explosive precursors (DNT & PNT) in acetonitrile solvent as an internal Raman standard were quantitatively evaluated using ultraviolet resonance Raman (UVRR) microscopy and normal Raman spectroscopy as a function of power and select excitation wavelengths. Use of an internal standard allowed resonance enhancements to be estimated at 229 nm and 244 nm. Investigations demonstrated that UVRR provided {approx}2000-fold enhancement at 244 nm and {approx}800-fold improvement at 229 nm while PETN showed a maximum of {approx}25-fold at 244 nm and {approx}190-fold enhancement at 229 nm solely from resonance effects when compared to normal Raman measurements. In addition to the observed resonance enhancements, additional Raman signal enhancements are obtained with ultraviolet excitation (i.e., Raman scattering scales as !4 for measurements based on scattered photons). A model, based partly on the resonance Raman enhancement results for HE solutions, is presented for estimating Raman enhancements for solid HE samples.

  1. Sensitivity calibration of an imaging extreme ultraviolet spectrometer-detector system for determining the efficiency of broadband extreme ultraviolet sources

    SciTech Connect (OSTI)

    Fuchs, S.; Roedel, C.; Bierbach, J.; Paz, A. E.; Foerster, E.; Paulus, G. G. [Institute of Optics und Quantum Electronics, Friedrich-Schiller-University Jena (Germany); Helmholtz-Institute Jena (Germany); Krebs, M. [Institute of Applied Physics, Friedrich-Schiller-University Jena (Germany); Haedrich, S.; Limpert, J. [Helmholtz-Institute Jena (Germany); Institute of Applied Physics, Friedrich-Schiller-University Jena (Germany); Kuschel, S.; Wuensche, M.; Hilbert, V.; Zastrau, U. [Institute of Optics und Quantum Electronics, Friedrich-Schiller-University Jena (Germany)

    2013-02-15T23:59:59.000Z

    We report on the absolute sensitivity calibration of an extreme ultraviolet (XUV) spectrometer system that is frequently employed to study emission from short-pulse laser experiments. The XUV spectrometer, consisting of a toroidal mirror and a transmission grating, was characterized at a synchrotron source in respect of the ratio of the detected to the incident photon flux at photon energies ranging from 15.5 eV to 99 eV. The absolute calibration allows the determination of the XUV photon number emitted by laser-based XUV sources, e.g., high-harmonic generation from plasma surfaces or in gaseous media. We have demonstrated high-harmonic generation in gases and plasma surfaces providing 2.3 {mu}W and {mu}J per harmonic using the respective generation mechanisms.

  2. Effect of aerosols and NO2 concentration on ultraviolet actinic flux near Mexico City during MILAGRO: Measurements and model calculations

    SciTech Connect (OSTI)

    Palancar, Gustavo G.; Lefer, Barry; Hall, Samual R.; Shaw, William J.; Corr, Chelsea A.; Herndon, Scott C.; Slusser, J. R.; Madronich, Sasha

    2013-01-24T23:59:59.000Z

    Ultraviolet (UV) actinic ?uxes (AF) measured with three Scanning Actinic Flux Spectroradiometers (SAFS) are compared with the Tropospheric Ultraviolet-Visible (TUV) model v.5 in order to assess the effects of aerosols and NO2 concentrations on the radiation. Measurements were made during the MILAGRO campaign near Mexico City in March 2006, at a ground-based station near Mexico City (the T1 supersite) and from the NSF/NCAR C-130 aircraft. At the surface, measurements are typically smaller by up to 25 % in the morning, 10% at noon, and 40% in the afternoon, than actinic flux modeled for clean, cloud-free conditions. When measurements of PBL height, NO2 concentration and aerosols optical properties are included in the model, the agreement improves to within ±10% in the morning and afternoon, and ±3% at noon. Based on daily averages, aerosols account for 68%, NO2 for 25%, and residual uncertainties for 7% of these AF reductions observed at the surface. Several overpasses from the C-130 aircraft provided the opportunity to examine the actinic flux perturbations aloft, and also show better agreement with the model when aerosol and NO2 effects are included above and below the flight altitude. TUV model simulations show that the vertical structure of the actinic flux is sensitive to the choice of the aerosol single scattering albedo (SSA) at UV wavelengths. Typically, aerosols caused enhanced AF above the PBL and reduced AF near the surface. However, for highly scattering aerosols (SSA > 0.95), enhancements can penetrate well into the PBL, while for strongly absorbing aerosols (SSA<0.7) reductions in AF are computed in the free troposphere as well as in the PBL. Additional measurements of the SSA at these wavelengths are needed to better constrain the effect of aerosols on the vertical structure of the actinic flux.

  3. Radiation-induced gene responses

    SciTech Connect (OSTI)

    Woloschak, G.E.; Paunesku, T.; Shearin-Jones, P.; Oryhon, J.

    1996-12-31T23:59:59.000Z

    In the process of identifying genes that are differentially regulated in cells exposed to ultraviolet radiation (UV), we identified a transcript that was repressed following the exposure of cells to a combination of UV and salicylate, a known inhibitor of NF-kappaB. Sequencing this band determined that it has identify to lactate dehydrogenase, and Northern blots confirmed the initial expression pattern. Analysis of the sequence of the LDH 5` region established the presence of NF-kappaB, Sp1, and two Ap-2 elements; two partial AP- 1; one partial RE, and two halves of E-UV elements were also found. Electromobility shift assays were then performed for the AP-1, NF- kappaB, and E-UV elements. These experiments revealed that binding to NF-kappaB was induced by UV but repressed with salicylic acid; UV did not affect AP-1 binding, but salicylic acid inhibited it alone or following UV exposure; and E-UV binding was repressed by UV, and salicylic acid had little effect. Since the binding of no single element correlated with the expression pattern of LDH, it is likely that multiple elements govern UV/salicylate-mediated expression.

  4. FAR-ULTRAVIOLET OBSERVATIONS OF THE SPICA NEBULA AND THE INTERACTION ZONE

    SciTech Connect (OSTI)

    Choi, Yeon-Ju; Min, Kyoung-Wook; Lim, Tae-Ho; Jo, Young-Soo [Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Seon, Kwang-Il [Korea Astronomy and Space Science Institute (KASI), 61-1 Hwaam-dong, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Park, Jae-Woo, E-mail: zmzm83@kaist.ac.kr [Korea Intellectual Property Office (KIPO), Government Complex Daejeon Building 4, 189 Cheongsa-ro, Seo-gu, Daejeon 305-348 (Korea, Republic of)

    2013-09-01T23:59:59.000Z

    We report the analysis results of far-ultraviolet (FUV) observations, made for a broad region around {alpha} Vir (Spica) including the interaction zone of Loop I and the Local Bubble. The whole region was optically thin and a general correlation was seen between the FUV continuum intensity and the dust extinction, except in the neighborhood of the bright central star, indicating the dust scattering nature of the FUV continuum. We performed Monte Carlo radiative transfer simulations to obtain the optical parameters related to the dust scattering as well as to the geometrical structure of the region. The albedo and asymmetry factor were found to be 0.38 {+-} 0.06 and 0.46 {+-} 0.06, respectively, in good agreement with the Milky Way dust grain models. The distance to and the thickness of the interaction zone were estimated to be 70{sup +4}{sub -8} pc and 40{sup +8}{sub -10} pc, respectively. The diffuse FUV continuum in the northern region above Spica was mostly the result of scattering of the starlight from Spica, while that in the southern region was mainly due to the background stars. The C IV {lambda}{lambda}1548, 1551 emission was found throughout the whole region, in contrast to the Si II* {lambda}1532 emission which was bright only within the H II region. This indicates that the C IV line arises mostly at the shell boundaries of the bubbles, with a larger portion likely from the Loop I than from the Local Bubble side, whereas the Si II* line is from the photoionized Spica Nebula.

  5. Investigating the effective range of vacuum ultraviolet-mediated breakdown in high-power microwave metamaterials

    SciTech Connect (OSTI)

    Liu, Chien-Hao, E-mail: cliu82@wisc.edu; Neher, Joel D., E-mail: jdneher@wisc.edu; Booske, John H., E-mail: booske@engr.wisc.edu; Behdad, Nader, E-mail: behdad@wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706 (United States)

    2014-10-14T23:59:59.000Z

    Metamaterials and periodic structures operating under high-power excitations are susceptible to breakdown. It was recently demonstrated that a localized breakdown created in a given region of a periodic structure can facilitate breakdown in other regions of the structure where the intensity of the incident electromagnetic fields may not be high enough to cause breakdown under normal circumstances. It was also demonstrated that this phenomenon is due to the generation of vacuum ultraviolet radiation at the location of the initial discharge, which propagates to the neighboring regions (e.g., other unit cells in a periodic structure) and facilitates the generation of a discharge at a lower incident power level. In this paper, we present the results of an experimental study conducted to determine the effective range of this physical phenomenon for periodic structures that operate in air and in pure nitrogen gas at atmospheric pressure levels. It is demonstrated that when breakdown is induced in a periodic structure using a high-power pulse with a frequency of 9.382 GHz, duration of 0.8 ?s, and peak power level of 25 kW, this phenomenon is highly likely to happen in radii of approximately 16–17 mm from the location of the initial discharge under these test conditions. The results of this study are significant in designing metamaterials and periodic structures for high-power microwave applications as they suggest that a localized discharge created in such a periodic structure with a periodicity less than 16–17 mm can spread over a large surface and result in a distributed discharge.

  6. Adaptors for radiation detectors

    DOE Patents [OSTI]

    Livesay, Ronald Jason

    2014-04-22T23:59:59.000Z

    Described herein are adaptors and other devices for radiation detectors that can be used to make accurate spectral measurements of both small and large bulk sources of radioactivity, such as building structures, soils, vessels, large equipment, and liquid bodies. Some exemplary devices comprise an adaptor for a radiation detector, wherein the adaptor can be configured to collimate radiation passing through the adapter from an external radiation source to the radiation detector and the adaptor can be configured to enclose a radiation source within the adapter to allow the radiation detector to measure radiation emitted from the enclosed radiation source.

  7. Radiation dosimeters

    DOE Patents [OSTI]

    Hoelsher, James W. (Pullman, WA); Hegland, Joel E. (Pullman, WA); Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA)

    1992-01-01T23:59:59.000Z

    Radiation dosimeters and dosimeter badges. The dosimeter badges include first and second parts which are connected to join using a securement to produce a sealed area in which at least one dosimeter is held and protected. The badge parts are separated to expose the dosimeters to a stimulating laser beam used to read dose exposure information therefrom. The badge is constructed to allow automated disassembly and reassembly in a uniquely fitting relationship. An electronic memory is included to provide calibration and identification information used during reading of the dosimeter. Dosimeter mounts which reduce thermal heating requirements are shown. Dosimeter constructions and production methods using thin substrates and phosphor binder-layers applied thereto are also taught.

  8. all-solid-state ultraviolet laser: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    C. S. Menoni, and J. J. Rocca NSFERC for Extreme Ultraviolet Science. J. E. Trebes, S. B. Brown, E. M. Campbell, D. L. Matthews, D. G. Nilson, G. F. Stone, and D. A amplifier,"...

  9. The development and application of a diode-laser-based ultraviolet absorption sensor for nitric oxide 

    E-Print Network [OSTI]

    Anderson, Thomas Nathan

    2004-09-30T23:59:59.000Z

    This thesis describes the development of a new type of sensor for nitric oxide (NO) that can be used in a variety of combustion diagnostics and control applications. The sensor utilizes the absorption of ultraviolet (UV) ...

  10. Table-top Extreme Ultraviolet Laser Aerial Imaging of Lithographic Masks

    E-Print Network [OSTI]

    Brizuela, F.

    2012-01-01T23:59:59.000Z

    Table-top Extreme Ultraviolet Laser Aerial Imaging ofmasks realized using a table-top aerial imaging systembased on a table-top X=\\3.2 laser. © 2 0 0 9 Optical Society

  11. Quantum Field Theory on Noncommutative Space-Times and the Persistence of Ultraviolet Divergences

    E-Print Network [OSTI]

    M. Chaichian; A. Demichev; P. Presnajder

    1999-04-13T23:59:59.000Z

    We study properties of a scalar quantum field theory on two-dimensional noncommutative space-times. Contrary to the common belief that noncommutativity of space-time would be a key to remove the ultraviolet divergences, we show that field theories on a noncommutative plane with the most natural Heisenberg-like commutation relations among coordinates or even on a noncommutative quantum plane with $E_q(2)$-symmetry have ultraviolet divergences, while the theory on a noncommutative cylinder is ultraviolet finite. Thus, ultraviolet behaviour of a field theory on noncommutative spaces is sensitive to the topology of the space-time, namely to its compactness. We present general arguments for the case of higher space-time dimensions and as well discuss the symmetry transformations of physical states on noncommutative space-times.

  12. EVIDENCE FOR TYPE Ia SUPERNOVA DIVERSITY FROM ULTRAVIOLET OBSERVATIONS WITH THE HUBBLE SPACE TELESCOPE

    E-Print Network [OSTI]

    Lewin, Walter H. G.

    We present ultraviolet (UV) spectroscopy and photometry of four Type Ia supernovae (SNe 2004dt, 2004ef, 2005M, and 2005cf) obtained with the UV prism of the Advanced Camera for Surveys on the Hubble Space Telescope. This ...

  13. The effect of the operation modes of a gas discharge low-pressure amalgam lamp on the intensity of generation of 185 nm UV vacuum radiation

    SciTech Connect (OSTI)

    Vasilyak, L. M., E-mail: vasilyak@ihed.ras.ru [Russian Academy of Sciences, Joint Institute of High Temperatures (Russian Federation); Drozdov, L. A., E-mail: lit@npo.lit.ru; Kostyuchenko, S. V.; Sokolov, D. V. [ZAO LIT (Russian Federation); Kudryavtsev, N. N.; Sobur, D. A., E-mail: soburda@gmail.com [Moscow Institute for Physics and Technology (Russian Federation)

    2011-12-15T23:59:59.000Z

    The effect of the discharge current, mercury vapor pressure, and the inert gas pressure on the intensity and efficiency of the 185 nm line generation are considered. The spectra of the UV radiation (vacuum ultraviolet) transmission by protective coatings from the oxides of rare earth metals and aluminum are investigated.

  14. Microbial Reduction on Eggshell Surfaces by the use of Hydrogen Peroxide and Ultraviolet Light

    E-Print Network [OSTI]

    Gottselig, Steven Michael

    2011-10-21T23:59:59.000Z

    MICROBIAL REDUCTION ON EGGSHELL SURFACES BY THE USE OF HYDROGEN PEROXIDE AND ULTRAVIOLET LIGHT A Thesis by STEVEN MICHAEL GOTTSELIG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 2011 Major Subject: Poultry Science Microbial Reduction on Eggshell Surfaces by the Use of Hydrogen Peroxide and Ultraviolet Light Copyright 2011...

  15. Ultraviolet light absorbers having two different chromophors in the same molecule

    DOE Patents [OSTI]

    Vogl, O.; Li, S.

    1983-10-06T23:59:59.000Z

    This invention relates to novel ultraviolet light absorbers having two chromophors in the same molecule, and more particularly to benzotriazole substituted dihydroxybenzophenones and acetophenones. More particularly, this invention relates to 3,5-(di(2H-benzotriazole-2-yl))-2,4-dihydroxybenzophenone and 3,5-(di(2H-benzotriazole-2-yl))-2,4-dihydroxyacetophenone which are particularly useful as an ultraviolet light absorbers.

  16. Gas-phase ultraviolet photoelectron spectroscopy and molecular orbital calculations on transition metal carbonyls and nitrosyls

    E-Print Network [OSTI]

    Morris-Sherwood, Betty Jeanne

    1981-01-01T23:59:59.000Z

    GAS-PHASE ULTRAVIOLET PHOTOELECTRON SPECTROSCOPY AND MOLECULAR ORBITAL CALCULATIONS ON TRANSITION METAL CARBONYLS AND NITROSYLS A Thesis by BETTY JEANNE MORRIS-SHERWOOD Submitted to the Graduate College of Texas ARM Uni ver s i ty in partial... JEANNE MORRIS-SHERWOOD Approved as to sty1e and content by: (Chairman of Committee) (Member): (Niember) r / )g (Head of Department) December 1981 ABSTRACT Gas-Phas Ultraviolet Photoelectron Spectroscopy and Molecular Orbital Calculations...

  17. environmental management radiation protection

    E-Print Network [OSTI]

    Entekhabi, Dara

    EHS environmental management biosafety radiation protection industrial hygiene safety Working: Biosafety, Environmental Management, Industrial Hygiene, Radiation Protection and Safety. Each specialized Management Program, Industrial Hygiene, Radiation Protection Program, and the Safety Program. (http

  18. DETECTORS FOR RADIATION DOSIMETRY

    E-Print Network [OSTI]

    Perez-Mendez, V.

    2010-01-01T23:59:59.000Z

    J. Price, "Nuclear Radiation Detection" (2nd ed. , New York:4) G. F. Knoll, "Radiation Detection and Measurement" (NewSons, Inc. from "Radiation Detection and Measurement," G. F.

  19. Radiative corrections to real and virtual muon Compton scattering revisited

    E-Print Network [OSTI]

    N. Kaiser

    2010-03-04T23:59:59.000Z

    We calculate in closed analytical form the one-photon loop radiative corrections to muon Compton scattering $\\mu^- \\gamma \\to \\mu^- \\gamma $. Ultraviolet and infrared divergencies are both treated in dimensional regularization. Infrared finiteness of the (virtual) radiative corrections is achieved (in the standard way) by including soft photon radiation below an energy cut-off $\\lambda$. We find that the anomalous magnetic moment $\\alpha/2\\pi$ provides only a very small portion of the full radiative corrections. Furthermore, we extend our calculation of radiative corrections to the muon-nucleus bremsstrahlung process (or virtual muon Compton scattering $\\mu^-\\gamma_0^* \\to \\mu^- \\gamma $). These results are particularly relevant for analyzing the COMPASS experiment at CERN in which muon-nucleus bremsstrahlung serves to calibrate the Primakoff scattering of high-energy pions off a heavy nucleus with the aim of measuring the pion electric and magnetic polarizabilities. We find agreement with an earlier calculation of these radiative corrections based on a different method.

  20. CDC Response to Advisory Committee on Childhood Lead Poisoning Prevention Recommendations in "Low Level Lead Exposure Harms Children: A Renewed Call of

    E-Print Network [OSTI]

    CDC Response to Advisory Committee on Childhood Lead Poisoning Prevention Recommendations in "Low Level Lead Exposure Harms Children: A Renewed Call of Primary Prevention" BACKGROUND In late 2010, the Centers for Disease Control and Prevention's (CDC) Advisory Committee for Childhood Lead Poisoning

  1. The Far-Ultraviolet Ups and Downs of Alpha Centauri

    E-Print Network [OSTI]

    Ayres, Thomas R

    2014-01-01T23:59:59.000Z

    Four years (2010-2014) of semiannual pointings by Hubble Space Telescope Imaging Spectrograph (STIS) on nearby Alpha Centauri have yielded a detailed time history of far-ultraviolet emissions of the solar-like primary (A: G2V) and the cooler, but more active, secondary (B: K1V). This period saw A climbing out of a prolonged coronal X-ray minimum, as documented by Chandra, while B was rising to, then falling from, a peak of its long-term (8 yr) starspot cycle. The FUV fluxes of the primary were steady over most of the STIS period, although the [Fe XII] 124 nm coronal forbidden line (T= 1.5 MK) partly mirrored the slowly rising X-ray fluxes. The FUV emissions of the secondary more closely tracked the rise and fall of its coronal luminosities, especially the "hot lines" like Si IV, C IV, and N V (T= 80,000-200,000 K), and coronal [Fe XII] itself. The hot lines of both stars were systematically redshifted, relative to narrow chromospheric emissions, by several km/s, showing little change in amplitude over the 4-y...

  2. AN EXTREME-ULTRAVIOLET WAVE ASSOCIATED WITH A SURGE

    SciTech Connect (OSTI)

    Zheng, Ruisheng; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Hong, Junchao; Yang, Bo; Yang, Dan, E-mail: zhrsh@ynao.ac.cn [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming 650011 (China)] [National Astronomical Observatories/Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming 650011 (China)

    2013-02-10T23:59:59.000Z

    Taking advantage of the high temporal and spatial resolution observations from the Solar Dynamics Observatory, we present an extreme-ultraviolet (EUV) wave associated with a surge on 2010 November 13. Due to the magnetic flux cancelation, some surges formed in the source active region (AR). The strongest surge produced our studied event. The surge was deflected by the nearby loops that connected to another AR, and disrupted the overlying loops that slowly expanded and eventually evolved into a weak coronal mass ejection (CME). The surge was likely associated with the core of the CME. The EUV wave happened after the surge deflected. The wave departed far from the flare center and showed a close location relative to the deflected surge. The wave propagated in a narrow angular extent, mainly in the ejection direction of the surge. The close timing and location relations between the EUV wave and the surge indicate that the wave was closely associated with the CME. The wave had a velocity of 310-350 km s{sup -1}, while the speeds of the surge and the expanding loops were about 130 and 150 km s{sup -1}, respectively. All of the results suggest that the EUV wave was a fast-mode wave and was most likely triggered by the weak CME.

  3. Ultraviolet laser ablation of polycarbonate and glass in air

    SciTech Connect (OSTI)

    Bormotova, T. A.; Blumenthal, R. [Auburn University, Alabama 36849 (United States)

    2009-02-01T23:59:59.000Z

    The fundamental physical processes that follow ultraviolet laser ablation of polycarbonate and borosilicate glass in air have been investigated using photodeflection as a function of the distance from the surface to probe laser. Four features were observed in the data sets for each material. Two of these features correlate well with gas dynamical predictions for the expansion of the shock wave and gas plume. The third feature is consistent with the propagation of the popping sound of the laser ablation event. The final feature, which occurs at very early times and does not shift significantly in time as the surface to probe distance is increased from 0 to greater than 6 mm, has been tentatively ascribed to the ejection of fast electrons. The final significant observation is complete blocking of the probe laser, only observed during borosilicate ablation, which is attributed to scattering of the probe laser light by macroscopic SiO{sub x} particles that grow in the final stages of plume expansion and cooling.

  4. Performance of multilayer coated concave gratings in the extreme ultraviolet

    SciTech Connect (OSTI)

    Bixler, J.V.; Barbee, T.W. Jr.; Dietrich, D.D.

    1989-06-13T23:59:59.000Z

    Recent advances in multilayer structures for the Extreme Ultraviolet now make it possible to construct diffraction gratings in the wavelength range below 250 /angstrom/ which can be used for precision measurements using normal incidence spectrometers. We report results from two such gratings, one conventionally ruled and other holographically ruled. Both are one meter radius, 1200 lines per millimeter gratings coated with a molybdenum-silicon multilayer for use in the 150 /angstrom/ wavelength region. A McPherson 225 one meter normal incidence spectrometer with a Garton flash tube source and a film detector was used to test the resolution. Semiquantitative efficiency measurements were made by comparing the spectra with that produced by an osmium coated gratings. Oxygen lines in the wavelength region of interest (characteristic of the source) are easily detected and well resolved with both multilayer coated gratings. The same lines are faint or undetected with the osmium coated grating. Quantitative efficiency measurement were performed using a Penning source and a photon counting detector. 9 refs., 4 figs., 1 tab.

  5. Courses on Synchrotron Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synchrotron Radiation The following is an incomplete list of courses on Synchrotron Radiation. For additional courses, check lightsources.org. XAFS School The APS XAFS School...

  6. Solar radiation resource assessment

    SciTech Connect (OSTI)

    Not Available

    1990-11-01T23:59:59.000Z

    The bulletin discusses the following: introduction; Why is solar radiation resource assessment important Understanding the basics; the solar radiation resource assessment project; and future activities.

  7. Radiation Control (Virginia)

    Broader source: Energy.gov [DOE]

    The Department of Health is responsible for regulating radiation and radioactive materials in the Commonwealth of Virginia. Although the Department's Radiation Control Program primarily focuses on...

  8. The Near-Ultraviolet Continuum of Late-Type Stars

    E-Print Network [OSTI]

    Carlos Allende Prieto; David L. Lambert

    2000-01-28T23:59:59.000Z

    Analyses of the near-ultraviolet continuum of late-type stars have led to controversial results regarding the performance of state-of-the-art model atmospheres. The release of the homogeneous IUE final archive and the availability of the high-accuracy Hipparcos parallaxes provide an opportunity to revisit this issue, as accurate stellar distances make it possible to compare observed absolute fluxes with the predictions of model atmospheres. The near-UV continuum is highly sensitive to Teff and [Fe/H], and once the gravity is constrained from the parallax, these parameters may be derived from the analysis of low-dispersion "long-wavelength" (2000-3000 A) IUE spectra for stars previously studied by Alonso et al. (1996; A&AS 117, 227) using the Infrared Flux Method (IRFM). A second comparison is carried out against the stars spectroscopically investigated by Gratton et al. (1996; A&A 314, 191). It is shown that there is a good agreement between Teffs obtained from the IRFM and from the near-UV continuum, and a remarkable correspondence between observed and synthetic fluxes for stars with 4000 <= Teff <= 6000 K of any metallicity and gravity. These facts suggest that model atmospheres provide an adequate description of the near-UV continuum forming region and that the opacities involved are essentially understood. For cooler stars, the results of the IRFM are no longer reliable, as shown by Alonso et al., but the discrepancy noticed for stars hotter than 6000 K may reflect problems in the model atmospheres and/or the opacities at these higher temperatures.

  9. Simulation of ultraviolet- and soft X-ray-pulse generation as a result of cooperative recombination of excitons in diamond nanocrystals embedded in a polymer film

    SciTech Connect (OSTI)

    Kukushkin, V. A., E-mail: vakuk@appl.sci-nnov.ru [Russian Academy of Sciences, Institute for Applied Physics (Russian Federation)

    2013-11-15T23:59:59.000Z

    Using numerical simulation, it is shown that the recombination of free excitons photoexcited in diamond nanocrystals embedded in a polymer film can occur in the cooperative mode. It is found that this mode can be implemented despite the fact that diamond is an 'indirect' semiconductor. It is shown that the power of the generated radiation at the pulse peak during the cooperative recombination of free excitons can exceed that of the incoherent spontaneous emission of the same initial number of free excitons by more than an order of magnitude. Finally, it is shown that the process under consideration can be used to generate picosecond pulses of ultraviolet and soft X-ray electromagnetic field at a wavelength of 235 nm.

  10. An upper limit on the ratio between the Extreme Ultraviolet and the bolometric luminosities of stars hosting habitable planets

    E-Print Network [OSTI]

    Sengupta, Sujan

    2015-01-01T23:59:59.000Z

    A large number of terrestrial planets in the classical habitable zone of stars of different spectral types has already been discovered and many are expected to be discovered in near future. However, owing to the lack of knowledge on the atmospheric properties, the ambient environment of such planets are unknown. It is known that sufficient amount of Extreme Ultraviolet (EUV) radiation from the star can drive hydrodynamic outflow of hydrogen that may drag heavier species from the atmosphere of the planet. If the rate of mass loss is sufficiently high then substantial amount of volatiles would escape causing the planet to become uninhabitable. Considering energy-limited hydrodynamical mass loss with an escape rate that causes oxygen to escape along with hydrogen, I present an upper limit for the ratio between the EUV and the bolometric luminosities of stars which constrains the habitability of planets around them. Application of the limit to planet-hosting stars with known EUV luminosities implies that many M-t...

  11. Desorption Dynamics, Internal Energies and Imaging of Organic Molecules from Surfaces with Laser Desorption and Vacuum Ultraviolet (VUV) Photoionization

    SciTech Connect (OSTI)

    Kostko, Oleg; Takahashi, Lynelle K.; Ahmed, Musahid

    2011-04-05T23:59:59.000Z

    There is enormous interest in visualizing the chemical composition of organic material that comprises our world. A convenient method to obtain molecular information with high spatial resolution is imaging mass spectrometry. However, the internal energy deposited within molecules upon transfer to the gas phase from a surface can lead to increased fragmentation and to complications in analysis of mass spectra. Here it is shown that in laser desorption with postionization by tunable vacuum ultraviolet (VUV) radiation, the internal energy gained during laser desorption leads to minimal fragmentation of DNA bases. The internal temperature of laser-desorbed triacontane molecules approaches 670 K, whereas the internal temperature of thymine is 800 K. A synchrotron-based VUV postionization technique for determining translational temperatures reveals that biomolecules have translational temperatures in the range of 216-346 K. The observed low translational temperatures, as well as their decrease with increased desorption laser power is explained by collisional cooling. An example of imaging mass spectrometry on an organic polymer, using laser desorption VUV postionization shows 5 mu m feature details while using a 30 mu m laser spot size and 7 ns duration. Applications of laser desorption postionization to the analysis of cellulose, lignin and humic acids are briefly discussed.

  12. Interactions between ultraviolet light and interleukin-1 on MSH binding in both mouse melanoma and human squamous carcinoma cells

    SciTech Connect (OSTI)

    Birchall, N.; Orlow, S.J.; Kupper, T.; Pawelek, J. (Univ. of Auckland, (New Zealand))

    1991-03-29T23:59:59.000Z

    Interactions between beta-melanotropin (MSH), interleukin 1-a (IL-1), and ultraviolet light (UV) were examined in Cloudman S91 mouse melanoma and RHEK human squamous carcinoma cell lines. The following points were established: (1) both cell lines produced IL-1 and their production was stimulated by exposure of the cells to UV; (2) both cell lines possessed high affinity binding sites for MSH, and their ability to bind MSH was modulated by IL-1; (3) IL-1 exhibited both stimulatory and inhibitory effects on MSH binding to Cloudman cells; and (4) the stimulatory effect of IL-1 on MSH binding to melanoma cells was reflected in enhanced cellular responsiveness to MSH regarding tyrosinase activity (E.C. 1.14.18.1) and melanin content. The findings raise the possibility that interactions between keratinocytes and melanocytes may be regulated by IL-1 and MSH, and suggest a possible mechanism for stimulation of cutaneous melanogenesis by solar radiation: enhancement of MSH receptor activity by induction of IL-1.

  13. HINODE/EXTREME-ULTRAVIOLET IMAGING SPECTROMETER OBSERVATIONS OF THE TEMPERATURE STRUCTURE OF THE QUIET CORONA

    SciTech Connect (OSTI)

    Brooks, David H.; Warren, Harry P. [Space Science Division, Code 7673, Naval Research Laboratory, Washington, DC 20375 (United States); Williams, David R. [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom); Watanabe, Tetsuya, E-mail: dhbrooks@ssd5.nrl.navy.mi [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2009-11-10T23:59:59.000Z

    We present a differential emission measure (DEM) analysis of the quiet solar corona on disk using data obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode. We show that the expected quiet-Sun DEM distribution can be recovered from judiciously selected lines, and that their average intensities can be reproduced to within 30%. We present a subset of these selected lines spanning the temperature range log T = 5.6-6.4 K that can be used to derive the DEM distribution reliably, including a subset of iron lines that can be used to derive the DEM distribution free of the possibility of uncertainties in the elemental abundances. The subset can be used without the need for extensive measurements, and the observed intensities can be reproduced to within the estimated uncertainty in the pre-launch calibration of EIS. Furthermore, using this subset, we also demonstrate that the quiet coronal DEM distribution can be recovered on size scales down to the spatial resolution of the instrument (1'' pixels). The subset will therefore be useful for studies of small-scale spatial inhomogeneities in the coronal temperature structure, for example, in addition to studies requiring multiple DEM derivations in space or time. We apply the subset to 45 quiet-Sun data sets taken in the period 2007 January to April, and show that although the absolute magnitude of the coronal DEM may scale with the amount of released energy, the shape of the distribution is very similar up to at least log T approx 6.2 K in all cases. This result is consistent with the view that the shape of the quiet-Sun DEM is mainly a function of the radiating and conducting properties of the plasma and is fairly insensitive to the location and rate of energy deposition. This universal DEM may be sensitive to other factors such as loop geometry, flows, and the heating mechanism, but if so they cannot vary significantly from quiet-Sun region to region.

  14. Development of extreme ultraviolet and soft x-ray multilayer optics for scientific studies with femtosecond/attosecond sources

    SciTech Connect (OSTI)

    Aquila, Andrew Lee

    2009-05-21T23:59:59.000Z

    The development of multilayer optics for extreme ultraviolet (EUV) radiation has led to advancements in many areas of science and technology, including materials studies, EUV lithography, water window microscopy, plasma imaging, and orbiting solar physics imaging. Recent developments in femtosecond and attosecond EUV pulse generation from sources such as high harmonic generation lasers, combined with the elemental and chemical specificity provided by EUV radiation, are opening new opportunities to study fundamental dynamic processes in materials. Critical to these efforts is the design and fabrication of multilayer optics to transport, focus, shape and image these ultra-fast pulses This thesis describes the design, fabrication, characterization, and application of multilayer optics for EUV femtosecond and attosecond scientific studies. Multilayer mirrors for bandwidth control, pulse shaping and compression, tri-material multilayers, and multilayers for polarization control are described. Characterization of multilayer optics, including measurement of material optical constants, reflectivity of multilayer mirrors, and metrology of reflected phases of the multilayer, which is critical to maintaining pulse size and shape, were performed. Two applications of these multilayer mirrors are detailed in the thesis. In the first application, broad bandwidth multilayers were used to characterize and measure sub-100 attosecond pulses from a high harmonic generation source and was performed in collaboration with the Max-Planck institute for Quantum Optics and Ludwig- Maximilians University in Garching, Germany, with Professors Krausz and Kleineberg. In the second application, multilayer mirrors with polarization control are useful to study femtosecond spin dynamics in an ongoing collaboration with the T-REX group of Professor Parmigiani at Elettra in Trieste, Italy. As new ultrafast x-ray sources become available, for example free electron lasers, the multilayer designs described in this thesis can be extended to higher photon energies, and such designs can be used with those sources to enable new scientific studies, such as molecular bonding, phonon, and spin dynamics.

  15. Extreme ultraviolet lithography: A few more pieces of the puzzle

    SciTech Connect (OSTI)

    Anderson, Christopher N.

    2009-05-20T23:59:59.000Z

    The work described in this dissertation has improved three essential components of extreme ultraviolet (EUV) lithography: exposure tools, photoresist, and metrology. Exposure tools. A field-averaging illumination stage is presented that enables nonuniform, high-coherence sources to be used in applications where highly uniform illumination is required. In an EUV implementation, it is shown that the illuminator achieves a 6.5% peak-to-valley intensity variation across the entire design field of view. In addition, a design for a stand-alone EUV printing tool capable of delivering 15 nm half-pitch sinusoidal fringes with available sources, gratings and nano-positioning stages is presented. It is shown that the proposed design delivers a near zero line-edge-rougness (LER) aerial image, something extremely attractive for the application of resist testing. Photoresist. Two new methods of quantifying the deprotection blur of EUV photoresists are described and experimentally demonstrated. The deprotection blur, LER, and sensitivity parameters of several EUV photoresists are quantified simultaneously as base weight percent, photoacid generator (PAG) weight percent, and post-exposure bake (PEB) temperature are varied. Two surprising results are found: (1) changing base weight percent does not significantly affect the deprotection blur of EUV photoresist, and (2) increasing PAG weight percent can simultaneously reduce LER and E-size in EUV photoresist. The latter result motivates the development of an EUV exposure statistics model that includes the effects of photon shot noise, the PAG spatial distribution, and the changing of the PAG distribution during the exposure. In addition, a shot noise + deprotection blur model is used to show that as deprotection blur becomes large relative to the size of the printed feature, LER reduction from improved counting statistics becomes dominated by an increase in LER due to reduced deprotection contrast. Metrology. Finally, this dissertation describes MOSAIC, a new wavefront metrology that enables complete wavefront recovery from print or aerial image based measurements. This new technique, based on measuring the local focal length of the optic at sampled positions in the pupil, recovers the curvature of the aberration and uses the curvature to recover the aberration itself. In a modeled EUV implementation, MOSAIC is shown to recover the SEMATECH Berkeley MET wavefront with a 4.2% RMS error: a 4% improvement over the reported errors of the original lateral shearing interferometry wavefront measurement.

  16. Laser triggered Z-pinch broadband extreme ultraviolet source for metrology

    SciTech Connect (OSTI)

    Tobin, I.; Lunney, J. G. [School of Physics, Trinity College Dublin, Dublin 2 (Ireland)] [School of Physics, Trinity College Dublin, Dublin 2 (Ireland); Juschkin, L. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland) [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Department of Physics, RWTH Aachen University, Steinbachstr. 15 D-52074 Aachen (Germany); Sidelnikov, Y. [ISAN Institute of Spectroscopy, Fizicheskaya Str. 5, Troitsk, Moscow Region 142190 (Russian Federation)] [ISAN Institute of Spectroscopy, Fizicheskaya Str. 5, Troitsk, Moscow Region 142190 (Russian Federation); O'Reilly, F.; Sokell, E. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)] [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Sheridan, P. [Newlambda Technologies, UCD Science Centre North, Belfield, Dublin 4 (Ireland)] [Newlambda Technologies, UCD Science Centre North, Belfield, Dublin 4 (Ireland)

    2013-05-20T23:59:59.000Z

    We compare the extreme ultraviolet emission characteristics of tin and galinstan (atomic %: Ga: 78.35, In: 14.93, Sn: 6.72) between 10 nm and 18 nm in a laser-triggered discharge between liquid metal-coated electrodes. Over this wavelength range, the energy conversion efficiency for galinstan is approximately half that of tin, but the spectrum is less strongly peaked in the 13-15 nm region. The extreme ultraviolet source dimensions were 110 {+-} 25 {mu}m diameter and 500 {+-} 125 {mu}m length. The flatter spectrum, and -19 Degree-Sign C melting point, makes this galinstan discharge a relatively simple high radiance extreme ultraviolet light source for metrology and scientific applications.

  17. Self-relevant disgust and self-harm urges in patients with borderline personality disorder and depression: a pilot study with a newly designed psychological challenge

    E-Print Network [OSTI]

    Abdul-Hamid, Sawsan; Denman, Chess; Dudas, Robert B.

    2014-06-23T23:59:59.000Z

    the task’s potential to be developed into an experimental model of self-harming for treatment trials. Methods: 17 BPD patients, 27 major depressive disorder (MDD) patients, and 25 healthy volunteers performed the SRT. Emotion labels were extracted from task... ] to establish the diagnoses required for inclusion and exclude volunteers who did not meet criteria. BPD patients were outpatients recruited via the Complex Cases Service (CCS), a specialized personality disorders unit, participants with unipolar depression...

  18. Plutonium radiation surrogate

    DOE Patents [OSTI]

    Frank, Michael I. (Dublin, CA)

    2010-02-02T23:59:59.000Z

    A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

  19. Nonadiabatic calculations of ultraviolet absorption cross section of sulfur monoxide: Isotopic effects on the photodissociation reaction

    SciTech Connect (OSTI)

    Danielache, Sebastian O.; Tomoya, Suzuki; Nanbu, Shinkoh [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Chiyoda Ku, Tokyo 102-8554 (Japan)] [Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Chiyoda Ku, Tokyo 102-8554 (Japan); Kondorsky, Alexey [P. N. Lebedev Physical Institute of Russian Academy of Science, Leninsky pr., 53, Moscow, 119991 (Russian Federation) [P. N. Lebedev Physical Institute of Russian Academy of Science, Leninsky pr., 53, Moscow, 119991 (Russian Federation); Moscow Institute of Physics and Technology (State University), Institutsky per., 9, Dolgoprudny Moscow region, 141700 (Russian Federation); Tokue, Ikuo [Department of Chemistry, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181 (Japan)] [Department of Chemistry, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181 (Japan)

    2014-01-28T23:59:59.000Z

    Ultraviolet absorption cross sections of the main and substituted sulfur monoxide (SO) isotopologues were calculated using R-Matrix expansion technique. Energies, transition dipole moments, and nonadiabatic coupling matrix elements were calculated at MRCI/AV6Z level. The calculated absorption cross section of {sup 32}S{sup 16}O was compared with experimental spectrum; the spectral feature and the absolute value of photoabsorption cross sections are in good agreement. Our calculation predicts a long lived photoexcited SO* species which causes large non-mass dependent isotopic effects depending on the excitation energy in the ultraviolet region.

  20. Radiation Protection Guidance Hospital Staff

    E-Print Network [OSTI]

    Kay, Mark A.

    Page 1 Radiation Protection Guidance For Hospital Staff Prepared for Stanford ..................................................................................................................... 17 The Basic Principles of Radiation Protection........................................................... 17 Protection against Radiation Exposure

  1. Dynamics and manipulation of the dominant 13.5 nm in-band extreme ultraviolet emitting region of laser-produced Sn plasmas

    E-Print Network [OSTI]

    Yuspeh, Samuel Edward

    2011-01-01T23:59:59.000Z

    manufacturing (HVM) of semiconductor microchips with nodes 32 nm and below is extreme ultraviolet (EUV) lithography using laser

  2. Maryland Radiation Act (Maryland)

    Broader source: Energy.gov [DOE]

    The policy of the state is to provide for the constructive use of radiation and control radiation emissions. This legislation authorizes the Department of the Environment to develop comprehensive...

  3. WI Radiation Protection

    Broader source: Energy.gov [DOE]

    This statute seeks to regulate radioactive materials, to encourage the constructive uses of radiation, and to prohibit and prevent exposure to radiation in amounts which are or may be detrimental...

  4. Operational Radiation Protection in High-Energy Physics Accelerators: Implementation of ALARA in Design and Operation of Accelerators

    SciTech Connect (OSTI)

    Fasso, A.; Rokni, S.; /SLAC

    2011-06-30T23:59:59.000Z

    It used to happen often, to us accelerator radiation protection staff, to be asked by a new radiation worker: ?How much dose am I still allowed?? And we smiled looking at the shocked reaction to our answer: ?You are not allowed any dose?. Nowadays, also thanks to improved training programs, this kind of question has become less frequent, but it is still not always easy to convince workers that staying below the exposure limits is not sufficient. After all, radiation is still the only harmful agent for which this is true: for all other risks in everyday life, from road speed limits to concentration of hazardous chemicals in air and water, compliance to regulations is ensured by keeping below a certain value. It appears that a tendency is starting to develop to extend the radiation approach to other pollutants (1), but it will take some time before the new attitude makes it way into national legislations.

  5. Radiation protection at CERN

    E-Print Network [OSTI]

    Forkel-Wirth, Doris; Silari, Marco; Streit-Bianchi, Marilena; Theis, Christian; Vincke, Heinz; Vincke, Helmut

    2013-01-01T23:59:59.000Z

    This paper gives a brief overview of the general principles of radiation protection legislation; explains radiological quantities and units, including some basic facts about radioactivity and the biological effects of radiation; and gives an overview of the classification of radiological areas at CERN, radiation fields at high-energy accelerators, and the radiation monitoring system used at CERN. A short section addresses the ALARA approach used at CERN.

  6. RADIONUCLIDE RADIATION PROTECTION

    E-Print Network [OSTI]

    Healy, Kevin Edward

    RADIONUCLIDE AND RADIATION PROTECTION DATA HANDBOOK 2002 D. Delacroix* J. P. Guerre** P. Leblanc'Energie Atomique, CEA/Saclay, France ISBN 1 870965 87 6 RADIATION PROTECTION DOSIMETRY Vol. 98 No 1, 2002 Published by Nuclear Technology Publishing #12;RADIONUCLIDE AND RADIATION PROTECTION DATA HANDBOOK 2nd Edition (2002

  7. Radiation Processing -an overview

    E-Print Network [OSTI]

    of radiation · Facilities ­ Gamma ­ electrons ­ X-ray ­ Safety · Sterilisation of medical devices · Food irradiation · Material modification #12;3 Content ­ Part 2 · Environmental applications · Other applications Radiation · Energy in the form of waves or moving subatomic particles Irradiation · Exposure to radiation

  8. What is Ozone? Ozone (O3) is a molecule made up of three atoms of oxygen (O), and is mostly found in the strato-

    E-Print Network [OSTI]

    What is Ozone? Ozone (O3) is a molecule made up of three atoms of oxygen (O), and is mostly found it represents only a tiny fraction of the atmosphere, ozone is crucial for life on Earth. Ozone--acts as a shield to protect Earth's surface from the sun's harmful ultraviolet radiation. With- out ozone, the Sun

  9. Use of diamond-turned mirrors for synchrotron radiation (SR)

    SciTech Connect (OSTI)

    Howells, M.R.; Takacs, P.Z.

    1981-01-01T23:59:59.000Z

    The diamond turning technique has great interest for users of synchrotron radiation because of its ability to produce surfaces of arbitrary shape. It also has the advantage of being well adapted to producing metal optics. These are of interest because they lend themselves to water cooling and hence represent one approach to the problem of high synchrotron radiation power loadings on optical surfaces. The optical figure produced by diamond turning is generally adequate for synchrotron radiation applications. The main difficulty centers around the question of smoothness. Diamond turned surfaces must receive a final polish after machining before they are sufficiently smooth for use with ultra-violet or x-ray radiation. The manufacturing stages can be carried out by various groups in the optics industry and the National Synchrotron Light Source has procured a considerable number of mirrors and is having them polished for use on the vuv storage ring. At the time of writing one mirror has been completed and evaluated and we give the results for this and discuss the indications for the future. The important measurement of the r.m.s. height of the surface roughness has given a value of 3 +- 0.9A using total integrated scatter of visible light at normal incidence.

  10. Infrared and ultraviolet problem for the Nelson model with variable coefficients

    E-Print Network [OSTI]

    Infrared and ultraviolet problem for the Nelson model with variable coefficients C. G´erard,1 , F of the Hamiltonian in the presence of the infrared problem, i.e. assuming that the boson mass tends to 0 at infinity state one usually speaks of the infrared problem or infrared divergence. The infrared problem arises

  11. Effect of carbon contamination on the printing performance of extreme ultraviolet masks

    E-Print Network [OSTI]

    Effect of carbon contamination on the printing performance of extreme ultraviolet masks Yu-Jen Fan November 2009; accepted 2 February 2010; published 22 March 2010 Carbon contamination is a significant on imaging performance. Current carbon contamination research is primarily focused on the lifetime

  12. Carbon Contamination of Extreme Ultraviolet (EUV) Masks and its Effect on Imaging

    E-Print Network [OSTI]

    Carbon Contamination of Extreme Ultraviolet (EUV) Masks and its Effect on Imaging Yu-Jen Fan1 3. CXRO, Lawrence Berkeley National Laboratory, Berkeley CA ABSTRACT Carbon contamination of extreme and potential effects on imaging performance. In this work, a series of carbon contamination experiments were

  13. Design and Evaluation of a Low-Cost Point-of-Use Ultraviolet Water Disinfection Device

    E-Print Network [OSTI]

    Kammen, Daniel M.

    receive chlorinated water while another receives contaminated water with no residual level of chlorineDesign and Evaluation of a Low-Cost Point-of-Use Ultraviolet Water Disinfection Device Alicia Cohn around the world to supply safe drinking water. We have developed a device for disinfecting drinking

  14. Flexible CO2 laser system for fundamental research related to an extreme ultraviolet lithography source

    E-Print Network [OSTI]

    Najmabadi, Farrokh

    Flexible CO2 laser system for fundamental research related to an extreme ultraviolet lithography 2009; published online 10 December 2009 A CO2 laser system with flexible parameters was developed 1010 W/cm2 . Utilizing this CO2 MOPA laser system, high conversion efficiency from laser to in-band 2

  15. THE PREFLIGHT PHOTOMETRIC CALIBRATION OF THE EXTREME-ULTRAVIOLET IMAGING TELESCOPE EIT

    E-Print Network [OSTI]

    K. P. Dere; J. D. Moses; J. -p. Delaboudinière; J. Brunaud; C. Carabetian; J. -f. Hochedez; X. Y. Song; R. C. Catura; F. Clette

    1999-01-01T23:59:59.000Z

    Abstract. This paper presents the preflight photometric calibration of the Extreme-ultraviolet Imaging Telescope (EIT) aboard the Solar and Heliospheric Observatory (SOHO). The EIT consists of a Ritchey–Chrétien telescope with multilayer coatings applied to four quadrants of the primary and secondary mirrors, several filters and a backside-thinned CCD detector. The quadrants of the EIT

  16. Assessment of a low-cost, point-of-use, ultraviolet water disinfection technology

    E-Print Network [OSTI]

    Kammen, Daniel M.

    lack access to safe drinking water and an accelerated effort is required if the MDG is to be met (WHOAssessment of a low-cost, point-of-use, ultraviolet water disinfection technology Sarah A. Brownell, Portland, OR, USA Rachel L. Peletz Centre for Affordable Water and Sanitation Technology, Calgary, Canada

  17. Non-thermal calcination by ultraviolet irradiation in the synthesis of microporous materials

    E-Print Network [OSTI]

    Parikh, Atul N.

    Non-thermal calcination by ultraviolet irradiation in the synthesis of microporous materials Atul N-directing agents in the synthesis of microporous materials. The method relies on the exposure of the sample. This method is applicable in making new materials from organic­inorganic pre- cursors and holds promise

  18. Nanowire Ultraviolet Photodetectors and Optical By Hannes Kind, Haoquan Yan, Benjamin Messer,

    E-Print Network [OSTI]

    Yang, Peidong

    of a Nd:YAG laser was used as the UV light source. Neutral density filters were used to change the incident UV light power. It was found that the photoresponse (Ipc) can be expressed by a simple power law is extremely sensitive to ultraviolet light exposure. The light-induced conductivity increase allows us

  19. Recent Experimental and Theoretical Advances in Microdrilling of Polymers with Ultraviolet Laser Beams

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Libération, F-33405 Talence, FRANCE E-mail: s.lazare@lpcm.u-bordeaux1.fr ABSTRACT Laser drilling becomes is now in progress. Keywords: Materials, laser, processing, drilling, model, profile, mechanisms, polymer1 Recent Experimental and Theoretical Advances in Microdrilling of Polymers with Ultraviolet Laser

  20. Simulation of Two-Dimensional Ultraviolet Spectroscopy of Amyloid Fibrils Darius Abramavicius,

    E-Print Network [OSTI]

    Mukamel, Shaul

    diseases. Amyloid fibrils are formed by a wide variety of peptides and proteins and can be distinguishedSimulation of Two-Dimensional Ultraviolet Spectroscopy of Amyloid Fibrils Jun Jiang, Darius, 2010 Revealing the structure and aggregation mechanism of amyloid fibrils is essential

  1. Liquid-tin-jet laser-plasma extreme ultraviolet generation P. A. C. Jansson,a)

    E-Print Network [OSTI]

    Liquid-tin-jet laser-plasma extreme ultraviolet generation P. A. C. Jansson,a) B. A. M. Hansson, O spectral signatures. The system is demonstrated using tin Sn as the target due to its strong emission materials with new spectral signatures. As an example we use tin, motivated by its current interest for EUV

  2. Signatures of the Protein Folding Pathway in Two-Dimensional Ultraviolet Spectroscopy

    E-Print Network [OSTI]

    Mukamel, Shaul

    Signatures of the Protein Folding Pathway in Two-Dimensional Ultraviolet Spectroscopy Jun Jiang of the signals provides a quantitative marker of protein folding status, accessible by both theoretical calculations and experiments. SECTION: Biophysical Chemistry and Biomolecules Protein folding is an important

  3. Synchrotron Radiation in Polymer Science

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Synchrotron Radiation in Polymer Science Synchrotron Radiation in Polymer Science March 30-April 2, 2012; San Francisco...

  4. TERSat: Trapped Energetic Radiation Satellite

    E-Print Network [OSTI]

    Clements, Emily B.

    2012-01-01T23:59:59.000Z

    Radiation damage caused by interactions with high-energy particles in the Van Allen Radiation Belts is a leading

  5. 1214 OPTICS LETTERS / Vol. 22, No. 16 / August 15, 1997 Tunable ultraviolet radiation by second-harmonic generation

    E-Print Network [OSTI]

    Fejer, Martin M.

    - optical interactions in the mid UV than lithium niobate (LiNbO3), which is transparent to 330 nm. Second-harmonic generation in periodically poled lithium tantalate J.-P. Meyn* and M. M. Fejer E. L. Ginzton Laboratory of fine-pitch ferroelectric domain gratings in lithium tantalate and character- ization of nonlinear

  6. Simultaneous measurement of nitrogen and hydrogen dissociation from vacuum ultraviolet self-absorption spectroscopy in a developing low temperature plasma at atmospheric pressure

    SciTech Connect (OSTI)

    Laity, George; Fierro, Andrew; Dickens, James; Neuber, Andreas [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States)] [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Frank, Klaus [Erlangen Centre for Astroparticle Physics, Department of Physics, Friedrich-Alexander University at Erlangen - Nuernberg, 91058 Erlangen (Germany)] [Erlangen Centre for Astroparticle Physics, Department of Physics, Friedrich-Alexander University at Erlangen - Nuernberg, 91058 Erlangen (Germany)

    2013-05-06T23:59:59.000Z

    We demonstrate a method for determining the dissociation density of N and H atoms present in a developing low temperature plasma, based on the emission and self-absorption of vacuum ultraviolet radiation produced from the plasma. Spark plasmas are produced via pulsed discharge in N{sub 2}/H{sub 2} mixtures at atmospheric pressure, where information on the dissociated densities of the constituent gas molecules is desired without employing invasive diagnostic techniques. By analyzing the self-absorption line profile of 121.5 nm Lyman-{alpha} H radiation emitted within the first {approx}1.0 mm of plasma near the anode tip, a peak dissociated H atom concentration of 5.6 Multiplication-Sign 10{sup 17} cm{sup -3} was observed {approx}100 ns into spark formation, with an estimated electron density of 2.65 Multiplication-Sign 10{sup 18} cm{sup -3} determined from Stark broadening. Similarly, simultaneous line fitting of the N 120.0/124.3 nm emission profiles revealed a peak dissociated N atom concentration of 3.8 Multiplication-Sign 10{sup 17} cm{sup -3} during the same discharge period.

  7. Could the Earth's surface Ultraviolet irradiance be blamed for the global warming? (II) ----Ozone layer depth reconstruction via HEWV effect

    E-Print Network [OSTI]

    Chen, Jilong; Zheng, Yujun

    2014-01-01T23:59:59.000Z

    It is suggested by Chen {\\it et al.} that the Earth's surface Ultraviolet irradiance ($280-400$ nm) could influence the Earth's surface temperature variation by "Highly Excited Water Vapor" (HEWV) effect. In this manuscript, we reconstruct the developing history of the ozone layer depth variation from 1860 to 2011 based on the HEWV effect. It is shown that the reconstructed ozone layer depth variation correlates with the observational variation from 1958 to 2005 very well ($R=0.8422$, $P>99.9\\%$). From this reconstruction, we may limit the spectra band of the surface Ultraviolet irradiance referred in HEWV effect to Ultraviolet B ($280-320$ nm).

  8. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.; Zaider, M.

    1993-05-01T23:59:59.000Z

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  9. The ultraviolet-bright, slowly declining transient PS1-11af as a partial tidal disruption event

    SciTech Connect (OSTI)

    Chornock, R.; Berger, E.; Zauderer, B. A.; Kamble, A.; Soderberg, A. M.; Czekala, I.; Dittmann, J.; Drout, M.; Foley, R. J.; Fong, W.; Kirshner, R. P.; Lunnan, R.; Marion, G. H.; Narayan, G. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Gezari, S. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Rest, A.; Riess, A. G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Chomiuk, L. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Huber, M. E. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Lawrence, A., E-mail: rchornock@cfa.harvard.edu [Institute for Astronomy, University of Edinburgh Scottish Universities Physics Alliance, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); and others

    2014-01-01T23:59:59.000Z

    We present the Pan-STARRS1 discovery of the long-lived and blue transient PS1-11af, which was also detected by Galaxy Evolution Explorer with coordinated observations in the near-ultraviolet (NUV) band. PS1-11af is associated with the nucleus of an early type galaxy at redshift z = 0.4046 that exhibits no evidence for star formation or active galactic nucleus activity. Four epochs of spectroscopy reveal a pair of transient broad absorption features in the UV on otherwise featureless spectra. Despite the superficial similarity of these features to P-Cygni absorptions of supernovae (SNe), we conclude that PS1-11af is not consistent with the properties of known types of SNe. Blackbody fits to the spectral energy distribution are inconsistent with the cooling, expanding ejecta of a SN, and the velocities of the absorption features are too high to represent material in homologous expansion near a SN photosphere. However, the constant blue colors and slow evolution of the luminosity are similar to previous optically selected tidal disruption events (TDEs). The shape of the optical light curve is consistent with models for TDEs, but the minimum accreted mass necessary to power the observed luminosity is only ?0.002 M {sub ?}, which points to a partial disruption model. A full disruption model predicts higher bolometric luminosities, which would require most of the radiation to be emitted in a separate component at high energies where we lack observations. In addition, the observed temperature is lower than that predicted by pure accretion disk models for TDEs and requires reprocessing to a constant, lower temperature. Three deep non-detections in the radio with the Very Large Array over the first two years after the event set strict limits on the production of any relativistic outflow comparable to Swift J1644+57, even if off-axis.

  10. Dynamics of Line-Driven Disk Winds in Active Galactic Nuclei II: Effects of Disk Radiation

    E-Print Network [OSTI]

    D. Proga; T. R. Kallman

    2004-08-16T23:59:59.000Z

    We explore consequences of a radiation driven disk wind model for mass outflows from active galactic nuclei (AGN). We performed axisymmetric time-dependent hydrodynamic calculations using the same computational technique as Proga, Stone and Kallman (2000). We test the robustness of radiation launching and acceleration of the wind for relatively unfavorable conditions. In particular, we take into account the central engine radiation as a source of ionizing photons but neglect its contribution to the radiation force. Additionally, we account for the attenuation of the X-ray radiation by computing the X-ray optical depth in the radial direction assuming that only electron scattering contributes to the opacity. Our new simulations confirm the main result from our previous work: the disk atmosphere can 'shield' itself from external X-rays so that the local disk radiation can launch gas off the disk photosphere. We also find that the local disk force suffices to accelerate the disk wind to high velocities in the radial direction. This is true provided the wind does not change significantly the geometry of the disk radiation by continuum scattering and absorption processes; we discuss plausibility of this requirement. Synthetic profiles of a typical resonance ultraviolet line predicted by our models are consistent with observations of broad absorption line (BAL) QSOs.

  11. Solar radiation intensity calculations

    E-Print Network [OSTI]

    Levine, Randolph Steven

    1978-01-01T23:59:59.000Z

    SOLAR RADIATION INTENSITY CALCULATIONS A Thesis by RANDOLPH STEVEN LEVINE Submitted to the Graduate College of Texas A&M University in partia'l fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1978 Major Subject...: Physics SOLAR RADIATION INTENSITY CALCULATIONS A Thesis by RANDOLPH STEVEN LEVINE Approved as to style and content by: (Chairman of Committee) (Member) (Member) ( member) (Head of Department) December 1978 f219 037 ABSTRACT Solar Radiation...

  12. Coherent Synchrotron Radiation Analysis

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Upton, NY 11973, USA Abstract Coherent Synchrotron Radiation (CSR) effects in bunch compressors are analyzed. Schemes for reducing the CSR effects are presented. 1 INTRODUCTION...

  13. Atomic Radiation (Illinois)

    Broader source: Energy.gov [DOE]

    This article states permissible levels of radiation in unrestricted areas, environmental standards for uranium fuel cycle and information about notification of incidents.

  14. Radiation Hazards Program (Minnesota)

    Broader source: Energy.gov [DOE]

    These regulations, promulgated by the Department of Health, set allowable radiation standards and mitigation practices, as well as procedures for the transportation of hazardous material.

  15. Rotating bubble membrane radiator

    DOE Patents [OSTI]

    Webb, Brent J. (West Richland, WA); Coomes, Edmund P. (West Richland, WA)

    1988-12-06T23:59:59.000Z

    A heat radiator useful for expelling waste heat from a power generating system aboard a space vehicle is disclosed. Liquid to be cooled is passed to the interior of a rotating bubble membrane radiator, where it is sprayed into the interior of the bubble. Liquid impacting upon the interior surface of the bubble is cooled and the heat radiated from the outer surface of the membrane. Cooled liquid is collected by the action of centrifical force about the equator of the rotating membrane and returned to the power system. Details regarding a complete space power system employing the radiator are given.

  16. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.

    1992-05-01T23:59:59.000Z

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

  17. Update on the SEMATECH 0.5 NA Extreme-Ultraviolet Lithography (EUVL) Microfield Exposure Tool (MET)

    E-Print Network [OSTI]

    Cummings, Kevin

    2014-01-01T23:59:59.000Z

    eld Exposure Tools with 0.5 NA,” Proc. SPIE TBP (2014) [6]microexposure tool at 0.5 NA for sub-16 nm lithography,&Update on the SEMATECH 0.5 NA Extreme Ultraviolet

  18. Synchrotron Vacuum-Ultraviolet Postionization Mass Spectrometry with Laser and Ion Probes for Intact Molecular Spatial Mapping of Lignin

    E-Print Network [OSTI]

    Takahashi, Lynelle Kazue

    2011-01-01T23:59:59.000Z

    27, 289. Thompson, M. W. Vacuum 2002, 66, 99. McPhail, D. J.Gibson, J. K. Journal of Vacuum Science and Technology 1995,Chemical Society. Vacuum ultraviolet photoionization coupled

  19. An Efficient Monte Carlo Algorithm for a Restricted Class of Scattering Problems in Radiation Transfer

    E-Print Network [OSTI]

    Alan M. Watson; William J. Henney

    2001-08-30T23:59:59.000Z

    We describe an efficient Monte Carlo algorithm for a restricted class of scattering problems in radiation transfer. This class includes many astrophysically interesting problems, including the scattering of ultraviolet and visible light by grains. The algorithm correctly accounts for multiply-scattered light. We describe the algorithm, present a number of important optimizations, and explicity show how the algorithm can be used to estimate quantities such as the emergent and mean intensity. We present two test cases, examine the importance of the optimizations, and show that this algorithm can be usefully applied to optically-thin problems, a regime sometimes considered limited to explicit single-scattering plus attenuation approximations.

  20. Final LDRD report :ultraviolet water purification systems for rural environments and mobile applications.

    SciTech Connect (OSTI)

    Banas, Michael Anthony; Crawford, Mary Hagerott; Ruby, Douglas Scott; Ross, Michael P.; Nelson, Jeffrey Scott; Allerman, Andrew Alan; Boucher, Ray

    2005-11-01T23:59:59.000Z

    We present the results of a one year LDRD program that has focused on evaluating the use of newly developed deep ultraviolet LEDs in water purification. We describe our development efforts that have produced an LED-based water exposure set-up and enumerate the advances that have been made in deep UV LED performance throughout the project. The results of E. coli inactivation with 270-295 nm LEDs are presented along with an assessment of the potential for applying deep ultraviolet LED-based water purification to mobile point-of-use applications as well as to rural and international environments where the benefits of photovoltaic-powered systems can be realized.

  1. DNA synthesis in pigmented and non-pigmented mutants of Serratia marcescens after ultra-violet irradiation

    E-Print Network [OSTI]

    Russo, Salvadore William

    1973-01-01T23:59:59.000Z

    DNA SYNTHESIS IN PIGNENTED AND NON-PIGKENTED MUTANTS OF SERRATIA MARCESCENS AFTER ULTRAVIOLET IRRADIATION A Thesis by SALVADORE NILLIAM RUSSO, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE August 1973 Major Subject: Biochemistry DNA SYNTHESIS IN PIGMENTED AND NON-PIGMENTED MUTANTS OF SERRATIA MARCESCENS AFTER ULTRAVIOLET IRRADIATION A' Thesis by SALVADORE WILLIAM RUSSO, JR. Approved...

  2. Efficient 13.5 nm extreme ultraviolet emission from Sn plasma irradiated by a long CO2 laser pulse

    E-Print Network [OSTI]

    Najmabadi, Farrokh

    Efficient 13.5 nm extreme ultraviolet emission from Sn plasma irradiated by a long CO2 laser pulse-band 2% bandwidth conversion efficiency CE from a CO2 laser to 13.5 nm extreme ultraviolet EUV light was investigated for Sn plasma. It was found that high in-band CE, 2.6%, is consistently obtained using a CO2 laser

  3. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    for increased protection from ionizing radiation for declared pregnant radiation workers. The radiation doseCOLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212 regulations of the Rules of the City of New York, Article 175, Radiation Control, there is a requirement

  4. Ultraviolet spectrophotometry of close binary systems: CV Velorum, RS Vulpeculae and DH Cephei

    SciTech Connect (OSTI)

    Wu, C.C.; Eaton, J.A.

    1981-01-01T23:59:59.000Z

    The ultraviolet magnitudes of CV Velorum, RS Vulpeculae and DH Cephei are reported. Aside from twenty observations of CV Velorum which fell inside the primary eclipse, all data were obtained for phases outside eclipse. Observations were made with the University of Greningen experiment on board the Astronomical Netherlands Satellite. The instrument consists of a 22 cm aperture Cassegrain telescope followed by a five channel grating spectrophotometer. Instrument operation modes and data correction procedures are briefly described.

  5. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2010-06-15T23:59:59.000Z

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  6. Nonclassicality of Thermal Radiation

    E-Print Network [OSTI]

    Lars M. Johansen

    2004-02-16T23:59:59.000Z

    It is demonstrated that thermal radiation of small occupation number is strongly nonclassical. This includes most forms of naturally occurring radiation. Nonclassicality can be observed as a negative weak value of a positive observable. It is related to negative values of the Margenau-Hill quasi-probability distribution.

  7. Radiative Flux Analysis

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Long, Chuck [NOAA

    The Radiative Flux Analysis is a technique for using surface broadband radiation measurements for detecting periods of clear (i.e. cloudless) skies, and using the detected clear-sky data to fit functions which are then used to produce continuous clear-sky estimates. The clear-sky estimates and measurements are then used in various ways to infer cloud macrophysical properties.

  8. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2007-01-09T23:59:59.000Z

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  9. Radiation detection system

    DOE Patents [OSTI]

    Franks, Larry A. (Santa Barbara, CA); Lutz, Stephen S. (Santa Barbara, CA); Lyons, Peter B. (Los Alamos, NM)

    1981-01-01T23:59:59.000Z

    A radiation detection system including a radiation-to-light converter and fiber optic wave guides to transmit the light to a remote location for processing. The system utilizes fluors particularly developed for use with optical fibers emitting at wavelengths greater than about 500 nm and having decay times less than about 10 ns.

  10. Heats of vaporization of room temperature ionic liquids by tunable vacuum ultraviolet photoionization

    SciTech Connect (OSTI)

    Chambreau, Steven D.; Vaghjiani, Ghanshyam L.; To, Albert; Koh, Christine; Strasser, Daniel; Kostko, Oleg; Leone, Stephen R.

    2009-11-25T23:59:59.000Z

    The heats of vaporization of the room temperature ionic liquids (RTILs) N-butyl-N-methylpyrrolidinium bistrifluorosulfonylimide, N-butyl-N-methylpyrrolidinium dicyanamide, and 1-butyl-3-methylimidazolium dicyanamide are determined using a heated effusive vapor source in conjunction with single photon ionization by a tunable vacuum ultraviolet synchrotron source. The relative gas phase ionic liquid vapor densities in the effusive beam are monitored by clearly distinguished dissociative photoionization processes via a time-of-flight mass spectrometer at a tunable vacuum ultraviolet beamline 9.0.2.3 (Chemical Dynamics Beamline) at the Advanced Light Source synchrotron facility. Resulting in relatively few assumptions, through the analysis of both parent cations and fragment cations, the heat of vaporization of N-butyl-N-methylpyrrolidinium bistrifluorosulfonylimide is determined to be Delta Hvap(298.15 K) = 195+-19 kJ mol-1. The observed heats of vaporization of 1-butyl-3-methylimidazolium dicyanamide (Delta Hvap(298.15 K) = 174+-12 kJ mol-1) and N-butyl-N-methylpyrrolidinium dicyanamide (Delta Hvap(298.15 K) = 171+-12 kJ mol-1) are consistent with reported experimental values using electron impact ionization. The tunable vacuum ultraviolet source has enabled accurate measurement of photoion appearance energies. These appearance energies are in good agreement with MP2 calculations for dissociative photoionization of the ion pair. These experimental heats of vaporization, photoion appearance energies, and ab initio calculations corroborate vaporization of these RTILs as intact cation-anion ion pairs.

  11. Proliferative and toxic effects of ultraviolet light and inflammation on epidermal pigment cells

    SciTech Connect (OSTI)

    Nordlund, J.J.; Ackles, A.E.; Traynor, F.F.

    1981-10-01T23:59:59.000Z

    The ear of the mouse is useful for studying the effects of ultraviolet light on epidermal pigment cells. The quantity of light penetrating into the skin causing an inflammatory response can be assessed easily by measuring with an engineering calipers the swelling of the ear. The inflammatory response of the ear exhibits a linear relationship to the dose of light delivered. We observed that doses of shortwave ultraviolet light which are noninflammatory when repeated at daily intervals induce moderate to severe inflammation. Small doses of psoralen and prolonged exposure to UVA (PUVA) were more inflammatory than larger amounts of psoralen and short exposure to light. Doses of shortwave ultraviolet light and PUVA which produce only a minimal inflammation of the skin stimulate the proliferation of epidermal melanocytes. In contrast, PUVA in doses sufficiently large to cause a marked inflammatory reaction in the skin seems injurious to pigment cells and kills them or causes only a minimal proliferative response. The inflammatory reaction itself does not seem to stimulate or inhibit the proliferation of melanocytes. Prostaglandins A, E, and F2 alpha have no effect on the proliferation of epidermal pigment cells. In contrast, dimethyl sulfoxide (DMSO) and allergic contact dermatitis increase the numerical density of pigment cells. Steroids may block the function of the enzyme tyrosinase. Our experiments indicate that pigment cells, like many other varieties of cells, are susceptible to injury and can be killed at least by large doses of PUVA.

  12. Nuclear radiation actuated valve

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA); Schively, Dixon P. (Richland, WA)

    1985-01-01T23:59:59.000Z

    A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  13. RADIATION SAFETY MANUAL POLICIES AND PROCEDURES

    E-Print Network [OSTI]

    Zhang, Yuanlin

    RADIATION SAFETY MANUAL POLICIES AND PROCEDURES FOR RADIATION PROTECTION AT TEXAS TECH UNIVERSITY................................................................................................................I-1 B. Radiation Protection Program...............................................................................I-3 D. Radiation Safety Management

  14. Radiative and climate impacts of absorbing aerosols

    E-Print Network [OSTI]

    Zhu, Aihua

    2010-01-01T23:59:59.000Z

    V. Ramanathan (2008), Solar radiation budget and radiativeV. Ramanathan (2008), Solar radiation budget and radiativeapproximation for solar radiation in the NCAR Community

  15. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212 Psychiatric Institute Radiation Safety Office (Please complete this form within 24 hours and send a copy to your supervisor and The Radiation Safety Office) Your Name

  16. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212: _______________ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Radiation Safety Office Approval: ______________________ Date: ________________________ Waste containers in place: Yes ___ No ___ Radiation signage on door: Yes ___ No ___ Room monitoring: Dates

  17. Radiation Safety (Revised March 2010)

    E-Print Network [OSTI]

    Kay, Mark A.

    to Workers; Inspections 27 10 CFR Part 20Standards for Protection Against Radiation 28 10 CFR Part 35Radiation Safety Manual (Revised March 2010) Updated December 2012 Stanford University, Stanford California #12; #12; Radiation Safety Manual (Revised March 2010) Updated

  18. Florida Radiation Protection Act (Florida)

    Broader source: Energy.gov [DOE]

    The Department of Public Health is responsible for administering a statewide radiation protection program. The program is designed to permit development and utilization of sources of radiation for...

  19. The Intense Radiation Gas

    E-Print Network [OSTI]

    M. Marklund; P. K. Shukla; B. Eliasson

    2005-03-08T23:59:59.000Z

    We present a new dispersion relation for photons that are nonlinearly interacting with a radiation gas of arbitrary intensity due to photon-photon scattering. It is found that the photon phase velocity decreases with increasing radiation intensity, it and attains a minimum value in the limit of super-intense fields. By using Hamilton's ray equations, a self-consistent kinetic theory for interacting photons is formulated. The interaction between an electromagnetic pulse and the radiation gas is shown to produce pulse self-compression and nonlinear saturation. Implications of our new results are discussed.

  20. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC)

    1994-01-01T23:59:59.000Z

    A composition for use as a radiation shield. The shield has a depleted urum core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container.

  1. Miniaturized radiation chirper

    DOE Patents [OSTI]

    Umbarger, C. John (Los Alamos, NM); Wolf, Michael A. (Los Alamos, NM)

    1980-01-01T23:59:59.000Z

    The disclosure relates to a miniaturized radiation chirper for use with a small battery supplying on the order of 5 volts. A poor quality CdTe crystal which is not necessarily suitable for high resolution gamma ray spectroscopy is incorporated with appropriate electronics so that the chirper emits an audible noise at a rate that is proportional to radiation exposure level. The chirper is intended to serve as a personnel radiation warning device that utilizes new and novel electronics with a novel detector, a CdTe crystal. The resultant device is much smaller and has much longer battery life than existing chirpers.

  2. The chemical transport model Oslo CTM3

    E-Print Network [OSTI]

    2012-01-01T23:59:59.000Z

    Ozone and Ultraviolet Radiation Data Centre (WOUDC), andOzone and Ultraviolet Radiation Data Centre (WOUDC). Also

  3. Portal radiation monitor

    DOE Patents [OSTI]

    Kruse, Lyle W. (Albuquerque, NM)

    1985-01-01T23:59:59.000Z

    A portal radiation monitor combines 0.1% FAR with high sensitivity to special nuclear material. The monitor utilizes pulse shape discrimination, dynamic compression of the photomultiplier output and scintillators sized to maintain efficiency over the entire portal area.

  4. The Gravitational Cherenkov Radiation

    E-Print Network [OSTI]

    A. M. Ignatov

    2001-10-26T23:59:59.000Z

    An example of discontinuity of the energy-momentum tensor moving at superluminal velocity is discussed. It is shown that the gravitational Mach cone is formed. The power spectrum of the corresponding Cherenkov radiation is evaluated.

  5. Radiation from Accelerated Branes

    E-Print Network [OSTI]

    Mohab Abou-Zeid; Miguel S. Costa

    2000-01-29T23:59:59.000Z

    The radiation emitted by accelerated fundamental strings and D-branes is studied within the linear approximation to the supergravity limit of string theory. We show that scalar, gauge field and gravitational radiation is generically emitted by such branes. In the case where an external scalar field accelerates the branes, we derive a Larmor-type formula for the emitted scalar radiation and study the angular distribution of the outgoing energy flux. The classical radii of the branes are calculated by means of the corresponding Thompson scattering cross sections. Within the linear approximation, the interaction of the external scalar field with the velocity fields of the branes gives a contribution to the observed gauge field and gravitational radiation.

  6. Adaptive multigroup radiation diffusion

    E-Print Network [OSTI]

    Williams, Richard B., Sc. D. Massachusetts Institute of Technology

    2005-01-01T23:59:59.000Z

    This thesis describes the development and implementation of an algorithm for dramatically increasing the accuracy and reliability of multigroup radiation diffusion simulations at low group counts. This is achieved by ...

  7. Ionizing radiation detector

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1990-01-01T23:59:59.000Z

    An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

  8. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, Robert A. (Palo Alto, CA); Perez-Mendez, Victor (Berkeley, CA); Kaplan, Selig N. (El Cerrito, CA)

    1992-01-01T23:59:59.000Z

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  9. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17T23:59:59.000Z

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  10. Radiation Safety Training Basic Radiation Safety Training for

    E-Print Network [OSTI]

    Dai, Pengcheng

    Radiation Safety Training Basic Radiation Safety Training for X-ray Users for Physics 461 & 462 Protocol Title: Basic Radiation Safety Training for X-ray Users Drafted By: Chris Millsaps, RSS Reviewers: ZB, TU, GS Purpose: To provide basic radiation safety training to the users of x-ray producing

  11. Radiation Safety Manual Dec 2012 Page 1 RADIATION SAFETY

    E-Print Network [OSTI]

    Grishok, Alla

    of External and Internal Doses E. Reports and Notices to Workers Chapter VII: Radiation ProtectionRadiation Safety Manual ­ Dec 2012 Page 1 RADIATION SAFETY MANUAL For Columbia University NewYork-Presbyterian Hospital New York State Psychiatric Institute Barnard College December 2012 #12;Radiation Safety Manual

  12. Method of enhancing radiation response of radiation detection materials

    DOE Patents [OSTI]

    Miller, Steven D. (Richland, WA)

    1997-01-01T23:59:59.000Z

    The present invention is a method of increasing radiation response of a radiation detection material for a given radiation signal by first pressurizing the radiation detection material. Pressurization may be accomplished by any means including mechanical and/or hydraulic. In this application, the term "pressure" includes fluid pressure and/or mechanical stress.

  13. Radiative Transitions in Charmonium

    SciTech Connect (OSTI)

    Jozef Dudek; Robert Edwards; David Richards

    2005-10-01T23:59:59.000Z

    The form factors for the radiative transitions between charmonium mesons are investigated. We employ an anisotropic lattice using a Wilson gauge action, and domain-wall fermion action. We extrapolate the form factors to Q{sup 2} = 0, corresponding to a real photon, using quark-model-inspired functions. Finally, comparison is made with photocouplings extracted from the measured radiative widths, where known. Our preliminary results find photocouplings commensurate with these experimentally extracted values.

  14. Radiative Processes Working Group

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection Radiation Protection Regulations: The

  15. Radiation analysis devices, radiation analysis methods, and articles of manufacture

    DOE Patents [OSTI]

    Roybal, Lyle Gene

    2010-06-08T23:59:59.000Z

    Radiation analysis devices include circuitry configured to determine respective radiation count data for a plurality of sections of an area of interest and combine the radiation count data of individual of sections to determine whether a selected radioactive material is present in the area of interest. An amount of the radiation count data for an individual section is insufficient to determine whether the selected radioactive material is present in the individual section. An article of manufacture includes media comprising programming configured to cause processing circuitry to perform processing comprising determining one or more correction factors based on a calibration of a radiation analysis device, measuring radiation received by the radiation analysis device using the one or more correction factors, and presenting information relating to an amount of radiation measured by the radiation analysis device having one of a plurality of specified radiation energy levels of a range of interest.

  16. Gravitational Tunneling Radiation

    E-Print Network [OSTI]

    Mario Rabinowitz

    2002-12-11T23:59:59.000Z

    The isolated black hole radiation of both Hawking and Zel'dovich are idealized abstractions as there is always another body to distort the potential. This is considered with respect to both gravitational tunneling, and black hole "no-hair" theorems. The effects of a second body are to lower the gravitational barrier of a black hole and to give the barrier a finite rather than infinite width so tha a particle can escape by tunneling (as in field emission) or over the top of the lowered barrier (as in Schottky emission). Thus radiation may be emitted from black holes in a process differing from that of Hawking radiation, P SH, which has been undetected for over 24 years. The radiated power from a black hole derived here is PR e ^2__ PSH, where e ^2__ is he ransmission probability for radiation through the barrier. This is similar to electric field emission of electrons from a metal in that the emission can in principle be modulated and beamed. The temperature and entropy of black holes are reexamined. Miniscule black holes herein may help explain the missing mass of the universe, accelerated expansion of the universe, and anomalous rotation of spiral galaxies. A gravitational interference effect for black hole radiation similar to the Aharonov-Bohm effect is also examined.

  17. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, James E. (Knoxville, TN)

    1989-01-01T23:59:59.000Z

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiation events, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible "chirp". The rate of the "chirps" is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field.

  18. Working With Radiation For Research

    E-Print Network [OSTI]

    Jia, Songtao

    working with radiation The radiation badge is not a protective device It cannot shield you from ­ Negative Exponential Protection From Radiation #12;18 Time Distance Shielding Basic Principles #121 Working With Radiation For Research Thomas Cummings Junior Physicist Environmental Health

  19. Radiation Safety Annual Refresher Training

    E-Print Network [OSTI]

    Thomas, David D.

    Radiation Safety Annual Refresher Training Radiation Protection Division Department of Environmental Health & Safety #12;Topics in Radiation Safety (applicable RPD Manual sections indicated) User;Topics in Radiation Safety (applicable RPD Manual sections indicated) User and Non-user topics Types

  20. Infrared and Ultraviolet QCD dynamics with quark mass for J=0,1 mesons

    E-Print Network [OSTI]

    Nicholas Souchlas

    2010-06-04T23:59:59.000Z

    By using a previously developed phenomenological kernel for the study of the light quark QCD sector and dynamical chiral symmetry breaking effects we will examine the relative infrared and ultraviolet QCD dynamics for J=0,1 meson properties. For the same reasons we extend and explore a quark mass depended generalization of the kernel in the heavy quark region and we also compare with the original model. The relation between the dynamics of the quark propagator and the effective kernel with the J=0,1 QQ and qQ mesons and quarks Compton size is also discussed.

  1. Evolution of laser-produced Sn extreme ultraviolet source diameter for high-brightness source

    SciTech Connect (OSTI)

    Roy, Amitava, E-mail: roy@fzu.cz, E-mail: aroy@barc.gov.in [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), Utsunomiya University, Utsunomiya, Tochigi 321-8585 (Japan); HiLASE Centre, Institute of Physics ASCR, v.v.i., Za Radnicí 828, 25241 Dolní B?ežany (Czech Republic); Arai, Goki; Hara, Hiroyuki; Higashiguchi, Takeshi, E-mail: higashi@cc.utsunomiya-u.ac.jp [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), Utsunomiya University, Utsunomiya, Tochigi 321-8585 (Japan); Ohashi, Hayato [Graduate School of Science and Engineering for Research, University of Toyama, Toyama, Toyama 930-8555 (Japan); Sunahara, Atsushi [Institute for Laser Technology, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Li, Bowen [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Dunne, Padraig; O'Sullivan, Gerry [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Miura, Taisuke; Mocek, Tomas; Endo, Akira [HiLASE Centre, Institute of Physics ASCR, v.v.i., Za Radnicí 828, 25241 Dolní B?ežany (Czech Republic)

    2014-08-18T23:59:59.000Z

    We have investigated the effect of irradiation of solid Sn targets with laser pulses of sub-ns duration and sub-mJ energy on the diameter of the extreme ultraviolet (EUV) emitting region and source conversion efficiency. It was found that an in-band EUV source diameter as low as 18??m was produced due to the short scale length of a plasma produced by a sub-ns laser. Most of the EUV emission occurs in a narrow region with a plasma density close to the critical density value. Such EUV sources are suitable for high brightness and high repetition rate metrology applications.

  2. Highly reproducible and reliable metal/graphene contact by ultraviolet-ozone treatment

    SciTech Connect (OSTI)

    Li, Wei [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China); Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Hacker, Christina A.; Cheng, Guangjun; Hight Walker, A. R.; Richter, Curt A.; Gundlach, David J., E-mail: david.gundlach@nist.gov, E-mail: liangxl@pku.edu.cn [Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Liang, Yiran; Tian, Boyuan; Liang, Xuelei, E-mail: david.gundlach@nist.gov, E-mail: liangxl@pku.edu.cn; Peng, Lianmao [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China)

    2014-03-21T23:59:59.000Z

    Resist residue from the device fabrication process is a significant source of contamination at the metal/graphene contact interface. Ultraviolet Ozone (UVO) treatment is proven here, by X-ray photoelectron spectroscopy and Raman measurement, to be an effective way of cleaning the metal/graphene interface. Electrical measurements of devices that were fabricated by using UVO treatment of the metal/graphene contact region show that stable and reproducible low resistance metal/graphene contacts are obtained and the electrical properties of the graphene channel remain unaffected.

  3. Chemo-physical properties of renal capsules under ultraviolet-c exposure

    SciTech Connect (OSTI)

    Baghapour, Sh.; Parvin, P., E-mail: parvin@aut.ac.ir; Mokhtari, S. [Department of Physics, Amirkabir University of Technology, P.O.Box 15875-4413 Tehran (Iran, Islamic Republic of); Reyhani, A.; Mortazavi, S. Z. [Department of Physics, Imam Khomeini International University, P.O.Box 34149-16818 Qazvin (Iran, Islamic Republic of); Amjadi, A. [Department of Physics, Sharif University of Technology, P.O.Box 11365-9567, Tehran (Iran, Islamic Republic of)

    2014-08-07T23:59:59.000Z

    The renal capsule tissue of lamb was irradiated with ultraviolet-C light and the treated samples were analyzed by uniaxial tensile test, dynamic mechanical analysis, attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and contact angle measurements. It was shown that the skin cross-linking is dominant in low doses in accordance with the contact angle assessment. Conversely, the strong bulk degradation takes place at high doses. Similarly, the bulk cross-linking affects the mechanical tests as to enhance the stiffness at low doses, whereas strong degradation occurs at high doses that mainly arises from the strong bulk chain scission.

  4. Passivating overcoat bilayer for multilayer reflective coatings for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Montcalm, Claude (Livermore, CA); Stearns, Daniel G. (Los Altos, CA); Vernon, Stephen P. (Pleasanton, CA)

    1999-01-01T23:59:59.000Z

    A passivating overcoat bilayer is used for multilayer reflective coatings for extreme ultraviolet (EUV) or soft x-ray applications to prevent oxidation and corrosion of the multilayer coating, thereby improving the EUV optical performance. The overcoat bilayer comprises a layer of silicon or beryllium underneath at least one top layer of an elemental or a compound material that resists oxidation and corrosion. Materials for the top layer include carbon, palladium, carbides, borides, nitrides, and oxides. The thicknesses of the two layers that make up the overcoat bilayer are optimized to produce the highest reflectance at the wavelength range of operation. Protective overcoat systems comprising three or more layers are also possible.

  5. Total to Selective Extinction Ratios and Visual Extinctions from Ultraviolet Data

    E-Print Network [OSTI]

    Anna Geminale; Piotr Popowski

    2004-09-21T23:59:59.000Z

    We present determinations of the total to selective extinction ratio R_V and visual extinction A_V values for Milky Way stars using ultraviolet color excesses. We extend the analysis of Gnacinski and Sikorski (1999) by using non-equal weights derived from observational errors. We present a detailed discussion of various statistical errors. In addition, we estimate the level of systematic errors by considering different normalization of the extinction curve adopted by Wegner (2002). Our catalog of 782 R_V and A_V values and their errors is available in the electronic form on the World Wide Web.

  6. Rare-earth plasma extreme ultraviolet sources at 6.5-6.7 nm

    SciTech Connect (OSTI)

    Otsuka, Takamitsu; Higashiguchi, Takeshi; Yugami, Noboru; Yatagai, Toyohiko [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan); Kilbane, Deirdre; White, John; Dunne, Padraig; O'Sullivan, Gerry [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Jiang, Weihua [Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 (Japan); Endo, Akira [Forschungszentrum Dresden, Bautzner Landstrs. 400, D-01328 Dresden (Germany)

    2010-09-13T23:59:59.000Z

    We have demonstrated a laser-produced plasma extreme ultraviolet source operating in the 6.5-6.7 nm region based on rare-earth targets of Gd and Tb coupled with a Mo/B{sub 4}C multilayer mirror. Multiply charged ions produce strong resonance emission lines, which combine to yield an intense unresolved transition array. The spectra of these resonant lines around 6.7 nm (in-band: 6.7 nm {+-}1%) suggest that the in-band emission increases with increased plasma volume by suppressing the plasma hydrodynamic expansion loss at an electron temperature of about 50 eV, resulting in maximized emission.

  7. Note: Enhancement of the extreme ultraviolet emission from a potassium plasma by dual laser irradiation

    SciTech Connect (OSTI)

    Higashiguchi, Takeshi, E-mail: higashi@cc.utsunomiya-u.ac.jp; Yamaguchi, Mami; Otsuka, Takamitsu; Nagata, Takeshi [Department of Advanced Interdisciplinary Sciences and Center for Optical Research (CORE), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 Japan (Japan); Ohashi, Hayato [Graduate School of Science and Engineering for Research, University of Toyama, Toyama, Toyama 930-8555 (Japan); Li, Bowen [School of Nuclear Science and Technology, Lanzhou University, Lanzhou, 730000 (China); School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); D’Arcy, Rebekah; Dunne, Padraig; O’Sullivan, Gerry [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)

    2014-09-15T23:59:59.000Z

    Emission spectra from multiply charged potassium ions ranging from K{sup 3+} to K{sup 5+} have been obtained in the extreme ultraviolet (EUV) spectral region. A strong emission feature peaking around 38?nm, corresponding to a photon energy of 32.6 eV, is the dominant spectral feature at time-averaged electron temperatures in the range of 8?12 eV. The variation of this emission with laser intensity and the effects of pre-pulses on the relative conversion efficiency (CE) have been explored experimentally and indicate that an enhancement of about 30% in EUV CE is readily attainable.

  8. Radiation delivery system and method

    DOE Patents [OSTI]

    Sorensen, Scott A. (Overland Park, KS); Robison, Thomas W. (Los Alamos, NM); Taylor, Craig M. V. (Jemez Springs, NM)

    2002-01-01T23:59:59.000Z

    A radiation delivery system and method are described. The system includes a treatment configuration such as a stent, balloon catheter, wire, ribbon, or the like, a portion of which is covered with a gold layer. Chemisorbed to the gold layer is a radiation-emitting self-assembled monolayer or a radiation-emitting polymer. The radiation delivery system is compatible with medical catheter-based technologies to provide a therapeutic dose of radiation to a lesion following an angioplasty procedure.

  9. Radiation Protection and Safety Training | Environmental Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeedingTechnicalPurchase, Delivery, andSmartRadiation EffectsProtection

  10. Solar UV-B in tropical forest gaps: Analysis using direct and diffuse radiation

    SciTech Connect (OSTI)

    Flint, S.D.; Caldwell, M.M. [Utah State Univ., Logan, UT (United States)

    1995-06-01T23:59:59.000Z

    Experiments with natural levels of solar ultraviolet-B radiation (UV-B) have recently shown inhibition of the growth of some tropical forest tree seedlings. A knowledge of forest radiation environments is needed to help assess UV-B effects in natural situations. Although forest canopies strongly attenuate solar radiation, treefall gaps provide a very different radiation environment. We simultaneously measured both UV-B and photosynthetically active radiation (PAR) in forest gaps on Barro Colorado Island, Panama. Outside the forest, UV-B is predominately diffuse even under clear sky conditions. In sunflecks of small forest gaps, most of the UV-B was in the direct beam component. Compared to conditions outside the forest, the UV-B in these sunflecks was low relative to PAR. Shaded portions of the gap, in contrast, had proportionately high levels of UV-B relative to PAR. There are indications in the literature that relatively low UV-B levels may be effective under low PFD. Seasonal trends of PAR and UV-B in different locations in gaps can be inferred from hemispherical canopy photographs.

  11. Remote radiation dosimetry

    DOE Patents [OSTI]

    Braunlich, P.F.; Tetzlaff, W.; Hegland, J.E.; Jones, S.C.

    1991-03-12T23:59:59.000Z

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via a transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission. 8 figures.

  12. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, J.E.

    1988-03-31T23:59:59.000Z

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiatonevents, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible ''chirp''. The rate of the ''chirps'' is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field. 2 figs.

  13. Applications of synchrotron radiation to Chemical Engineering Science: Workshop report

    SciTech Connect (OSTI)

    Not Available

    1991-07-01T23:59:59.000Z

    This report contains extended abstracts that summarize presentations made at the Workshop on Applications of Synchrotron Radiation to Chemical Engineering Science held at Argonne National Laboratory (ANL), Argonne, IL, on April 22--23, 1991. The talks emphasized the application of techniques involving absorption fluorescence, diffraction, and reflection of synchrotron x-rays, with a focus on problems in applied chemistry and chemical engineering, as well as on the use of x-rays in topographic, tomographic, and lithographic procedures. The attendees at the workshop included experts in the field of synchrotron science, scientists and engineers from ANL, other national laboratories, industry, and universities; and graduate and undergraduate students who were enrolled in ANL educational programs at the time of the workshop. Talks in the Plenary and Overview Session described the status of and special capabilities to be offered by the Advanced Photon Source (APS), as well as strategies and opportunities for utilization of synchrotron radiation to solve science and engineering problems. Invited talks given in subsequent sessions covered the use of intense infrared, ultraviolet, and x-ray photon beams (as provided by synchrotrons) in traditional and nontraditional areas of chemical engineering research related to electrochemical and corrosion science, catalyst development and characterization, lithography and imaging techniques, and microanalysis.

  14. Coherent Nuclear Radiation

    E-Print Network [OSTI]

    V. I. Yukalov; E. P. Yukalova

    2004-06-22T23:59:59.000Z

    The main part of this review is devoted to the comprehensive description of coherent radiation by nuclear spins. The theory of nuclear spin superradiance is developed and the experimental observations of this phenomenon are considered. The intriguing problem of how coherence develops from initially incoherent quantum fluctuations is analysed. All main types of coherent radiation by nuclear spins are discussed, which are: free nuclear induction, collective induction, maser generation, pure superradiance, triggered superradiance, pulsing superradiance, punctuated superradiance, and induced emission. The influence of electron-nuclear hyperfine interactions and the role of magnetic anisotropy are studied. Conditions for realizing spin superradiance by magnetic molecules are investigated. The possibility of nuclear matter lasing, accompanied by pion or dibaryon radiation, is briefly touched.

  15. Pediatric radiation oncology

    SciTech Connect (OSTI)

    Halperin, E.C.; Kun, L.E.; Constine, L.S.; Tarbell, N.J.

    1989-01-01T23:59:59.000Z

    This text covers all aspects of radiation therapy for treatment of pediatric cancer. The book describes the proper use of irradiation in each of the malignancies of childhood, including tumors that are rarely encountered in adult practice. These include acute leukemia; supratentorial brain tumors; tumors of the posterior fossa of the brain and spinal canal; retinoblastoma and optic nerve glioma; neuroblastoma; Hodgkin's disease; malignant lymphoma; Ewing's sarcoma; osteosarcoma; rhabdomyosarcoma; Desmoid tumor; Wilms' tumor; liver and biliary tumors; germ cell and stromal cell tumors of the gonads; endocrine, aerodigestive tract, and breast tumors; Langerhans' cell histiocytosis; and skin cancer and hemangiomas. For each type of malignancy, the authors describe the epidemiology, common presenting signs and symptoms, staging, and proper diagnostic workup. Particular attention is given to the indications for radiation therapy and the planning of a course of radiotherapy, including the optimal radiation dose, field size, and technique.

  16. Composition for radiation shielding

    DOE Patents [OSTI]

    Kronberg, J.W.

    1994-08-02T23:59:59.000Z

    A composition for use as a radiation shield is disclosed. The shield has a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container. 2 figs.

  17. ultraviolet | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and early disease diagnostic applications. Citation: Lee AC, D Du, B Chen, CK Heng, TM Lim, and Y Lin.2014."Electrochemical detection of leukemia oncogenes using...

  18. EMSL - ultraviolet

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    class"field-item even" property"schema:citation">Lee AC, D Du, B Chen, CK Heng, TM Lim, and Y Lin.2014."Electrochemical detection of leukemia oncogenes using...

  19. Time-resolved visible and extreme ultraviolet spectroscopy of laser-produced tin plasma

    E-Print Network [OSTI]

    O'Shay, Joseph Fred

    2007-01-01T23:59:59.000Z

    Characterization of laser-produced tin plasma. Part I: XUVof laser-produced tin plasma. Part II: Radiation-expanding laser-produced tin plasma,” Eighth International

  20. Quasi-Coherent Oscillations in the Extreme Ultraviolet Flux of the Dwarf Nova SS Cygni

    E-Print Network [OSTI]

    Christopher W. Mauche

    1996-03-18T23:59:59.000Z

    Quasi-coherent oscillations have been detected in the extreme ultraviolet flux of the dwarf nova SS Cygni during observations with the Extreme Ultraviolet Explorer satellite of the rise and plateau phases of an anomalous outburst in 1993 August and a normal outburst in 1994 June/July. On both occasions, the oscillation turned on during the rise to outburst and persisted throughout the observation. During the 1993 outburst, the period of the oscillation fell from 9.3 s to 7.5 s over an interval of 4.4 days; during the 1994 outburst, the period fell from 8.9 s to 7.19 s (the shortest period ever observed in SS Cyg, or any other dwarf nova) within less than a day, and then rose to 8.0 s over an interval of 8.0 days. For both outbursts, the period $P$ of the oscillation was observed to correlate with the 75--120 \\AA \\ count rate $I_{\\rm EUV}$ according to $P\\propto I_{\\rm EUV}^{-0.094}$. A magnetospheric model is considered to reproduce this variation. It is found that an effective high-order multipole field is required, and that the field strength at the surface of the white dwarf is 0.1--1 MG. Such a field strength is at the lower extreme of those measured or inferred for bona fide magnetic cataclysmic variables.

  1. Support of the balloon-borne ultraviolet stellar spectrograph. Final report

    SciTech Connect (OSTI)

    Timothy, J.G.

    1986-05-01T23:59:59.000Z

    A (256 x 1024)-pixel imaging ultraviolet Multi-mode Microchannel Array (MAMA) detector system for flight was fabricated, evaluated, and environmentally tested for flight on the Balloon Borne Ultraviolet Stellar Spectrograph (BUSS). The goal of the program was to replace the existing SEC Vidicon with the pulse-counting MAMA detector in order to, first, improve the overall sensitivity of the BUSS telescope and spectrograph for observations of stars down to m sub v = 7 and fainter, and, second, to improve the spectral resolution and wavelength accuracy by eliminating the image drifts in the Vidicon caused by magnetic field effects. A sealed MAMA detector tube structure employing a remotely processed photocathode mounted on a window in proximity focus with the front face of the MCP was developed to avoid contamination produced by a noisy and unstable device. The configuration of the BUSS detector system in its flight ready configuration is shown. The quantum efficiency curve for the semi-transparent Cs/sub 2/Te photocathode is also shown.

  2. Constraints to the magnetospheric properties of T Tauri stars - II. The Mg II ultraviolet feature

    E-Print Network [OSTI]

    Lopez-Martinez, Fatima

    2015-01-01T23:59:59.000Z

    The atmospheric structure of T Tauri Stars (TTSs) and its connection with the large scale outflow is poorly known. Neither the effect of the magnetically mediated inter- action between the star and the disc in the stellar atmosphere is well understood. The Mg II multiplet is a fundamental tracer of TTSs atmospheres and outflows, and is the strongest feature in the near-ultraviolet spectrum of TTSs. The International Ultraviolet Explorer and Hubble Space Telescope data archives provide a unique set to study the main physical compounds contributing to the line profile and to derive the properties of the line formation region. The Mg II profiles of 44 TTSs with resolution 13,000 to 30,000 are available in these archives. In this work, we use this data set to measure the main observables: flux, broadening, asymmetry, terminal velocity of the outflow, and the velocity of the Discrete Absorption Components. For some few sources repeated observations are available and variability has been studied. There is a warm wi...

  3. Radiation monitor for liquids

    DOE Patents [OSTI]

    Koster, J.E.; Bolton, R.D.

    1999-03-02T23:59:59.000Z

    A radiation monitor for use with liquids that utilizes air ions created by alpha radiation emitted by the liquids as its detectable element. A signal plane, held at an electrical potential with respect to ground, collects these air ions. A guard plane or guard rings is used to limit leakage currents. In one embodiment, the monitor is used for monitoring liquids retained in a tank. Other embodiments monitor liquids flowing through a tank, and bodies of liquids, such as ponds, lakes, rivers and oceans. 4 figs.

  4. Radiation monitor for liquids

    DOE Patents [OSTI]

    Koster, James E. (Los Alamos, NM); Bolton, Richard D. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    A radiation monitor for use with liquids that utilizes air ions created by alpha radiation emitted by the liquids as its detectable element. A signal plane, held at an electrical potential with respect to ground, collects these air ions. A guard plane or guard rings is used to limit leakage currents. In one embodiment, the monitor is used for monitoring liquids retained in a tank. Other embodiments monitor liquids flowing through a tank, and bodies of liquids, such as ponds, lakes, rivers and oceans.

  5. Wireless passive radiation sensor

    DOE Patents [OSTI]

    Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

    2013-12-03T23:59:59.000Z

    A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

  6. Radiation.cdr

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeedingTechnicalPurchase, Delivery, andSmartRadiationRadiation Safety Work

  7. Local microwave background radiation

    E-Print Network [OSTI]

    Domingos Soares

    2014-11-13T23:59:59.000Z

    An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

  8. Radiation Source Replacement Workshop

    SciTech Connect (OSTI)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01T23:59:59.000Z

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  9. Thermostatic Radiator Valve Evaluation

    SciTech Connect (OSTI)

    Dentz, Jordan [Advanced Residential Integrated Energy Solutions Collaborative, New York, NY (United States); Ansanelli, Eric [Advanced Residential Integrated Energy Solutions Collaborative, New York, NY (United States)

    2015-01-01T23:59:59.000Z

    A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market.

  10. Three Dimensional Radiative Transfer

    E-Print Network [OSTI]

    Tom Abel

    2000-05-09T23:59:59.000Z

    Radiative Transfer (RT) effects play a crucial role in the thermal history of the intergalactic medium. Here I discuss recent advances in the development of numerical methods that introduce RT to cosmological hydrodynamics. These methods can also readily be applied to time dependent problems on interstellar and galactic scales.

  11. Radiation detector spectrum simulator

    DOE Patents [OSTI]

    Wolf, M.A.; Crowell, J.M.

    1985-04-09T23:59:59.000Z

    A small battery operated nuclear spectrum simulator having a noise source generates pulses with a Gaussian distribution of amplitudes. A switched dc bias circuit cooperating therewith to generate several nominal amplitudes of such pulses and a spectral distribution of pulses that closely simulates the spectrum produced by a radiation source such as Americium 241.

  12. Photovoltaic radiation detector element

    DOE Patents [OSTI]

    Agouridis, D.C.

    1980-12-17T23:59:59.000Z

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein in the edge of which closely approaches but is spaced from the current collector strips.

  13. Radiation Characteristics of Glass Containing Gas Bubbles

    E-Print Network [OSTI]

    Pilon, Laurent; Viskanta, Raymond

    2003-01-01T23:59:59.000Z

    B. L. Drolen, “Thermal radiation in particulate media withRadiation Characteristics of Glass Containing Gas Bubblesthermophysical properties and radiation characteristics of

  14. Radiation damage evolution in ceramics. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiation damage evolution in ceramics. Radiation damage evolution in ceramics. Abstract: A review is presented of recent results on radiation damage production, defect...

  15. Preliminary radiation shielding design for BOOMERANG

    E-Print Network [OSTI]

    Donahue, Richard J.

    2002-01-01T23:59:59.000Z

    Preliminary Radiation Shielding Design for BOOMERANG R. J.2003 Abstract Preliminary radiation shielding speci?cationsElectron Photon Stray Radiation from a High Energy Electron

  16. Terahertz radiation from laser accelerated electron bunches

    E-Print Network [OSTI]

    2004-01-01T23:59:59.000Z

    NUMBER 5 MAY 2004 Terahertz radiation from laser acceleratedand millimeter wave radiation from laser acceleratedNo. 5, May 2004 Terahertz radiation from laser accelerated

  17. Meeting Report--NASA Radiation Biomarker Workshop

    E-Print Network [OSTI]

    Straume, Tore

    2008-01-01T23:59:59.000Z

    ionizing radiation. In: Advances in Medical Physics (A. B.for medical management of radiation casualties. ADVANCES INMedical Center presented the radiation oncology perspective on biomarkers. Advances

  18. Nanoscale Engineering Of Radiation Tolerant Silicon Carbide....

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Engineering Of Radiation Tolerant Silicon Carbide. Nanoscale Engineering Of Radiation Tolerant Silicon Carbide. Abstract: Radiation tolerance is determined by how effectively the...

  19. Radiation Safety Training Basic Radiation Safety Training for

    E-Print Network [OSTI]

    Dai, Pengcheng

    Radiation Safety Training Basic Radiation Safety Training for Sealed Source Users for Physics 461 Protocol Title: Training for Sealed Source Users Drafted By: Chris Millsaps, RSS Reviewers: ZB, TU, GS Purpose: To provide basic radiation safety training to the users of sealed sources located

  20. Growth of Nanoscale Nickel Ferrite on Carbonaceous Matrix- A Novel Method of Turning Harmful Particulates into a Functional Nanocomposite: An XAFS Study

    SciTech Connect (OSTI)

    Pattanaik, S.; Huggins, F; Huffman, G

    2010-01-01T23:59:59.000Z

    Particulate matter (PM) emission from residual oil combustion typically consists of carbonaceous material accompanied by inorganic matter notably transition metal sulfates. Often a minor sulfide form is found in the coarse fraction while an oxide form is more common in the fine and ultrafine fractions. A composite comprising of nanoscale nickel ferrite dispersed on carbonaceous matrix has been obtained following liberation of metal sulfates from the fine PM - a novel method of turning harmful particulates into a functional nanocomposite without the need for elaborate preparation using expensive precursors. The nickel ferrite content in the composite varies with the Fe/Ni ratio in particulate, fuel type, and combustion condition. Such variation may lead to the composite exhibiting diverse physical behaviors. Detailed structure and cation distribution in dispersed ferrite have been studied using Fe and Ni K-edges XAFS spectroscopy. Peaks are identified in the radial structure function with specific atom pair correlations within the spinel ferrite from which the relative occupancy of the cations in the octahedral and tetrahedral sites can be discerned. The results show that Ni(II) has strong preference for the octahedral site, while Fe(III) prefers both sites which is consistent with that of an inverted spinel ferrite.

  1. Pacific Northwest Solar Radiation Data

    E-Print Network [OSTI]

    Oregon, University of

    Pacific Northwest Solar Radiation Data UO SOLAR MONITORING LAB Physics Department -- Solar Energy Center 1274 University of Oregon Eugene, Oregon 97403-1274 April 1, 1999 #12;Hourly solar radiation data

  2. RADIATION DAMAGE OF GERMANIUM DETECTORS

    E-Print Network [OSTI]

    Pehl, Richard H.

    2011-01-01T23:59:59.000Z

    the high-energy proton damage than was the planar detector.as far as radiation damage is concerned. Unfortunately, some28-29, 1978 LBL-7967 RADIATION DAMAGE OF GERMANIUM DETECTORS

  3. DOE Radiation Records Contacts List

    Broader source: Energy.gov [DOE]

    DOE radiation records contact list for individuals to obtain records of occupational exposure directly from a DOE site.

  4. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1994-08-16T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  5. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1995-01-01T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  6. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1995-10-17T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  7. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1994-01-01T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  8. NCSRNCSR ""DEMOKRITOSDEMOKRITOS"" INSTITUTE OF NUCLEAR TECHNOLOGY & RADIATION PROTECTIONINSTITUTE OF NUCLEAR TECHNOLOGY & RADIATION PROTECTION

    E-Print Network [OSTI]

    PROTECTIONINSTITUTE OF NUCLEAR TECHNOLOGY & RADIATION PROTECTION ·· ENVIRONMENTAL RESEARCH LABORATORYENVIRONMENTAL·· NCSRNCSR ""DEMOKRITOSDEMOKRITOS"" ·· INSTITUTE OF NUCLEAR TECHNOLOGY & RADIATION

  9. High efficiency single Ag nanowire/p-GaN substrate Schottky junction-based ultraviolet light emitting diodes

    E-Print Network [OSTI]

    Wu, Y.; Hasan, T.; Li, X.; Xu, P.; Wang, Y.; Shen, X.; Liu, X.; Yang, Q.

    2015-02-05T23:59:59.000Z

    We report a high efficiency single Ag nanowire (NW)/p-GaN substrate Schottky junction-based ultraviolet light emitting diode (UV-LED). The device demonstrates deep UV free exciton electroluminescence at 362.5?nm. The dominant emission, detectable...

  10. Self-heating in a GaN based heterostructure field effect transistor: Ultraviolet and visible Raman measurements and simulations

    E-Print Network [OSTI]

    Holtz, Mark

    Self-heating in a GaN based heterostructure field effect transistor: Ultraviolet and visible Raman online 8 December 2006 We report direct self-heating measurements for AlGaN/GaN heterostructure field density can be commensurately high, collisional energy loss from electrons to the crystal leads to self-heating

  11. Interaction of methanol and water on MgO,,100... studied by ultraviolet photoelectron and metastable impact electron spectroscopies

    E-Print Network [OSTI]

    Goodman, Wayne

    Interaction of methanol and water on MgO,,100... studied by ultraviolet photoelectron; accepted 27 October 1998 The coadsorption of methanol (CH3OH) and water (D2O) on the MgO 100 /Mo 100 photoelectron spectroscopy UPS HeI , and by thermal programmed desorption TPD . Methanol wets the MgO surface

  12. Devices useful for vacuum ultraviolet beam characterization including a movable stage with a transmission grating and image detector

    DOE Patents [OSTI]

    Gessner, Oliver; Kornilov, Oleg A; Wilcox, Russell B

    2013-10-29T23:59:59.000Z

    The invention provides for a device comprising an apparatus comprising (a) a transmission grating capable of diffracting a photon beam into a diffracted photon output, and (b) an image detector capable of detecting the diffracted photon output. The device is useful for measuring the spatial profile and diffraction pattern of a photon beam, such as a vacuum ultraviolet (VUV) beam.

  13. DO THE INFRARED EMISSION FEATURES NEED ULTRAVIOLET EXCITATION? THE POLYCYCLIC AROMATIC HYDROCARBON MODEL IN UV-POOR REFLECTION NEBULAE

    E-Print Network [OSTI]

    Draine, Bruce T.

    '' PAHs in reflection nebulae near stars as cool as Teff ¼ 3000 K can result in observable emis- sion at 6DO THE INFRARED EMISSION FEATURES NEED ULTRAVIOLET EXCITATION? THE POLYCYCLIC AROMATIC HYDROCARBON MODEL IN UV-POOR REFLECTION NEBULAE Aigen Li and B. T. Draine Department of Astrophysical Sciences

  14. Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of benzene: Vibrational analysis of C6H6

    E-Print Network [OSTI]

    Kim, Myung Soo

    Vacuum ultraviolet mass-analyzed threshold ionization spectroscopy of benzene: Vibrational analysis-photon spectra agrees with the previous suggestion that the geometry of benzene cation in the ground electronic. INTRODUCTION Benzene cation has been the focus of an intensive re- search effort, both experimental1

  15. Optimization of extreme ultraviolet photons emission and collection in mass-limited laser produced plasmas for lithography application

    E-Print Network [OSTI]

    Harilal, S. S.

    Optimization of extreme ultraviolet photons emission and collection in mass-limited laser produced in DPP or with pre-pulsing in LPP provide wide area for optimization in regards to conversion efficiency and collection as well as calculating photons source location and size. We optimized several parameters of dual

  16. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212-305-0318 rso-clinical@columbia by more than 50 percent. #12;COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212 ________________________________________________________ ________________________________________________________ #12;COLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212-305-0318 rso-clinical@columbia

  17. 6, 52315250, 2006 Radiative properties

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the short- wave (SW) and longwave (LW) cloud radiative effects (CRE), but the impact is small: 0.02 W m-2 tests are conducted to evaluate the impact that5 such an over-layer would have on the radiative effects, terrestrial) radiation. The SW "albedo" effect brings about cooling and the LW "greenhouse" effect warming

  18. Apparatus having reduced background for measuring radiation activity in aerosol particles

    DOE Patents [OSTI]

    Rodgers, John C. (Santa Fe, NM); McFarland, Andrew R. (College Station, TX); Oritz, Carlos A. (Bryan, TX); Marlow, William H. (College Station, TX)

    1992-01-01T23:59:59.000Z

    Apparatus having reduced background for measuring radiation activity in aerosol particles. A continuous air monitoring sampler is described for use in detecting the presence of alpha-emitting aerosol particles. An inlet fractionating screen has been demonstrated to remove about 95% of freshly formed radon progeny from the aerosol sample, and approximately 33% of partially aged progeny. Addition of an electrical condenser and a modified dichotomous virtual impactor are expected to produce considerable improvement in these numbers, the goal being to enrich the transuranic (TRU) fraction of the aerosols. This offers the possibility of improving the signal-to-noise ratio for the detected alpha-particle energy spectrum in the region of interest for detecting TRU materials associated with aerosols, thereby enhancing the performance of background-compensation algorithms for improving the quality of alarm signals intended to warn personnel of potentially harmful quantities of TRU materials in the ambient air.

  19. Delayed Ultrafast X-ray Auger Probing (DUXAP) of Nucleobase Ultraviolet Photoprotection

    E-Print Network [OSTI]

    McFarland, B K; Miyabe, S; Tarantelli, F; Aguilar, A; Berrah, N; Bostedt, C; Bozek, J; Bucksbaum, P H; Castagna, J C; Coffee, R; Cryan, J; Fang, L; Feifel, R; Gaffney, K; Glownia, J; Martinez, T; Mucke, M; Murphy, B; Natan, A; Osipov, T; Petrovic, V; Schorb, S; Schultz, Th; Spector, L; Swiggers, M; Tenney, I; Wang, S; White, W; White, J; Gühr, M

    2013-01-01T23:59:59.000Z

    We present a new method for ultrafast spectroscopy of molecular photoexcited dynamics. The technique uses a pair of femtosecond pulses: a photoexcitation pulse initiating excited state dynamics followed by a soft x-ray (SXR) probe pulse that core ionizes certain atoms inside the molecule. We observe the Auger decay of the core hole as a function of delay between the photoexcitation and SXR pulses. The core hole decay is particularly sensitive to the local valence electrons near the core and shows new types of propensity rules, compared to dipole selection rules in SXR absorption or emission spectroscopy. We apply the delayed ultrafast x-ray Auger probing (DUXAP) method to the specific problem of nucleobase photoprotection to demonstrate its potential. The ultraviolet photoexcited \\pi\\pi* states of nucleobases are prone to chemical reactions with neighboring bases. To avoid this, the single molecules funnel the \\pi\\pi* population to lower lying electronic states on an ultrafast timescale under violation of the...

  20. Ultraviolet stimulated electron source for use with low energy plasma instrument calibration

    SciTech Connect (OSTI)

    Henderson, Kevin; Harper, Ron; Funsten, Herb; MacDonald, Elizabeth [Space Science and Applications, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2012-07-15T23:59:59.000Z

    We have developed and demonstrated a versatile, compact electron source that can produce a mono-energetic electron beam up to 50 mm in diameter from 0.1 to 30 keV with an energy spread of <10 eV. By illuminating a metal cathode plate with a single near ultraviolet light emitting diode, a spatially uniform electron beam with 15% variation over 1 cm{sup 2} can be generated. A uniform electric field in front of the cathode surface accelerates the electrons into a beam with an angular divergence of <1 Degree-Sign at 1 keV. The beam intensity can be controlled from 10 to 10{sup 9} electrons cm{sup -2} s{sup -1}.

  1. Dynamics of the solar chromosphere. V. High-frequency modulation in ultraviolet image sequences from TRACE

    E-Print Network [OSTI]

    A. G. de Wijn; R. J. Rutten; T. D. Tarbell

    2007-06-13T23:59:59.000Z

    We search for signatures of high-frequency oscillations in the upper solar photosphere and low chromosphere in the context of acoustic heating of outer stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk area from the Transition Region and Coronal Explorer (TRACE) mission which were taken with strict cadence regularity. The latter permits more reliable high-frequency diagnosis than in earlier work. Spatial Fourier power maps, spatially averaged coherence and phase-difference spectra, and spatio-temporal k-f decompositions all contain high-frequency features that at first sight seem of considerable intrinsic interest but actually are more likely to represent artifacts of different nature. Spatially averaged phase difference measurement provides the most sensitive diagnostic and indicates the presence of acoustic modulation up to f=20 mHz (periods down to 50 seconds) in internetwork areas.

  2. Functionalization of carbon nanotubes by argon plasma-assisted ultraviolet grafting

    SciTech Connect (OSTI)

    Yan, Y.H.; Chan-Park, M.B.; Zhou, Q.; Li, C.M.; Yue, C.Y. [School of Mechanical and Aerospace Engineering and School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 639798 (Singapore); School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 639798 (Singapore); School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2005-11-21T23:59:59.000Z

    We have demonstrated the functionalization of single-wall carbon nanotubes (SWNTs) by argon (Ar) plasma-assisted ultraviolet (UV) grafting of 1-vinylimidazole (VZ). The Ar plasma treatment generates defect sites at the tube ends and sidewalls, which act as the active sites for the subsequent UV grafting of VZ monomer. Atomic force microscopy analyses indicate that the original nanotube bundles exfoliate to individual tubes after the VZ grafting. By control of the deposited energy of Ar plasma treatment (200 W) and treatment time (5 min), no visible chopping of the functionalized SWNT was observed. This method may be extended to other vinyl monomers and offers another diverse way of sidewall functionalization of SWNT.

  3. Extreme Ultraviolet Imaging of Three-dimensional Magnetic Reconnection in a Solar Eruption

    E-Print Network [OSTI]

    Sun, J Q; Ding, M D; Guo, Y; Priest, E R; Parnell, C E; Edwards, S J; Zhang, J; Chen, P F; Fang, C

    2015-01-01T23:59:59.000Z

    Magnetic reconnection, a change of magnetic field connectivity, is a fundamental physical process in which magnetic energy is released explosively. It is responsible for various eruptive phenomena in the universe. However, this process is difficult to observe directly. Here, the magnetic topology associated with a solar reconnection event is studied in three dimensions (3D) using the combined perspectives of two spacecraft. The sequence of extreme ultraviolet (EUV) images clearly shows that two groups of oppositely directed and non-coplanar magnetic loops gradually approach each other, forming a separator or quasi-separator and then reconnecting. The plasma near the reconnection site is subsequently heated from $\\sim$1 to $\\ge$5 MK. Shortly afterwards, warm flare loops ($\\sim$3 MK) appear underneath the hot plasma. Other observational signatures of reconnection, including plasma inflows and downflows, are unambiguously revealed and quantitatively measured. These observations provide direct evidence of magneti...

  4. The effects of concentrated ultraviolet light on high-efficiency silicon solar cells

    SciTech Connect (OSTI)

    Ruby, D.S.; Schubert, W.K.

    1991-01-01T23:59:59.000Z

    The importance of stability in the performance of solar cells is clearly recognized as fundamental. Some of the highest efficiency silicon solar cells demonstrated to date, such as the Point Contact solar cell and the Passivated Emitter solar cell, rely upon the passivation of cell surfaces in order to minimize recombination, which reduces cell power output. Recently, it has been shown that exposure to ultraviolet (UV) light of wavelengths present in the terrestrial solar spectrum can damage a passivating silicon-oxide interface and increase recombination. In this study, we compared the performance of Point Contact and Passivated Emitter solar cells after exposure to UV light. We also examined the effect of UV exposure on oxide-passivated silicon wafers. We found that current Passivated Emitter designs are stable at both one-sun and under concentrated sunlight. The evolution of Point Contact concentrator cell performance shows a clear trend towards more stable cells. 15 refs., 18 figs.

  5. Evaluation of Ultra-Violet Photocatalytic Oxidation for Indoor AirApplications

    SciTech Connect (OSTI)

    Hodgson, A.T.; Sullivan, D.P.; Fisk, W.J.

    2006-02-01T23:59:59.000Z

    Acceptable indoor air quality in office buildings may be achieved with less energy by combining effective air cleaning systems for volatile organic compounds (VOCs) with particle filtration then by relying solely on ventilation. For such applications, ultraviolet photocatalytic oxidation (UVPCO) systems are being developed for VOC destruction. An experimental evaluation of a UVPCO system is reported. The evaluation was unique in that it employed complex mixtures of VOCs commonly found in office buildings at realistically low concentrations. VOC conversion efficiencies varied over a broad range, usually exceeded 20%, and were as high as {approx}80%. Conversion efficiency generally diminished with increased air flow rate. Significant amounts of formaldehyde and acetaldehyde were produced due to incomplete mineralization. The results indicate that formaldehyde and acetaldehyde production rates may need to be reduced before such UVPCO systems can be deployed safely in occupied buildings.

  6. Electronic Excitations in B12As2 and their Temperature Dependence by Vacuum Ultraviolet Ellipsometry

    SciTech Connect (OSTI)

    S Bakalova; Y Gong; C Cobet; N Esser; Y Zhang; J Edgar; Y Zhang; M Dudley; M Kuball

    2011-12-31T23:59:59.000Z

    The dielectric response function of epitaxial B{sub 12}As{sub 2} films on 4H-SiC was determined at room temperature and at 10 K in the spectral region of 3.6-9.8 eV, i.e., in the vacuum ultraviolet (VUV) spectral region, by synchrotron ellipsometry. The experimental dielectric function was simulated with the critical point parabolic band model. The parameters of the dispersive structures were derived by numerical fitting of the experimental data to the proposed model. New high energy optical transitions are resolved at 5.95, 7.8 and 8.82 eV and their lineshape and origin are discussed. The temperature dependence of the critical point energies and transition strengths was determined, and the excitonic effect is considered.

  7. Validity of the thin mask approximation in extreme ultraviolet mask roughness simulations

    SciTech Connect (OSTI)

    Naulleau, Patrick; George, Simi

    2011-01-26T23:59:59.000Z

    In the case of extreme ultraviolet (EUV) lithography, modeling has shown that reflector phase roughness on the lithographic mask is a significant concern due to the image plan speckle it causes and the resulting line-edge roughness on imaged features. Modeling results have recently been used to determine the requirements for future production worthy masks yielding the extremely stringent specification of 50 pm rms roughness. Owing to the scale of the problem in terms of memory requirements, past modeling results have all been based on the thin mask approximation. EUV masks, however, are inherently three dimensional in nature and thus the question arises as to the validity of the thin mask approximation. Here we directly compare image plane speckle calculation results using the fast two dimensional thin mask model to rigorous finite-difference time-domain results and find the two methods to be comparable.

  8. QUIET-SUN INTENSITY CONTRASTS IN THE NEAR-ULTRAVIOLET AS MEASURED FROM SUNRISE

    SciTech Connect (OSTI)

    Hirzberger, J.; Feller, A.; Riethmueller, T. L.; Schuessler, M.; Borrero, J. M.; Gandorfer, A.; Solanki, S. K.; Barthol, P. [Max-Planck-Institut fuer Sonnensystemforschung, D-37434 Katlenburg-Lindau (Germany); Afram, N.; Unruh, Y. C. [Astrophysics Group, Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom); Berdyugina, S. V.; Berkefeld, T.; Schmidt, W. [Kiepenheuer-Institut fuer Sonnenphysik, D-79104 Freiburg (Germany); Bonet, J. A.; MartInez Pillet, V. [Instituto de Astrofisica de Canarias, E-38200 La Laguna (Spain); Knoelker, M. [High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307 (United States); Title, A. M., E-mail: hirzberger@mps.mpg.d [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94305 (United States)

    2010-11-10T23:59:59.000Z

    We present high-resolution images of the Sun in the near-ultraviolet spectral range between 214 nm and 397 nm as obtained from the first science flight of the 1 m SUNRISE balloon-borne solar telescope. The quiet-Sun rms intensity contrasts found in this wavelength range are among the highest values ever obtained for quiet-Sun solar surface structures-up to 32.8% at a wavelength of 214 nm. We compare the rms contrasts obtained from the observational data with theoretical intensity contrasts obtained from numerical magnetohydrodynamic simulations. For 388 nm and 312 nm the observations agree well with the numerical simulations whereas at shorter wavelengths discrepancies between observed and simulated contrasts remain.

  9. Injection locking of a high power ultraviolet laser diode for laser cooling of ytterbium atoms

    E-Print Network [OSTI]

    Toshiyuki Hosoya; Martin Miranda; Ryotaro Inoue; Mikio Kozuma

    2014-12-02T23:59:59.000Z

    We developed a high-power laser system at a wavelength of 399 nm for laser cooling of ytterbium atoms with ultraviolet laser diodes. The system is composed of an external cavity laser diode providing frequency stabilized output at a power of 40 mW and another laser diode for amplifying the laser power up to 220 mW by injection locking. The systematic method for optimization of our injection locking can also be applied to high power light sources at any other wavelengths. Our system, which does not depend on complex nonlinear frequency-doubling, has great importance for implementing transportable optical lattice clocks, and is also useful for investigations on condensed matter physics or quantum information processing using cold atoms.

  10. Tabletop Nanometer Extreme Ultraviolet Imaging in an Extended Reflection Mode using Coherent Fresnel Ptychography

    E-Print Network [OSTI]

    Seaberg, Matthew D; Gardner, Dennis F; Shanblatt, Elisabeth R; Murnane, Margaret M; Kapteyn, Henry C; Adams, Daniel E

    2013-01-01T23:59:59.000Z

    We demonstrate high resolution extreme ultraviolet (EUV) coherent diffractive imaging in the most general reflection geometry by combining ptychography with tilted plane correction. This method makes it possible to image extended surfaces at any angle of incidence. Refocused light from a tabletop coherent high harmonic light source at 29 nm illuminates a nanopatterned surface at 45 degree angle of incidence. The reconstructed image contains quantitative amplitude and phase (in this case pattern height) information, comparing favorably with both scanning electron microscope and atomic force microscopy images. In the future, this approach will enable imaging of complex surfaces and nanostructures with sub-10 nm-spatial resolution and fs-temporal resolution, which will impact a broad range of nanoscience and nanotechnology including for direct application in actinic inspection in support of EUV lithography.

  11. Reliable self-powered highly spectrum-selective ZnO ultraviolet photodetectors

    SciTech Connect (OSTI)

    Shen, H. [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China) [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shan, C. X., E-mail: shancx@ciomp.ac.cn, E-mail: binghuili@163.com; Li, B. H., E-mail: shancx@ciomp.ac.cn, E-mail: binghuili@163.com; Shen, D. Z. [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)] [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Xuan, B. [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)] [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

    2013-12-02T23:59:59.000Z

    Ultraviolet photodetectors (PDs) have been fabricated from p-ZnO:(Li,N)/n-ZnO structures in this Letter. The PDs can operate without any external power supply and show response only to a very narrow spectrum range. The self-power character of the devices is due to the built-in electric field in the p-n junctions that can separate the photogenerated electrons and holes while the high spectrum-selectivity has been attributed to the filter effect of the neutral region in the ZnO:(Li,N) layer. The performance of the self-powered highly spectrum-selective PDs degrades little after five months, indicating their good reliability.

  12. Ultraviolet stimulated electron source for use with low energy plasma instrument calibration

    E-Print Network [OSTI]

    Henderson, Kevin; Funsten, Herb; MacDonald, Elizabeth

    2011-01-01T23:59:59.000Z

    We report the development of a versatile, compact, low to medium energy electron source. A collimated, monoenergetic beam of electrons, up to 50 mm in diameter, is produced with energies ranging from 0.03 to 30 keV. A uniform electron beam profile is generated by illuminating a metal cathode plate with a near ultraviolet (UV) light emitting diode (LED). A parallel electric field accelerates the electrons away from the cathode plate towards a grounded grid. The beam intensity can be controlled from 10 - 10^9 electrons cm-2 s-1 and the angular divergence of the beam is less than 1 degree FWHM for energies greater than 1 keV.

  13. Tailoring plasmon resonances in the deep-ultraviolet by size-tunable fabrication of aluminum nanostructures

    SciTech Connect (OSTI)

    Taguchi, Atsushi [Nanophotonics Laboratory, RIKEN, Wako, Saitama 351-0198 (Japan); Saito, Yuika; Watanabe, Koichi; Yijian, Song [Department of Applied Physics, Osaka University, Suita, Osaka 565-0871 (Japan); Kawata, Satoshi [Nanophotonics Laboratory, RIKEN, Wako, Saitama 351-0198 (Japan); Department of Applied Physics, Osaka University, Suita, Osaka 565-0871 (Japan)

    2012-08-20T23:59:59.000Z

    Localized surface plasmon resonances were controlled at deep-ultraviolet (DUV) wavelengths by fabricating aluminum (Al) nanostructures in a size-controllable manner. Plasmon resonances were obtained at wavelengths from near-UV down to 270 nm (4.6 eV) depending on the fabricated structure size. Such precise size control was realized by the nanosphere lithography technique combined with additional microwave heating to shrink the spaces in a close-packed monolayer of colloidal nanosphere masks. By adjusting the microwave heating time, the sizes of the Al nanostructures could be controlled from 80 nm to 50 nm without the need to use nanosphere beads of different sizes. With the outstanding controllability and versatility of the presented fabrication technique, the fabricated Al nanostructure is promising for use as a DUV plasmonic substrate, a light-harvesting platform for mediating strong light-matter interactions between UV photons and molecules placed near the metal nanostructure.

  14. Tunable vacuum ultraviolet laser based spectrometer for angle resolved photoemission spectroscopy

    SciTech Connect (OSTI)

    Jiang, Rui; Mou, Daixiang; Wu, Yun; Huang, Lunan; Kaminski, Adam [Division of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States) [Division of Materials Science and Engineering, Ames Laboratory, Ames, Iowa 50011 (United States); Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); McMillen, Colin D.; Kolis, Joseph [Department of Chemistry, Clemson University, Clemson, South Carolina 29634 (United States)] [Department of Chemistry, Clemson University, Clemson, South Carolina 29634 (United States); Giesber, Henry G.; Egan, John J. [Advanced Photonic Crystals LLC, Fort Mill, South Carolina 29708 (United States)] [Advanced Photonic Crystals LLC, Fort Mill, South Carolina 29708 (United States)

    2014-03-15T23:59:59.000Z

    We have developed an angle-resolved photoemission spectrometer with tunable vacuum ultraviolet laser as a photon source. The photon source is based on the fourth harmonic generation of a near IR beam from a Ti:sapphire laser pumped by a CW green laser and tunable between 5.3 eV and 7 eV. The most important part of the set-up is a compact, vacuum enclosed fourth harmonic generator based on potassium beryllium fluoroborate crystals, grown hydrothermally in the US. This source can deliver a photon flux of over 10{sup 14} photon/s. We demonstrate that this energy range is sufficient to measure the k{sub z} dispersion in an iron arsenic high temperature superconductor, which was previously only possible at synchrotron facilities.

  15. Time exposure performance of Mo-Au Gibbsian segregating alloys for extreme ultraviolet collector optics

    SciTech Connect (OSTI)

    Qiu Huatan; Srivastava, Shailendra N.; Thompson, Keith C.; Neumann, Martin J.; Ruzic, David N

    2008-05-01T23:59:59.000Z

    Successful implementation of extreme ultraviolet (EUV) lithography depends on research and progress toward minimizing collector optics degradation from intense plasma erosion and debris deposition. Thus studying the surface degradation process and implementing innovative methods, which could enhance the surface chemistry causing the mirrors to suffer less damage, is crucial for this technology development. A Mo-Au Gibbsian segregation (GS) alloy is deposited on Si using a dc dual-magnetron cosputtering system and the damage is investigated as a result of time dependent exposure in an EUV source. A thin Au segregating layer is maintained through segregation during exposure, even though overall erosion in the Mo-Au sample is taking place in the bulk. The reflective material, Mo, underneath the segregating layer is protected by this sacrificial layer, which is lost due to preferential sputtering. In addition to theoretical work, experimental results are presented on the effectiveness of the GS alloys to be used as potential EUV collector optics material.

  16. Deep ultraviolet photoluminescence of Tm-doped AlGaN alloys

    SciTech Connect (OSTI)

    Nepal, N.; Zavada, J. M. [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Lee, D. S.; Steckl, A. J. [Nanoelectronics Laboratory, University of Cincinnati, Cincinnati, Ohio 45221 (United States); Sedhain, A.; Lin, J. Y.; Jiang, H. X. [Department of Electrical and Computer Engineering and Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States)

    2009-03-16T23:59:59.000Z

    The ultraviolet (UV) photoluminescence (PL) properties of Tm-doped Al{sub x}Ga{sub 1-x}N (0.39{<=}x{<=}1) alloys grown by solid-source molecular beam epitaxy were probed using above-bandgap excitation from a laser source at 197 nm. The PL spectra show dominant UV emissions at 298 and 358 nm only for samples with x=1 and 0.81. Temperature dependence of the PL intensities of these emission lines reveals exciton binding energies of 150 and 57 meV, respectively. The quenching of these UV emissions appears related to the thermal activation of the excitons bound to rare-earth structured isovalent (RESI) charge traps, which transfer excitonic energy to Tm{sup 3+} ions resulting in the UV emissions. A model of the RESI trap levels in AlGaN alloys is presented.

  17. Terahertz radiation mixer

    DOE Patents [OSTI]

    Wanke, Michael C. (Albuquerque, NM); Allen, S. James (Santa Barbara, CA); Lee, Mark (Albuquerque, NM)

    2008-05-20T23:59:59.000Z

    A terahertz radiation mixer comprises a heterodyned field-effect transistor (FET) having a high electron mobility heterostructure that provides a gatable two-dimensional electron gas in the channel region of the FET. The mixer can operate in either a broadband pinch-off mode or a narrowband resonant plasmon mode by changing a grating gate bias of the FET. The mixer can beat an RF signal frequency against a local oscillator frequency to generate an intermediate frequency difference signal in the microwave region. The mixer can have a low local oscillator power requirement and a large intermediate frequency bandwidth. The terahertz radiation mixer is particularly useful for terahertz applications requiring high resolution.

  18. National Ambient Radiation Database

    SciTech Connect (OSTI)

    Dziuban, J.; Sears, R.

    2003-02-25T23:59:59.000Z

    The U.S. Environmental Protection Agency (EPA) recently developed a searchable database and website for the Environmental Radiation Ambient Monitoring System (ERAMS) data. This site contains nationwide radiation monitoring data for air particulates, precipitation, drinking water, surface water and pasteurized milk. This site provides location-specific as well as national information on environmental radioactivity across several media. It provides high quality data for assessing public exposure and environmental impacts resulting from nuclear emergencies and provides baseline data during routine conditions. The database and website are accessible at www.epa.gov/enviro/. This site contains (1) a query for the general public which is easy to use--limits the amount of information provided, but includes the ability to graph the data with risk benchmarks and (2) a query for a more technical user which allows access to all of the data in the database, (3) background information on ER AMS.

  19. Time encoded radiation imaging

    DOE Patents [OSTI]

    Marleau, Peter; Brubaker, Erik; Kiff, Scott

    2014-10-21T23:59:59.000Z

    The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.

  20. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    2000-12-26T23:59:59.000Z

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  1. Semiconductor radiation detector

    DOE Patents [OSTI]

    Patt, Bradley E. (Sherman Oaks, CA); Iwanczyk, Jan S. (Los Angeles, CA); Tull, Carolyn R. (Orinda, CA); Vilkelis, Gintas (Westlake Village, CA)

    2002-01-01T23:59:59.000Z

    A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

  2. General Relativistic Radiative Transfer

    E-Print Network [OSTI]

    S. Knop; P. H. Hauschildt; E. Baron

    2006-11-30T23:59:59.000Z

    We present a general method to calculate radiative transfer including scattering in the continuum as well as in lines in spherically symmetric systems that are influenced by the effects of general relativity (GR). We utilize a comoving wavelength ansatz that allows to resolve spectral lines throughout the atmosphere. The used numerical solution is an operator splitting (OS) technique that uses a characteristic formal solution. The bending of photon paths and the wavelength shifts due to the effects of GR are fully taken into account, as is the treatment of image generation in a curved spacetime. We describe the algorithm we use and demonstrate the effects of GR on the radiative transport of a two level atom line in a neutron star like atmosphere for various combinations of continuous and line scattering coefficients. In addition, we present grey continuum models and discuss the effects of different scattering albedos on the emergent spectra and the determination of effective temperatures and radii of neutron star atmospheres.

  3. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, William J. (Idaho Falls, ID); Lessing, Paul A. (Idaho Falls, ID)

    1998-01-01T23:59:59.000Z

    A composition for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm.sup.3 and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile.

  4. Radiation shielding composition

    DOE Patents [OSTI]

    Quapp, W.J.; Lessing, P.A.

    1998-07-28T23:59:59.000Z

    A composition is disclosed for use as a radiation shield. The shield is a concrete product containing a stable uranium aggregate for attenuating gamma rays and a neutron absorbing component, the uranium aggregate and neutron absorbing component being present in the concrete product in sufficient amounts to provide a concrete having a density between about 4 and about 15 grams/cm{sup 3} and which will at a predetermined thickness, attenuate gamma rays and absorb neutrons from a radioactive material of projected gamma ray and neutron emissions over a determined time period. The composition is preferably in the form of a container for storing radioactive materials that emit gamma rays and neutrons. The concrete container preferably comprises a metal liner and/or a metal outer shell. The resulting radiation shielding container has the potential of being structurally sound, stable over a long period of time, and, if desired, readily mobile. 5 figs.

  5. Multilayer radiation shield

    DOE Patents [OSTI]

    Urbahn, John Arthur (Saratoga Springs, NY); Laskaris, Evangelos Trifon (Niskayuna, NY)

    2009-06-16T23:59:59.000Z

    A power generation system including: a generator including a rotor including a superconductive rotor coil coupled to a rotatable shaft; a first prime mover drivingly coupled to the rotatable shaft; and a thermal radiation shield, partially surrounding the rotor coil, including at least a first sheet and a second sheet spaced apart from the first sheet by centripetal force produced by the rotatable shaft. A thermal radiation shield for a generator including a rotor including a super-conductive rotor coil including: a first sheet having at least one surface formed from a low emissivity material; and at least one additional sheet having at least one surface formed from a low emissivity material spaced apart from the first sheet by centripetal force produced by the rotatable shaft, wherein each successive sheet is an incrementally greater circumferential arc length and wherein the centripetal force shapes the sheets into a substantially catenary shape.

  6. Handheld CZT radiation detector

    DOE Patents [OSTI]

    Murray, William S.; Butterfield, Kenneth B.; Baird, William

    2004-08-24T23:59:59.000Z

    A handheld CZT radiation detector having a CZT gamma-ray sensor, a multichannel analyzer, a fuzzy-logic component, and a display component is disclosed. The CZT gamma-ray sensor may be a coplanar grid CZT gamma-ray sensor, which provides high-quality gamma-ray analysis at a wide range of operating temperatures. The multichannel analyzer categorizes pulses produce by the CZT gamma-ray sensor into channels (discrete energy levels), resulting in pulse height data. The fuzzy-logic component analyzes the pulse height data and produces a ranked listing of radioisotopes. The fuzzy-logic component is flexible and well-suited to in-field analysis of radioisotopes. The display component may be a personal data assistant, which provides a user-friendly method of interacting with the detector. In addition, the radiation detector may be equipped with a neutron sensor to provide an enhanced mechanism of sensing radioactive materials.

  7. Far-ultraviolet observations of comet C/2001 Q4 (NEAT) with FIMS/SPEAR

    SciTech Connect (OSTI)

    Lim, Y.-M.; Min, K.-W. [Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Feldman, P. D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Han, W. [Korea Astronomy and Space Science Institute (KASI), 776 Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Edelstein, J., E-mail: ymlim@kaist.ac.kr [Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States)

    2014-02-01T23:59:59.000Z

    We present the results of far-ultraviolet observations of comet C/2001 Q4 (NEAT) that were made with the Far-Ultraviolet Imaging Spectrograph on board the Korean satellite STSAT-1. The observations were conducted in two campaigns during its perihelion approach between 2004 May 8 and 15. Based on the scanning mode observations in the wavelength band of 1400-1700 Å, we have constructed an image of the comet with an angular size of 5°×5°, which corresponds to the central coma region. Several important fluorescence emission lines were detected including S I multiplets at 1429 and 1479 Å, C I multiplets at 1561 and 1657 Å, and the CO A{sup 1}?-X{sup 1}?{sup +} Fourth Positive system; we have estimated the production rates of the corresponding species from the fluxes of these emission lines. The estimated production rate of CO was Q {sub CO} = (2.65 ± 0.63) × 10{sup 28} s{sup –1}, which is 6.2%-7.4% of the water production rate and is consistent with earlier predictions. The average carbon production rate was estimated to be Q{sub C} = ?1.59 × 10{sup 28} s{sup –1}, which is ?60% of the CO production rate. However, the observed carbon profile was steeper than that predicted using the two-component Haser model in the inner coma region, while it was consistent with the model in the outer region. The average sulfur production rate was Q{sub S} = (4.03±1.03) × 10{sup 27} s{sup –1}, which corresponds to ?1% of the water production rate.

  8. STUDYING LARGE- AND SMALL-SCALE ENVIRONMENTS OF ULTRAVIOLET LUMINOUS GALAXIES

    SciTech Connect (OSTI)

    Basu-Zych, Antara R.; Schiminovich, David [Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Heinis, Sebastien; Heckman, Tim; Bianchi, Luciana [Center for Astrophysical Sciences, The Johns Hopkins' University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Overzier, Roderik [Max-Planck-Institut fuer Astrophysik, D-85748 Garching (Germany); Zamojski, Michel; Barlow, Tom A.; Conrow, Tim; Forster, Karl G.; Friedman, Peter G.; Martin, D. Christopher; Morrissey, Patrick [California Institute of Technology, MC 405-47, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Ilbert, Olivier [Institute for Astronomy, 2680 Woodlawn Dr., University of Hawaii, Honolulu, HI 96822 (United States); Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Donas, Jose; Milliard, Bruno [Laboratoire d'Astrophysique de Marseille, BP8, Traverse du Siphon, F-13376 Marseille (France); Lee, Young-Wook [Center for Space Astrophysics, Yonsei University, Seoul 120-749 (Korea, Republic of); Madore, Barry F. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Neff, Susan G. [Laboratory for Astronomy and Solar Physics, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)], E-mail: antara@astro.columbia.edu (and others)

    2009-07-10T23:59:59.000Z

    Studying the environments of 0.4 < z < 1.2 ultraviolet (UV)-selected galaxies, as examples of extreme star-forming galaxies (with star formation rates (SFRs) in the range of 3-30 M{sub sun} yr{sup -1}), we explore the relationship between high rates of star formation, host halo mass, and pair fractions. We study the large- and small-scale environments of local ultraviolet luminous galaxies (UVLGs) by measuring angular correlation functions. We cross-correlate these systems with other galaxy samples: a volume-limited sample (ALL), a blue luminous galaxy sample, and a luminous red galaxy (LRG) sample. We determine the UVLG comoving correlation length to be r{sub 0} = 4.8{sup +11.6}{sub -2.4} h {sup -1} Mpc at (z) = 1.0, which is unable to constrain the halo mass for this sample. However, we find that UVLGs form close (separation <30 kpc) pairs with the ALL sample, but do not frequently form pairs with LRGs. A rare subset of UVLGs, those with the highest FUV surface brightnesses, are believed to be local analogs of high-redshift Lyman break galaxies (LBGs) and are called Lyman break analogs (LBAs). LBGs and LBAs share similar characteristics (i.e., color, size, surface brightness, specific SFRs, metallicities, and dust content). Recent Hubble Space Telescope images of z {approx} 0.2 LBAs show disturbed morphologies, signs of mergers and interactions. UVLGs may be influenced by interactions with other galaxies and we discuss this result in terms of other high star-forming, merging systems.

  9. The Morality of Collective Harm

    E-Print Network [OSTI]

    Nefsky, Julia

    2012-01-01T23:59:59.000Z

    global warming poses a serious threat; so we all ought to conserve electricity,electricity. That is all wonderful, but it does little or nothing to stop global warming,

  10. Training For Radiation Emergencies, First Responder Operations...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Training For Radiation Emergencies, First Responder Operations - Instructors Guide Training For Radiation Emergencies, First Responder Operations - Instructors Guide COURSE...

  11. POLARIZATION OF THE COSMIC BACKGROUND RADIATION

    E-Print Network [OSTI]

    Lubin, Philip Lubin

    2010-01-01T23:59:59.000Z

    a 45° angle. Radiation whose electric field (polarization)radiation field, it can be uniquely characterized by its electric

  12. Global aspects of radiation memory

    E-Print Network [OSTI]

    J. Winicour

    2014-10-11T23:59:59.000Z

    Gravitational radiation has a memory effect represented by a net change in the relative positions of test particles. Both the linear and nonlinear sources proposed for this radiation memory are of the "electric" type, or E mode, as characterized by the even parity of the polarization pattern. Although "magnetic" type, or B mode, radiation memory is mathematically possible, no physically realistic source has been identified. There is an electromagnetic counterpart to radiation memory in which the velocity of charged particles obtain a net "kick". Again, the physically realistic sources of electromagnetic radiation memory that have been identified are of the electric type. In this paper, a global null cone description of the electromagnetic field is applied to establish the non-existence of B mode radiation memory and the non-existence of E mode radiation memory due to a bound charge distribution.

  13. Method for microbeam radiation therapy

    DOE Patents [OSTI]

    Slatkin, D.N.; Dilmanian, F.A.; Spanne, P.O.

    1994-08-16T23:59:59.000Z

    A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue. No Drawings

  14. OPTICAL CONSTANTS OF SILICON CARBIDE FOR ASTROPHYSICAL APPLICATIONS. II. EXTENDING OPTICAL FUNCTIONS FROM INFRARED TO ULTRAVIOLET USING SINGLE-CRYSTAL ABSORPTION SPECTRA

    SciTech Connect (OSTI)

    Hofmeister, A. M.; Pitman, K. M. [Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130 (United States); Goncharov, A. F. [Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015 (United States); Speck, A. K. [Department of Physics and Astronomy, University of Missouri-Columbia, Columbia, MO 65211 (United States)], E-mail: hofmeist@levee.wustl.edu

    2009-05-10T23:59:59.000Z

    Laboratory measurements of unpolarized and polarized absorption spectra of various samples and crystal structures of silicon carbide (SiC) are presented from 1200-35000 cm{sup -1} ({lambda} {approx} 8-0.28 {mu}m) and used to improve the accuracy of optical functions (n and k) from the infrared (IR) to the ultraviolet (UV). Comparison with previous {lambda} {approx} 6-20 {mu}m thin-film spectra constrains the thickness of the films and verifies that recent IR reflectivity data provide correct values for k in the IR region. We extract n and k needed for radiative transfer models using a new 'difference method', which utilizes transmission spectra measured from two SiC single-crystals with different thicknesses. This method is ideal for near-IR to visible regions where absorbance and reflectance are low and can be applied to any material. Comparing our results with previous UV measurements of SiC, we distinguish between chemical and structural effects at high frequency. We find that for all spectral regions, 3C ({beta}-SiC) and the E-vector perpendicular c-vector polarization of 6H (a type of {alpha}-SiC) have almost identical optical functions that can be substituted for each other in modeling astronomical environments. Optical functions for E-vector || c-vector of 6H SiC have peaks shifted to lower frequency, permitting identification of this structure below {lambda} {approx} 4 {mu}m. The onset of strong UV absorption for pure SiC occurs near 0.2 {mu}m, but the presence of impurities redshifts the rise to 0.33 {mu}m. Optical functions are similarly impacted. Such large differences in spectral characteristics due to structural and chemical effects should be observable and provide a means to distinguish chemical variation of SiC dust in space.

  15. Study of extreme-ultraviolet emission and properties of a coronal streamer from PROBA2/SWAP, HINODE/EIS and Mauna Loa Mk4 observations

    SciTech Connect (OSTI)

    Goryaev, F.; Slemzin, V.; Vainshtein, L. [P.N. Lebedev Physical Institute of the RAS (LPI), Moscow 119991 (Russian Federation); Williams, David R., E-mail: goryaev_farid@mail.ru [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Surrey, RH5 6NT (United Kingdom)

    2014-02-01T23:59:59.000Z

    Wide-field extreme-ultraviolet (EUV) telescopes imaging in spectral bands sensitive to 1 MK plasma on the Sun often observe extended, ray-like coronal structures stretching radially from active regions to distances of 1.5-2 R {sub ?}, which represent the EUV counterparts of white-light streamers. To explain this phenomenon, we investigated the properties of a streamer observed on 2010 October 20 and 21, by the PROBA2/SWAP EUV telescope together with the Hinode/EIS (HOP 165) and the Mauna Loa Mk4 white-light coronagraph. In the SWAP 174 Å band comprising the Fe IX-Fe XI lines, the streamer was detected to a distance of 2 R {sub ?}. We assume that the EUV emission is dominated by collisional excitation and resonant scattering of monochromatic radiation coming from the underlying corona. Below 1.2 R {sub ?}, the plasma density and temperature were derived from the Hinode/EIS data by a line-ratio method. Plasma conditions in the streamer and in the background corona above 1.2 R {sub ?} from the disk center were determined by forward-modeling the emission that best fit the observational data in both EUV and white light. It was found that the plasma in the streamer above 1.2 R {sub ?} is nearly isothermal, with a temperature of T = 1.43 ± 0.08 MK. The hydrostatic scale-height temperature determined from the evaluated density distribution was significantly higher (1.72 ± 0.08 MK), which suggests the existence of outward plasma flow along the streamer. We conclude that, inside the streamer, collisional excitation provided more than 90% of the observed EUV emission, whereas, in the background corona, the contribution of resonance scattering became comparable with that of collisions at R ? 2 R {sub ?}.

  16. Shining New Light on Protein Structure and Function thru Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy

    SciTech Connect (OSTI)

    Wallace,B.

    2005-01-01T23:59:59.000Z

    Circular dichroism (CD) spectroscopy has been employed for more than 50 years for the study of the structure and dynamics of proteins. It is now a workhorse of structural biology, finding applications in the determination of protein secondary structures, monitoring and deciphering protein folding, examining macromolecular interactions, and defining and quantitating protein-ligand binding. For the most part, CD studies have used laboratory-based instruments to measure electronic transitions in the far (190-250 nm), near ultraviolet (UV) (250-300 nm) and visible (> 400 nm) wavelength ranges, which have enabled studies of polypeptide backbones, aromatic amino acids and colored chromophores, respectively. Additional transitions exist at lower wavelengths in the vacuum ultraviolet (VUV) region (<190 nm); however, these transitions tend to be inaccessible to conventional CD instruments, due to the low intensity of their Xenon arc lamp light sources at wavelengths below190 nm. In 1980, the first synchrotron-based CD instruments were constructed, which took advantage of the high photon flux available from synchrotron light sources at these wavelengths. However, the technique of synchrotron radiation circular dichroism (SRCD) did not really take off until enabling studies had been done to show that additional data were obtainable for proteins in the VUV region, that these data were readily accessible with modern beamlines, and most importantly, that new applications of these data existed in structural molecular biology.

  17. Patient-Physician Communication About Complementary and Alternative Medicine in a Radiation Oncology Setting

    SciTech Connect (OSTI)

    Ge Jin [Perelman School of Medicine at University of Pennsylvania, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States)] [Perelman School of Medicine at University of Pennsylvania, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Fishman, Jessica [Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States) [Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Annenberg School for Communication at University of Pennsylvania, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Vapiwala, Neha [Abramson Comprehensive Cancer Center, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States) [Abramson Comprehensive Cancer Center, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Department of Radiation Oncology, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Li, Susan Q.; Desai, Krupali [Department of Family Medicine and Community Health, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States)] [Department of Family Medicine and Community Health, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Xie, Sharon X. [Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States)] [Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Mao, Jun J., E-mail: maoj@uphs.upenn.edu [Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Abramson Comprehensive Cancer Center, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States); Department of Family Medicine and Community Health, University of Pennsylvania Health System, Philadelphia, Pennsylvania (United States)

    2013-01-01T23:59:59.000Z

    Purpose: Despite the extensive use of complementary and alternative medicine (CAM) among cancer patients, patient-physician communication regarding CAM therapies remains limited. This study quantified the extent of patient-physician communication about CAM and identified factors associated with its discussion in radiation therapy (RT) settings. Methods and Materials: We conducted a cross-sectional survey of 305 RT patients at an urban academic cancer center. Patients with different cancer types were recruited in their last week of RT. Participants self-reported their demographic characteristics, health status, CAM use, patient-physician communication regarding CAM, and rationale for/against discussing CAM therapies with physicians. Multivariate logistic regression was used to identify relationships between demographic/clinical variables and patients' discussion of CAM with radiation oncologists. Results: Among the 305 participants, 133 (43.6%) reported using CAM, and only 37 (12.1%) reported discussing CAM therapies with their radiation oncologists. In multivariate analyses, female patients (adjusted odds ratio [AOR] 0.45, 95% confidence interval [CI] 0.21-0.98) and patients with full-time employment (AOR 0.32, 95% CI 0.12-0.81) were less likely to discuss CAM with their radiation oncologists. CAM users (AOR 4.28, 95% CI 1.93-9.53) were more likely to discuss CAM with their radiation oncologists than were non-CAM users. Conclusions: Despite the common use of CAM among oncology patients, discussions regarding these treatments occur rarely in the RT setting, particularly among female and full-time employed patients. Clinicians and patients should incorporate discussions of CAM to guide its appropriate use and to maximize possible benefit while minimizing potential harm.

  18. Radiation imaging apparatus

    DOE Patents [OSTI]

    Anger, Hal O. (Berkeley, CA); Martin, Donn C. (Berkeley, CA); Lampton, Michael L. (Berkeley, CA)

    1983-01-01T23:59:59.000Z

    A radiation imaging system using a charge multiplier and a position sensitive anode in the form of periodically arranged sets of interconnected anode regions for detecting the position of the centroid of a charge cloud arriving thereat from the charge multiplier. Various forms of improved position sensitive anodes having single plane electrode connections are disclosed. Various analog and digital signal processing systems are disclosed, including systems which use the fast response of microchannel plates, anodes and preamps to perform scintillation pulse height analysis digitally.

  19. Radiation Field on Superspace

    E-Print Network [OSTI]

    P. F. Gonzalez-Diaz

    1994-03-18T23:59:59.000Z

    We study the dynamics of multiwormhole configurations within the framework of the Euclidean Polyakov approach to string theory, incorporating a modification to the Hamiltonian which makes it impossible to interpret the Coleman Alpha parameters of the effective interactions as a quantum field on superspace, reducible to an infinite tower of fields on space-time. We obtain a Planckian probability measure for the Alphas that allows $\\frac{1}{2}\\alpha^{2}$ to be interpreted as the energy of the quanta of a radiation field on superspace whose values may still fix the coupling constants.

  20. Solar radiation intensity calculations 

    E-Print Network [OSTI]

    Levine, Randolph Steven

    1978-01-01T23:59:59.000Z

    , radiation per unit area per unit time, on a flat-plate collector is given by: I = I cos B (2. 1a) where I is the solar constant. insolation received at one astro- nomical unit from the sun. Since clear sky conditions are assumed I o w i 1 1 b e a.... INSOLATION EQUATIONS TABLE OF CONTENTS Page III. RESULTS AND CONCLUSIONS REFERENCES APPENDIX VITA 25 47 48 52 Vi LIST OF TABLES TABLE I. Optimal Inclination for Ap=O, No Checks for Ip &0 and a Time Independent Solar Constant. II. Optimal...

  1. Radiative ?(1S) decays

    E-Print Network [OSTI]

    Baringer, Philip S.

    1990-03-01T23:59:59.000Z

    — wW~ ii~ ~ + v~ 1''&WV'' V 0.20 0.45 0.70 ~y ~ EBFA~ 0.95 l.20 FIG. 4. Energy spectrum (normalized to beam energy) for Y~y2(h+h ) event candidates, with continuum data and ex- pected background from Y~m 2(h +h ) overplotted. 40 30— ~ 20— LLI IO— hl...PHYSICAL REVIEW 0 VOLUME 41, NUMBER 5 Radiative T(lS) decays 1 MARCH 1990 R. Fulton, M. Hempstead, T. Jensen, D. R. Johnson, H. Kagan, R. Kass, F. Morrow, and J. Whitmore Ohio State University, Columbus, Ohio 43210 W.-Y. Chen, J. Dominick, R. L. Mc...

  2. Radiation imaging apparatus

    DOE Patents [OSTI]

    Anger, H.O.; Martin, D.C.; Lampton, M.L.

    1983-07-26T23:59:59.000Z

    A radiation imaging system using a charge multiplier and a position sensitive anode in the form of periodically arranged sets of interconnected anode regions for detecting the position of the centroid of a charge cloud arriving thereat from the charge multiplier. Various forms of improved position sensitive anodes having single plane electrode connections are disclosed. Various analog and digital signal processing systems are disclosed, including systems which use the fast response of microchannel plates, anodes and preamps to perform scintillation pulse height analysis digitally. 15 figs.

  3. Radiation Emergency Procedure Demonstrations

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeedingTechnicalPurchase, Delivery, andSmartRadiation Effects

  4. Radiation Safety Test

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)IntegratedSpeedingTechnicalPurchase, Delivery, andSmartRadiation

  5. Radiation Control Program and Radiation Control Act (Nebraska)

    Broader source: Energy.gov [DOE]

    This statute authorizes the state to implement a regulatory program for sources of radiation, and contains rules for the Department, licensing and registration, and taxation of radioactive materials.

  6. Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

    SciTech Connect (OSTI)

    Scott Wilde, Raymond Keegan

    2008-07-01T23:59:59.000Z

    The countrate response of a gamma spectrometry system from a neutron radiation source behind a plane of moderating material doped with a nuclide of a large radiative neutron capture cross-section exhibits a countrate response analogous to a gamma radiation source at the same position from the detector. Using a planar, surface area of the neutron moderating material exposed to the neutron radiation produces a larger area under the prompt gamma ray peak in the detector than a smaller area of dimensions relative to the active volume of the gamma detection system.

  7. RADIATIVE RAYLEIGH-TAYLOR INSTABILITIES

    SciTech Connect (OSTI)

    Jacquet, Emmanuel [Laboratoire de Mineralogie et Cosmochimie de Museum (LMCM), CNRS and Museum National d'Histoire Naturelle, UMR 7202, 57 rue Cuvier, 75005 Paris (France); Krumholz, Mark R., E-mail: ejacquet@mnhn.fr, E-mail: krumholz@ucolick.org [Department of Astronomy, University of California, Santa Cruz, CA 95064 (United States)

    2011-04-01T23:59:59.000Z

    We perform analytic linear stability analyses of an interface separating two stratified media threaded by a radiation flux, a configuration relevant in several astrophysical contexts. We develop a general framework for analyzing such systems and obtain exact stability conditions in several limiting cases. In the optically thin, isothermal regime, where the discontinuity is chemical in nature (e.g., at the boundary of a radiation pressure-driven H II region), radiation acts as part of an effective gravitational field, and instability arises if the effective gravity per unit volume toward the interface overcomes that away from it. In the optically thick 'adiabatic' regime where the total (gas plus radiation) specific entropy of a Lagrangian fluid element is conserved, for example at the edge of radiation pressure-driven bubble around a young massive star, we show that radiation acts like a modified equation of state and derive a generalized version of the classical Rayleigh-Taylor stability condition.

  8. Radiator Labs | Department of Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiation Protection Radiation Protection Regulations: TheCompetition » Radiator Labs

  9. Split SUSY Radiates Flavor

    E-Print Network [OSTI]

    Matthew Baumgart; Daniel Stolarski; Thomas Zorawski

    2014-09-19T23:59:59.000Z

    Radiative flavor models where the hierarchies of Standard Model (SM) fermion masses and mixings are explained via loop corrections are elegant ways to solve the SM flavor puzzle. Here we build such a model in the context of Mini-Split Supersymmetry (SUSY) where both flavor and SUSY breaking occur at a scale of 1000 TeV. This model is consistent with the observed Higgs mass, unification, and WIMP dark matter. The high scale allows large flavor mixing among the sfermions, which provides part of the mechanism for radiative flavor generation. In the deep UV, all flavors are treated democratically, but at the SUSY breaking scale, the third, second, and first generation Yukawa couplings are generated at tree level, one loop, and two loops, respectively. Save for one, all the dimensionless parameters in the theory are O(1), with the exception being a modest and technically natural tuning that explains both the smallness of the bottom Yukawa coupling and the largeness of the Cabibbo angle.

  10. Radiation Embrittlement Archive Project

    SciTech Connect (OSTI)

    Klasky, Hilda B [ORNL] [ORNL; Bass, Bennett Richard [ORNL] [ORNL; Williams, Paul T [ORNL] [ORNL; Phillips, Rick [ORNL] [ORNL; Erickson, Marjorie A [ORNL] [ORNL; Kirk, Mark T [ORNL] [ORNL; Stevens, Gary L [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    The Radiation Embrittlement Archive Project (REAP), which is being conducted by the Probabilistic Integrity Safety Assessment (PISA) Program at Oak Ridge National Laboratory under funding from the U.S. Nuclear Regulatory Commission s (NRC) Office of Nuclear Regulatory Research, aims to provide an archival source of information about the effect of neutron radiation on the properties of reactor pressure vessel (RPV) steels. Specifically, this project is an effort to create an Internet-accessible RPV steel embrittlement database. The project s website, https://reap.ornl.gov, provides information in two forms: (1) a document archive with surveillance capsule(s) reports and related technical reports, in PDF format, for the 104 commercial nuclear power plants (NPPs) in the United States, with similar reports from other countries; and (2) a relational database archive with detailed information extracted from the reports. The REAP project focuses on data collected from surveillance capsule programs for light-water moderated, nuclear power reactor vessels operated in the United States, including data on Charpy V-notch energy testing results, tensile properties, composition, exposure temperatures, neutron flux (rate of irradiation damage), and fluence, (Fast Neutron Fluence a cumulative measure of irradiation for E>1 MeV). Additionally, REAP contains data from surveillance programs conducted in other countries. REAP is presently being extended to focus on embrittlement data analysis, as well. This paper summarizes the current status of the REAP database and highlights opportunities to access the data and to participate in the project.

  11. EPIDEMIOLOGICAL STUDIES ON RADIATION CARCINOGENESIS IN HUMAN POPULATIONS FOLLOWING ACUTE EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01T23:59:59.000Z

    EXPOSURE: NUCLEAR EXPLOSIONS AND MEDICAL RADIATION . Jacobexposed to nuclear explosions and medical radiation. Sinceto nuclear explo ions or medical radiation, describes the

  12. On the Escape of Ionizing Radiation from Starbursts

    E-Print Network [OSTI]

    Heckman, T; Meurer, G; Leitherer, C; Calzetti, D; Martin, C L

    2001-01-01T23:59:59.000Z

    Far-ultraviolet spectra obtained with $FUSE$ show that the strong $CII\\lambda$1036 interstellar absorption-line is essentially black in five of the UV-brightest local starburst galaxies. Since the opacity of the neutral ISM below the Lyman-edge will be significantly larger than in the $CII$ line, these data provide strong constraints on the escape of ionizing radiation from these starbursts. Interpreted as a a uniform absorbing slab, the implied optical depth at the Lyman edge is huge ($\\tau_0 \\geq 10^2$). Alternatively, the areal covering factor of opaque material is typically $\\geq$ 94%. Thus, the fraction of ionizing stellar photons that escape the ISM of each galaxy is small: our conservative estimates typically yield $f_{esc} \\leq 6%$. Inclusion of extinction due to dust will further decrease $f_{esc}$. An analogous analysis of the rest-UV spectrum of the star-forming galaxy $MS 1512-CB58$ at $z$ =2.7 leads to similar constraints on $f_{esc}$. These new results agree with the constraints provided by dire...

  13. Coastal-inland solar radiation difference study. Final report

    SciTech Connect (OSTI)

    Bach, W.D. Jr.; Vukovich, F.M.

    1980-04-01T23:59:59.000Z

    The purpose of this study was to quantify the characteristics of solar insolation in the coastal zone and to determine the effect of the sea breeze circulation on the global insolation. In order to satisfy these objectives, a six station sampling network was established in the coastal plain of southeastern North Carolina, where previous evidence has indicated that the sea breeze circulation is almost a daily occurrence from late May through October. Three sites (Sloop Point, Onslow Beach, and Cape Fear Technical Institute (CFTI)) were located near the coast (coastal sites) to assess the insolation at the coast. A site (Clinton) was located in an area seldom affected by the sea breeze (about 100 km from the coast). Two additional sites, Wallace and Ellis Airport, located between the coastal sites and the control site, were to be used to assess the transient impact of the sea breeze upon the insolation. Pyranometers were located at each site to measure the global insolation. Direct normal insolation measured by a pyrheliometer and ultraviolet radiation measured by uv radiometers were observed at the Sloop Point and Clinton sites only. Data were collected during the calendar year 1978. The results of the study indicated that the global insolation had greater variability over the network during the summer season (June, July, and August). During the summer, there was a systematicdiurnal variation of the difference in global insolation between the inland and the coastal sites.

  14. Radiation Safety Work Control Form

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiation Safety Work Control Form (see instructions on pg-3) Rev. May 2014 Area: Form : Date: Preliminary Applicability Screen: (a) Will closing the beam line injection stoppers...

  15. Inverse problem for Bremsstrahlung radiation

    SciTech Connect (OSTI)

    Voss, K.E.; Fisch, N.J.

    1991-10-01T23:59:59.000Z

    For certain predominantly one-dimensional distribution functions, an analytic inversion has been found which yields the velocity distribution of superthermal electrons given their Bremsstrahlung radiation. 5 refs.

  16. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, P.B.; Looney, L.D.

    1993-11-30T23:59:59.000Z

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  17. Radiating Levi-Civita Spacetime

    E-Print Network [OSTI]

    Ozgur Delice

    2005-06-06T23:59:59.000Z

    This paper has been withdrawn by the author, See J.Krishna Rao, J. Phys. A: Gen. Phys., 4, 17 (1971) for radiating Levi-Civita metric.

  18. Scintillator Waveguide For Sensing Radiation

    DOE Patents [OSTI]

    Bliss, Mary (West Richland, WA); Craig, Richard A. (West Richland, WA); Reeder; Paul L. (Richland, WA)

    2003-04-22T23:59:59.000Z

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  19. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, Peter B. (Los Alamos, NM); Looney, Larry D. (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    A process for producing an optical fiber having enhanced radiation resitance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation.

  20. Quality Services: Radiation (New York)

    Broader source: Energy.gov [DOE]

    These regulations establish standards for protection against ionizing radiation resulting from the disposal and discharge of radioactive material to the environment. The regulations apply to any...

  1. Ultraviolet emission from a multi-layer graphene/MgZnO/ZnO light-emitting diode

    SciTech Connect (OSTI)

    Kang, Jang-Won; Choi, Yong-Seok; Goo Kang, Chang; Hun Lee, Byoung [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Kim, Byeong-Hyeok [Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Tu, C. W. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093-0407 (United States); Park, Seong-Ju, E-mail: sjpark@gist.ac.kr [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

    2014-02-03T23:59:59.000Z

    We report on ultraviolet emission from a multi-layer graphene (MLG)/MgZnO/ZnO light-emitting diodes (LED). The p-type MLG and MgZnO in the MLG/MgZnO/ZnO LED are used as transparent hole injection and electron blocking layers, respectively. The current-voltage characteristics of the MLG/MgZnO/ZnO LED show that current transport is dominated by tunneling processes in the MgZnO barrier layer under forward bias conditions. The holes injected from p-type MLG recombine efficiently with the electrons accumulated in ZnO, and the MLG/MgZnO/ZnO LED shows strong ultraviolet emission from the band edge of ZnO and weak red-orange emission from the deep levels of ZnO.

  2. Could the Earth's surface Ultraviolet irradiance be blamed for the global warming? A new effect may exist

    E-Print Network [OSTI]

    Chen, Jilong; Zhao, Juan; Zheng, Yujun

    2014-01-01T23:59:59.000Z

    Whether natural factors could interpret the rise of the Earth's surface temperature is still controversial. Though numerous recent researches have reported apparent correlations between solar activity and the Earth's climate, solar activity has encountered a big problem when describing the rapid global warming after 1970s. Our investigation shows the good positive correlations between the Earth's surface Ultraviolet irradiance (280-400 nm) and the Earth's surface temperature both in temporal and spatial variations by analyzing the global surface Ultraviolet irradiance (280-400 nm) and global surface temperature data from 1980-1999. The rise of CO$_2$ cannot interpret the good positive correlations, and we could even get an opposite result to the good correlations when employing the rise of CO$_2$ to describe the relation between them. Based on the good positive correlations, we suggest a new effect, named "Highly Excited Water Vapor" (HEWV) effect, which can interpret how the Sun influences the Earth's surfac...

  3. Conflicting paradigms in radiation protection: 20 Questions with answers from the regulator, the health physicist, the scientist, and the lawyers

    SciTech Connect (OSTI)

    Strom, D.J.; Stansbury, P.S. [Pacific Northwest Lab., Richland, WA (United States); Porter, S.W. Jr. [Porter Consultants, Inc., Ardmore, PA (United States)

    1995-01-01T23:59:59.000Z

    George Orwell`s {open_quotes}doublethink{close_quotes} should be generalized to {open_quotes}polythink{close_quotes} to describe the multiplicity of views that radiation protection professionals must simultaneously accommodate. The paradigms, that is, organizing principles and beliefs, that (1) regulators, (2) operational health physicists, (3) scientists, (4) lawyers for the defendant, and (5) lawyers for the plaintiff use in their approaches to radiation protection are presented. What we believe as scientists often conflicts with what we do for purposes of radiation protection. What we need to do merely to protect humankind and the environment from harmful effects of radiation is far less than what we must do to satisfy the regulator, whose paradigm has checklists, score-keeping, and penalties. In the hands of lawyers, our work must overcome different challenges. Even if the paradigms of the operational health physicist, the scientist, and the regulator match, the odds against the lawyers paradigms also matching are astronomical. The differing paradigms are illustrated by example questions and answers. It is important for educators, trainers, and health physicists to recognize and separate the score-keeping, practice, science, and legal issues in health physics.

  4. Hot-electron-driven charge transfer processes on O2 Pt,,111... surface probed by ultrafast extreme-ultraviolet pulses

    E-Print Network [OSTI]

    Bauer, Michael

    it with an ultrafast laser pulse, charge transfer induced changes in the platinum-oxygen bond were observedHot-electron-driven charge transfer processes on O2 Ã?Pt,,111... surface probed by ultrafast extreme-ultraviolet pulses C. Lei,1, * M. Bauer,2 K. Read,1 R. Tobey,1 Y. Liu,3 T. Popmintchev,1 M. M. Murnane,1 and H. C

  5. The effects of cerium doping on the size, morphology, and optical properties of ?-hematite nanoparticles for ultraviolet filtration

    SciTech Connect (OSTI)

    Cardillo, Dean [Institute for Superconducting and Electronic Materials, AIIM Facility, University of Wollongong Innovation Campus, Squires Way, North Wollongong, NSW 2500 (Australia); Konstantinov, Konstantin, E-mail: konstan@uow.edu.au [Institute for Superconducting and Electronic Materials, AIIM Facility, University of Wollongong Innovation Campus, Squires Way, North Wollongong, NSW 2500 (Australia); Devers, Thierry [Centre de Recherche sur la Matière Divisée, Institut de Physique, site de Chartres, Université d’Orléans (France)

    2013-11-15T23:59:59.000Z

    Highlights: • Possible application of cerium-doped ?-hematite as ultraviolet filter. • Nanoparticles obtained through co-precipitation technique using various cerium doping levels followed by annealing. • Comprehensive materials characterisation utilizing XRD, DSC/TGA, STEM, UV–vis spectroscopy. • Increasing cerium content reduces particle sizing and alters morphology. • Solubility of cerium in hematite seen between 5 and 10% doping, 10% cerium doping greatly enhances attenuation in ultraviolet region and increases optical bandgap. - Abstract: Metal oxide nanoparticles have potential use in energy storage, electrode materials, as catalysts and in the emerging field of nanomedicine. Being able to accurately tailor the desirable properties of these nanoceramic materials, such as particle size, morphology and optical bandgap (E{sub g}) is integral in the feasibility of their use. In this study we investigate the altering of both the structure and physical properties through the doping of hematite (?-Fe{sub 2}O{sub 3}) nanocrystals with cerium at a range of concentrations, synthesised using a one-pot co-precipitation method. This extremely simple synthesis followed by thermal treatment results in stable Fe{sub 2?x}Ce{sub x}O{sub y} nanoceramics resulting from the burning of any unreacted precursors and transformation of goethite-cerium doped nanoparticle intermediate. The inclusion of Ce into the crystal lattice of these ?-Fe{sub 2}O{sub 3} nanoparticles causes a significantly large reduction in mean crystalline size and alteration in particle morphology with increasing cerium content. Finally we report an increase optical semiconductor bandgap, along with a substantial increase in the ultraviolet attenuation found for a 10% Ce-doping concentration which shows the potential application of cerium-doped hematite nanocrystals to be used as a pigmented ultraviolet filter for cosmetic products.

  6. Multiple pulse thermal damage thresholds of materials for x-ray free electron laser optics investigated with an ultraviolet laser

    SciTech Connect (OSTI)

    Hau-Riege, Stefan P.; London, Richard A.; Bionta, Richard M.; Soufli, Regina; Ryutov, Dmitri; Shirk, Michael; Baker, Sherry L. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94539 (United States); Smith, Patrick M.; Nataraj, Pradeep [Kovio, Inc., 1145 Sonora Court, Sunnyvale, California 94086 (United States)

    2008-11-17T23:59:59.000Z

    Optical elements to be used for x-ray free electron lasers (XFELs) must withstand multiple high-fluence pulses. We have used an ultraviolet laser to study the damage of two candidate materials, crystalline Si and B{sub 4}C-coated Si, emulating the temperature profile expected to occur in optics exposed to XFEL pulses. We found that the damage threshold for 10{sup 5} pulses is {approx}20% to 70% lower than the melting threshold.

  7. Ultrafast time dynamics studies of periodic lattices with free electron laser radiation

    SciTech Connect (OSTI)

    Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Krasniqi, F.; Rudenko, A. [Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Tschentscher, T. [European XFEL GmbH, Albert-Einstein-Ring 19, 22671 Hamburg (Germany); Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M. [HASYLAB at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Techert, S. [Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Goettingen (Germany); Max Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany)

    2012-11-01T23:59:59.000Z

    It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.

  8. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

    SciTech Connect (OSTI)

    Hilbert, Vinzenz; Fuchs, Silvio; Paulus, Gerhard G.; Zastrau, Ulf [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany)] [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Blinne, Alexander [Institute for Theoretical Physics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany)] [Institute for Theoretical Physics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Feigl, Torsten [Fraunhofer Institute for Applied Optics and Precision Engineering, Albert-Einstein-Straße 7, 07745 Jena (Germany)] [Fraunhofer Institute for Applied Optics and Precision Engineering, Albert-Einstein-Straße 7, 07745 Jena (Germany); Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Förster, Eckhart [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany) [Institute of Optics and Quantum Electronics, Friedrich-Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz Institute, Fröbelstieg 3, 07743 Jena (Germany)

    2013-09-15T23:59:59.000Z

    We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

  9. Effect of motions in prominences on the helium resonance lines in the extreme ultraviolet

    E-Print Network [OSTI]

    Nicolas Labrosse; Pierre Gouttebroze; Jean-Claude Vial

    2006-12-08T23:59:59.000Z

    We aim at studying the effect of radial motions on the spectrum emitted by moving prominences in the helium resonance lines and at facilitating the interpretation of observations, in order to improve our understanding of these dynamic structures. We develop our non-local thermodynamic equilibrium radiative transfer code formerly used for the study of quiescent prominences. The new numerical code is now able to solve the statistical equilibrium and radiative transfer equations in the non-static case by using velocity-dependent boundary conditions for the solution of the radiative transfer problem. This first study investigates the effects of different physical conditions (temperature, pressure, geometrical thickness) on the emergent helium radiation. The motion of the prominence plasma induces a Doppler dimming effect on the resonance lines of He I and He II. The velocity effects are particularly important for the He II 304 A line as it is mostly formed by resonant diffusion of incident radiation under prominence conditions. The He I resonance lines at 584 and 537 A also show some sensitivity to the motion of the plasma, all the more when thermal emission is not too important in these lines. We also show that it is necessary to consider partial redistribution in frequency for the scattering of the incident radiation. This set of helium lines offers strong diagnostic possibilities that can be exploited with the SOHO spectrometers and with the EIS spectrometer on board the Hinode satellite. The addition of other helium lines and of lines from other elements (in particular hydrogen) in the diagnostics will further enhance the strength of the method.

  10. Final Scientific/Technical Report for DE-FG03-02NA00063 Coherent imaging of laser-plasma interactions using XUV high harmonic radiation

    SciTech Connect (OSTI)

    Henry Kapteyn

    2006-06-06T23:59:59.000Z

    The objective of this project was to develop experimental techniques for using coherent extreme-ultraviolet (EUV) radiation generated using the high-order harmonic generation technique, as an illumination source for studies of high-density plasmas relevant to the stockpile stewardship mission. In this project, we made considerable progress, including the first demonstration of imaging of dynamic processes using this coherent ultrashort pulse light. This work also stimulated considerable progress in the development of the required ultrashort EUV pulses, and in the development of new laser technologies that have been commercialized. We also demonstrated the first EUV sources that exhibit full intrinsic optical coherence. This work resulted in 12 publications.

  11. Exploring the Origin and Fate of the Magellanic Stream with Ultraviolet and Optical Absorption

    E-Print Network [OSTI]

    Fox, Andrew J; Smoker, Jonathan V; Richter, Philipp; Savage, Blair D; Sembach, Kenneth R

    2010-01-01T23:59:59.000Z

    (Abridged) We present an analysis of ionization and metal enrichment in the Magellanic Stream (MS), the nearest gaseous tidal stream, using HST/STIS and FUSE ultraviolet spectroscopy of two background AGN, NGC 7469 and Mrk 335. For NGC 7469, we include optical spectroscopy from VLT/UVES. In both sightlines the MS is detected in low-ion and high-ion absorption. Toward NGC 7469, we measure a MS oxygen abundance [O/H]_MS=[OI/HI]=-1.00+/-0.05(stat)+/-0.08(syst), supporting the view that the Stream originates in the SMC rather than the LMC. We use CLOUDY to model the low-ion phase of the Stream as a photoionized plasma using the observed Si III/Si II and C III/C II ratios. Toward Mrk 335 this yields an ionization parameter log U between -3.45 and -3.15 and a gas density log (n_H/cm^-3) between -2.51 and -2.21. Toward NGC 7469 we derive sub-solar abundance ratios for [Si/O], [Fe/O], and [Al/O], indicating the presence of dust in the MS. The high-ion column densities are too large to be explained by photoionization,...

  12. Development of substrate-removal-free vertical ultraviolet light-emitting diode (RefV-LED)

    SciTech Connect (OSTI)

    Kurose, N., E-mail: kurose@fc.ritsumei.ac.jp; Aoyagi, Y. [The Research Organization of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)] [The Research Organization of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan); Shibano, K.; Araki, T. [Department of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)] [Department of Science and Technology, Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577 (Japan)

    2014-02-15T23:59:59.000Z

    A vertical ultraviolet (UV) light-emitting diode (LED) that does not require substrate removal is developed. Spontaneous via holes are formed in n-AlN layer epitaxially grown on a high conductive n+Si substrate and the injected current flows directly from the p-electrode to high doped n{sup +} Si substrate through p-AlGaN, multi-quantum wells, n-AlGaN and spontaneous via holes in n-AlN. The spontaneous via holes were formed by controlling feeding-sequence of metal-organic gas sources and NH{sub 3} and growth temperature in MOCVD. The via holes make insulating n-AlN to be conductive. We measured the current-voltage, current-light intensity and emission characteristics of this device. It exhibited a built-in voltage of 3.8 V and emission was stated at 350 nm from quantum wells with successive emission centered at 400?nm. This UV LED can be produced, including formation of n and p electrodes, without any resist process.

  13. Tunnel-injection GaN quantum dot ultraviolet light-emitting diodes

    SciTech Connect (OSTI)

    Verma, Jai; Kandaswamy, Prem Kumar; Protasenko, Vladimir; Verma, Amit; Grace Xing, Huili; Jena, Debdeep [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)] [Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)

    2013-01-28T23:59:59.000Z

    We demonstrate a GaN quantum dot ultraviolet light-emitting diode that uses tunnel injection of carriers through AlN barriers into the active region. The quantum dot heterostructure is grown by molecular beam epitaxy on AlN templates. The large lattice mismatch between GaN and AlN favors the formation of GaN quantum dots in the Stranski-Krastanov growth mode. Carrier injection by tunneling can mitigate losses incurred in hot-carrier injection in light emitting heterostructures. To achieve tunnel injection, relatively low composition AlGaN is used for n- and p-type layers to simultaneously take advantage of effective band alignment and efficient doping. The small height of the quantum dots results in short-wavelength emission and are simultaneously an effective tool to fight the reduction of oscillator strength from quantum-confined Stark effect due to polarization fields. The strong quantum confinement results in room-temperature electroluminescence peaks at 261 and 340 nm, well above the 365 nm bandgap of bulk GaN. The demonstration opens the doorway to exploit many varied features of quantum dot physics to realize high-efficiency short-wavelength light sources.

  14. Finding gas-rich dwarf galaxies betrayed by their ultraviolet emission

    E-Print Network [OSTI]

    Meyer, Jennifer Donovan; Putman, Mary; Grcevich, Jana

    2015-01-01T23:59:59.000Z

    We present ultraviolet (UV) follow-up of a sample of potential dwarf galaxy candidates selected for their neutral hydrogen (HI) properties, taking advantage of the low UV background seen by the GALEX satellite and its large and publicly available imaging footprint. The HI clouds, which are drawn from published GALFA-HI and ALFALFA HI survey compact cloud catalogs, are selected to be galaxy candidates based on their spatial compactness and non-association with known high-velocity cloud complexes or Galactic HI emission. Based on a comparison of their UV characteristics to those of known dwarf galaxies, half (48%) of the compact HI clouds have at least one potential stellar counterpart with UV properties similar to those of nearby dwarf galaxies. If galaxies, the star formation rates, HI masses, and star formation efficiencies of these systems follow the trends seen for much larger galaxies. The presence of UV emission is an efficient method to identify the best targets for spectroscopic follow-up, which is nec...

  15. Demonstration and evaluation of the pulsed ultraviolet-irradiation gas-treatment system, Savannah River Site

    SciTech Connect (OSTI)

    Schneider, J.; Wilkey, M.; Peters, R.; Tomczyk, N.; Friedlund, J.; Farber, P. [Argonne National Lab., IL (United States). Energy Systems Div.; Mass, B.; Haag, W. [Purus, Inc., San Jose, CA (United States)

    1994-10-01T23:59:59.000Z

    Argonne National Laboratory was asked to demonstrate and evaluate a pulsed ultraviolet-irradiation system developed by Purus, Inc., at the Volatile Organic Compounds Non-Arid Integrated Demonstration at the Savannah River Site near aiken, South Carolina. The Purus system consists of four reactor chambers, each containing a xenon flash lamp. During the two weeks of testing, samples were taken and analyzed from the inlet and outlet sides of the Purus system. The contaminants of concern on the inlet were tetrachloroethylene (PCE), trichloroethylene (TCE), and 1,1,1-trichloroethane (TCA); the contaminants of concern on the outlet were PCE, TCE, TCA, carbon tetrachloride (CT), and chloroform. The evaluation of the Purus system included an examination of the reduction of both TCE and PCE and a search for any change in the concentrations. (Operating conditions included flow rates, ranging from 25 to 100 standard cubic feet per minute; inlet concentration of PCE, ranging from 360 to 10,700 parts per million volume; and flash lamp rates, ranging from 1 to 30 hertz.) The Purus system was quite efficient at reducing the concentrations of both PCE and TCE. The potential by-products, TCA, CT, and chloroform, showed no significant increases throughout the range of the various operating parameters. Overall, the Purus system appears to be a cost-efficient means of reducing the concentrations of PCE and TCE, while the removal of the initial photo-oxidation products and TCA is slower and needs further evaluation.

  16. Nanostructured High Performance Ultraviolet and Blue Light Emitting Diodes for Solid State Lighting

    SciTech Connect (OSTI)

    Arto V. Nurmikko; Jung Han

    2005-09-30T23:59:59.000Z

    We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and near ultraviolet for Solid State Lighting applications. Accomplishments in the second 12 month contract period include (i) new means of synthesizing AlGaN and InN quantum dots by droplet heteroepitaxy, (ii) synthesis of AlGaInN nanowires as building blocks for GaN-based microcavity devices, (iii) progress towards direct epitaxial alignment of the dense arrays of nanowires, (iv) observation and measurements of stimulated emission in dense InGaN nanopost arrays, (v) design and fabrication of InGaN photonic crystal emitters, and (vi) observation and measurements of enhanced fluorescence from coupled quantum dot and plasmonic nanostructures. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

  17. NANOSTRUCTURED HIGH PERFORMANCE ULTRAVIOLET AND BLUE LIGHT EMITTING DIODES FOR SOLID STATE LIGHTING

    SciTech Connect (OSTI)

    Arto V. Nurmikko; Jung Han

    2004-10-01T23:59:59.000Z

    We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and near ultraviolet for Solid State Lighting applications. Accomplishments in the first 12 month contract period include (1) new means of synthesizing zero- and one-dimensional GaN nanostructures, (2) establishment of the building blocks for making GaN-based microcavity devices, and (3) demonstration of top-down approach to nano-scale photonic devices for enhanced spontaneous emission and light extraction. These include a demonstration of eight-fold enhancement of the external emission efficiency in new InGaN QW photonic crystal structures. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

  18. System for time-discretized vacuum ultraviolet spectroscopy of spark breakdown in air

    SciTech Connect (OSTI)

    Ryberg, D.; Fierro, A.; Dickens, J.; Neuber, A. [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-10-15T23:59:59.000Z

    A system for time-discretized spectroscopic measurements of the vacuum ultraviolet (VUV) emission from spark discharges in the 60-160 nm range has been developed for the study of early plasma-forming phenomena. The system induces a spark discharge in an environment close to atmospheric conditions created using a high speed puff value, but is otherwise kept at high vacuum to allow for the propagation of VUV light. Using a vertical slit placed 1.5 mm from the discharge the emission from a small cross section of the discharge is allowed to pass into the selection chamber consisting of a spherical grating, with 1200 grooves/mm, and an exit slit set to 100 ?m. Following the exit slit is a photomultiplier tube with a sodium salicylate scintillator that is used for the time discretized measurement of the VUV signal with a temporal resolution limit of 10 ns. Results from discharges studied in dry air, Nitrogen, SF{sub 6}, and Argon indicate the emission of light with wavelengths shorter than 120 nm where the photon energy begins to approach the regime of direct photoionization.

  19. Ultraviolet Morphologies and Star-Formation Rates of CLASH Brightest Cluster Galaxies

    E-Print Network [OSTI]

    Donahue, Megan; Fogarty, Kevin; Li, Yuan; Voit, G Mark; Postman, Marc; Koekemoer, Anton; Moustakas, John; Bradley, Larry; Ford, Holland

    2015-01-01T23:59:59.000Z

    Brightest cluster galaxies (BCGs) are usually quiescent, but many exhibit star formation. Here we exploit the opportunity provided by rest-frame UV imaging of galaxy clusters in the CLASH (Cluster Lensing and Supernovae with Hubble) Multi-Cycle Treasury Project to reveal the diversity of UV morphologies in BCGs and to compare them with recent simulations of the cool, star-forming gas structures produced by precipitation-driven feedback. All of the CLASH BCGs are detected in the rest-frame UV (280 nm), regardless of their star-formation activity, because evolved stellar populations produce a modest amount of UV light that traces the relatively smooth, symmetric, and centrally peaked stellar distribution seen in the near infrared. Ultraviolet morphologies among the BCGs with strong UV excesses exhibit distinctive knots, multiple elongated clumps, and extended filaments of emission that distinctly differ from the smooth profiles of the UV-quiet BCGs. These structures, which are similar to those seen in the few s...

  20. METALLICITY DIFFERENCES IN TYPE Ia SUPERNOVA PROGENITORS INFERRED FROM ULTRAVIOLET SPECTRA

    SciTech Connect (OSTI)

    Foley, Ryan J.; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-05-20T23:59:59.000Z

    Two ''twin'' Type Ia supernovae (SNe Ia), SNe 2011by and 2011fe, have extremely similar optical light-curve shapes, colors, and spectra, yet have different ultraviolet (UV) continua as measured in Hubble Space Telescope spectra and measurably different peak luminosities. We attribute the difference in the UV continua to significantly different progenitor metallicities. This is the first robust detection of different metallicities for SN Ia progenitors. Theoretical reasoning suggests that differences in metallicity also lead to differences in luminosity. SNe Ia with higher progenitor metallicities have lower {sup 56}Ni yields and lower luminosities for the same light-curve shape. SNe 2011by and 2011fe have different peak luminosities ({Delta}M{sub V} Almost-Equal-To 0.6 mag), which correspond to different {sup 56}Ni yields: M{sub 11fe}({sup 56}Ni) / M{sub 11by}({sup 56}Ni) = 1.7{sup +0.7}{sub -0.5}. From theoretical models that account for different neutron-to-proton ratios in progenitors, the differences in {sup 56}Ni yields for SNe 2011by and 2011fe imply that their progenitor stars were above and below solar metallicity, respectively. Although we can distinguish progenitor metallicities in a qualitative way from UV data, the quantitative interpretation in terms of abundances is limited by the present state of theoretical models.

  1. TEMPERATURE AND EXTREME-ULTRAVIOLET INTENSITY IN A CORONAL PROMINENCE CAVITY AND STREAMER

    SciTech Connect (OSTI)

    Kucera, T. A. [NASA/GSFC, Code 671, Greenbelt, MD 20771 (United States); Gibson, S. E.; Schmit, D. J. [HAO/NCAR, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Landi, E. [Department of Atmospheric, Oceanic and Space Science, Space Research Building, University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109-2143 (United States); Tripathi, D. [Inter-University Centre for Astronomy and Astrophysics, Post Bag-4, Ganeshkhind, Pune University Campus, Pune 411 007 (India)

    2012-09-20T23:59:59.000Z

    We analyze the temperature and EUV line emission of a coronal cavity and surrounding streamer in terms of a morphological forward model. We use a series of iron line ratios observed with the Hinode Extreme-ultraviolet Imaging Spectrograph (EIS) on 2007 August 9 to constrain temperature as a function of altitude in a morphological forward model of the streamer and cavity. We also compare model predictions to the EIS EUV line intensities and polarized brightness (pB) data from the Mauna Loa Solar Observatory (MLSO) Mark 4 K-coronameter. This work builds on earlier analysis using the same model to determine geometry of and density in the same cavity and streamer. The fit to the data with altitude-dependent temperature profiles indicates that both the streamer and cavity have temperatures in the range 1.4-1.7 MK. However, the cavity exhibits substantial substructure such that the altitude-dependent temperature profile is not sufficient to completely model conditions in the cavity. Coronal prominence cavities are structured by magnetism so clues to this structure are to be found in their plasma properties. These temperature substructures are likely related to structures in the cavity magnetic field. Furthermore, we find that the model overestimates the EUV line intensities by a factor of 4-10, without overestimating pB. We discuss this difference in terms of filling factors and uncertainties in density diagnostics and elemental abundances.

  2. A Survey of Intrinsic Absorption in Active Galaxies using the Far Ultraviolet Spectroscopic Explorer

    E-Print Network [OSTI]

    Jay P. Dunn; D. Michael Crenshaw; S. B. Kraemer; J. R. Gabel

    2007-06-20T23:59:59.000Z

    We present a survey of 72 Seyfert galaxies and quasars observed by the it Far Ultraviolet Spectroscopic Explorer (FUSE). We have determined that 72 of 253 available active galactic nuclei (AGN) targets are viable targets for detection of intrinsic absorption lines. We examined these spectra for signs of intrinsic absorption in the O VI doublet (lambda 1031.9, 1037.6) and Lyman beta (lambda 1025.7). The fraction of Seyfert 1 galaxies and low-redshift quasars at z absorption is ~50%, which is slightly lower than Crenshaw et al. (1999) found (60%) based on a smaller sample of Seyfert 1 galaxies observed with the Hubble Space Telescope (HST). With this new fraction we find a global covering factor of the absorbing gas with respect to the central nucleus of ~0.4. Our survey is to date the largest searching for intrinsic UV absorption with high spectral resolution, and is the first step toward a more comprehensive study of intrinsic absorption in low-redshift AGN.

  3. Intrinsic Absorption Properties in Active Galaxies Observed with the Far Ultraviolet Spectroscopic Explorer

    E-Print Network [OSTI]

    Jay P. Dunn; D. Michael Crenshaw; S. B. Kraemer; M. L. Trippe

    2008-07-01T23:59:59.000Z

    In a continuing survey of active galactic nuclei observed by the Far Ultraviolet Spectroscopic Explorer, we provide a deeper analysis of intrinsic absorption features found in 35 objects. Our survey is for low-redshift and moderate-luminosity objects, mostly Seyfert galaxies. We find a strong correlation between maximum radial velocity and luminosity. We also examine the relationships between equivalent width (EW), full width at half maximum, velocity: and continuum flux. The correlation between velocity and luminosity has been explored previously by Laor & Brandt, but at a significantly higher redshift and heavily weighted by broad absorption line quasars. We also have examined each object with multiple observations for variability in each of the aforementioned quantities, and have characterized the variation of EW with the continuum flux. In our survey, we find that variability of O VI lambda1032, lambda1038 is less common than of the UV doublets of CIV and N V seen at longer wavelengths, because the O VI absorption is usually saturated. Lyman beta absorption variability is more frequent. In a target-by-target examination we find that broad absorption line absorption and narrow absorption line absorbers are related in terms of maximum outflow velocity and luminosity, and both can be exhibited in similar luminosity objects. We also find one object that shows radial velocity change, seven objects that show equivalent width variability, and two objects that show either transverse velocity changes or a change in ionization.

  4. Hawking radiation and Quasinormal modes

    E-Print Network [OSTI]

    SangChul Yoon

    2005-10-05T23:59:59.000Z

    The spectrum of Hawking radiation by quantum fields in the curved spacetime is continuous, so the explanation of Hawking radiation using quasinormal modes can be suspected to be impossible. We find that quasinormal modes do not explain the relation between the state observed in a region far away from a black hole and the short distance behavior of the state on the horizon.

  5. Radiation trapping in coherent media

    E-Print Network [OSTI]

    A. B. Matsko; I. Novikova; M. O. Scully; G. R. Welch

    2001-01-31T23:59:59.000Z

    We show that the effective decay rate of Zeeman coherence, generated in a Rb87 vapor by linearly polarized laser light, increases significantly with the atomic density. We explain this phenomenon as the result of radiation trapping. Our study shows that radiation trapping must be taken into account to fully understand many electromagnetically induced transparency experiments with optically thick media.

  6. Review Article RADIATION SHIELDING TECHNOLOGY

    E-Print Network [OSTI]

    Shultis, J. Kenneth

    Review Article RADIATION SHIELDING TECHNOLOGY J. Kenneth Shultis and Richard E. Faw* Abstract Physics Society INTRODUCTION THIS IS a review of the technology of shielding against the effects to the review. The first treats the evolution of radiation-shielding technology from the beginning of the 20th

  7. Abdominal radiation causes bacterial translocation

    SciTech Connect (OSTI)

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-02-01T23:59:59.000Z

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

  8. Gravitational Radiation From Cosmological Turbulence

    E-Print Network [OSTI]

    Arthur Kosowsky; Andrew Mack; Tinatin Kahniashvili

    2002-06-27T23:59:59.000Z

    An injection of energy into the early Universe on a given characteristic length scale will result in turbulent motions of the primordial plasma. We calculate the stochastic background of gravitational radiation arising from a period of cosmological turbulence, using a simple model of isotropic Kolmogoroff turbulence produced in a cosmological phase transition. We also derive the gravitational radiation generated by magnetic fields arising from a dynamo operating during the period of turbulence. The resulting gravitational radiation background has a maximum amplitude comparable to the radiation background from the collision of bubbles in a first-order phase transition, but at a lower frequency, while the radiation from the induced magnetic fields is always subdominant to that from the turbulence itself. We briefly discuss the detectability of such a signal.

  9. Transition Radiation in QCD matter

    E-Print Network [OSTI]

    Magdalena Djordjevic

    2005-12-22T23:59:59.000Z

    In ultrarelativistic heavy ion collisions a finite size QCD medium is created. In this paper we compute radiative energy loss to zeroth order in opacity by taking into account finite size effects. Transition radiation occurs on the boundary between the finite size medium and the vacuum, and we show that it lowers the difference between medium and vacuum zeroth order radiative energy loss relative to the infinite size medium case. Further, in all previous computations of light parton radiation to zeroth order in opacity, there was a divergence caused by the fact that the energy loss is infinite in the vacuum and finite in the QCD medium. We show that this infinite discontinuity is naturally regulated by including the transition radiation.

  10. Radiation Reaction in Quantum Vacuum

    E-Print Network [OSTI]

    Keita Seto

    2014-11-02T23:59:59.000Z

    From the development of the electron theory by H. A. Lorentz in 1906, many authors have tried to reformulate this model named "radiation reaction". P. A. M. Dirac derived the relativistic-classical electron model in 1938, which is now called the Lorentz-Abraham-Dirac model. But this model has the big difficulty of the run-away solution. Recently, this equation has become important for ultra-intense laser-electron (plasma) interactions. Therefore, it is desirable to stabilize this model of the radiation reaction for estimations. Via my recent research, I found a stabilized model of radiation reaction in quantum vacuum. This leads us to an updated Fletcher-Millikan's charge to mass ratio including radiation, de/dm, derived as the 4th order tensor measure. In this paper, I will discuss the latest update of the model and the ability of the equation of motion with radiation reaction in quantum vacuum via photon-photon scatterings.

  11. Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides

    SciTech Connect (OSTI)

    Tobin, J G

    2011-03-17T23:59:59.000Z

    The subjects of discussion included: VUV photoelectron spectroscopy, X-ray photoelectron spectroscopy, Synchrotron-radiation-based photoelectron spectroscopy, Soft x-ray absorption spectroscopy, Soft x-ray emission spectroscopy, Inverse photoelectron spectroscopy, Bremstrahlung Isochromat Spectroscopy, Low energy IPES, Resonant inverse photoelectron spectroscopy.

  12. The development and application of a diode-laser-based ultraviolet absorption sensor for nitric oxide

    E-Print Network [OSTI]

    Anderson, Thomas Nathan

    2004-09-30T23:59:59.000Z

    by the NO molecule to determine the concentration via optical absorption spectroscopy. UV radiation at 226.8 nm is generated by sum frequency mixing the outputs from a 395-nm external cavity diode laser (ECDL) and a 532-nm diode-pumped, intracavity frequency doubled...

  13. Combined effects of prepulsing and target geometry on efficient extreme ultraviolet

    E-Print Network [OSTI]

    Harilal, S. S.

    and the deposition of EUV and out of band radiation can fur- ther cause surface erosion and damage at the required targets geometries with special grooves as developed previously by the authors. C 2011 Society of Photo-Optical. Damage of multilayer Mo/Si mirrors by the de- bris products of laser beam interaction with target

  14. Radiation events in astronomical CCD images

    E-Print Network [OSTI]

    2001-01-01T23:59:59.000Z

    268. 10. “On the Rates of Radiation Events in CCD’s (Excerpt23 Jan 2002 LBNL-49316 Radiation events in astronomical CCDof depleted silicon to ionizing radiation is a nuisance to

  15. High efficiency, radiation-hard solar cells

    E-Print Network [OSTI]

    Ager III, J.W.; Walukiewicz, W.

    2004-01-01T23:59:59.000Z

    J. F. Geisz, “Superior radiation resistance of In 1-x Ga x Nand H. Itoh, “Proton radiation analysis of multi-junction56326 High efficiency, radiation-hard solar cells Final

  16. Radiation-induced lung injury

    SciTech Connect (OSTI)

    Rosiello, R.A.; Merrill, W.W. (Yale Univ. Medical Center, New Haven, CT (USA))

    1990-03-01T23:59:59.000Z

    The use of radiation therapy is limited by the occurrence of the potentially fatal clinical syndromes of radiation pneumonitis and fibrosis. Radiation pneumonitis usually becomes clinically apparent from 2 to 6 months after completion of radiation therapy. It is characterized by fever, cough, dyspnea, and alveolar infiltrates on chest roentgenogram and may be difficult to differentiate from infection or recurrent malignancy. The pathogenesis is uncertain, but appears to involve both direct lung tissue toxicity and an inflammatory response. The syndrome may resolve spontaneously or may progress to respiratory failure. Corticosteroids may be effective therapy if started early in the course of the disease. The time course for the development of radiation fibrosis is later than that for radiation pneumonitis. It is usually present by 1 year following irradiation, but may not become clinically apparent until 2 years after radiation therapy. It is characterized by the insidious onset of dyspnea on exertion. It most often is mild, but can progress to chronic respiratory failure. There is no known successful treatment for this condition. 51 references.

  17. Synchrotron radiation from massless charge

    E-Print Network [OSTI]

    Gal'tsov, D V

    2015-01-01T23:59:59.000Z

    Classical radiation power from an accelerated massive charge diverges in the zero-mass limit, while some general arguments suggest that strictly massless charge does not not radiate at all. On the other hand, the regularized classical radiation reaction force, though looking odd, is non-zero and finite. To clarify this controversy, we consider radiation problem in massless scalar quantum electrodynamics in the external magnetic field. In this framework, synchrotron radiation is found to be non-zero, finite, and essentially quantum. Its spectral distribution is calculated using Schwinger's proper time technique for {\\em ab initio} massless particle of zero spin. Provided $E^2\\gg eH$, the maximum in the spectrum is shown to be at $\\hbar \\omega=E/3$, and the average photon energy is $4E/9$. The normalized spectrum is universal, depending neither on $E$ nor on $H$. Quantum nature of radiation makes classical radiation reaction equation meaningless for massless charge. Our results are consistent with the view (sup...

  18. Annual DOE Occupational Radiation Exposure | 1974 Report

    Broader source: Energy.gov [DOE]

    The Seventh Annual Report of Radiation Exposures for AEC & AEC Contractor Employees analyzes occupational radiation exposures at the Atomic Energy Commission (AEC) and its contractor employees during 1974.

  19. ORISE: REAC/TS Radiation Accident Registries

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Accident Registries The Radiation Emergency Assistance CenterTraining Site (REACTS) at the Oak Ridge Institute for Science and Education (ORISE) maintains a number of radiation...

  20. ORISE: REAC/TS Radiation Treatment Medications

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Treatment Medications The Radiation Emergency Assistance CenterTraining Site (REACTS) is a valuable resource in the use of drug therapies to treat radiation exposure. REACTS...

  1. 10 CFR 835- Occupational Radiation Protection

    Broader source: Energy.gov [DOE]

    The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities.

  2. Hybrid Radiator Cooling System | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Radiator Cooling System Technology available for licensing: Hybrid radiator cooling system uses conventional finned air cooling under most driving conditions that would be...

  3. Standards for Protection Against Radiation (Michigan)

    Broader source: Energy.gov [DOE]

    This rule establishes standards for protection against radiation hazards. In addition to complying with requirements set forth, every reasonable effort should be made to maintain radiation levels...

  4. Radiation detection system

    DOE Patents [OSTI]

    Riedel, Richard A. (Knoxville, TN); Wintenberg, Alan L. (Knoxville, TN); Clonts, Lloyd G. (Knoxville, TN); Cooper, Ronald G. (Oak Ridge, TN)

    2012-02-14T23:59:59.000Z

    A preamplifier circuit for processing a signal provided by a radiation detector includes a transimpedance amplifier coupled to receive a current signal from a detector and generate a voltage signal at its output. A second amplification stage has an input coupled to an output of the transimpedance amplifier for providing an amplified voltage signal. Detector electronics include a preamplifier circuit having a first and second transimpedance amplifier coupled to receive a current signal from a first and second location on a detector, respectively, and generate a first and second voltage signal at respective outputs. A second amplification stage has an input coupled to an output of the transimpedance amplifiers for amplifying the first and said second voltage signals to provide first and second amplified voltage signals. A differential output stage is coupled to the second amplification stage for receiving the first and second amplified voltage signals and providing a pair of outputs from each of the first and second amplified voltage signals. Read out circuitry has an input coupled to receive both of the pair of outputs, the read out circuitry having structure for processing each of the pair of outputs, and providing a single digital output having a time-stamp therefrom.

  5. Non-LTE model atmosphere analysis of the early ultraviolet spectra of nova OS Andromedae 1986

    E-Print Network [OSTI]

    Greg Schwarz; Peter H. Hauschildt; Sumner Starrfield; Eddie Baron; France Allard; Steve Shore; George Sonneborn

    1996-08-29T23:59:59.000Z

    We have analyzed the early optically thick ultraviolet spectra of Nova OS And 1986 using a grid of spherically symmetric, non-LTE, line-blanketed, expanding model atmospheres and synthetic spectra with the following set of parameters: $5,000\\le$ T$_{model}$ $\\le 60,000$K, solar abundances, $\\rho \\propto r^{-3}$, $\\v_{max} = 2000\\kms$, $L=6 \\times 10^{4}\\Lsun$, and a statistical or microturbulent velocity of 50 $\\kms$. We used the synthetic spectra to estimate the model parameters corresponding to the observed {\\it IUE} spectra. The fits to the observations were then iteratively improved by changing the parameters of the model atmospheres, in particular T$_{model}$ and the abundances, to arrive at the best fits to the optically thick pseudo-continuum and the features found in the {\\it IUE} spectra. The {\\it IUE} spectra show two different optically thick subphases. The earliest spectra, taken a few days after maximum optical light, show a pseudo-continuum created by overlapping absorption lines. The later observations, taken approximately 3 weeks after maximum light, show the simultaneous presence of allowed, semi-forbidden, and forbidden lines in the observed spectra. Analysis of these phases indicate that OS And 86 had solar metallicities except for Mg which showed evidence of being underabundant by as much as a factor of 10. We determine a distance of 5.1 kpc to OS And 86 and derive a peak bolometric luminosity of $\\sim$ 5 $\\times$ 10$^4$ L$_{\\odot}$. The computed nova parameters provide insights into the physics of the early outburst and explain the spectra seen by {\\it IUE}. Lastly, we find evidence in the later observations for large non-LTE effects of Fe{\\sc ii} which, when included, lead to much better agreement with the observations.

  6. Vacuum-Ultraviolet Photoionization and Mass Spectrometric Characterization of Lignin Monomers Coniferyl and Sinapyl Alcohols

    SciTech Connect (OSTI)

    Takahashi, Lynelle K.; Zhou, Jia; Kostko, Oleg; Golan, Amir; Leone, Stephen R.; Ahmed, Musahid

    2011-02-09T23:59:59.000Z

    The fragmentation mechanisms of monolignols under various energetic processes are studied with jet-cooled thermal desorption molecular beam (TDMB) mass spectrometry (MS), 25 keV Bi3+ secondary ion MS (SIMS), synchrotron vacuum-ultraviolet secondary neutral MS (VUV-SNMS) and theoretical methods. Experimental and calculated appearance energies of fragments observed in TDMB MS indicate that the coniferyl alcohol photoionization mass spectra contain the molecular parent and several dissociative photoionization products. Similar results obtained for sinapyl alcohol are also discussed briefly. Ionization energies of 7.60 eV ? 0.05 eV for coniferyl alcohol and<7.4 eV for both sinapyl and dihydrosinapyl alcohols are determined. The positive ion SIMS spectrum of coniferyl alcohol shares few characteristic peaks (m/z = 137 and 151) with the TDMB mass spectra, shows extensive fragmentation, and does not exhibit clear molecular parent signals. VUV-SNMS spectra, on the other hand, are dominated by the parent ion and main fragments also present in the TDMB spectra. Molecular fragmentation in VUV-SNMS spectra can be reduced by increasing the extraction delay time. Some features resembling the SIMS spectra are also observed in the desorbed neutral products. The monolignol VUV-SNMS peaks shared with the TDMB mass spectra suggest that dissociative photoionization of ion-sputtered neutral molecules predominate in the VUV-SNMS mass spectra, despite the extra internal energy imparted in the initial ion impact. The potential applications of these results to imaging mass spectrometry of bio-molecules are discussed.

  7. ACTIVE REGION MOSS: DOPPLER SHIFTS FROM HINODE/EXTREME-ULTRAVIOLET IMAGING SPECTROMETER OBSERVATIONS

    SciTech Connect (OSTI)

    Tripathi, Durgesh [Inter-University Centre for Astronomy and Astrophysics, Pune University Campus, Pune 411007 (India); Mason, Helen E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Klimchuk, James A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2012-07-01T23:59:59.000Z

    Studying the Doppler shifts and the temperature dependence of Doppler shifts in moss regions can help us understand the heating processes in the core of the active regions. In this paper, we have used an active region observation recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode on 2007 December 12 to measure the Doppler shifts in the moss regions. We have distinguished the moss regions from the rest of the active region by defining a low-density cutoff as derived by Tripathi et al. in 2010. We have carried out a very careful analysis of the EIS wavelength calibration based on the method described by Young et al. in 2012. For spectral lines having maximum sensitivity between log T = 5.85 and log T = 6.25 K, we find that the velocity distribution peaks at around 0 km s{sup -1} with an estimated error of 4-5 km s{sup -1}. The width of the distribution decreases with temperature. The mean of the distribution shows a blueshift which increases with increasing temperature and the distribution also shows asymmetries toward blueshift. Comparing these results with observables predicted from different coronal heating models, we find that these results are consistent with both steady and impulsive heating scenarios. However, the fact that there are a significant number of pixels showing velocity amplitudes that exceed the uncertainty of 5 km s{sup -1} is suggestive of impulsive heating. Clearly, further observational constraints are needed to distinguish between these two heating scenarios.

  8. Ultraviolet observations of Super-Chandrasekhar mass type Ia supernova candidates with swift UVOT

    SciTech Connect (OSTI)

    Brown, Peter J.; Smitka, Michael T.; Krisciunas, Kevin; Wang, Lifan [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, 4242 TAMU, College Station, TX 77843 (United States); Kuin, Paul; De Pasquale, Massimiliano [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking Surrey, RH5 6NT (United Kingdom); Scalzo, Richard [Research School of Astronomy and Astrophysics, The Australian National University, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Holland, Stephen [Space Telescope Science Center 3700 San Martin Drive, Baltimore, MD 21218 (United States); Milne, Peter, E-mail: pbrown@physics.tamu.edu [Steward Observatory, University of Arizona, Tucson, AZ 85719 (United States)

    2014-05-20T23:59:59.000Z

    Among Type Ia supernovae (SNe Ia), a class of overluminous objects exist whose ejecta mass is inferred to be larger than the canonical Chandrasekhar mass. We present and discuss the UV/optical photometric light curves, colors, absolute magnitudes, and spectra of three candidate Super-Chandrasekhar mass SNe—2009dc, 2011aa, and 2012dn—observed with the Swift Ultraviolet/Optical Telescope. The light curves are at the broad end for SNe Ia, with the light curves of SN 2011aa being among the broadest ever observed. We find all three to have very blue colors which may provide a means of excluding these overluminous SNe from cosmological analysis, though there is some overlap with the bluest of 'normal' SNe Ia. All three are overluminous in their UV absolute magnitudes compared to normal and broad SNe Ia, but SNe 2011aa and 2012dn are not optically overluminous compared to normal SNe Ia. The integrated luminosity curves of SNe 2011aa and 2012dn in the UVOT range (1600-6000 Å) are only half as bright as SN 2009dc, implying a smaller {sup 56}Ni yield. While it is not enough to strongly affect the bolometric flux, the early time mid-UV flux makes a significant contribution at early times. The strong spectral features in the mid-UV spectra of SNe 2009dc and 2012dn suggest a higher temperature and lower opacity to be the cause of the UV excess rather than a hot, smooth blackbody from shock interaction. Further work is needed to determine the ejecta and {sup 56}Ni masses of SNe 2011aa and 2012dn and to fully explain their high UV luminosities.

  9. Actively driven thermal radiation shield

    DOE Patents [OSTI]

    Madden, Norman W. (Livermore, CA); Cork, Christopher P. (Pleasant Hill, CA); Becker, John A. (Alameda, CA); Knapp, David A. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    A thermal radiation shield for cooled portable gamma-ray spectrometers. The thermal radiation shield is located intermediate the vacuum enclosure and detector enclosure, is actively driven, and is useful in reducing the heat load to mechanical cooler and additionally extends the lifetime of the mechanical cooler. The thermal shield is electrically-powered and is particularly useful for portable solid-state gamma-ray detectors or spectrometers that dramatically reduces the cooling power requirements. For example, the operating shield at 260K (40K below room temperature) will decrease the thermal radiation load to the detector by 50%, which makes possible portable battery operation for a mechanically cooled Ge spectrometer.

  10. Phys. Med. Biol. 45 (2000) 18631868. Printed in the UK PII: S0031-9155(00)10622-0 Ultraviolet radiation dosimetry with radiochromic film

    E-Print Network [OSTI]

    Yu, K.N.

    of high energy x-rays and electron beams (McLaughlin et al 1991, Muench et al 1991, Butson et al 1998) has-band radiometers measure the total irradiance over a selected waveband (Berger 1976, Wengraitis et al 1998

  11. arXiv:0704.2794v1[physics.bio-ph]20Apr2007 Strong far field coherent scattering of ultraviolet radiation by holococcolithophores.

    E-Print Network [OSTI]

    is an increase in light scattering. The light backscattering properties of oceanic mesoscale coccolithophore

  12. Performance of a silicon photovoltaic module under enhanced illumination and selective filtration of incoming radiation with simultaneous cooling

    SciTech Connect (OSTI)

    Maiti, Subarna; Vyas, Kairavi; Ghosh, Pushpito K. [Process Design and Engineering Cell, Central Salt and Marine Chemicals Research Institute (Council of Scientific and Industrial Research), G.B. Marg, Bhavnagar 364002, Gujarat (India)

    2010-08-15T23:59:59.000Z

    A promising option to reduce the cost of silicon photovoltaic systems is to concentrate the sunlight incident on the solar cells to increase the output power. However, this leads to higher module temperatures which affects performance adversely and may also cause long term damage. Proper cooling is therefore necessary to operate the system under concentrated radiation. The present work was undertaken to circumvent the problem in practical manner. A suitable liquid, connected to a heat exchanger, was placed in the housing of the photovoltaic module and unwanted wavelengths of solar radiation were filtered out to minimise overheating of the cells. The selection of the liquid was based on factors such as boiling point, transparency towards visible radiation, absorption of infrared and ultraviolet radiation, stability, flow characteristics, heat transfer properties, and electrical nonconductivity. Using a square parabolic type reflector, more than two fold increase in output power was realised on a clear sunny day employing a 0.13 m{sup 2} silicon solar module. Without the cooling arrangement the panel temperature rose uncontrollably. (author)

  13. X-ray survival characteristics and genetic analysis for nine saccharomyces deletion mutants that show altered radiation sensitivity

    SciTech Connect (OSTI)

    Game, John C.; Williamson, Marsha S.; Baccari, Clelia

    2004-01-07T23:59:59.000Z

    The availability of a genome-wide set of Saccharomyces deletion mutants provides a chance to identify all the yeast genes involved in DNA repair. Using X-rays, we are screening these mutants to identify additional genes that show increased sensitivity to the lethal effects of ionizing radiation. For each mutant identified as sensitive, we are confirming that the sensitivity phenotype co-segregates with the deletion allele and are obtaining multipoint survival-versus-dose assays in at least two haploid and one homozygous diploid strains. We present data for deletion mutants involving the genes DOT1, MDM20, NAT3, SPT7, SPT20, GCN5, HFI1, DCC1 and VID21/EAF1, and discuss their potential roles in repair. Eight of these genes have a clear radiation-sensitive phenotype when deleted, but the ninth, GCN5, has at most a borderline phenotype. None of the deletions confer substantial sensitivity to ultra-violet radiation, although one or two may confer marginal sensitivity. The DOT1 gene is of interest because its only known function is to methylate one lysine residue in the core of the histone H3 protein. We find that histone H3 mutants (supplied by K. Struhl) in which this residue is replaced by other amino-acids are also X-ray sensitive, seeming to confirm that methylation of the lysine-79 residue is required for effective repair of radiation damage.

  14. Radiation-induced Genomic Instability and Radiation Sensitivity

    SciTech Connect (OSTI)

    Varnum, Susan M.; Sowa, Marianne B.; Kim, Grace J.; Morgan, William F.

    2013-01-19T23:59:59.000Z

    The obvious relationships between reactive oxygen and nitrogen species, mitochondrial dysfunction, inflammatory type responses and reactive chemokines and cytokines suggests a general stress response induced by ionizing radiation most likely leads to the non-targeted effects described after radiation exposure. We argue that true bystander effects do not occur in the radiation therapy clinic. But there is no question that effects outside the target volume do occur. These “out of field effects” are considered very low dose effects in the context of therapy. So what are the implications of non-targeted effects on radiation sensitivity? The primary goal of therapy is to eradicate the tumor. Given the genetic diversity of the human population, lifestyle and environment factors it is likely some combination of these will influence patient outcome. Non-targeted effects may contribute to a greater or lesser extent. But consider the potential situation involving a partial body exposure due to a radiation accident or radiological terrorism. Non-targeted effects suggest that the tissue at risk for demonstrating possible detrimental effects of radiation exposure might be greater than the volume actually irradiated.

  15. Cluster beam targets for laser plasma extreme ultraviolet and soft x-ray sources

    DOE Patents [OSTI]

    Kublak, Glenn D. (124 Turquoise Way, Livermore, Alameda County, CA 94550); Richardson, Martin C. (CREOL

    1996-01-01T23:59:59.000Z

    Method and apparatus for producing extreme ultra violet (EUV) and soft x-ray radiation from an ultra-low debris plasma source are disclosed. Targets are produced by the free jet expansion of various gases through a temperature controlled nozzle to form molecular clusters. These target clusters are subsequently irradiated with commercially available lasers of moderate intensity (10.sup.11 -10.sup.12 watts/cm.sup.2) to produce a plasma radiating in the region of 0.5 to 100 nanometers. By appropriate adjustment of the experimental conditions the laser focus can be moved 10-30 mm from the nozzle thereby eliminating debris produced by plasma erosion of the nozzle.

  16. Energy Flow in Interjet Radiation

    E-Print Network [OSTI]

    Carola F. Berger; Tibor Kucs; George Sterman

    2002-03-05T23:59:59.000Z

    We study the distribution of transverse energy, Q_Omega, radiated into an arbitrary interjet angular region, Omega, in high-p_T two-jet events. Using an approximation that emphasizes radiation directly from the partons that undergo the hard scattering, we find a distribution that can be extrapolated smoothly to Q_Omega=Lambda_QCD, where it vanishes. This method, which we apply numerically in a valence quark approximation, provides a class of predictions on transverse energy radiated between jets, as a function of jet energy and rapidity, and of the choice of the region Omega in which the energy is measured. We discuss the relation of our approximation to the radiation from unobserved partons of intermediate energy, whose importance was identified by Dasgupta and Salam.

  17. Texas Radiation Control Act (Texas)

    Broader source: Energy.gov [DOE]

    It is the policy of the state to institute and maintain a regulatory program for radiation sources that is compatible with federal standards and regulatory programs, and, to the degree possible,...

  18. Ionizing Radiation Injury (South Carolina)

    Broader source: Energy.gov [DOE]

    This legislation applies to employers that have more than one employee who engages in activities which involve the presence of ionizing radiation. Employers with less than three employees can...

  19. Survivable pulse power space radiator

    DOE Patents [OSTI]

    Mims, J.; Buden, D.; Williams, K.

    1988-03-11T23:59:59.000Z

    A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometerorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length. 5 figs.

  20. MULTI-POINT RADIATION MONITOR

    SciTech Connect (OSTI)

    Hofstetter, K; Donna Beals, D; Ken Odell, K; Robert Eakle, R; Russell Huffman, R; Larry Harpring, L

    2006-05-12T23:59:59.000Z

    A unique radiation monitor has been developed for performing wide-area field surveys for radiation sources. This device integrates the real-time output of multiple radiation detectors into a hand-held personal computer (e.g., a PDA) containing an intuitive graphical user interface. An independent hardware module supplies high voltage to the detectors and contains a rapid sampling system for transferring the detector count rates through an interface to the PDA. The imbedded firmware can be changed for various applications using a programmable memory card. As presently configured, the instrument contains a series of Geiger-Mueller (GM) tubes in a flexible detector string. This linear array of multiple sensors can be used by US Coast Guard and Customs container inspection personnel to measure radiation intensity in stacks of transport containers where physical access is impeded.