National Library of Energy BETA

Sample records for investigating extreme ultraviolet

  1. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    Investigating Extreme Ultraviolet Lithography Mask Defects Investigating Extreme Ultraviolet Lithography Mask Defects Print Wednesday, 28 July 2010 00:00 Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using

  2. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    Investigating Extreme Ultraviolet Lithography Mask Defects Print Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper

  3. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    Investigating Extreme Ultraviolet Lithography Mask Defects Print Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper

  4. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    Investigating Extreme Ultraviolet Lithography Mask Defects Print Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper

  5. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    Investigating Extreme Ultraviolet Lithography Mask Defects Print Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper

  6. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    Investigating Extreme Ultraviolet Lithography Mask Defects Print Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper

  7. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    Investigating Extreme Ultraviolet Lithography Mask Defects Print Since the 1970s, the semiconductor industry has strived to shrink the cost and size of circuit patterns printed onto computer chips in accordance with Moore's law, doubling the number of transistors on a computer's central processing unit (CPU) every two years. The introduction of extreme ultraviolet (EUV) lithography, printing chips using 13-nm-wavelength light, opens the way to future generations of smaller, faster, and cheaper

  8. Extreme ultraviolet lithography machine

    DOE Patents [OSTI]

    Tichenor, Daniel A.; Kubiak, Glenn D.; Haney, Steven J.; Sweeney, Donald W.

    2000-01-01

    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.

  9. 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)

    2000-01-01

    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.

  10. Method for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Felter, T. E.; Kubiak, Glenn D.

    1999-01-01

    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.

  11. Photoresist composition for extreme ultraviolet lithography

    DOE Patents [OSTI]

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

    1999-01-01

    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.

  12. Angular distribution of ions and extreme ultraviolet emission in laser-produced tin droplet plasma

    SciTech Connect (OSTI)

    Chen, Hong; Duan, Lian; Lan, Hui; Wang, Xinbing Chen, Ziqi; Zuo, Duluo; Lu, Peixiang

    2015-05-21

    Angular-resolved ion time-of-flight spectra as well as extreme ultraviolet radiation in laser-produced tin droplet plasma are investigated experimentally and theoretically. Tin droplets with a diameter of 150 μm are irradiated by a pulsed Nd:YAG laser. The ion time-of-flight spectra measured from the plasma formed by laser irradiation of the tin droplets are interpreted in terms of a theoretical elliptical Druyvesteyn distribution to deduce ion density distributions including kinetic temperatures of the plasma. The opacity of the plasma for extreme ultraviolet radiation is calculated based on the deduced ion densities and temperatures, and the angular distribution of extreme ultraviolet radiation is expressed as a function of the opacity using the Beer–Lambert law. Our results show that the calculated angular distribution of extreme ultraviolet radiation is in satisfactory agreement with the experimental data.

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

    DOE Patents [OSTI]

    Hassanein, Ahmed; Konkashbaev, Isak

    2006-10-03

    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.

  14. Xe capillary target for laser-plasma extreme ultraviolet source

    SciTech Connect (OSTI)

    Inoue, Takahiro; Okino, Hideyasu; Nica, Petru Edward; Amano, Sho; Miyamoto, Shuji; Mochizuki, Takayasu

    2007-10-15

    A cryogenic Xe jet system with an annular nozzle has been developed in order to continuously fast supply a Xe capillary target for generating a laser-plasma extreme ultraviolet (EUV) source. The cooling power of the system was evaluated to be 54 W, and the temperature stability was {+-}0.5 K at a cooling temperature of about 180 K. We investigated experimentally the influence of pressure loss inside an annular nozzle on target formation by shortening the nozzle length. Spraying caused by cavitation was mostly suppressed by mitigating the pressure loss, and a focused jet was formed. Around a liquid-solid boundary, a solid-Xe capillary target (100/70 {mu}m {phi}) was formed with a velocity of {<=}0.01 m/s. Laser-plasma EUV generation was tested by focusing a Nd:YAG laser beam on the target. The results suggested that an even thinner-walled capillary target is required to realize the inertial confinement effect.

  15. Condenser for ring-field deep-ultraviolet and extreme-ultraviolet lithography

    DOE Patents [OSTI]

    Chapman, Henry N.; Nugent, Keith A.

    2001-01-01

    A condenser for use with a ring-field deep ultraviolet or extreme ultraviolet lithography system. A condenser includes a ripple-plate mirror which is illuminated by a collimated beam at grazing incidence. The ripple plate comprises a plate mirror into which is formed a series of channels along an axis of the mirror to produce a series of concave surfaces in an undulating pattern. Light incident along the channels of the mirror is reflected onto a series of cones. The distribution of slopes on the ripple plate leads to a distribution of angles of reflection of the incident beam. This distribution has the form of an arc, with the extremes of the arc given by the greatest slope in the ripple plate. An imaging mirror focuses this distribution to a ring-field arc at the mask plane.

  16. Condenser for ring-field deep ultraviolet and extreme ultraviolet lithography

    DOE Patents [OSTI]

    Chapman, Henry N.; Nugent, Keith A.

    2002-01-01

    A condenser for use with a ring-field deep ultraviolet or extreme ultraviolet lithography system. A condenser includes a ripple-plate mirror which is illuminated by a collimated or converging beam at grazing incidence. The ripple plate comprises a flat or curved plate mirror into which is formed a series of channels along an axis of the mirror to produce a series of concave surfaces in an undulating pattern. Light incident along the channels of the mirror is reflected onto a series of cones. The distribution of slopes on the ripple plate leads to a distribution of angles of reflection of the incident beam. This distribution has the form of an arc, with the extremes of the arc given by the greatest slope in the ripple plate. An imaging mirror focuses this distribution to a ring-field arc at the mask plane.

  17. MoRu/Be multilayers for extreme ultraviolet applications

    DOE Patents [OSTI]

    Bajt, Sasa C.; Wall, Mark A.

    2001-01-01

    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.

  18. Self-cleaning optic for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Klebanoff, Leonard E.; Stulen, Richard H.

    2003-12-16

    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.

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

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

    Sistrunk, Emily; Lawrence Livermore National Lab.; Grilj, Jakob; Ecole Polytechnique Federal de Lausanne; Jeong, Jaewoo; Samant, Mahesh G.; Gray, Alexander X.; Temple Univ. Philadelphia, PA; Drr, Hermann A.; Parkin, Stuart S. P.; et al

    2015-02-11

    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. High numerical aperture projection system for extreme ultraviolet projection lithography

    DOE Patents [OSTI]

    Hudyma, Russell M.

    2000-01-01

    An optical system is described that is compatible with extreme ultraviolet radiation and comprises five reflective elements for projecting a mask image onto a substrate. The five optical elements are characterized in order from object to image as concave, convex, concave, convex, and concave mirrors. The optical system is particularly suited for ring field, step and scan lithography methods. The invention uses aspheric mirrors to minimize static distortion and balance the static distortion across the ring field width which effectively minimizes dynamic distortion. The present invention allows for higher device density because the optical system has improved resolution that results from the high numerical aperture, which is at least 0.14.

  1. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    Tool The AIT is the world's highest-performing EUV microscope dedicated to photomask research. It operates on bend-magnet Beamline 11.3.2 at the Advanced Light Source, Lawrence...

  2. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    blemishes. In lithography, the complex process used to create computer chips, a six-inch glass plate called a mask carries one layer of a circuit pattern-the image of which is...

  3. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    ... Tchikoulaeva, and C. Holfeld, "Actinic imaging of native and programmed defects on a full-field mask," Proc. SPIE 7636, 76361A (2010). ALS Science Highlight 213 ALSNews Vol. 311

  4. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    ... La Fontaine, A. Tchikoulaeva, and C. Holfeld, "Actinic imaging of native and programmed defects on a full-field mask," Proc. SPIE 7636, 76361A (2010). ALS Science Highlight 213

  5. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    the size of this defect, which appears as a dark line surrounded by a transparent halo. Actinic inspection with the AIT shows that the halo is completely opaque to EUV. This...

  6. Investigating Extreme Ultraviolet Lithography Mask Defects

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

    At the center of the viewable 30-micron region, the aberration-corrected "sweet spot" covers 5 to 8 microns. The AIT team has developed methods to optimize the alignment of the ...

  7. Extreme ultraviolet induced defects on few-layer graphene

    SciTech Connect (OSTI)

    Gao, A.; Zoethout, E.; Lee, C. J.; Rizo, P. J.; Scaccabarozzi, L.; Banine, V.; Bijkerk, F.; MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede

    2013-07-28

    We use Raman spectroscopy to show that exposing few-layer graphene to extreme ultraviolet (EUV, 13.5 nm) radiation, i.e., relatively low photon energy, results in an increasing density of defects. Furthermore, exposure to EUV radiation in a H{sub 2} background increases the graphene dosage sensitivity, due to reactions caused by the EUV induced hydrogen plasma. X-ray photoelectron spectroscopy results show that the sp{sup 2} bonded carbon fraction decreases while the sp{sup 3} bonded carbon and oxide fraction increases with exposure dose. Our experimental results confirm that even in reducing environment oxidation is still one of the main source of inducing defects.

  8. THE EXTREME-ULTRAVIOLET EMISSION FROM SUN-GRAZING COMETS

    SciTech Connect (OSTI)

    Bryans, P.; Pesnell, W. D.

    2012-11-20

    The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory has observed two Sun-grazing comets as they passed through the solar atmosphere. Both passages resulted in a measurable enhancement of extreme-ultraviolet (EUV) radiance in several of the AIA bandpasses. We explain this EUV emission by considering the evolution of the cometary atmosphere as it interacts with the ambient solar atmosphere. Molecules in the comet rapidly sublimate as it approaches the Sun. They are then photodissociated by the solar radiation field to create atomic species. Subsequent ionization of these atoms produces a higher abundance of ions than normally present in the corona and results in EUV emission in the wavelength ranges of the AIA telescope passbands.

  9. Method for the protection of extreme ultraviolet lithography optics

    DOE Patents [OSTI]

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

    2010-06-22

    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.

  10. 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.; Krebs, M.; Haedrich, S.; Limpert, J.; Kuschel, S.; Wuensche, M.; Hilbert, V.; Zastrau, U.

    2013-02-15

    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.

  11. Graphene defect formation by extreme ultraviolet generated photoelectrons

    SciTech Connect (OSTI)

    Gao, A. Lee, C. J.; Bijkerk, F.

    2014-08-07

    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.

  12. Four-mirror extreme ultraviolet (EUV) lithography projection system

    DOE Patents [OSTI]

    Cohen, Simon J; Jeong, Hwan J; Shafer, David R

    2000-01-01

    The invention is directed to a four-mirror catoptric projection system for extreme ultraviolet (EUV) lithography to transfer a pattern from a reflective reticle to a wafer substrate. In order along the light path followed by light from the reticle to the wafer substrate, the system includes a dominantly hyperbolic convex mirror, a dominantly elliptical concave mirror, spherical convex mirror, and spherical concave mirror. The reticle and wafer substrate are positioned along the system's optical axis on opposite sides of the mirrors. The hyperbolic and elliptical mirrors are positioned on the same side of the system's optical axis as the reticle, and are relatively large in diameter as they are positioned on the high magnification side of the system. The hyperbolic and elliptical mirrors are relatively far off the optical axis and hence they have significant aspherical components in their curvatures. The convex spherical mirror is positioned on the optical axis, and has a substantially or perfectly spherical shape. The spherical concave mirror is positioned substantially on the opposite side of the optical axis from the hyperbolic and elliptical mirrors. Because it is positioned off-axis to a degree, the spherical concave mirror has some asphericity to counter aberrations. The spherical concave mirror forms a relatively large, uniform field on the wafer substrate. The mirrors can be tilted or decentered slightly to achieve further increase in the field size.

  13. 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

    2013-02-10

    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.

  14. Attosecond extreme ultraviolet generation in cluster by using spatially inhomogeneous field

    SciTech Connect (OSTI)

    Feng, Liqiang; Liu, Hang

    2015-01-15

    A promising method to generate the attosecond extreme ultraviolet (XUV) sources has been theoretically investigated emerging from the two-dimensional Ar{sup +} cluster driven by the spatially inhomogeneous field. The results show that with the introduction of the Ar{sup +} cluster model, not only the harmonic cutoffs are enhanced, but also the harmonic yields are reinforced. Furthermore, by properly moderating the inhomogeneity as well as the laser parameters of the inhomogeneous field, the harmonic cutoff can be further extended. As a result, three almost linearly polarized XUV pulses with durations of 40 as, 42 as, and 45 as can be obtained.

  15. Europium (Z=63) n=3-3 lines in the extreme ultraviolet: Na- through...

    Office of Scientific and Technical Information (OSTI)

    Title: Europium (Z63) n3-3 lines in the extreme ultraviolet: Na- through Si-like ions Authors: Trabert, E ; Beiersdorfer, P ; Hell, N ; Brown, G V Publication Date: 2014-08-22 ...

  16. Bright high-repetition-rate source of narrowband extreme-ultraviolet...

    Office of Scientific and Technical Information (OSTI)

    femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ... Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz ...

  17. Correlated proton-electron hole dynamics in protonated water clusters upon extreme ultraviolet photoionization

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

    Li, Zheng; Vendrell, Oriol

    2016-01-13

    The ultrafast nuclear and electronic dynamics of protonated water clusters H+(H2O)n after extreme ultraviolet photoionization is investigated. In particular, we focus on cluster cations with n = 3, 6, and 21. Upon ionization, two positive charges are present in the cluster related to the excess proton and the missing electron, respectively. A correlation is found between the cluster's geometrical conformation and initial electronic energy with the size of the final fragments produced. As a result, for situations in which the electron hole and proton are initially spatially close, the two entities become correlated and separate in a time-scale of 20more » to 40 fs driven by strong non-adiabatic effects.« less

  18. Wave-mixing with high-order harmonics in extreme ultraviolet region

    SciTech Connect (OSTI)

    Dao, Lap Van; Dinh, Khuong Ba; Le, Hoang Vu; Gaffney, Naylyn; Hannaford, Peter

    2015-01-12

    We report studies of the wave-mixing process in the extreme ultraviolet region with two near-infrared driving and controlling pulses with incommensurate frequencies (at 1400 nm and 800 nm). A non-collinear scheme for the two beams is used in order to spatially separate and to characterise the properties of the high-order wave-mixing field. We show that the extreme ultraviolet frequency mixing can be treated by perturbative, very high-order nonlinear optics; the modification of the wave-packet of the free electron needs to be considered in this process.

  19. Low-cost method for producing extreme ultraviolet lithography optics

    DOE Patents [OSTI]

    Folta, James A.; Montcalm, Claude; Taylor, John S.; Spiller, Eberhard A.

    2003-11-21

    Spherical and non-spherical optical elements produced by standard optical figuring and polishing techniques are extremely expensive. Such surfaces can be cheaply produced by diamond turning; however, the roughness in the diamond turned surface prevent their use for EUV lithography. These ripples are smoothed with a coating of polyimide before applying a 60 period Mo/Si multilayer to reflect a wavelength of 134 .ANG. and have obtained peak reflectivities close to 63%. The savings in cost are about a factor of 100.

  20. Supersonic cluster jet source for debris-free extreme ultraviolet production

    SciTech Connect (OSTI)

    Kubiak, G.D.; Bernardez, L.J.

    1997-09-01

    The supersonic cluster jet has been developed and characterized for use as a target medium to produce a clean source of extreme ultraviolet radiation for extreme ultraviolet lithography and other applications. Spectroscopic characterization of the laser plasma emission produced from Xe, O{sub 2} and Kr cluster gas targets has been performed. Xe is the most efficient target gas, exhibiting a conversion efficiency at 13.5 nm of 0.8% into the relevant 2.5% spectral bandwidth. The other target gases are less efficient in the spectral region of interest and, in the case of oxygen, emit {approximately}5 times less off-band radiation. The angular distribution of the Xe plasma emission has also been characterized.

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

    DOE Patents [OSTI]

    Hassanein, Ahmed; Konkashbaev, Isak; Rice, Bryan

    2007-02-20

    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.

  2. Extreme Ultraviolet Imaging of Electron Heated Targets in Petawatt Laser Experiments

    SciTech Connect (OSTI)

    Ma, T; MacPhee, A; Key, M; Akli, K; Mackinnon, A; Chen, C; Barbee, T; Freeman, R; King, J; Link, A; Offermann, D; Ovchinnikov, V; Patel, P; Stephens, R; VanWoerkom, L; Zhang, B; Beg, F

    2007-11-29

    The study of the transport of electrons, and the flow of energy into a solid target or dense plasma, is instrumental in the development of fast ignition inertial confinement fusion. An extreme ultraviolet (XUV) imaging diagnostic at 256 eV and 68 eV provides information about heating and energy deposition within petawatt laser-irradiated targets. XUV images of several irradiated solid targets are presented.

  3. 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; Barkusky, Frank; Mann, Klaus; Mueller, Matthias

    2013-05-28

    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.

  4. 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.; Elettra Sincrotrone Trieste, Trieste ; Callegari, C.; Spezzani, C.; Ciavardini, A.; Coreno, M.; Institute of Inorganic Methodologies and Plasmas , Montelibretti, Roma ; Frassetto, F.; Miotti, P.; Poletto, L.; Golob, D.; Kivimäki, A.; Mahieu, B.; Service des Photons Atomes et Molécules, Commissariat à l'Energie Atomique, Centre d'Etudes de Saclay, Bâtiment 522, 91191 Gif-sur-Yvette ; Bučar, B.; Merhar, M.; Polo, E.; Ressel, B.

    2014-02-15

    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.

  5. Extreme ultraviolet emission and confinement of tin plasmas in the presence of a magnetic field

    SciTech Connect (OSTI)

    Roy, Amitava E-mail: aroy@barc.gov.in; Murtaza Hassan, Syed; Harilal, Sivanandan S.; Hassanein, Ahmed; Endo, Akira; Mocek, Tomas

    2014-05-15

    We investigated the role of a guiding magnetic field on extreme ultraviolet (EUV) and ion emission from a laser produced Sn plasma for various laser pulse duration and intensity. For producing plasmas, planar slabs of pure Sn were irradiated with 1064?nm, Nd:YAG laser pulses with varying pulse duration (515?ns) and intensity. A magnetic trap was fabricated with the use of two neodymium permanent magnets which provided a magnetic field strength ?0.5?T along the plume expansion direction. Our results indicate that the EUV conversion efficiency do not depend significantly on applied axial magnetic field. Faraday Cup ion analysis of Sn plasma show that the ion flux reduces by a factor of ?5 with the application of an axial magnetic field. It was found that the plasma plume expand in the lateral direction with peak velocity measured to be ?1.2?cm/?s and reduced to ?0.75?cm/?s with the application of an axial magnetic field. The plume expansion features recorded using fast photography in the presence and absence of 0.5?T axial magnetic field are simulated using particle-in-cell code. Our simulation results qualitatively predict the plasma behavior.

  6. Multilayer mirror with enhanced spectral selectivity for the next generation extreme ultraviolet lithography

    SciTech Connect (OSTI)

    Medvedev, V. V. Kruijs, R. W. E. van de; Yakshin, A. E.; Novikova, N. N.; Krivtsun, V. M.; Louis, E.; Bijkerk, F.; MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede ; Yakunin, A. M.

    2013-11-25

    We have demonstrated a hybrid extreme ultraviolet (EUV) multilayer mirror for 6.x nm radiation that provides selective suppression for infrared (IR) radiation. The mirror consists of an IR-transparent LaN∕B multilayer stack which is used as EUV-reflective coating and antireflective (AR) coating to suppress IR. The AR coating can be optimized to suppress CO{sub 2} laser radiation at the wavelength of 10.6 μm, which is of interest for application in next-generation EUV lithography systems.

  7. 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)

    1999-01-01

    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.

  8. Improving Ramsey spectroscopy in the extreme-ultraviolet region with a random-sampling approach

    SciTech Connect (OSTI)

    Eramo, R.; Bellini, M. [Istituto Nazionale di Ottica (INO-CNR), Largo E. Fermi 6, I-50125 Florence (Italy); European Laboratory for Non-linear Spectroscopy (LENS), I-50019 Sesto Fiorentino, Florence (Italy); Corsi, C.; Liontos, I. [European Laboratory for Non-linear Spectroscopy (LENS), I-50019 Sesto Fiorentino, Florence (Italy); Cavalieri, S. [European Laboratory for Non-linear Spectroscopy (LENS), I-50019 Sesto Fiorentino, Florence (Italy); Department of Physics, University of Florence, I-50019 Sesto Fiorentino, Florence (Italy)

    2011-04-15

    Ramsey-like techniques, based on the coherent excitation of a sample by delayed and phase-correlated pulses, are promising tools for high-precision spectroscopic tests of QED in the extreme-ultraviolet (xuv) spectral region, but currently suffer experimental limitations related to long acquisition times and critical stability issues. Here we propose a random subsampling approach to Ramsey spectroscopy that, by allowing experimentalists to reach a given spectral resolution goal in a fraction of the usual acquisition time, leads to substantial improvements in high-resolution spectroscopy and may open the way to a widespread application of Ramsey-like techniques to precision measurements in the xuv spectral region.

  9. Compact multi-bounce projection system for extreme ultraviolet projection lithography

    DOE Patents [OSTI]

    Hudyma, Russell M.

    2002-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four optical elements providing five reflective surfaces for projecting a mask image onto a substrate. The five optical surfaces are characterized in order from object to image as concave, convex, concave, convex and concave mirrors. The second and fourth reflective surfaces are part of the same optical element. The optical system is particularly suited for ring field step and scan lithography methods. The invention uses aspheric mirrors to minimize static distortion and balance the static distortion across the ring field width, which effectively minimizes dynamic distortion.

  10. Properites of ultrathin films appropriate for optics capping layers in extreme ultraviolet lithography (EUVL)

    SciTech Connect (OSTI)

    Bajt, S; Edwards, N V; Madey, T E

    2007-06-25

    The contamination of optical surfaces by irradiation shortens optics lifetime and is one of the main concerns for optics used in conjunction with intense light sources, such as high power lasers, 3rd and 4th generation synchrotron sources or plasma sources used in extreme ultraviolet lithography (EUVL) tools. This paper focuses on properties and surface chemistry of different materials, which as thin layers, could be used as capping layers to protect and extend EUVL optics lifetime. The most promising candidates include single element materials such as ruthenium and rhodium, and oxides such as TiO{sub 2} and ZrO{sub 2}.

  11. Overlying extreme-ultraviolet arcades preventing eruption of a filament observed by AIA/SDO

    SciTech Connect (OSTI)

    Chen, Huadong; Ma, Suli; Zhang, Jun

    2013-11-20

    Using the multi-wavelength data from the Atmospheric Imaging Assembly/Solar Dynamic Observatory (AIA/SDO) and the Sun Earth Connection Coronal and Heliospheric Investigation/Solar Terrestrial Relations Observatory (SECCHI/STEREO), we report a failed filament eruption in NOAA AR 11339 on 2011 November 3. The eruption was associated with an X1.9 flare, but without any coronal mass ejection (CME), coronal dimming, or extreme ultraviolet (EUV) waves. Some magnetic arcades above the filament were observed distinctly in EUV channels, especially in the AIA 94 and 131 wavebands, before and during the filament eruption process. Our results show that the overlying arcades expanded along with the ascent of the filament at first until they reached a projected height of about 49 Mm above the Sun's surface, where they stopped. The following filament material was observed to be confined by the stopped EUV arcades and not to escape from the Sun. After the flare, a new filament formed at the low corona where part of the former filament remained before its eruption. These results support that the overlying arcades play an important role in preventing the filament from successfully erupting outward. We also discuss in this paper the EUV emission of the overlying arcades during the flare. It is rare for a failed filament eruption to be associated with an X1.9 class flare, but not with a CME or EUV waves. Therefore, this study also provides valuable insight into the triggering mechanism of the initiation of CMEs and EUV waves.

  12. LARGE-SCALE EXTREME-ULTRAVIOLET DISTURBANCES ASSOCIATED WITH A LIMB CORONAL MASS EJECTION

    SciTech Connect (OSTI)

    Dai, Y.; Auchere, F.; Vial, J.-C.; Tang, Y. H.; Zong, W. G.

    2010-01-10

    We present composite observations of a coronal mass ejection (CME) and the associated large-scale extreme-ultraviolet (EUV) disturbances on 2007 December 31 by the Extreme-ultraviolet Imager (EUVI) and COR1 coronagraph on board the recent Solar Terrestrial Relations Observatory mission. For this limb event, the EUV disturbances exhibit some typical characteristics of EUV Imaging Telescope waves: (1) in the 195 A bandpass, diffuse brightenings are observed propagating oppositely away from the flare site with a velocity of approx260 km s{sup -1}, leaving dimmings behind; (2) when the brightenings encounter the boundary of a polar coronal hole, they stop there to form a stationary front. Multi-temperature analysis of the propagating EUV disturbances favors a heating process over a density enhancement in the disturbance region. Furthermore, the EUVI-COR1 composite display shows unambiguously that the propagation of the diffuse brightenings coincides with a large lateral expansion of the CME, which consequently results in a double-loop-structured CME leading edge. Based on these observational facts, we suggest that the wave-like EUV disturbances are a result of magnetic reconfiguration related to the CME liftoff rather than true waves in the corona. Reconnections between the expanding CME magnetic field lines and surrounding quiet-Sun magnetic loops account for the propagating diffuse brightenings; dimmings appear behind them as a consequence of volume expansion. X-ray and radio data provide us with complementary evidence.

  13. Optimizing laser produced plasmas for efficient extreme ultraviolet and soft X-ray light sources

    SciTech Connect (OSTI)

    Sizyuk, Tatyana; Hassanein, Ahmed [Center for Materials under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-08-15

    Photon sources produced by laser beams with moderate laser intensities, up to 10{sup 14?}W/cm{sup 2}, are being developed for many industrial applications. The performance requirements for high volume manufacture devices necessitate extensive experimental research supported by theoretical plasma analysis and modeling predictions. We simulated laser produced plasma sources currently being developed for several applications such as extreme ultraviolet lithography using 13.5%??1% nm bandwidth, possibly beyond extreme ultraviolet lithography using 6. nm wavelengths, and water-window microscopy utilizing 2.48?nm (La-?) and 2.88?nm (He-?) emission. We comprehensively modeled plasma evolution from solid/liquid tin, gadolinium, and nitrogen targets as three promising materials for the above described sources, respectively. Results of our analysis for plasma characteristics during the entire course of plasma evolution showed the dependence of source conversion efficiency (CE), i.e., laser energy to photons at the desired wavelength, on plasma electron density gradient. Our results showed that utilizing laser intensities which produce hotter plasma than the optimum emission temperatures allows increasing CE for all considered sources that, however, restricted by the reabsorption processes around the main emission region and this restriction is especially actual for the 6.?nm sources.

  14. Enhancement of laser plasma extreme ultraviolet emission by shockwave-laser interaction

    SciTech Connect (OSTI)

    Bruijn, Rene de; Koshelev, Konstantin N.; Zakharov, Serguei V.; Novikov, Vladimir G.; Bijkerk, Fred

    2005-04-15

    A double laser pulse heating scheme has been applied to generate plasmas with enhanced emission in the extreme ultraviolet (EUV). The plasmas were produced by focusing two laser beams (prepulse and main pulse) with a small spatial separation between the foci on a xenon gas jet target. Prepulses with ps-duration were applied to obtain high shockwave densities, following indications of earlier published results obtained using ns prepulses. EUV intensities around 13.5 nm and in the range 5-20 nm were recorded, and a maximum increase in intensity exceeding 2 was measured at an optimal delay of 140 ns between prepulse and main pulse. The gain in intensity is explained by the interaction of the shockwave produced by the prepulse with the xenon in the beam waist of the main pulse. Extensive simulation was done using the radiative magnetohydrodynamic code Z{sup *}.

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

    DOE Patents [OSTI]

    Stearns, Daniel G.; Sweeney, Donald W.; Mirkarimi, Paul B.

    2004-11-23

    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.

  16. Study of the extreme ultraviolet spectrum of O/sub 2/ by electron impact

    SciTech Connect (OSTI)

    Ajello, J.M.; Franklin, B.

    1985-03-15

    We have measured in the laboratory the electron impact emission cross sections for O/sub 2/ at 200 eV. Included in the study are all emission features in the extreme ultraviolet from 40 to 131 nm at a resolution of 0.5 nm. The features are entirely from the dissociation products (OI, OII, OIII). Additionally we have measured the excitation functions from 0 to 400 eV for characteristic OI multiplets at 98.9 and 102.6 nm and for OII multiplets at 53.9 and 83.3 nm. We find the OI multiplets are formed near the dissociation limit whereas the OII multiplets have a threshold about 10 eV above the dissociation limit. We also determine the total VUV emission cross section of O/sub 2/ from 40 to 200 nm and indicate the effects of autoionization to the measured emission spectrum.

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

    DOE Patents [OSTI]

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

    1996-11-19

    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.

  18. THE HIGH-RESOLUTION EXTREME-ULTRAVIOLET SPECTRUM OF N{sub 2} BY ELECTRON IMPACT

    SciTech Connect (OSTI)

    Heays, A. N.; Ajello, J. M.; Aguilar, A.; Lewis, B. R.; Gibson, S. T.

    2014-04-01

    We have analyzed high-resolution (FWHM = 0.2 ) extreme-ultraviolet (EUV, 800-1350 ) laboratory emission spectra of molecular nitrogen excited by an electron impact at 20 and 100 eV under (mostly) optically thin, single-scattering experimental conditions. A total of 491 emission features were observed from N{sub 2} electronic-vibrational transitions and atomic N I and N II multiplets and their emission cross sections were measured. Molecular emission was observed at vibrationally excited ground-state levels as high as v'' = 17, from the a {sup 1}? {sub g} , b {sup 1}? {sub u} , and b'{sup 1}? {sub u} {sup +} excited valence states and the Rydberg series c'{sub n} {sub +1} {sup 1}? {sub u} {sup +}, c{sub n} {sup 1}? {sub u} , and o{sub n} {sup 1}? {sub u} for n between 3 and 9. The frequently blended molecular emission bands were disentangled with the aid of a sophisticated and predictive quantum-mechanical model of excited states that includes the strong coupling between valence and Rydberg electronic states and the effects of predissociation. Improved model parameters describing electronic transition moments were obtained from the experiment and allowed for a reliable prediction of the vibrationally summed electronic emission cross section, including an extrapolation to unobserved emission bands and those that are optically thick in the experimental spectra. Vibrationally dependent electronic excitation functions were inferred from a comparison of emission features following 20 and 100 eV electron-impact collisional excitation. The electron-impact-induced fluorescence measurements are compared with Cassini Ultraviolet Imaging Spectrograph observations of emissions from Titan's upper atmosphere.

  19. A Molecular- and Nano-Electronics Test (MONET) platform fabricated using extreme ultraviolet lithography.

    SciTech Connect (OSTI)

    Dentinger, Paul M.; Cardinale, Gregory F.; Hunter, Luke L.; Talin, Albert Alec

    2003-12-01

    We describe the fabrication and characterization of an electrode array test structure, designed for electrical probing of molecules and nanocrystals. We use Extreme Ultraviolet Lithography (EUVL) to define the electrical test platform features. As fabricated, the platform includes nominal electrode gaps of 0 nm, 40 nm, 60 nm, and 80 nm. Additional variation in electrode gap is achieved by controlling the exposure conditions, such as dose and focus. To enable EUVL based nanofabrication, we develop a novel bi-level photoresist process. The bi-level photoresist consists of a combination of a commercially available polydimethylglutarimide (PMGI) bottom layer and an experimental EUVL photoresist top (imaging) layer. We measure the sensitivity of PMGI to EUV exposure dose as a function of photoresist pre-bake temperature, and using this data, optimize a metal lift-off process. Reliable fabrication of 700 Angstrom thick Au structures with sub-1000 Angstrom critical dimensions is achieved, even without the use of a Au adhesion layer, such as Ti. Several test platforms are used to characterize electrical properties of organic molecules deposited as self assembled monolayers.

  20. Characterization of gas targets for laser produced extreme ultraviolet plasmas with a Hartmann-Shack sensor

    SciTech Connect (OSTI)

    Peth, Christian; Kranzusch, Sebastian; Mann, Klaus; Vioel, Wolfgang

    2004-10-01

    A table top extreme ultraviolet (EUV)-source was developed at Laser-Laboratorium Goettingen for the characterization of optical components and sensoric devices in the wavelength region from 11 to 13 nm. EUV radiation is generated by focusing the beam of a Q-switched Nd:YAG laser into a pulsed xenon gas jet. Since a directed gas jet with a high number density is needed for an optimal performance of the source, conical nozzles with different cone angles were drilled with an excimer laser to produce a supersonic gas jet. The influence of the nozzle geometry on the gas jet was characterized with a Hartmann-Shack wave front sensor. The deformation of a planar wave front after passing the gas jet was analyzed with this sensor, allowing a reconstruction of the gas density distribution. Thus, the gas jet was optimized resulting in an increase of EUV emission by a factor of two and a decrease of the plasma size at the same time.

  1. Diagnosis of energy transport in iron buried layer targets using an extreme ultraviolet laser

    SciTech Connect (OSTI)

    Shahzad, M.; Culfa, O.; Rossall, A. K.; Tallents, G. J.; Wilson, L. A.; Guilbaud, O.; Kazamias, S.; Delmas, O.; Demailly, J.; Maitrallain, A.; Pittman, M.; Baynard, E.; Farjardo, M.

    2015-02-15

    We demonstrate the use of extreme ultra-violet (EUV) laboratory lasers in probing energy transport in laser irradiated solid targets. EUV transmission through targets containing a thin layer of iron (50 nm) encased in plastic (CH) after irradiation by a short pulse (35 fs) laser focussed to irradiances 3 × 10{sup 16} Wcm{sup −2} is measured. Heating of the iron layer gives rise to a rapid decrease in EUV opacity and an increase in the transmission of the 13.9 nm laser radiation as the iron ionizes to Fe{sup 5+} and above where the ion ionisation energy is greater than the EUV probe photon energy (89 eV). A one dimensional hydrodynamic fluid code HYADES has been used to simulate the temporal variation in EUV transmission (wavelength 13.9 nm) using IMP opacity values for the iron layer and the simulated transmissions are compared to measured transmission values. When a deliberate pre-pulse is used to preform an expanding plastic plasma, it is found that radiation is important in the heating of the iron layer while for pre-pulse free irradiation, radiation transport is not significant.

  2. THE EXTREME ULTRAVIOLET DEFICIT AND MAGNETICALLY ARRESTED ACCRETION IN RADIO-LOUD QUASARS

    SciTech Connect (OSTI)

    Punsly, Brian

    2014-12-20

    The Hubble Space Telescope composite quasar spectra presented in Telfer et al. show a significant deficit of emission in the extreme ultraviolet for the radio-loud component of the quasar population (RLQs) compared to the radio-quiet component of the quasar population. The composite quasar continuum emission between 1100 Å and ∼580 Å is generally considered to be associated with the innermost regions of the accretion flow onto the central black hole. The deficit between 1100 Å and 580 Å in RLQs has a straightforward interpretation as a missing or a suppressed innermost region of local energy dissipation in the accretion flow. It is proposed that this can be the result of islands of large-scale magnetic flux in RLQs that are located close to the central black hole that remove energy from the accretion flow as Poynting flux (sometimes called magnetically arrested accretion). These magnetic islands are natural sites for launching relativistic jets. Based on the Telfer et al. data and the numerical simulations of accretion flows in Penna et al., the magnetic islands are concentrated between the event horizon and an outer boundary of <2.8 M (in geometrized units) for rapidly rotating black holes and <5.5 M for modestly rotating black holes.

  3. Bright high-repetition-rate source of narrowband extreme-ultraviolet...

    Office of Scientific and Technical Information (OSTI)

    This enhancement exceeds the expected dipole scaling, evidencing improved phase-matching for ultraviolet-driven HHG under tight focusing as corroborated by simulations. Spectral ...

  4. Tin removal from extreme ultraviolet collector optics by inductively coupled plasma reactive ion etching

    SciTech Connect (OSTI)

    Shin, H.; Srivastava, S. N.; Ruzic, D. N. [Center for Plasma Material Interactions, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2008-05-15

    Tin (Sn) has the advantage of delivering higher conversion efficiency compared to other fuel materials (e.g., Xe or Li) in an extreme ultraviolet (EUV) source, a necessary component for the leading next generation lithography. However, the use of a condensable fuel in a lithography system leads to some additional challenges for maintaining a satisfactory lifetime of the collector optics. A critical issue leading to decreased mirror lifetime is the buildup of debris on the surface of the primary mirror that comes from the use of Sn in either gas discharge produced plasma (GDPP) or laser produced plasma (LPP). This leads to a decreased reflectivity from the added material thickness and increased surface roughness that contributes to scattering. Inductively coupled plasma reactive ion etching with halide ions is one potential solution to this problem. This article presents results for etch rate and selectivity of Sn over SiO{sub 2} and Ru. The Sn etch rate in a chlorine plasma is found to be much higher (of the order of hundreds of nm/min) than the etch rate of other materials. A thermally evaporated Sn on Ru sample was prepared and cleaned using an inductively coupled plasma etching method. Cleaning was confirmed using several material characterization techniques. Furthermore, a collector mock-up shell was then constructed and etching was performed on Sn samples prepared in a Sn EUV source using an optimized etching recipe. The sample surface before and after cleaning was analyzed by atomic force microscopy, x-ray photoelectron spectroscopy, and Auger electron spectroscopy. The results show the dependence of etch rate on the location of Sn samples placed on the collector mock-up shell.

  5. 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)

    2012-07-01

    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.

  6. A chain of winking (oscillating) filaments triggered by an invisible extreme-ultraviolet wave

    SciTech Connect (OSTI)

    Shen, Yuandeng; Tian, Zhanjun; Zhao, Ruijuan; Ichimoto, Kiyoshi; Ishii, Takako T.; Shibata, Kazunari

    2014-05-10

    Winking (oscillating) filaments have been observed for many years. However, observations of successive winking filaments in one event have not yet been reported. In this paper, we present the observations of a chain of winking filaments and a subsequent jet that are observed right after the X2.1 flare in AR11283. The event also produced an extreme-ultraviolet (EUV) wave that has two components: an upward dome-like wave (850 km s{sup 1}) and a lateral surface wave (554 km s{sup 1}) that was very weak (or invisible) in imaging observations. By analyzing the temporal and spatial relationships between the oscillating filaments and the EUV waves, we propose that all the winking filaments and the jet were triggered by the weak (or invisible) lateral surface EUV wave. The oscillation of the filaments last for two or three cycles, and their periods, Doppler velocity amplitudes, and damping times are 11-22 minutes, 6-14 km s{sup 1}, and 25-60 minutes, respectively. We further estimate the radial component magnetic field and the maximum kinetic energy of the filaments, and they are 5-10 G and ?10{sup 19} J, respectively. The estimated maximum kinetic energy is comparable to the minimum energy of ordinary EUV waves, suggesting that EUV waves can efficiently launch filament oscillations on their path. Based on our analysis results, we conclude that the EUV wave is a good agent for triggering and connecting successive but separated solar activities in the solar atmosphere, and it is also important for producing solar sympathetic eruptions.

  7. Note: On the wavelength dependence of the intensity calibration factor of extreme ultraviolet spectrometer determined with profile measurement of bremsstrahlung continuum

    SciTech Connect (OSTI)

    Yamaguchi, N.; Morita, S.; Dong, C. F.; Goto, M.; Maezawa, H.; Miyauchi, H.

    2015-06-15

    The absolute calibration factor of extreme ultraviolet spectroscopic instrument which has recently been determined from absolute radiation profile measurement of bremsstrahlung continuum has been investigated by comparing the calculated diffraction efficiency of grating. An overall tendency of the wavelength dependence of the calibration factor from 40 Å to 500 Å can be reproduced by that of the grating efficiency, especially the agreement between the measured calibration factor and the calculated grating efficiency has been found to be fairly good for the wavelength range 200 Å-500 Å.

  8. JET ROTATION INVESTIGATED IN THE NEAR-ULTRAVIOLET WITH THE HUBBLE SPACE TELESCOPE IMAGING SPECTROGRAPH

    SciTech Connect (OSTI)

    Coffey, Deirdre; Ray, Thomas P.; Rigliaco, Elisabetta; Bacciotti, Francesca; Eisloeffel, Jochen

    2012-04-20

    We present results of the second phase of our near-ultraviolet investigation into protostellar jet rotation using the Hubble Space Telescope Imaging Spectrograph. We obtain long-slit spectra at the base of five T Tauri jets to determine if there is a difference in radial velocity between the jet borders which may be interpreted as a rotation signature. These observations are extremely challenging and push the limits of current instrumentation, but have the potential to provide long-awaited observational support for the magnetocentrifugal mechanism of jet launching in which jets remove angular momentum from protostellar systems. We successfully detect all five jet targets (from RW Aur, HN Tau, DP Tau, and CW Tau) in several near-ultraviolet emission lines, including the strong Mg II doublet. However, only RW Aur's bipolar jet presents a sufficiently high signal-to-noise ratio to allow for analysis. The approaching jet lobe shows a difference of 10 km s{sup -1} in a direction which agrees with the disk rotation sense, but is opposite to previously published optical measurements for the receding jet. The near-ultraviolet difference is not found six months later, nor is it found in the fainter receding jet. Overall, in the case of RW Aur, differences are not consistent with a simple jet rotation interpretation. Indeed, given the renowned complexity and variability of this system, it now seems likely that any rotation signature is confused by other influences, with the inevitable conclusion that RW Aur is not suited to a jet rotation study.

  9. 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)

    2009-11-10

    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.

  10. A study of the terrestrial thermosphere by remote sensing of OI dayglow in the far and extreme ultraviolet

    SciTech Connect (OSTI)

    Cotton, D.M.

    1991-01-01

    The upper region of the Earth's atmosphere, the thermosphere, is a key part of the coupled solar-terrestrial system. An important method of obtaining information in the this region is through analysis of radiation excited through the interactions of the thermosphere with solar ionizing, extreme and far ultraviolet radiation. This dissertation presents one such study by the remote sensing of OI in the far and extreme ultraviolet dayglow. The research program included the development construction, and flight of a sounding rocket spectrometer to test this current understanding of the excitation and transport mechanisms of the OI 1356, 1304, 1027, and 989 {angstrom} emissions. This data set was analyzed using current electron and radiative transport models with the purpose of checking the viability of OI remote sensing; that is, whether existing models and input parameters are adequate to predict these detailed measurements. From discrepancies between modeled and measured emissions, inferences about these input parameters were made. Among other things, the data supports a 40% optically thick cascade contribution to the 1304 {angstrom} emission. From upper lying states corresponding to 1040, 1027 and 989 {angstrom} about half of this cascade has been accounted for in this study. There is also evidence that the Lyman {beta} airglow from the geo-corona contributes a significant proportion (30-50%) to the OI 1027 {angstrom} feature. Furthermore, the photoelectron contribution to the 1027 {angstrom} feature appears to be underestimated in the current models by a factor of 20.

  11. Time-resolved extreme-ultraviolet spectroscopy of laser-produced plasmas originating at the parylene layer of microballon targets

    SciTech Connect (OSTI)

    Griem, H.R.; Moreno, J.

    1991-03-01

    In experiments this past year at the University of Rochester's Laboratory for Laser Energetics we obtained time-integrated and time-resolved spectra from the ultraviolet to the x-ray region. We have investigated various phenomena in laser-produced plasmas including spectral line broadening, plasma expansion velocities, ionization and recombination of low-Z materials in spherical targets, and the formation of satellites near some resonance lines. In addition we have improved our spectroscopic instrumentation.

  12. Method for high-precision multi-layered thin film deposition for deep and extreme ultraviolet mirrors

    DOE Patents [OSTI]

    Ruffner, J.A.

    1999-06-15

    A method for coating (flat or non-flat) optical substrates with high-reflectivity multi-layer coatings for use at Deep Ultra-Violet (DUV) and Extreme Ultra-Violet (EUV) wavelengths. The method results in a product with minimum feature sizes of less than 0.10 [micro]m for the shortest wavelength (13.4 nm). The present invention employs a computer-based modeling and deposition method to enable lateral and vertical thickness control by scanning the position of the substrate with respect to the sputter target during deposition. The thickness profile of the sputter targets is modeled before deposition and then an appropriate scanning algorithm is implemented to produce any desired, radially-symmetric thickness profile. The present invention offers the ability to predict and achieve a wide range of thickness profiles on flat or figured substrates, i.e., account for 1/R[sup 2] factor in a model, and the ability to predict and accommodate changes in deposition rate as a result of plasma geometry, i.e., over figured substrates. 15 figs.

  13. Method for high-precision multi-layered thin film deposition for deep and extreme ultraviolet mirrors

    DOE Patents [OSTI]

    Ruffner, Judith Alison

    1999-01-01

    A method for coating (flat or non-flat) optical substrates with high-reflectivity multi-layer coatings for use at Deep Ultra-Violet ("DUV") and Extreme Ultra-Violet ("EUV") wavelengths. The method results in a product with minimum feature sizes of less than 0.10-.mu.m for the shortest wavelength (13.4-nm). The present invention employs a computer-based modeling and deposition method to enable lateral and vertical thickness control by scanning the position of the substrate with respect to the sputter target during deposition. The thickness profile of the sputter targets is modeled before deposition and then an appropriate scanning algorithm is implemented to produce any desired, radially-symmetric thickness profile. The present invention offers the ability to predict and achieve a wide range of thickness profiles on flat or figured substrates, i.e., account for 1/R.sup.2 factor in a model, and the ability to predict and accommodate changes in deposition rate as a result of plasma geometry, i.e., over figured substrates.

  14. A solar type II radio burst from coronal mass ejection-coronal ray interaction: Simultaneous radio and extreme ultraviolet imaging

    SciTech Connect (OSTI)

    Chen, Yao; Du, Guohui; Feng, Shiwei; Kong, Xiangliang; Wang, Bing; Feng, Li; Guo, Fan; Li, Gang

    2014-05-20

    Simultaneous radio and extreme ultraviolet (EUV)/white-light imaging data are examined for a solar type II radio burst occurring on 2010 March 18 to deduce its source location. Using a bow-shock model, we reconstruct the three-dimensional EUV wave front (presumably the type-II-emitting shock) based on the imaging data of the two Solar TErrestrial RElations Observatory spacecraft. It is then combined with the Nanay radio imaging data to infer the three-dimensional position of the type II source. It is found that the type II source coincides with the interface between the coronal mass ejection (CME) EUV wave front and a nearby coronal ray structure, providing evidence that the type II emission is physically related to the CME-ray interaction. This result, consistent with those of previous studies, is based on simultaneous radio and EUV imaging data for the first time.

  15. Effects of the dynamics of droplet-based laser-produced plasma on angular extreme ultraviolet emission profile

    SciTech Connect (OSTI)

    Giovannini, Andrea Z.; Abhari, Reza S.

    2014-05-12

    The emission distribution of extreme ultraviolet (EUV) radiation from droplet targets is dependent on the dynamics of the laser-produced plasma. The EUV emission is measured on a 2% bandwidth centered at 13.5 nm (in-band). The targets of the laser are small (sub-50 μm) tin droplets, and the in-band emission distribution is measured for different laser irradiances and droplet sizes at various angular positions. Larger droplets lead to a faster decay of EUV emission at larger angles with respect to the laser axis. A decrease in laser irradiance has the opposite effect. The measurements are used together with an analytical model to estimate plume dynamics. Additionally, the model is used to estimate EUV emission distribution for a desired droplet diameter and laser irradiance.

  16. Extended-range grazing-incidence spectrometer for high-resolution extreme ultraviolet measurements on an electron beam ion trap

    SciTech Connect (OSTI)

    Beiersdorfer, P.; Magee, E. W.; Brown, G. V.; Träbert, E.; Widmann, K.; Hell, N.

    2014-11-15

    A high-resolution grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for performing very high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 Å to above 300 Å. The instrument operates without an entrance slit and focuses the light emitted by highly charged ions located in the roughly 50 μm wide electron beam onto a cryogenically cooled back-illuminated charge-coupled device detector. The measured line widths are below 0.025 Å above 100 Å, and the resolving power appears to be limited by the source size and Doppler broadening of the trapped ions. Comparisons with spectra obtained with existing grating spectrometers show an order of magnitude improvement in spectral resolution.

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

    DOE Patents [OSTI]

    Kublak, Glenn D.; Richardson, Martin C. (CREOL

    1996-01-01

    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.

  18. AN ULTRAVIOLET INVESTIGATION OF ACTIVITY ON EXOPLANET HOST STARS

    SciTech Connect (OSTI)

    Shkolnik, Evgenya L.

    2013-03-20

    Using the far-UV (FUV) and near-UV (NUV) photometry from the NASA Galaxy Evolution Explorer (GALEX), we searched for evidence of increased stellar activity due to tidal and/or magnetic star-planet interactions (SPI) in the 272 known FGK planetary hosts observed by GALEX. With the increased sensitivity of GALEX, we are able probe systems with lower activity levels and at larger distances than what has been done to date with X-ray satellites. We compared samples of stars with close-in planets (a < 0.1 AU) to those with far-out planets (a > 0.5 AU) and looked for correlations of excess activity with other system parameters. This statistical investigation found no clear correlations with a, M{sub p} , or M{sub p} /a, in contrast to some X-ray and Ca II studies. However, there is tentative evidence (at a level of 1.8{sigma}) that stars with radial-velocity-(RV)-detected close-in planets are more FUV-active than stars with far-out planets, in agreement with several published X-ray and Ca II results. The case is strengthened to a level of significance to 2.3{sigma} when transit-detected close-in planets are included. This is most likely because the RV-selected sample of stars is significantly less active than the field population of comparable stars, while the transit-selected sample is similarly active. Given the factor of 2-3 scatter in fractional FUV luminosity for a given stellar effective temperature, it is necessary to conduct a time-resolved study of the planet hosts in order to better characterize their UV variability and generate a firmer statistical result.

  19. Quantitative analysis of electron energy loss spectra and modelling of optical properties of multilayer systems for extreme ultraviolet radiation regime

    SciTech Connect (OSTI)

    Gusenleitner, S.; Hauschild, D.; Reinert, F.; Handick, E.

    2014-03-28

    Ruthenium capped multilayer coatings for use in the extreme ultraviolet (EUV) radiation regime have manifold applications in science and industry. Although the Ru cap shall protect the reflecting multilayers, the surface of the heterostructures suffers from contamination issues and surface degradation. In order to get a better understanding of the effects of these impurities on the optical parameters, reflection electron energy loss spectroscopy (REELS) measurements of contaminated and H cleaned Ru multilayer coatings were taken at various primary electron beam energies. Experiments conducted at low primary beam energies between 100?eV and 1000?eV are very surface sensitive due to the short inelastic mean free path of the electrons in this energy range. Therefore, influences of the surface condition on the above mentioned characteristics can be appraised. In this paper, it can be shown that carbon and oxide impurities on the mirror surface decrease the transmission of the Ru cap by about 0.75% and the overall reflectance of the device is impaired as the main share of the non-transmitted EUV light is absorbed in the contamination layer.

  20. HELIOS—A laboratory based on high-order harmonic generation of extreme ultraviolet photons for time-resolved spectroscopy

    SciTech Connect (OSTI)

    Plogmaker, S. E-mail: Joachim.Terschluesen@physics.uu.se Terschlüsen, J. A. E-mail: Joachim.Terschluesen@physics.uu.se Krebs, N.; Svanqvist, M.; Forsberg, J.; Cappel, U. B.; Rubensson, J.-E.; Siegbahn, H.; Söderström, J. E-mail: Joachim.Terschluesen@physics.uu.se

    2015-12-15

    In this paper, we present the HELIOS (High Energy Laser Induced Overtone Source) laboratory, an in-house high-order harmonic generation facility which generates extreme ultraviolet (XUV) photon pulses in the range of 15-70 eV with monochromatized XUV pulse lengths below 35 fs. HELIOS is a source for time-resolved pump-probe/two-color spectroscopy in the sub-50 fs range, which can be operated at 5 kHz or 10 kHz. An optical parametric amplifier is available for pump-probe experiments with wavelengths ranging from 240 nm to 20 000 nm. The produced XUV radiation is monochromatized by a grating in the so-called off-plane mount. Together with overall design parameters, first monochromatized spectra are shown with an intensity of 2 ⋅ 10{sup 10} photons/s (at 5 kHz) in the 29th harmonic, after the monochromator. The XUV pulse duration is measured to be <25 fs after monochromatization.

  1. Radiation damage resistance of AlGaN detectors for applications in the extreme-ultraviolet spectral range

    SciTech Connect (OSTI)

    Barkusky, Frank; Peth, Christian; Bayer, Armin; Mann, Klaus; John, Joachim; Malinowski, Pawel E.

    2009-09-15

    We report on the fabrication of aluminum gallium nitride (AlGaN) Schottky-photodiode-based detectors. AlGaN layers were grown using metal-organic chemical vapor deposition (MOCVD) on Si(111) wafers. The diodes were characterized at a wavelength of 13.5 nm using a table-top extreme-ultraviolet (EUV) radiation source, consisting of a laser-produced xenon plasma and a Schwarzschild objective. The responsivity of the diodes was tested between EUV energies ranging from 320 nJ down to several picojoules. For low fluences, a linear responsivity of 7.14 mAs/J could be determined. Saturation starts at approximately 1 nJ, merging into a linear response of 0.113 mAs/J, which could be attributed to the photoeffect on the Au electrodes on top of the diode. Furthermore, degradation tests were performed up to an absolute dose of 3.3x10{sup 19} photons/cm{sup 2}. AlGaN photodiodes were compared to commercially available silicon-based photodetectors. For AlGaN diodes, responsivity does not change even for the highest EUV dose, whereas the response of the Si diode decreases linearly to {approx}93% after 2x10{sup 19} photons/cm{sup 2}.

  2. DIFFRACTION, REFRACTION, AND REFLECTION OF AN EXTREME-ULTRAVIOLET WAVE OBSERVED DURING ITS INTERACTIONS WITH REMOTE ACTIVE REGIONS

    SciTech Connect (OSTI)

    Shen Yuandeng; Liu Yu; Zhao Ruijuan; Tian Zhanjun; Su Jiangtao; Li Hui; Ichimoto, Kiyoshi; Shibata, Kazunari

    2013-08-20

    We present observations of the diffraction, refraction, and reflection of a global extreme-ultraviolet (EUV) wave propagating in the solar corona. These intriguing phenomena are observed when the wave interacts with two remote active regions, and together they exhibit properties of an EUV wave. When the wave approached AR11465, it became weaker and finally disappeared in the active region, but a few minutes later a new wavefront appeared behind the active region, and it was not concentric with the incoming wave. In addition, a reflected wave was also simultaneously observed on the wave incoming side. When the wave approached AR11459, it transmitted through the active region directly and without reflection. The formation of the new wavefront and the transmission could be explained with diffraction and refraction effects, respectively. We propose that the different behaviors observed during the interactions may be caused by different speed gradients at the boundaries of the two active regions. We find that the EUV wave formed ahead of a group of expanding loops a few minutes after the start of the loops' expansion, which represents the initiation of the associated coronal mass ejection (CME). Based on these results, we conclude that the EUV wave should be a nonlinear magnetosonic wave or shock driven by the associated CME, which propagated faster than the ambient fast mode speed and gradually slowed down to an ordinary linear wave. Our observations support the hybrid model that includes both fast wave and slow non-wave components.

  3. Chemical Effect of Dry and Wet Cleaning of the Ru Protective Layer of the Extreme ultraviolet (EUV) Lithography Reflector

    SciTech Connect (OSTI)

    Belau, Leonid; Park, Jeong Y.; Liang, Ted; Seo, Hyungtak; Somorjai, Gabor A.

    2009-04-10

    The authors report the chemical influence of cleaning of the Ru capping layer on the extreme ultraviolet (EUV) reflector surface. The cleaning of EUV reflector to remove the contamination particles has two requirements: to prevent corrosion and etching of the reflector surface and to maintain the reflectivity functionality of the reflector after the corrosive cleaning processes. Two main approaches for EUV reflector cleaning, wet chemical treatments [sulfuric acid and hydrogen peroxide mixture (SPM), ozonated water, and ozonated hydrogen peroxide] and dry cleaning (oxygen plasma and UV/ozone treatment), were tested. The changes in surface morphology and roughness were characterized using scanning electron microscopy and atomic force microscopy, while the surface etching and change of oxidation states were probed with x-ray photoelectron spectroscopy. Significant surface oxidation of the Ru capping layer was observed after oxygen plasma and UV/ozone treatment, while the oxidation is unnoticeable after SPM treatment. Based on these surface studies, the authors found that SPM treatment exhibits the minimal corrosive interactions with Ru capping layer. They address the molecular mechanism of corrosive gas and liquid-phase chemical interaction with the surface of Ru capping layer on the EUV reflector.

  4. NON-POTENTIAL FIELDS IN THE QUIET SUN NETWORK: EXTREME-ULTRAVIOLET AND MAGNETIC FOOTPOINT OBSERVATIONS

    SciTech Connect (OSTI)

    Chesny, D. L.; Oluseyi, H. M.; Orange, N. B.

    2013-11-20

    The quiet Sun (QS) magnetic network is known to contain dynamics which are indicative of non-potential fields. Non-potential magnetic fields forming ''S-shaped'' loop arcades can lead to the breakdown of static activity and have only been observed in high temperature X-ray coronal structuressome of which show eruptive behavior. Thus, analysis of this type of atmospheric structuring has been restricted to large-scale coronal fields. Here we provide the first identification of non-potential loop arcades exclusive to the QS supergranulation network. High-resolution Atmospheric Imaging Assembly data from the Solar Dynamics Observatory have allowed for the first observations of fine-scale ''S-shaped'' loop arcades spanning the network. We have investigated the magnetic footpoint flux evolution of these arcades from Heliospheric and Magnetic Imager data and find evidence of evolving footpoint flux imbalances accompanying the formation of these non-potential fields. The existence of such non-potentiality confirms that magnetic field dynamics leading to the build up of helicity exist at small scales. QS non-potentiality also suggests a self-similar formation process between the QS network and high temperature corona and the existence of self-organized criticality (SOC) in the form of loop-pair reconnection and helicity dissipation. We argue that this type of behavior could lead to eruptive forms of SOC as seen in active region (AR) and X-ray sigmoids if sufficient free magnetic energy is available. QS magnetic network dynamics may be considered as a coronal proxy at supergranular scales, and events confined to the network can even mimic those in coronal ARs.

  5. 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

    2009-01-01

    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.

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

    SciTech Connect (OSTI)

    Aquila, Andrew Lee

    2009-05-21

    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

  7. Formation and direct writing of color centers in LiF using a laser-induced extreme ultraviolet plasma in combination with a Schwarzschild objective

    SciTech Connect (OSTI)

    Barkusky, Frank; Peth, Christian; Mann, Klaus; Feigl, Torsten; Kaiser, Norbert

    2005-10-15

    In order to generate high-energy densities of 13.5 nm radiation, an extreme ultraviolet (EUV) Schwarzschild mirror objective with a numerical aperture of 0.44 and a demagnification of 10 was developed and adapted to a compact laser-based EUV source. The annular spherical mirror substrates were coated with Mo/Si multilayer systems. With a single mirror reflectance of more than 65% the total transmittance of the Schwarzschild objective exceeds 40% at 13.5 nm. From the properties of the EUV source (pulse energy 3 mJ at 13.5 nm and plasma diameter approximately 300 {mu}m), energy densities of 73 mJ/cm{sup 2} at a pulse length of 6 ns can be estimated in the image plane of the objective. As a first application, the formation of color centers in lithium fluoride crystals by EUV radiation was investigated. F{sub 2}, F{sub 3}, and F{sub 3}{sup +} color centers could be identified by absorption spectroscopy. The formation dynamics was studied as a function of the EUV dose. By imaging of a pinhole positioned behind the plasma, an EUV spot of 5 {mu}m diameter was generated, which accomplishes direct writing of color centers with micrometer resolution.

  8. Direct photo-etching of poly(methyl methacrylate) using focused extreme ultraviolet radiation from a table-top laser-induced plasma source

    SciTech Connect (OSTI)

    Barkusky, Frank; Peth, Christian; Bayer, Armin; Mann, Klaus

    2007-06-15

    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-based EUV plasma source (pulse energy 3 mJ at {lambda}=13.5 nm, plasma diameter {approx}300 {mu}m). By 10x demagnified imaging of the plasma a pulse energy density of {approx}75 mJ/cm{sup 2} at a pulse length of 6 ns can be achieved in the image plane of the objective. As demonstrated for poly(methyl methacrylate) (PMMA), photoetching of polymer surfaces is possible at this EUV fluence level. This paper presents first results, including a systematic determination of PMMA etching rates under EUV irradiation. Furthermore, the contribution of out-of-band radiation to the surface etching of PMMA was investigated by conducting a diffraction experiment for spectral discrimination from higher wavelength radiation. Imaging of a pinhole positioned behind the plasma accomplished the generation of an EUV spot of 1 {mu}m diameter, which was employed for direct writing of surface structures in PMMA.

  9. Extreme ultraviolet reflector

    DOE Patents [OSTI]

    Newnam, Brian E.

    1990-01-01

    A multi-faceted mirror forms a retroreflector for a resonator loop in a free electron laser (FEL) operating in the XUV (.lambda.=10-100 nm). The number of facets is determined by the angle-of-incidence needed to obtain total external reflectance (TER) from the facet surface and the angle through which the FEL beam is to be turned. Angles-of-incidence greater than the angle for TER may be used to increase the area of the beam incident on the surface and reduce energy absorption density. Suitable surface films having TER in the 10-100 nm range may be formed from a variety of materials, including Al, single-crystal Si, Ag, and Rh. One of the facets is formed as an off-axis conic section to collimate the output beam with minimum astigmatism.

  10. A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak

    SciTech Connect (OSTI)

    Zhang, Ling; Xu, Zong; Wu, Zhenwei; Zhang, Pengfei; Wu, Chengrui; Gao, Wei; Shen, Junsong; Chen, Yingjie; Liu, Xiang; Wang, Yumin; Gong, Xianzu; Hu, Liqun; Chen, Junlin; Zhang, Xiaodong; Wan, Baonian; Li, Jiangang; Morita, Shigeru; Ohishi, Tetsutarou; Goto, Motoshi; Dong, Chunfeng; and others

    2015-12-15

    A flat-field extreme ultraviolet (EUV) spectrometer working in the 20-500 Å wavelength range with fast time response has been newly developed to measure line emissions from highly ionized tungsten in the Experimental Advanced Superconducting Tokamak (EAST) with a tungsten divertor, while the monitoring of light and medium impurities is also an aim in the present development. A flat-field focal plane for spectral image detection is made by a laminar-type varied-line-spacing concave holographic grating with an angle of incidence of 87°. A back-illuminated charge-coupled device (CCD) with a total size of 26.6 × 6.6 mm{sup 2} and pixel numbers of 1024 × 255 (26 × 26 μm{sup 2}/pixel) is used for recording the focal image of spectral lines. An excellent spectral resolution of Δλ{sub 0} = 3-4 pixels, where Δλ{sub 0} is defined as full width at the foot position of a spectral line, is obtained at the 80-400 Å wavelength range after careful adjustment of the grating and CCD positions. The high signal readout rate of the CCD can improve the temporal resolution of time-resolved spectra when the CCD is operated in the full vertical binning mode. It is usually operated at 5 ms per frame. If the vertical size of the CCD is reduced with a narrow slit, the time response becomes faster. The high-time response in the spectral measurement therefore makes possible a variety of spectroscopic studies, e.g., impurity behavior in long pulse discharges with edge-localized mode bursts. An absolute intensity calibration of the EUV spectrometer is also carried out with a technique using the EUV bremsstrahlung continuum at 20-150 Å for quantitative data analysis. Thus, the high-time resolution tungsten spectra have been successfully observed with good spectral resolution using the present EUV spectrometer system. Typical tungsten spectra in the EUV wavelength range observed from EAST discharges are presented with absolute intensity and spectral identification.

  11. 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)

    2014-02-01

    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 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 ?}.

  12. EVIDENCE FOR THE WAVE NATURE OF AN EXTREME ULTRAVIOLET WAVE OBSERVED BY THE ATMOSPHERIC IMAGING ASSEMBLY ON BOARD THE SOLAR DYNAMICS OBSERVATORY

    SciTech Connect (OSTI)

    Shen Yuandeng; Liu Yu

    2012-07-20

    Extreme-ultraviolet (EUV) waves have been found for about 15 years. However, significant controversy remains over their physical natures and origins. In this paper, we report an EUV wave that was accompanied by an X1.9 flare and a partial halo coronal mass ejection (CME). Using high temporal and spatial resolution observations taken by the Solar Dynamics Observatory and the Solar-TErrestrial RElations Observatory, we are able to investigate the detailed kinematics of the EUV wave. We find several arguments that support the fast-mode wave scenario. (1) The speed of the EUV wave (570 km s{sup -1}) is higher than the sound speed of the quiet-Sun corona. (2) Significant deceleration of the EUV wave (-130 m s{sup -2}) is found during its propagation. (3) The EUV wave resulted in the oscillations of a loop and a filament along its propagation path, and a reflected wave from the polar coronal hole is also detected. (4) Refraction or reflection effect is observed when the EUV wave was passing through two coronal bright points. (5) The dimming region behind the wavefront stopped to expand when the wavefront started to become diffuse. (6) The profiles of the wavefront exhibited a dispersive nature, and the magnetosonic Mach number of the EUV wave derived from the highest intensity jump is about 1.4. In addition, triangulation indicates that the EUV wave propagated within a height range of about 60-100 Mm above the photosphere. We propose that the EUV wave observed should be a nonlinear fast-mode magnetosonic wave that propagated freely in the corona after it was driven by the CME expanding flanks during the initial period.

  13. Gradient descent algorithm applied to wavefront retrieval from through-focus images by an extreme ultraviolet microscope with partially coherent source

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

    Yamazoe, Kenji; Mochi, Iacopo; Goldberg, Kenneth A.

    2014-12-01

    The wavefront retrieval by gradient descent algorithm that is typically applied to coherent or incoherent imaging is extended to retrieve a wavefront from a series of through-focus images by partially coherent illumination. For accurate retrieval, we modeled partial coherence as well as object transmittance into the gradient descent algorithm. However, this modeling increases the computation time due to the complexity of partially coherent imaging simulation that is repeatedly used in the optimization loop. To accelerate the computation, we incorporate not only the Fourier transform but also an eigenfunction decomposition of the image. As a demonstration, the extended algorithm is appliedmore » to retrieve a field-dependent wavefront of a microscope operated at extreme ultraviolet wavelength (13.4 nm). The retrieved wavefront qualitatively matches the expected characteristics of the lens design.« less

  14. Gradient descent algorithm applied to wavefront retrieval from through-focus images by an extreme ultraviolet microscope with partially coherent source

    SciTech Connect (OSTI)

    Yamazoe, Kenji; Mochi, Iacopo; Goldberg, Kenneth A.

    2014-12-01

    The wavefront retrieval by gradient descent algorithm that is typically applied to coherent or incoherent imaging is extended to retrieve a wavefront from a series of through-focus images by partially coherent illumination. For accurate retrieval, we modeled partial coherence as well as object transmittance into the gradient descent algorithm. However, this modeling increases the computation time due to the complexity of partially coherent imaging simulation that is repeatedly used in the optimization loop. To accelerate the computation, we incorporate not only the Fourier transform but also an eigenfunction decomposition of the image. As a demonstration, the extended algorithm is applied to retrieve a field-dependent wavefront of a microscope operated at extreme ultraviolet wavelength (13.4 nm). The retrieved wavefront qualitatively matches the expected characteristics of the lens design.

  15. Temporal characterization of a time-compensated monochromator for high-efficiency selection of extreme-ultraviolet pulses generated by high-order harmonics

    SciTech Connect (OSTI)

    Poletto, L.; Villoresi, P.; Benedetti, E.; Ferrari, F.; Stagira, S.; Sansone, G.; Nisoli, M.

    2008-07-15

    Ultrafast extreme-ultraviolet pulses are spectrally selected by a time-delay-compensated grating monochromator. The intrinsic very short duration of the pulses is obtained by exploiting the high-order harmonic generation process. The temporal characterization of the harmonic pulses is obtained using a cross-correlation method: pulses as short as 8 fs are measured at the output of the monochromator in the case of the 23rd harmonic. This value is in agreement with the expected duration of such pulses, indicating that the influence of the monochromator is negligible. The photon flux has been measured with a calibrated photodiode, pointing out the good efficiency of the monochromator, derived by the exploitation for the two gratings of the conical diffraction mounting.

  16. 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 Juschkin, Larissa; Weier, Christian; Adam, Roman; Schneider, Claus M.; Winkler, Gerrit; Frmter, Robert; Danylyuk, Serhiy; Bergmann, Klaus; Grtzmacher, Detlev

    2014-10-15

    Generation of circularly polarized light in the extreme ultraviolet (EUV) spectral region (about 25 eV250 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.

  17. Photoionized plasmas induced in neon with extreme ultraviolet and soft X-ray pulses produced using low and high energy laser systems

    SciTech Connect (OSTI)

    Bartnik, A.; Wachulak, P.; Fok, T.; Węgrzyński, Ł.; Fiedorowicz, H.; Pisarczyk, T.; Chodukowski, T.; Kalinowska, Z.; Dudzak, R.; Dostal, J.; Krousky, E.; Skala, J.; Ullschmied, J.; Hrebicek, J.; Medrik, T.

    2015-04-15

    A comparative study of photoionized plasmas created by two soft X-ray and extreme ultraviolet (SXR/EUV) laser plasma sources with different parameters is presented. The two sources are based on double-stream Xe/He gas-puff targets irradiated with high (500 J/0.3 ns) and low energy (10 J/1 ns) laser pulses. In both cases, the SXR/EUV beam irradiated the gas stream, injected into a vacuum chamber synchronously with the radiation pulse. Irradiation of gases resulted in formation of photoionized plasmas emitting radiation in the SXR/EUV range. The measured Ne plasma radiation spectra are dominated by emission lines corresponding to radiative transitions in singly charged ions. A significant difference concerns origin of the lines: K-shell or L-shell emissions occur in case of the high and low energy irradiating system, respectively. In high energy system, the electron density measurements were also performed by laser interferometry, employing a femtosecond laser system. A maximum electron density for Ne plasma reached the value of 2·10{sup 18 }cm{sup −3}. For the low energy system, a detection limit was too high for the interferometric measurements, thus only an upper estimation for electron density could be made.

  18. Initiation and early evolution of the coronal mass ejection on 2009 May 13 from extreme-ultraviolet and white-light observations

    SciTech Connect (OSTI)

    Reva, A. A.; Ulyanov, A. S.; Bogachev, S. A.; Kuzin, S. V.

    2014-10-01

    We present the results of the observations of a coronal mass ejection (CME) that occurred on 2009 May 13. The most important feature of these observations is that the CME was observed from the very early stage (the solar surface) up to a distance of 15 solar radii (R {sub ?}). Below 2 R {sub ?}, we used the data from the TESIS extreme-ultraviolet telescopes obtained in the Fe 171 and He 304 lines, and above 2 R {sub ?}, we used the observations of the LASCO C2 and C3 coronagraphs. The CME was formed at a distance of 0.2-0.5R {sub ?} from the Sun's surface as a U-shaped structure, which was observed both in the 171 images and in the white light. Observations in the He 304 line showed that the CME was associated with an erupting prominence, which was not located aboveas the standard model predictsbut rather in the lowest part of the U-shaped structure close to the magnetic X point. The prominence location can be explained with the CME breakout model. Estimates showed that CME mass increased with time. The CME trajectory was curvedits heliolatitude decreased with time. The CME started at a latitude of 50 and reached the ecliptic plane at distances of 2.5 R {sub ?}. The CME kinematics can be divided into three phases: initial acceleration, main acceleration, and propagation with constant velocity. After the CME, onset GOES registered a sub-A-class flare.

  19. Space-resolved extreme ultraviolet spectroscopy free of high-energy neutral particle noise in wavelength range of 10–130 Å on the large helical device

    SciTech Connect (OSTI)

    Huang, Xianli; Morita, Shigeru; Oishi, Tetsutarou; Goto, Motoshi; National Institute for Fusion Science, Toki 509-5292 Gifu ; Dong, Chunfeng

    2014-04-15

    A flat-field space-resolved extreme ultraviolet (EUV) spectrometer system working in wavelength range of 10–130 Å has been constructed in the Large Helical Device (LHD) for profile measurements of bremsstrahlung continuum and line emissions of heavy impurities in the central column of plasmas, which are aimed at studies on Z{sub eff} and impurity transport, respectively. Until now, a large amount of spike noise caused by neutral particles with high energies (≤180 keV) originating in neutral beam injection has been observed in EUV spectroscopy on LHD. The new system has been developed with an aim to delete such a spike noise from the signal by installing a thin filter which can block the high-energy neutral particles entering the EUV spectrometer. Three filters of 11 μm thick beryllium (Be), 3.3 μm thick polypropylene (PP), and 0.5 μm thick polyethylene terephthalate (PET: polyester) have been examined to eliminate the spike noise. Although the 11 μm Be and 3.3 μm PP filters can fully delete the spike noise in wavelength range of λ ≤ 20 Å, the signal intensity is also reduced. The 0.5 μm PET filter, on the other hand, can maintain sufficient signal intensity for the measurement and the spike noise remained in the signal is acceptable. As a result, the bremsstrahlung profile is successfully measured without noise at 20 Å even in low-density discharges, e.g., 2.9 × 10{sup 13} cm{sup −3}, when the 0.5 μm PET filter is used. The iron n = 3–2 Lα transition array consisting of FeXVII to FeXXIV is also excellently observed with their radial profiles in wavelength range of 10–18 Å. Each transition in the Lα array can be accurately identified with its radial profile. As a typical example of the method a spectral line at 17.62 Å is identified as FeXVIII transition. Results on absolute intensity calibration of the spectrometer system, pulse height and noise count analyses of the spike noise between holographic and ruled gratings and wavelength

  20. SECONDARY WAVES AND/OR THE 'REFLECTION' FROM AND 'TRANSMISSION' THROUGH A CORONAL HOLE OF AN EXTREME ULTRAVIOLET WAVE ASSOCIATED WITH THE 2011 FEBRUARY 15 X2.2 FLARE OBSERVED WITH SDO/AIA AND STEREO/EUVI

    SciTech Connect (OSTI)

    Olmedo, Oscar; Vourlidas, Angelos; Zhang Jie; Cheng Xin

    2012-09-10

    For the first time, the kinematic evolution of a coronal wave over the entire solar surface is studied. Full Sun maps can be made by combining images from the Solar Terrestrial Relations Observatory satellites, Ahead and Behind, and the Solar Dynamics Observatory, thanks to the wide angular separation between them. We study the propagation of a coronal wave, also known as the 'Extreme Ultraviolet Imaging Telescope' wave, and its interaction with a coronal hole (CH) resulting in secondary waves and/or reflection and transmission. We explore the possibility of the wave obeying the law of reflection. In a detailed example, we find that a loop arcade at the CH boundary cascades and oscillates as a result of the extreme ultraviolet (EUV) wave passage and triggers a wave directed eastward that appears to have reflected. We find that the speed of this wave decelerates to an asymptotic value, which is less than half of the primary EUV wave speed. Thanks to the full Sun coverage we are able to determine that part of the primary wave is transmitted through the CH. This is the first observation of its kind. The kinematic measurements of the reflected and transmitted wave tracks are consistent with a fast-mode magnetohydrodynamic wave interpretation. Eventually, all wave tracks decelerate and disappear at a distance. A possible scenario of the whole process is that the wave is initially driven by the expanding coronal mass ejection and subsequently decouples from the driver and then propagates at the local fast-mode speed.

  1. Investigating Operating System Noise in Extreme-Scale High-Performance Computing Systems using Simulation

    SciTech Connect (OSTI)

    Engelmann, Christian

    2013-01-01

    Hardware/software co-design for future-generation high-performance computing (HPC) systems aims at closing the gap between the peak capabilities of the hardware and the performance realized by applications (application-architecture performance gap). Performance profiling of architectures and applications is a crucial part of this iterative process. The work in this paper focuses on operating system (OS) noise as an additional factor to be considered for co-design. It represents the first step in including OS noise in HPC hardware/software co-design by adding a noise injection feature to an existing simulation-based co-design toolkit. It reuses an existing abstraction for OS noise with frequency (periodic recurrence) and period (duration of each occurrence) to enhance the processor model of the Extreme-scale Simulator (xSim) with synchronized and random OS noise simulation. The results demonstrate this capability by evaluating the impact of OS noise on MPI_Bcast() and MPI_Reduce() in a simulated future-generation HPC system with 2,097,152 compute nodes.

  2. Investigation of exposure to Extremely Low Frequency (ELF) magnetic and electric fields: Ongoing animal studies

    SciTech Connect (OSTI)

    Anderson, L.E.

    1994-03-01

    There is now convincing evidence from a large number of laboratories, that exposure to extremely low frequency (ELF) magnetic and electric fields produces biological responses in animals. Many of the observed effects appear to be directly or indirectly associated with the neural or neuroendocrine systems. Such effects include increased neuronal excitability, chemical and hormonal changes in the nervous system, altered behavioral responses, some of which are related to sensing the presence of the field, and changes in endogenous biological rhythms. Additional indices of general physiological status appear relatively unaffected by exposure, although effects have occasionally been described in bone growth and fracture repair, reproduction and development, and immune system function. A major current emphasis in laboratory research is to determine whether or not the reported epidemiological studies that suggest an association between EMF exposure and risk of cancer are supported in studies using animal models. Three major challenges exist for ongoing research: (1) knowledge about the mechanisms underlying observed bioeffects is incomplete, (2) researchers do not as yet understand what physical aspects of exposure produce biological responses, and (3) health consequences resulting from ELF exposure are unknown. Although no animal studies clearly demonstrate deleterious effects of ELF fields, several are suggestive of potential health impacts. From the perspective of laboratory animal studies, this paper will discuss biological responses to ELF magnetic and/or electric field exposures.

  3. Investigating the Influence of Anthropogenic Forcing on Observed Mean and Extreme Sea Level Pressure Trends over the Mediterranean Region

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

    Barkhordarian, Armineh

    2012-01-01

    We investigate whether the observed mean sea level pressure (SLP) trends over the Mediterranean region in the period from 1975 to 2004 are significantly consistent with what 17 models projected as response of SLP to anthropogenic forcing (greenhouse gases and sulphate aerosols, GS). Obtained results indicate that the observed trends in mean SLP cannot be explained by natural (internal) variability. Externally forced changes are detectable in all seasons, except spring. The large-scale component (spatial mean) of the GS signal is detectable in all the 17 models in winter and in 12 of the 17 models in summer. However, the small-scalemore » component (spatial anomalies about the spatial mean) of GS signal is only detectable in winter within 11 of the 17 models. We also show that GS signal has a detectable influence on observed decreasing (increasing) tendency in the frequencies of extremely low (high) SLP days in winter and that these changes cannot be explained by internal climate variability. While the detection of GS forcing is robust in winter and summer, there are striking inconsistencies in autumn, where analysis points to the presence of an external forcing, which is not GS forcing.« less

  4. Investigating nearby star-forming galaxies in the ultraviolet with HST/COS spectroscopy. I. Spectral analysis and interstellar abundance determinations

    SciTech Connect (OSTI)

    James, B. L.; Aloisi, A.; Sohn, S. T.; Wolfe, M. A.; Heckman, T.

    2014-11-10

    This is the first in a series of three papers describing a project with the Cosmic Origins Spectrograph on the Hubble Space Telescope to measure abundances of the neutral interstellar medium (ISM) in a sample of nine nearby star-forming galaxies. The goal is to assess the (in)homogeneities of the multiphase ISM in galaxies where the bulk of metals can be hidden in the neutral phase, yet the metallicity is inferred from the ionized gas in the H II regions. The sample, spanning a wide range in physical properties, is to date the best suited to investigate the metallicity behavior of the neutral gas at redshift z = 0. ISM absorption lines were detected against the far-ultraviolet spectra of the brightest star-forming region(s) within each galaxy. Here we report on the observations, data reduction, and analysis of these spectra. Column densities were measured by a multicomponent line-profile fitting technique, and neutral-gas abundances were obtained for a wide range of elements. Several caveats were considered, including line saturation, ionization corrections, and dust depletion. Ionization effects were quantified with ad hoc CLOUDY models reproducing the complex photoionization structure of the ionized and neutral gas surrounding the UV-bright sources. An 'average spectrum of a redshift z = 0 star-forming galaxy' was obtained from the average column densities of unsaturated profiles of neutral-gas species. This template can be used as a powerful tool for studies of the neutral ISM at both low and high redshift.

  5. Ultraviolet absorption hygrometer

    DOE Patents [OSTI]

    Gersh, Michael E.; Bien, Fritz; Bernstein, Lawrence S.

    1986-01-01

    An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined.

  6. Ultraviolet absorption hygrometer

    DOE Patents [OSTI]

    Gersh, M.E.; Bien, F.; Bernstein, L.S.

    1986-12-09

    An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined. 5 figs.

  7. Extreme ultra-violet burst, particle heating, and whistler wave...

    Office of Scientific and Technical Information (OSTI)

    induced by kink-driven Rayleigh-Taylor instability This content will become ... induced by kink-driven Rayleigh-Taylor instability Authors: Chai, Kil-Byoung 1 ...

  8. PROMINENCE PLASMA DIAGNOSTICS THROUGH EXTREME-ULTRAVIOLET ABSORPTION

    SciTech Connect (OSTI)

    Landi, E.; Reale, F.

    2013-07-20

    In this paper, we introduce a new diagnostic technique that uses EUV and UV absorption to determine the electron temperature and column emission measure, as well as the He/H relative abundance of the absorbing plasma. If a realistic assumption on the geometry of the latter can be made and a spectral code such as CHIANTI is used, then this technique can also yield the absorbing plasma hydrogen and electron density. This technique capitalizes on the absorption properties of hydrogen and helium at different wavelength ranges and temperature regimes. Several cases where this technique can be successfully applied are described. This technique works best when the absorbing plasma is hotter than 15,000 K. We demonstrate this technique on AIA observations of plasma absorption during a coronal mass ejection eruption. This technique can be easily applied to existing observations of prominences and cold plasmas in the Sun from almost all space missions devoted to the study of the solar atmosphere, which we list.

  9. Reflective optical imaging system for extreme ultraviolet wavelengths

    DOE Patents [OSTI]

    Viswanathan, V.K.; Newnam, B.E.

    1993-05-18

    A projection reflection optical system has two mirrors in a coaxial, four reflection configuration to reproduce the image of an object. The mirrors have spherical reflection surfaces to provide a very high resolution of object feature wavelengths less than 200 [mu]m, and preferably less than 100 [mu]m. An image resolution of features less than 0.05-0.1 [mu]m, is obtained over a large area field; i.e., 25.4 mm [times] 25.4 mm, with a distortion less than 0.1 of the resolution over the image field.

  10. Erosion resistant nozzles for laser plasma extreme ultraviolet (EUV) sources

    DOE Patents [OSTI]

    Kubiak, Glenn D.; Bernardez, II, Luis J.

    2000-01-04

    A gas nozzle having an increased resistance to erosion from energetic plasma particles generated by laser plasma sources. By reducing the area of the plasma-facing portion of the nozzle below a critical dimension and fabricating the nozzle from a material that has a high EUV transmission as well as a low sputtering coefficient such as Be, C, or Si, it has been shown that a significant reduction in reflectance loss of nearby optical components can be achieved even after exposing the nozzle to at least 10.sup.7 Xe plasma pulses.

  11. Reflective optical imaging system for extreme ultraviolet wavelengths

    DOE Patents [OSTI]

    Viswanathan, Vriddhachalam K.; Newnam, Brian E.

    1993-01-01

    A projection reflection optical system has two mirrors in a coaxial, four reflection configuration to reproduce the image of an object. The mirrors have spherical reflection surfaces to provide a very high resolution of object feature wavelengths less than 200 .mu.m, and preferably less than 100 .mu.m. An image resolution of features less than 0.05-0.1 .mu.m, is obtained over a large area field; i.e., 25.4 mm .times.25.4 mm, with a distortion less than 0.1 of the resolution over the image field.

  12. Ultraviolet radiation induced discharge laser

    DOE Patents [OSTI]

    Gilson, Verle A.; Schriever, Richard L.; Shearer, James W.

    1978-01-01

    An ultraviolet radiation source associated with a suitable cathode-anode electrode structure, disposed in a gas-filled cavity of a high pressure pulsed laser, such as a transverse electric atmosphere (TEA) laser, to achieve free electron production in the gas by photoelectric interaction between ultraviolet radiation and the cathode prior to the gas-exciting cathode-to-anode electrical discharge, thereby providing volume ionization of the gas. The ultraviolet radiation is produced by a light source or by a spark discharge.

  13. Type B Accident Investigation Board Report on the June 2002 High Radiation Dose to Extremities in Building 151, Lawrence Livermore National Laboratory

    Broader source: Energy.gov [DOE]

    This report is an independent product of the Type B Accident Investigation Board appointed by Camille Yuan-Soo Hoo, Manager of the U.S. Department of Energy, Oakland Operations Office.

  14. Diffractive element in extreme-UV lithography condenser

    DOE Patents [OSTI]

    Sweatt, William C.; Ray-Chaudhurl, Avijit K.

    2000-01-01

    Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

  15. Diffractive element in extreme-UV lithography condenser

    DOE Patents [OSTI]

    Sweatt, William C.; Ray-Chaudhuri, Avijit

    2001-01-01

    Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

  16. THE ULTRAVIOLET BRIGHTEST TYPE Ia SUPERNOVA 2011de

    SciTech Connect (OSTI)

    Brown, Peter J., E-mail: pbrown@physics.tamu.edu [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)

    2014-11-20

    We present and discuss the ultraviolet (UV)/optical photometric light curves and absolute magnitudes of the TypeIa supernova (SN Ia) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observedmore than a factor of 10 brighter than normal SNe Ia in the mid-ultraviolet. We find that the UV/optical brightness and broad light curve evolution can be modeled with additional flux from the shock of the ejecta hitting a relatively large red giant companion separated by 6 10{sup 13} cm. However, the post-maximum behavior of other UV-bright SNe Ia can also be modeled in a similar manner, including objects with UV spectroscopy or pre-maximum photometry which is inconsistent with this model. This suggests that similar UV luminosities can be intrinsic or caused by other forms of shock interaction. The high velocities reported for SN 2011de make it distinct from the UV-bright ''super-Chandrasekhar'' SNe Ia and the NUV-blue group of normal SNe Ia. SN 2011de is an extreme example of the UV variations in SNe Ia.

  17. Wafer chamber having a gas curtain for extreme-UV lithography

    DOE Patents [OSTI]

    Kanouff, Michael P.; Ray-Chaudhuri, Avijit K.

    2001-01-01

    An EUVL device includes a wafer chamber that is separated from the upstream optics by a barrier having an aperture that is permeable to the inert gas. Maintaining an inert gas curtain in the proximity of a wafer positioned in a chamber of an extreme ultraviolet lithography device can effectively prevent contaminants from reaching the optics in an extreme ultraviolet photolithography device even though solid window filters are not employed between the source of reflected radiation, e.g., the camera, and the wafer. The inert gas removes the contaminants by entrainment.

  18. Microgap ultra-violet detector

    DOE Patents [OSTI]

    Wuest, Craig R.; Bionta, Richard M.

    1994-01-01

    A microgap ultra-violet detector of photons with wavelengths less than 400 run (4000 Angstroms) which comprises an anode and a cathode separated by a gas-filled gap and having an electric field placed across the gap. 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.

  19. Microgap ultra-violet detector

    DOE Patents [OSTI]

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

    1994-09-20

    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.

  20. Extreme-UV electrical discharge source

    DOE Patents [OSTI]

    Fornaciari, Neal R.; Nygren, Richard E.; Ulrickson, Michael A.

    2002-01-01

    An extreme ultraviolet and soft x-ray radiation electric capillary discharge source that includes a boron nitride housing defining a capillary bore that is positioned between two electrodes one of which is connected to a source of electric potential can generate a high EUV and soft x-ray radiation flux from the capillary bore outlet with minimal debris. The electrode that is positioned adjacent the capillary bore outlet is typically grounded. Pyrolytic boron nitride, highly oriented pyrolytic boron nitride, and cubic boron nitride are particularly suited. The boron nitride capillary bore can be configured as an insert that is encased in an exterior housing that is constructed of a thermally conductive material. Positioning the ground electrode sufficiently close to the capillary bore outlet also reduces bore erosion.

  1. Advanced Instrumentation for Extreme Environments

    SciTech Connect (OSTI)

    Melin, Alexander M; Kisner, Roger; Fugate, David L

    2013-01-01

    The Department of Energy (DOE) Office of Nuclear Energy (NE) is pursuing embedded instrumentation and controls (I&C) technology for next generation nuclear power generation applications. Embedded systems encompass a wide range of configurations and technologies; we define embedding in this instance as the integration of the sensors and the control system design into the component design using a systems engineering process. Embedded I&C systems are often an essential part of developing new capabilities, improving reliability, enhancing performance, and reducing operational costs. The new intrinsically safe, more efficient, and cost effective reactor technologies (Next Generation Nuclear Plant and Small Modular Reactors) require the development and application of new I&C technologies. These new designs raise extreme environmental challenges such as high temperatures (over 700 C) and material compatibility (e.g., molten salts). The desired reliability and functionality requires measurements in these extreme conditions including high radiation environments which were not previously monitored in real time. The DOE/NE Nuclear Energy Enabling Technologies (NEET) program currently has several projects investigating I&C technologies necessary to make these reactor designs realizable. The project described in this paper has the specific goal of investigating embedded I&C with the following objectives: 1.Explore and quantify the potential gains from embedded I&C improved reliability, increased performance, and reduced cost 2.Identify practical control, sensing, and measurement techniques for the extreme environments found in high-temperature reactors 3.Design and fabricate a functional prototype high-temperature cooling pump for molten salts represents target demonstration of improved performance, reliability, and widespread usage There are many engineering challenges in the design of a high-temperature liquid salt cooling pump. The pump and motor are in direct contact with

  2. Ultraviolet Behavior of N = 8 supergravity

    SciTech Connect (OSTI)

    Dixon, Lance J.

    2010-06-07

    In these lectures the author describes the remarkable ultraviolet behavior of N = 8 supergravity, which through four loops is no worse than that of N = 4 super-Yang-Mills theory (a finite theory). I also explain the computational tools that allow multi-loop amplitudes to be evaluated in this theory - the KLT relations and the unitarity method - and sketch how ultraviolet divergences are extracted from the amplitudes.

  3. Extreme Environments (EFree) Center

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

    Extreme Environments (EFree ) Center LLNL Co-PI: Jonathon Crowhurst [e-mail] [bio] Novel materials for energy applications Ultrafast reflectivity measurements under high pressure Transient reflectivity of BaFe2As2 at the indicated pressures in neon. In this experiment we measure pump-driven ultrafast reflectivity changes in order to infer the time scale of electron phonon coupling, and help to assess its role and importance in new superconducting systems. We believe this is the first time such

  4. High numerical aperture ring field projection system for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Hudyma, Russell; Shafer, David R.

    2001-01-01

    An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first convex mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receive a chief ray at an incidence angle of less than substantially 9.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 14.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Each of the six reflecting surfaces has an aspheric departure of less than substantially 16 .mu.m.

  5. High numerical aperture ring field projection system for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Hudyma, Russell

    2000-01-01

    An all-refelctive optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first concave mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receives a chief ray at an incidence angle less than substantially 12.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 15.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 7 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 14 .mu.m. Each of the six refelecting surfaces has an aspheric departure of less than 16.0 .mu.m.

  6. High numerical aperture ring field projection system for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Hudyma, Russell

    2001-01-01

    An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first concave mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receives a chief ray at an incidence angle of less than substantially 12.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 15.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 7 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 14 .mu.m. Each of the six reflecting surfaces has an aspheric departure of less than 16.0 .mu.m.

  7. High numerical aperture ring field projection system for extreme ultraviolet lithography

    DOE Patents [OSTI]

    Hudyma, Russell; Shafer, David

    2001-01-01

    An all-reflective optical system for a projection photolithography camera has a source of EUV radiation, a wafer and a mask to be imaged on the wafer. The optical system includes a first convex mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror and a sixth concave mirror. The system is configured such that five of the six mirrors receives a chief ray at an incidence angle of less than substantially 9.degree., and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 14.degree.. Four of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Five of the six reflecting surfaces have an aspheric departure of less than substantially 12 .mu.m. Each of the six reflecting surfaces has an aspheric departure of less than substantially 16 .mu.m.

  8. Nanometer-scale ablation using focused, coherent extreme ultraviolet/soft x-ray light

    DOE Patents [OSTI]

    Menoni, Carmen S.; Rocca, Jorge J.; Vaschenko, Georgiy; Bloom, Scott; Anderson, Erik H.; Chao, Weilun; Hemberg, Oscar

    2011-04-26

    Ablation of holes having diameters as small as 82 nm and having clean walls was obtained in a poly(methyl methacrylate) on a silicon substrate by focusing pulses from a Ne-like Ar, 46.9 nm wavelength, capillary-discharge laser using a freestanding Fresnel zone plate diffracting into third order is described. Spectroscopic analysis of light from the ablation has also been performed. These results demonstrate the use of focused coherent EUV/SXR light for the direct nanoscale patterning of materials.

  9. UBIQUITOUS ROTATING NETWORK MAGNETIC FIELDS AND EXTREME-ULTRAVIOLET CYCLONES IN THE QUIET SUN

    SciTech Connect (OSTI)

    Zhang Jun; Liu Yang E-mail: yliu@sun.stanford.edu

    2011-11-01

    We present Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) observations of EUV cyclones in the quiet Sun. These cyclones are rooted in the rotating network magnetic fields (RNFs). Such cyclones can last several to more than 10 hr and, at the later phase, they are found to be associated with EUV brightenings (microflares) and even EUV waves. SDO Helioseismic and Magnetic Imager (HMI) observations show a ubiquitous presence of RNFs. Using HMI line-of-sight magnetograms on 2010 July 8, we find 388 RNFs in an area of 800 x 980 arcsec{sup 2} near the disk center where no active region is present. The sense of rotation shows a weak hemisphere preference. The unsigned magnetic flux of the RNFs is about 4.0 x 10{sup 21} Mx, or 78% of the total network flux. These observational phenomena at small scale reported in this Letter are consistent with those at large scale in active regions. The ubiquitous RNFs and EUV cyclones over the quiet Sun may suggest an effective way to heat the corona.

  10. Sparkling extreme-ultraviolet bright dots observed with Hi-C

    SciTech Connect (OSTI)

    Régnier, S.; Alexander, C. E.; Walsh, R. W.; Winebarger, A. R.; Cirtain, J.; Golub, L.; Korreck, K. E.; Weber, M.; Mitchell, N.; Platt, S.; De Pontieu, B.; Title, A.; Kobayashi, K.; Kuzin, S.; DeForest, C. E.

    2014-04-01

    Observing the Sun at high time and spatial scales is a step toward understanding the finest and fundamental scales of heating events in the solar corona. The high-resolution coronal (Hi-C) instrument has provided the highest spatial and temporal resolution images of the solar corona in the EUV wavelength range to date. Hi-C observed an active region on 2012 July 11 that exhibits several interesting features in the EUV line at 193 Å. One of them is the existence of short, small brightenings 'sparkling' at the edge of the active region; we call these EUV bright dots (EBDs). Individual EBDs have a characteristic duration of 25 s with a characteristic length of 680 km. These brightenings are not fully resolved by the SDO/AIA instrument at the same wavelength; however, they can be identified with respect to the Hi-C location of the EBDs. In addition, EBDs are seen in other chromospheric/coronal channels of SDO/AIA, which suggests a temperature between 0.5 and 1.5 MK. Based on their frequency in the Hi-C time series, we define four different categories of EBDs: single peak, double peak, long duration, and bursty. Based on a potential field extrapolation from an SDO/HMI magnetogram, the EBDs appear at the footpoints of large-scale, trans-equatorial coronal loops. The Hi-C observations provide the first evidence of small-scale EUV heating events at the base of these coronal loops, which have a free magnetic energy of the order of 10{sup 26} erg.

  11. Extreme ultraviolet spectra of highly ionized Ge, Kr and Mo emitted by imploding plasmas

    SciTech Connect (OSTI)

    Goldsmith, S.; Feldman, U.; Cohen, L.; Behring, W.E.

    1984-01-01

    Spectra of highly ionized Ge, Kr and Mo in the spectral region of 10 to 80A were excited in laser-produced plasmas. The plasma was obtained by focusing the energy of the 24 laser beams of the University of Rochester Omega system on 0.4 mm diameter microballoon targets. The laser pulse duration was in the range of 0.87 to 1.09 ns, with total energy in the range of 1.8 to 2.2 kJ. The observed spectral lines include n = 2-2 transitions in the oxygen and fluorine isoelectronic sequences and n = 3 to 4 transitions in the sodium, magnesium and aluminum isoelectronic sequences. The present observations are compared with previous experimental and theoretical studies.

  12. Europium (Z=63) n=3-3 lines in the extreme ultraviolet: Na- through...

    Office of Scientific and Technical Information (OSTI)

    Authors: Trabert, E ; Beiersdorfer, P ; Hell, N ; Brown, G V Publication Date: 2014-08-22 OSTI Identifier: 1228017 Report Number(s): LLNL-JRNL-659246 DOE Contract Number: ...

  13. The diffuse galactic far-ultraviolet sky

    SciTech Connect (OSTI)

    Hamden, Erika T.; Schiminovich, David; Seibert, Mark

    2013-12-20

    We present an all-sky map of the diffuse Galactic far ultraviolet (1344-1786 Å) background using Galaxy Evolution Explorer data, covering 65% of the sky with 11.79 arcmin{sup 2} pixels. We investigate the dependence of the background on Galactic coordinates, finding that a standard cosecant model of intensity is not a valid fit. Furthermore, we compare our map to Galactic all-sky maps of 100 μm emission, N {sub H} {sub I} column, and Hα intensity. We measure a consistent low level far-UV (FUV) intensity at zero points for other Galactic quantities, indicating a 300 photons cm{sup –2} s{sup –1} sr{sup –1} Å{sup –1} non-scattered isotropic component to the diffuse FUV. There is also a linear relationship between FUV and 100 μm emission below 100 μm values of 8 MJy sr{sup –1}. We find a similar linear relationship between FUV and N {sub H} {sub I} below 10{sup 21} cm{sup –2}. The relationship between FUV and Hα intensity has no such constant cutoff. For all Galactic quantities, the slope of the linear portion of the relationship decreases with Galactic latitude. A modified cosecant model, taking into account dust scattering asymmetry and albedo, is able to accurately fit the diffuse FUV at latitudes above 20°. The best fit model indicates an albedo, a, of 0.62 ± 0.04 and a scattering asymmetry function, g, of 0.78 ± 0.05. Deviations from the model fit may indicate regions of excess FUV emission from fluorescence or shock fronts, while low latitude regions with depressed FUV emission are likely the result of self-shielding dusty clouds.

  14. ULTRAVIOLET NUMBER COUNTS OF GALAXIES FROM SWIFT ULTRAVIOLET/OPTICAL TELESCOPE DEEP IMAGING OF THE CHANDRA DEEP FIELD SOUTH

    SciTech Connect (OSTI)

    Hoversten, E. A.; Gronwall, C.; Koch, T. S.; Roming, P. W. A.; Siegel, M. H.; Berk, D. E. Vanden; Breeveld, A. A.; Curran, P. A.; Still, M.

    2009-11-10

    Deep Swift UV/Optical Telescope (UVOT) imaging of the Chandra Deep Field South is used to measure galaxy number counts in three near-ultraviolet (NUV) filters (uvw2: 1928 A, uvm2: 2246 A, and uvw1: 2600 A) and the u band (3645 A). UVOT observations cover the break in the slope of the NUV number counts with greater precision than the number counts by the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Galaxy Evolution Explorer, spanning a range 21 approx< m{sub AB} approx< 25. Model number counts confirm earlier investigations in favoring models with an evolving galaxy luminosity function.

  15. Vacuum ultraviolet laser (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Vacuum ultraviolet laser Citation Details In-Document Search Title: Vacuum ultraviolet laser Transitions from the 2p.sup.4 (.sup.1 S.sub.0)3s .sup.2 S.sub.12 state of atomic ...

  16. Suppression of H_2 Cooling in the Ultraviolet Background (Journal...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ASTROPHYSICS; HYDROGEN; COOLING; ULTRAVIOLET RADIATION; ...

  17. Microwave-driven ultraviolet light sources

    DOE Patents [OSTI]

    Manos, Dennis M.; Diggs, Jessie; Ametepe, Joseph D.

    2002-01-29

    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.

  18. Detectors in Extreme Conditions

    SciTech Connect (OSTI)

    Blaj, G.; Carini, G.; Carron, S.; Haller, G.; Hart, P.; Hasi, J.; Herrmann, S.; Kenney, C.; Segal, J.; Tomada, A.

    2015-08-06

    Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012 - 1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising. Radiation damage is a constant threat due to accidental exposure to insufficiently attenuated beam, focused beam and formation of ice crystals reflecting the beam onto the detector. Often high power optical lasers are also used (e.g., 25TW), increasing the risk of damage or impeding data acquisition through electromagnetic pulses (EMP). The sample can contaminate the detector surface or even produce shrapnel damage. Some experiments require ultra high vacuum (UHV) with strict design, surface contamination and cooling requirements - also for detectors. The setup is often changed between or during experiments with short turnaround times, risking mechanical and ESD damage, requiring work planning, training of operators and sometimes continuous participation of the LCLS Detector Group in the experiments. The detectors used most often at LCLS are CSPAD cameras for hard x-rays and pnCCDs for soft x-rays.

  19. Surface photoconductivity of organosilicate glass dielectrics induced by vacuum-ultraviolet radiation

    SciTech Connect (OSTI)

    Zheng, H.; Nichols, M. T.; Pei, D.; Shohet, J. L.; Nishi, Y.

    2013-08-14

    The temporary increase in the electrical surface conductivity of low-k organosilicate glass (SiCOH) during exposure to vacuum-ultraviolet radiation (VUV) is investigated. To measure the photoconductivity, patterned comb structures are deposited on dielectric films and exposed to synchrotron radiation in the range of 825 eV, which is in the energy range of most plasma vacuum-ultraviolet radiation. The change in photo surface conductivity induced by VUV radiation may be beneficial in limiting charging damage of dielectrics by depleting the plasma-deposited charge.

  20. Nonmaximality of known extremal metrics on torus and Klein bottle

    SciTech Connect (OSTI)

    Karpukhin, M A

    2013-12-31

    The El Soufi-Ilias theorem establishes a connection between minimal submanifolds of spheres and extremal metrics for eigenvalues of the Laplace-Beltrami operator. Recently, this connection was used to provide several explicit examples of extremal metrics. We investigate the properties of these metrics and prove that none of them is maximal. Bibliography: 24 titles.

  1. Ultraviolet nightglow production near the magnetic equator by neutral-particle precipitation

    SciTech Connect (OSTI)

    Abreu, V.J.; Eastes, R.W.; Yee, J.H.; Solomon, S.C.; Chakrabarti, S.

    1986-10-01

    The near-modnight latitudinal (+/-45) distribution of the OI 911-A, 1304-A, and 1356-A emissions, observed by the extreme ultraviolet (EUV) spectrometer on the STP 78-1 satellite, were analyzed and compared as a function of geomagnetic activity. The dominant source of these emissions is radiative recombination of atomic oxygen ions; however, for geomagnetically distributed periods, excess OI 1304-A and 1356-A emission is observed within +/-5 of the dip equator. Neutral-particle precipitation from the ring current is discussed as a possible source of the excess OI 1304-A and 1356-A emission.

  2. Bipolar charging of dust particles under ultraviolet radiation

    SciTech Connect (OSTI)

    Filippov, A. V. Babichev, V. N.; Fortov, V. E.; Gavrikov, A. V.; Pal', A. F.; Petrov, O. F.; Starostin, A. N.; Sarkarov, N. E.

    2011-05-15

    The photoemission charging of dust particles under ultraviolet radiation from a xenon lamp has been investigated. The velocities of yttrium dust particles with a work function of 3.3 eV and their charges have been determined experimentally; the latter are about 400-500 and about 100 elementary charges per micron of radius for the positively and negatively charged fractions, respectively. The dust particle charging and the dust cloud evolution in a photoemission cell after exposure to an ultraviolet radiation source under the applied voltage have been simulated numerically. The photoemission charging of dust particles has been calculated on the basis of nonlocal and local charging models. Only unipolar particle charging is shown to take place in a system of polydisperse dust particles with the same photoemission efficiency. It has been established that bipolar charging is possible in the case of monodisperse particles with different quantum efficiencies. Polydispersity in this case facilitates the appearance of oppositely charged particles in a photoemission plasma.

  3. Intergalactic magnetic fields and gamma-ray observations of extreme TeV blazars

    SciTech Connect (OSTI)

    Arlen, Timothy C.; Vassilev, Vladimir V.; Weisgarber, Thomas; Wakely, Scott P.; Shafi, S. Yusef

    2014-11-20

    The intergalactic magnetic field (IGMF) in cosmic voids can be indirectly probed through its effect on electromagnetic cascades initiated by a source of teraelectronvolt (TeV) gamma-rays, such as active galactic nuclei (AGNs). AGNs that are sufficiently luminous at TeV energies, 'extreme TeV blazars', can produce detectable levels of secondary radiation from inverse Compton scattering of the electrons in the cascade, provided that the IGMF is not too large. We review recent work in the literature that utilizes this idea to derive constraints on the IGMF for three TeV-detected blazars, 1ES 0229+200, 1ES 1218+304, and RGB J0710+591, and we also investigate four other hard-spectrum TeV blazars in the same framework. Through a recently developed, detailed, three-dimensional particle-tracking Monte Carlo code, incorporating all major effects of QED and cosmological expansion, we research the effects of major uncertainties, such as the spectral properties of the source, uncertainty in the ultraviolet and far-infrared extragalactic background light, undersampled very high energy (energy ≥100 GeV) coverage, past history of gamma-ray emission, source versus observer geometry, and the jet AGN Doppler factor. The implications of these effects on the recently reported lower limits of the IGMF are thoroughly examined to conclude that the presently available data are compatible with a zero-IGMF hypothesis.

  4. Is N=8 Supergravity Ultraviolet Finite?

    SciTech Connect (OSTI)

    Bern, Zvi; Dixon, Lance J.; Roiban, Radu

    2006-11-15

    Conventional wisdom holds that no four-dimensional gravity field theory can be ultraviolet finite. This understanding is based mainly on power counting. Recent studies confirm that one-loop N = 8 supergravity amplitudes satisfy the so-called 'no-triangle hypothesis', which states that triangle and bubble integrals cancel from these amplitudes. A consequence of this hypothesis is that for any number of external legs, at one loop N = 8 supergravity and N = 4 super-Yang-Mills have identical superficial degrees of ultraviolet behavior in D dimensions. We describe how the unitarity method allows us to promote these one-loop cancellations to higher loops, suggesting that previous power counts were too conservative. We discuss higher-loop evidence suggesting that N = 8 supergravity has the same degree of divergence as N = 4 super-Yang-Mills theory and is ultraviolet finite in four dimensions. We comment on calculations needed to reinforce this proposal, which are feasible using the unitarity method.

  5. ARM - Measurement - Extreme event time

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

    govMeasurementsExtreme event time ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Extreme event time The time of extreme meteorological events such as min/max temperature and wind gusts. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all

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

    SciTech Connect (OSTI)

    Sarantopoulou, E. Stefi, A.; Kollia, Z.; Palles, D.; Cefalas, A. C.; Petrou, P. S.; Bourkoula, A.; Koukouvinos, G.; Kakabakos, S.; Velentzas, A. D.

    2014-09-14

    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, μ-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.

  7. COMPREHENSIVE OBSERVATIONS OF THE ULTRAVIOLET SPECTRUM AND IMPROVED...

    Office of Scientific and Technical Information (OSTI)

    SPECTRUM AND IMPROVED ENERGY LEVELS FOR SINGLY IONIZED CHROMIUM (Cr II) Citation Details In-Document Search Title: COMPREHENSIVE OBSERVATIONS OF THE ULTRAVIOLET SPECTRUM AND ...

  8. Vacuum-ultraviolet photoreduction of graphene oxide: Electrical...

    Office of Scientific and Technical Information (OSTI)

    Vacuum-ultraviolet photoreduction of graphene oxide: Electrical conductivity of entirely reduced single sheets and reduced micro line patterns Citation Details In-Document Search...

  9. Open-source extreme conditions modeling tools

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

    ... HomeEnergy, Modeling & Analysis, News, Renewable Energy, Water PowerOpen-source extreme ... numerical tools for use in modeling extreme conditions of wave energy converters (WECs). ...

  10. Data triage enables extreme-scale computing

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

    Data triage enables extreme-scale computing Data triage enables extreme-scale computing Data selection and triage are important techniques for large-scale data, which can ...

  11. Extreme Conditions Modeling Workshop Report

    SciTech Connect (OSTI)

    Coe, R. G.; Neary, V. S.; Lawson, M. J.; Yu, Y.; Weber, J.

    2014-07-01

    Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, NM on May 13th-14th, 2014. The objective of the workshop was to review the current state of knowledge on how to model WECs in extreme conditions (e.g. hurricanes and other large storms) and to suggest how U.S. Department of Energy (DOE) and national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry.

  12. 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

    2009-06-03

    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

  13. Extremism

    Office of Scientific and Technical Information (OSTI)

    ... included members of the Black Panthers and the Republic of New Africa (RNA) (Smith, 1994). ... where he was recovering after a bomb he was building exploded in his hands (Smith, 1994). ...

  14. Ultraviolet laser beam monitor using radiation responsive crystals

    DOE Patents [OSTI]

    McCann, Michael P.; Chen, Chung H.

    1988-01-01

    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.

  15. Photoluminescence performance of thulium doped Li{sub 4}SrCa(SiO{sub 4}){sub 2} under irradiation of ultraviolet and vacuum ultraviolet lights

    SciTech Connect (OSTI)

    Wang, Zhaofeng; Li, Yezhou; Liu, Xiong; Wei, Xingmin; Chen, Yueling; Zhou, Fei; Wang, Yuhua

    2014-11-15

    Highlights: A novel blue-emitting phosphor Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} was reported. Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} exhibited excellent thermal and irradiation stability. Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} was found to possess high color purity. - Abstract: In this work, we synthesized Tm{sup 3+} doped Li{sub 4}SrCa(SiO{sub 4}){sub 2} phosphors and investigated their photoluminescence properties under the excitation of ultraviolet and vacuum ultraviolet lights. The crystal structure analysis and variation of cell parameters confirm that Tm{sup 3+} ions have been successfully doped in the structure of Li{sub 4}SrCa(SiO{sub 4}){sub 2} host by occupying the sites of Ca{sup 2+} with the coordination number of 6. The luminescence results suggest that Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} is a good blue-emitting phosphor when excited by ultraviolet and vacuum ultraviolet irradiations. In addition, it is observed that there is nearly no degradation for Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} after undergoing thermal and irradiation treatments. Possible mechanisms for the luminescence processes are proposed on the basis of the discussion of excitation and emission spectra. In particular, the emission color of Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} by excitation of 147 and 172 nm irradiations is very close to the standard blue color, suggesting that it could be potentially applied in plasma display panels and mercury-free fluorescence lamps.

  16. Extremely high frequency RF effects on electronics.

    SciTech Connect (OSTI)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  17. Biological applications of ultraviolet free-electron lasers

    SciTech Connect (OSTI)

    Sutherland, J.C.

    1997-10-01

    This review examines the possibilities for biological research using the three ultraviolet free-electron lasers that are nearing operational status in the US. The projected operating characteristics of major interest in biological research of the free-electron lasers at Brookhaven National Laboratory, the Thomas Jefferson National Accelerator Facility, and Duke University are presented. Experimental applications in the areas of far- and vacuum ultraviolet photophysics and photochemistry, structural biology, environmental photobiology, and medical research are discussed and the prospects for advances in these areas, based upon the characteristics of the new ultraviolet free-electron lasers, are evaluated.

  18. Laser Makes New Shade of Ultraviolet (COSMIC Log on MSNBC.com...

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

    cosmiclog.nbcnews.comnews201012285725603-laser-makes-new-shade-of-ultraviolet Submitted: Wednesday, December 29...

  19. Ultraviolet Thomson scattering measurements of the electron feature...

    Office of Scientific and Technical Information (OSTI)

    Title: Ultraviolet Thomson scattering measurements of the electron feature with an energetic 263 nm probe Authors: Ross, J S ; Divol, L ; Sorce, C ; Froula, D H ; Glenzer, S H ...

  20. THE LONGITUDINAL PROPERTIES OF A SOLAR ENERGETIC PARTICLE EVENT INVESTIGATED USING MODERN SOLAR IMAGING

    SciTech Connect (OSTI)

    Rouillard, A. P.; Sheeley, N. R.; Tylka, A.; Vourlidas, A.; Rakowski, C.; Ng, C. K.; Cohen, C. M. S.; Mewaldt, R. A.; Mason, G. M.; Reames, D.; Savani, N. P.; StCyr, O. C.; Szabo, A.

    2012-06-10

    We use combined high-cadence, high-resolution, and multi-point imaging by the Solar-Terrestrial Relations Observatory (STEREO) and the Solar and Heliospheric Observatory to investigate the hour-long eruption of a fast and wide coronal mass ejection (CME) on 2011 March 21 when the twin STEREO spacecraft were located beyond the solar limbs. We analyze the relation between the eruption of the CME, the evolution of an Extreme Ultraviolet (EUV) wave, and the onset of a solar energetic particle (SEP) event measured in situ by the STEREO and near-Earth orbiting spacecraft. Combined ultraviolet and white-light images of the lower corona reveal that in an initial CME lateral 'expansion phase', the EUV disturbance tracks the laterally expanding flanks of the CME, both moving parallel to the solar surface with speeds of {approx}450 km s{sup -1}. When the lateral expansion of the ejecta ceases, the EUV disturbance carries on propagating parallel to the solar surface but devolves rapidly into a less coherent structure. Multi-point tracking of the CME leading edge and the effects of the launched compression waves (e.g., pushed streamers) give anti-sunward speeds that initially exceed 900 km s{sup -1} at all measured position angles. We combine our analysis of ultraviolet and white-light images with a comprehensive study of the velocity dispersion of energetic particles measured in situ by particle detectors located at STEREO-A (STA) and first Lagrange point (L1), to demonstrate that the delayed solar particle release times at STA and L1 are consistent with the time required (30-40 minutes) for the CME to perturb the corona over a wide range of longitudes. This study finds an association between the longitudinal extent of the perturbed corona (in EUV and white light) and the longitudinal extent of the SEP event in the heliosphere.

  1. 50MW extreme-scale turbine

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

    MW extreme-scale turbine - Sandia Energy Energy Search Icon Sandia Home Locations Contact ... SunShot Grand Challenge: Regional Test Centers 50MW extreme-scale turbine HomeTag:50MW ...

  2. Lamp for generating high power ultraviolet radiation

    DOE Patents [OSTI]

    Morgan, Gary L.; Potter, James M.

    2001-01-01

    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.

  3. Photodegradation of aniline by goethite doped with boron under ultraviolet and visible light irradiation

    SciTech Connect (OSTI)

    Liu, Guanglong; Liao, Shuijiao; College of Basic Sciences of Huazhong Agricultural University, Wuhan 430070 ; Zhu, Duanwei; Liu, Linghua; Cheng, Dongsheng; Zhou, Huaidong

    2011-08-15

    Highlights: {yields} Goethite modified by boron was prepared by sol-gel method in presence of boron acid at the low temperature. {yields} B-goethite has slight red shift in the band gap transition beside their stronger light absorption compared with pristine goethite. {yields} The results showed that semiconductor photocatalytic reaction mechanism should exist in the process of aniline degradation with goethite and B-goethite as photocatalyst. -- Abstract: In the present study, goethite and goethite doped with boron (B-goethite) were employed to detect the presence or absence of semiconductor photocatalytic reaction mechanism in the reaction systems. B-goethite was prepared by sol-gel method in presence of boron acid in order to improve its photocatalystic efficiency under the ultraviolet and visible light irradiation. The optical properties of goethite and B-goethite were characterized by ultraviolet and visible absorption spectra and the result indicated that B-goethite has slight red shift in the band gap transition beside their stronger light absorption compared with pristine goethite. Degradation of aniline was investigated in presence of goethite and B-goethite in aqueous solution. It was found that the B-goethite photocatalyst exhibited enhanced ultraviolet and visible light photocatalytic activity in degradation of aniline compared with the pristine goethite. The photocatalytic degradation mechanism of B-goethite was discussed.

  4. Characterization of extreme precipitation within atmospheric river events over California

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

    Jeon, S.; Prabhat,; Byna, S.; Gu, J.; Collins, W. D.; Wehner, M. F.

    2015-11-17

    Atmospheric rivers (ARs) are large, spatially coherent weather systems with high concentrations of elevated water vapor. These systems often cause severe downpours and flooding over the western coastal United States – and with the availability of more atmospheric moisture in the future under global warming we expect ARs to play an important role as potential causes of extreme precipitation changes. Therefore, we aim to investigate changes in extreme precipitation properties correlated with AR events in a warmer climate, which are large-scale meteorological patterns affecting the weather and climate of California. We have recently developed the TECA (Toolkit for Extreme Climatemore » Analysis) software for automatically identifying and tracking features in climate data sets. Specifically, we can now identify ARs that make landfall on the western coast of North America. Based on this detection procedure, we can investigate the impact of ARs by exploring the spatial extent of AR precipitation using climate model (CMIP5) simulations and characterize spatial patterns of dependence for future projections between AR precipitation extremes under climate change within the statistical framework. Our results show that AR events in the future RCP (Representative Concentration Pathway)8.5 scenario (2076–2100) tend to produce heavier rainfall with higher frequency and longer days than events from the historical run (1981–2005). We also find that the dependence between extreme precipitation events has a shorter spatial range, within localized areas in California, under the high future emissions scenario than under the historical run.« less

  5. Response of Simple, Model Systems to Extreme Conditions

    SciTech Connect (OSTI)

    Ewing, Rodney C.; Lang, Maik

    2015-07-30

    The focus of the research was on the application of high-pressure/high-temperature techniques, together with intense energetic ion beams, to the study of the behavior of simple oxide systems (e.g., SiO2, GeO2, CeO2, TiO2, HfO2, SnO2, ZnO and ZrO2) under extreme conditions. These simple stoichiometries provide unique model systems for the analysis of structural responses to pressure up to and above 1 Mbar, temperatures of up to several thousands of kelvin, and the extreme energy density generated by energetic heavy ions (tens of keV/atom). The investigations included systematic studies of radiation- and pressure-induced amorphization of high P-T polymorphs. By studying the response of simple stoichiometries that have multiple structural “outcomes”, we have established the basic knowledge required for the prediction of the response of more complex structures to extreme conditions. We especially focused on the amorphous state and characterized the different non-crystalline structure-types that result from the interplay of radiation and pressure. For such experiments, we made use of recent technological developments, such as the perforated diamond-anvil cell and in situ investigation using synchrotron x-ray sources. We have been particularly interested in using extreme pressures to alter the electronic structure of a solid prior to irradiation. We expected that the effects of modified band structure would be evident in the track structure and morphology, information which is much needed to describe theoretically the fundamental physics of track-formation. Finally, we investigated the behavior of different simple-oxide, composite nanomaterials (e.g., uncoated nanoparticles vs. core/shell systems) under coupled, extreme conditions. This provided insight into surface and boundary effects on phase stability under extreme conditions.

  6. Extreme luminosity imaging conical spectrograph

    SciTech Connect (OSTI)

    Pikuz, S. A.; Shelkovenko, T. A.; Mitchell, M. D.; Chandler, K. M.; Douglass, J. D.; McBride, R. D.; Jackson, D. P.; Hammer, D. A.

    2006-10-15

    A new configuration for a two-dimensional (2D) imaging x-ray spectrograph based on a conically bent crystal is introduced: extreme luminosity imaging conical spectrograph (ELICS). The ELICS configuration has important advantages over spectrographs that are based on cylindrically and spherically bent crystals. The main advantages are that a wide variety of large-aperture crystals can be used, and any desired magnification in the spatial direction (the direction orthogonal to spectral dispersion) can be achieved by the use of different experimental arrangements. The ELICS can be set up so that the detector plane is almost perpendicular to the incident rays, a good configuration for time-resolved spectroscopy. ELICSs with mica crystals of 45x90 mm{sup 2} aperture have been successfully used for imaging on the XP and COBRA pulsed power generators, yielding spectra with spatial resolution in 2D of Z pinches and X pinches.

  7. Deinococcus geothermalis: The Pool of Extreme Radiation Resistance Genes Shrinks

    SciTech Connect (OSTI)

    Makarova, Kira S.; Omelchenko, Marina V.; Gaidamakova, Elena K.; Matrosova, Vera Y.; Vasilenko, Alexander; Zhai, Min; Lapidus, Alla; Copeland, Alex; Kim, Edwin; Land, Miriam; Mavrommatis, Konstantinos; Pitluck, Samuel; Richardson, Paul M.; Detter, Chris; Brettin, Thomas; Saunders, Elizabeth; Lai, Barry; Ravel, Bruce; Kemner, Kenneth M.; Wolf, Yuri I.; Sorokin, Alexander; Gerasimova, Anna V.; Gelfand, Mikhail S.; Fredrickson, James K.; Koonin, Eugene V.; Daly, Michael J.

    2007-07-24

    Bacteria of the genus Deinococcus are extremely resistant to ionizing radiation (IR), ultraviolet light (UV) and desiccation. The mesophile Deinococcus radiodurans was the first member of this group whose genome was completely sequenced. Analysis of the genome sequence of D. radiodurans, however, failed to identify unique DNA repair systems. To further delineate the genes underlying the resistance phenotypes, we report the whole-genome sequence of a second Deinococcus species, the thermophile Deinococcus geothermalis, which at itsoptimal growth temperature is as resistant to IR, UV and desiccation as D. radiodurans, and a comparative analysis of the two Deinococcus genomes. Many D. radiodurans genes previously implicated in resistance, but for which no sensitive phenotype was observed upon disruption, are absent in D. geothermalis. In contrast, most D. radiodurans genes whose mutants displayed a radiation-sensitive phenotype in D. radiodurans are conserved in D. geothermalis. Supporting the existence of a Deinococcus radiation response regulon, a common palindromic DNA motif was identified in a conserved set of genes associated with resistance, and a dedicated transcriptional regulator was predicted. We present the case that these two species evolved essentially the same diverse set of gene families, and that the extreme stress-resistance phenotypes of the Deinococcus lineage emerged progressively by amassing cell-cleaning systems from different sources, but not by acquisition of novel DNA repair systems. Our reconstruction of the genomic evolution of the Deinococcus-Thermus phylum indicates that the corresponding set of enzymes proliferated mainly in the common ancestor of Deinococcus. Results of the comparative analysis weaken the arguments for a role of higher-order chromosome alignment structures in resistance; more clearly define and substantially revise downward the number of uncharacterized genes that might participate in DNA repair and contribute to

  8. Electron-Heated Target Temperature Measurements in Petawatt Laser Experiments Based on Extreme Ultraviolet Imaging and Spectroscopy

    SciTech Connect (OSTI)

    Ma, T; Beg, F; Macphee, A; Chung, H; Key, M; Mackinnon, A; Patel, P; Hatchett, S; Akli, K; Stephens, R; Chen, C; Freeman, R; Link, A; Offermann, D; Ovchinnikov, V; VanWoerkom, L; Zhang, B

    2008-05-02

    Three independent methods (XUV spectroscopy, imaging at 68 eV and 256 eV) have been used to measure planar target rear surface plasma temperature due to heating by hot electrons. The hot electrons are produced by ultra-intense laser plasma interactions using the 150 J, 0.5 ps Titan laser. Soft x-ray spectroscopy in the 50-400 eV region and imaging at the 68 eV and 256 eV photon energies were used to determine the rear surface temperature of planar CD targets. Temperatures were found to be in the 60-150 eV range, with good agreement between the three diagnostics.

  9. Replication of a Holographic Ion-etched Spherical Blazed Grating for use at Extreme-Ultraviolet Wavelengths: Efficiency

    SciTech Connect (OSTI)

    Kowalski,M.; Barbee, T.; Hunter, W.

    2006-01-01

    Using synchrotron radiation, we have measured the efficiency at an angle of incidence of 10 deg of a holographic ion-etched spherical blazed grating and three of its fourth-generation replicas. The measured efficiency profile of replicas 1 and 3 prior to multilayer coating oscillated from thin-film interference produced by the replicas' Al/Al2O3?/SiO2 structure. A Mo2C/Si multilayer coating was applied to the master grating and replicas 1 and 2. After coating, the maximum grating efficiency occurred in the -2nd order and the maximum values were 12.4% at 143.8 Angstroms for the master and 11.6% at 145.2 Angstroms for replicas 1 and 2. On the basis of measurements obtained after coating, the derived groove efficiency was 22.2% for the master, 19.4% for replica 1, and 19.3% for replica 2. The groove efficiency of the uncoated replica 3 was 24.3% at 142.5 Angstroms. We find that the replicas are reasonably faithful copies of the ion-etched master, and models based on measured atomic force microscope groove profiles are in general agreement with measured results. However, subtle issues remain regarding the widths of the peak order profile and the location of its maximum wavelength.

  10. Extreme Scale Computing, Co-design

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

    Extreme Scale Computing, Co-design Informing system design, ensuring productive and efficient code Project Description To address the increasingly complex problems of the modern ...

  11. Extreme Scale Computing, Co-design

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

    datasets and extremely high rate data streams needed to address problems in national security, cyber security, energy ... All Stories Turning windows into solar generators Turning ...

  12. Extremely Low Temperature | Open Energy Information

    Open Energy Info (EERE)

    Extremely Low Temperature: No definition has been provided for this term. Add a Definition Sanyal Temp Classification This temperature scheme was developed by Sanyal in...

  13. Extreme Weather Events and Climate Change

    Broader source: Energy.gov [DOE]

    The presentation will review known variability in extreme weather such as excessive heat, cold waves, floods, droughts, hurricanes, severe thunderstorms and tornadoes. Projections and uncertainties...

  14. Wave Energy Converter Extreme Conditions Modeling Workshop |...

    Open Energy Info (EERE)

    process. The WEC industry has adopted extreme conditions design, modeling, and analysis techniques developed for offshore oil & gas and naval architecture applications. While...

  15. Extreme Scale Computing, Co-Design

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

    Information Science, Computing, Applied Math Extreme Scale Computing, Co-design Publications Publications Ramon Ravelo, Qi An, Timothy C. Germann, and Brad Lee Holian, ...

  16. CHARACTERIZING ULTRAVIOLET AND INFRARED OBSERVATIONAL PROPERTIES FOR GALAXIES. I. INFLUENCES OF DUST ATTENUATION AND STELLAR POPULATION AGE

    SciTech Connect (OSTI)

    Mao Yewei; Kong Xu [Center for Astrophysics, University of Science and Technology of China, Hefei 230026 (China); Kennicutt, Robert C. Jr. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Hao, Cai-Na [Tianjin Astrophysics Center, Tianjin Normal University, Tianjin 300387 (China); Zhou Xu, E-mail: owen81@mail.ustc.edu.cn, E-mail: xkong@ustc.edu.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2012-09-20

    The correlation between infrared-to-ultraviolet luminosity ratio and ultraviolet color (or ultraviolet spectral slope), i.e., the IRX-UV (or IRX-{beta}) relation, found in studies of starburst galaxies is a prevalent recipe for correcting extragalactic dust attenuation. Considerable dispersion in this relation discovered for normal galaxies, however, complicates its usability. In order to investigate the cause of the dispersion and to have a better understanding of the nature of the IRX-UV relation, in this paper, we select five nearby spiral galaxies, and perform spatially resolved studies on each of the galaxies, with a combination of ultraviolet and infrared imaging data. We measure all positions within each galaxy and divide the extracted regions into young and evolved stellar populations. By means of this approach, we attempt to discover separate effects of dust attenuation and stellar population age on the IRX-UV relation for individual galaxies. In this work, in addition to dust attenuation, stellar population age is interpreted to be another parameter in the IRX-UV function, and the diversity of star formation histories is suggested to disperse the age effects. At the same time, strong evidence shows the need for more parameters in the interpretation of observational data, such as variations in attenuation/extinction law. Fractional contributions of different components to the integrated luminosities of the galaxies suggest that the integrated measurements of these galaxies, which comprise different populations, would weaken the effect of the age parameter on IRX-UV diagrams. The dependence of the IRX-UV relation on luminosity and radial distance in galaxies presents weak trends, which offers an implication of selective effects. The two-dimensional maps of the UV color and the infrared-to-ultraviolet ratio are displayed and show a disparity in the spatial distributions between the two galaxy parameters, which offers a spatial interpretation of the scatter

  17. Extremely durable biofouling-resistant metallic surfaces based...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel Title: Extremely durable ...

  18. Complete genome sequences for the anaerobic, extremely thermophilic...

    Office of Scientific and Technical Information (OSTI)

    Complete genome sequences for the anaerobic, extremely thermophilic plant ... Title: Complete genome sequences for the anaerobic, extremely thermophilic plant ...

  19. Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides...

    Office of Scientific and Technical Information (OSTI)

    Conference: Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides Citation Details In-Document Search Title: Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of ...

  20. Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides...

    Office of Scientific and Technical Information (OSTI)

    Conference: Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides Citation Details In-Document Search Title: Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of...

  1. Key issues of ultraviolet radiation of OH at high altitudes

    SciTech Connect (OSTI)

    Zhang, Yuhuai; Wan, Tian; Jiang, Jianzheng; Fan, Jing

    2014-12-09

    Ultraviolet (UV) emissions radiated by hydroxyl (OH) is one of the fundamental elements in the prediction of radiation signature of high-altitude and high-speed vehicle. In this work, the OH A{sup 2}?{sup +}?X{sup 2}? ultraviolet emission band behind the bow shock is computed under the experimental condition of the second bow-shock ultraviolet flight (BSUV-2). Four related key issues are discussed, namely, the source of hydrogen element in the high-altitude atmosphere, the formation mechanism of OH species, efficient computational algorithm of trace species in rarefied flows, and accurate calculation of OH emission spectra. Firstly, by analyzing the typical atmospheric model, the vertical distributions of the number densities of different species containing hydrogen element are given. According to the different dominating species containing hydrogen element, the atmosphere is divided into three zones, and the formation mechanism of OH species is analyzed in the different zones. The direct simulation Monte Carlo (DSMC) method and the Navier-Stokes equations are employed to compute the number densities of the different OH electronically and vibrationally excited states. Different to the previous work, the trace species separation (TSS) algorithm is applied twice in order to accurately calculate the densities of OH species and its excited states. Using a non-equilibrium radiation model, the OH ultraviolet emission spectra and intensity at different altitudes are computed, and good agreement is obtained with the flight measured data.

  2. Changes in Concurrent Precipitation and Temperature Extremes

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

    Hao, Zengchao; AghaKouchak, Amir; Phillips, Thomas J.

    2013-08-01

    While numerous studies have addressed changes in climate extremes, analyses of concurrence of climate extremes are scarce, and climate change effects on joint extremes are rarely considered. This study assesses the occurrence of joint (concurrent) monthly continental precipitation and temperature extremes in Climate Research Unit (CRU) and University of Delaware (UD) observations, and in 13 Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate simulations. Moreover, the joint occurrences of precipitation and temperature extremes simulated by CMIP5 climate models are compared with those derived from the CRU and UD observations for warm/wet, warm/dry, cold/wet, and cold/dry combinations of joint extremes.more » The number of occurrences of these four combinations during the second half of the 20th century (1951–2004) is assessed on a common global grid. CRU and UD observations show substantial increases in the occurrence of joint warm/dry and warm/wet combinations for the period 1978–2004 relative to 1951–1977. The results show that with respect to the sign of change in the concurrent extremes, the CMIP5 climate model simulations are in reasonable overall agreement with observations. The results reveal notable discrepancies between regional patterns and the magnitude of change in individual climate model simulations relative to the observations of precipitation and temperature.« less

  3. Changes in Concurrent Precipitation and Temperature Extremes

    SciTech Connect (OSTI)

    Hao, Zengchao; AghaKouchak, Amir; Phillips, Thomas J.

    2013-08-01

    While numerous studies have addressed changes in climate extremes, analyses of concurrence of climate extremes are scarce, and climate change effects on joint extremes are rarely considered. This study assesses the occurrence of joint (concurrent) monthly continental precipitation and temperature extremes in Climate Research Unit (CRU) and University of Delaware (UD) observations, and in 13 Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate simulations. Moreover, the joint occurrences of precipitation and temperature extremes simulated by CMIP5 climate models are compared with those derived from the CRU and UD observations for warm/wet, warm/dry, cold/wet, and cold/dry combinations of joint extremes. The number of occurrences of these four combinations during the second half of the 20th century (1951–2004) is assessed on a common global grid. CRU and UD observations show substantial increases in the occurrence of joint warm/dry and warm/wet combinations for the period 1978–2004 relative to 1951–1977. The results show that with respect to the sign of change in the concurrent extremes, the CMIP5 climate model simulations are in reasonable overall agreement with observations. The results reveal notable discrepancies between regional patterns and the magnitude of change in individual climate model simulations relative to the observations of precipitation and temperature.

  4. Ultraviolet germicidal irradiation and its effects on elemental distributions in mouse embryonic fibroblast cells in x-ray fluorescence microanalysis

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

    Jin, Qiaoling; Vogt, Stefan; Lai, Barry; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Ward, Jesse; Deng, Junjing; Mak, Rachel; Moonier, Nena; et al

    2015-02-23

    Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with x-ray fluorescence microscopy. We show that the contents and distributions of most biologicallymore » important elements remain nearly unchanged when compared with non-ultraviolet-irradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results.« less

  5. Ultraviolet germicidal irradiation and its effects on elemental distributions in mouse embryonic fibroblast cells in x-ray fluorescence microanalysis

    SciTech Connect (OSTI)

    Jin, Qiaoling; Vogt, Stefan; Lai, Barry; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Ward, Jesse; Deng, Junjing; Mak, Rachel; Moonier, Nena; Jacobsen, Chris; Brody, James P.

    2015-02-23

    Rapidly-frozen hydrated (cryopreserved) specimens combined with cryo-scanning x-ray fluorescence microscopy provide an ideal approach for investigating elemental distributions in biological cells and tissues. However, because cryopreservation does not deactivate potentially infectious agents associated with Risk Group 2 biological materials, one must be concerned with contamination of expensive and complicated cryogenic x-ray microscopes when working with such materials. We employed ultraviolet germicidal irradiation to decontaminate previously cryopreserved cells under liquid nitrogen, and then investigated its effects on elemental distributions under both frozen hydrated and freeze dried states with x-ray fluorescence microscopy. We show that the contents and distributions of most biologically important elements remain nearly unchanged when compared with non-ultraviolet-irradiated counterparts, even after multiple cycles of ultraviolet germicidal irradiation and cryogenic x-ray imaging. This provides a potential pathway for rendering Risk Group 2 biological materials safe for handling in multiuser cryogenic x-ray microscopes without affecting the fidelity of the results.

  6. Electrode configuration for extreme-UV electrical discharge source

    DOE Patents [OSTI]

    Spence, Paul Andrew; Fornaciari, Neal Robert; Chang, Jim Jihchyun

    2002-01-01

    It has been demonstrated that debris generation within an electric capillary discharge source, for generating extreme ultraviolet and soft x-ray, is dependent on the magnitude and profile of the electric field that is established along the surfaces of the electrodes. An electrode shape that results in uniform electric field strength along its surface has been developed to minimize sputtering and debris generation. The electric discharge plasma source includes: (a) a body that defines a circular capillary bore that has a proximal end and a distal end; (b) a back electrode positioned around and adjacent to the distal end of the capillary bore wherein the back electrode has a channel that is in communication with the distal end and that is defined by a non-uniform inner surface which exhibits a first region which is convex, a second region which is concave, and a third region which is convex wherein the regions are viewed outwardly from the inner surface of the channel that is adjacent the distal end of the capillary bore so that the first region is closest to the distal end; (c) a front electrode positioned around and adjacent to the proximal end of the capillary bore wherein the front electrode has an opening that is communication with the proximal end and that is defined by a non-uniform inner surface which exhibits a first region which is convex, a second region which is substantially linear, and third region which is convex wherein the regions are viewed outwardly from the inner surface of the opening that is adjacent the proximal end of the capillary bore so that the first region is closest to the proximal end; and (d) a source of electric potential that is connected across the front and back electrodes.

  7. Extreme Balance of System Hardware Cost Reduction

    Broader source: Energy.gov [DOE]

    On September 1, 2011, DOE announced $42.4 million in funding over three years for the Extreme Balance of System Hardware Cost Reduction (BOS-X) funding opportunity. Part of the SunShot Systems...

  8. Slides summary for ExtremeMat project

    SciTech Connect (OSTI)

    Martinez Saez, Enrique

    2015-06-22

    These slides are part of the final report of the Project s14-ExtremeMat, an Institutional Computing project giving us access to LANL’s computers for the CMIME EFRC computational work

  9. Extreme Scale Computing, Co-design

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

    Information Science, Computing, Applied Math » Extreme Scale Computing, Co-design Extreme Scale Computing, Co-design Computational co-design may facilitate revolutionary designs in the next generation of supercomputers. Get Expertise Tim Germann Physics and Chemistry of Materials Email Allen McPherson Energy and Infrastructure Analysis Email Turab Lookman Physics and Condensed Matter and Complex Systems Email Computational co-design involves developing the interacting components of a

  10. Preconditioned iterations to calculate extreme eigenvalues

    SciTech Connect (OSTI)

    Brand, C.W.; Petrova, S.

    1994-12-31

    Common iterative algorithms to calculate a few extreme eigenvalues of a large, sparse matrix are Lanczos methods or power iterations. They converge at a rate proportional to the separation of the extreme eigenvalues from the rest of the spectrum. Appropriate preconditioning improves the separation of the eigenvalues. Davidson`s method and its generalizations exploit this fact. The authors examine a preconditioned iteration that resembles a truncated version of Davidson`s method with a different preconditioning strategy.

  11. Extreme Scale Computing, Co-design

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

    Extreme Scale Computing, Co-design Informing system design, ensuring productive and efficient code Project Description To address the increasingly complex problems of the modern world, scientists at Los Alamos are pushing the scale of computing to the extreme, forming partnerships with other national laboratories and industry to develop supercomputers that can achieve "exaflop" speeds-that is, a quintillion (a million trillion) calculations per second. To put such speed in perspective,

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

    SciTech Connect (OSTI)

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

    2008-04-24

    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.

  13. Defect-Enabled Electrical Current Leakage in Ultraviolet Light-Emitting Diodes

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

    Moseley, Michael William; Allerman, Andrew A.; Crawford, Mary H.; Wierer, Jonathan; Smith, Michael L.; Biedermann, Laura

    2015-04-13

    The AlGaN materials system offers a tunable, ultra-wide bandgap that is exceptionally useful for high-power electronics and deep ultraviolet optoelectronics. Moseley et al. (pp. 723–726) investigate a structural defect known as an open-core threading dislocation or ''nanopipe'' that is particularly detrimental to devices that employ these materials. Furthermore, an AlGaN thin film was synthesized using metal-organic chemical-vapor deposition. Electrical current leakage is detected at a discrete point using a conductive atomic-force microscope (CAFM). However, no physical feature or abnormality at this location was visible by an optical microscope. The AlGaN thin film was then etched in hot phosphoric acid, andmore » the same location that was previously analyzed was revisited with the CAFM. The point that previously exhibited electrical current leakage had been decorated with a 1.1 μm wide hexagonal pit, which identified the site of electrical current leakage as a nanopipe and allows these defects to be easily observed by optical microscopy. Moreover, with this nanopipe identification and quantification strategy, the authors were able to correlate decreasing ultraviolet light-emitting diode optical output power with increasing nanopipe density.« less

  14. A Network Contention Model for the Extreme-scale Simulator

    SciTech Connect (OSTI)

    Engelmann, Christian [ORNL; Naughton, III, Thomas J [ORNL

    2015-01-01

    The Extreme-scale Simulator (xSim) is a performance investigation toolkit for high-performance computing (HPC) hardware/software co-design. It permits running a HPC application with millions of concurrent execution threads, while observing its performance in a simulated extreme-scale system. This paper details a newly developed network modeling feature for xSim, eliminating the shortcomings of the existing network modeling capabilities. The approach takes a different path for implementing network contention and bandwidth capacity modeling using a less synchronous and accurate enough model design. With the new network modeling feature, xSim is able to simulate on-chip and on-node networks with reasonable accuracy and overheads.

  15. High extraction efficiency ultraviolet light-emitting diode

    DOE Patents [OSTI]

    Wierer, Jonathan; Montano, Ines; Allerman, Andrew A.

    2015-11-24

    Ultraviolet light-emitting diodes with tailored AlGaN quantum wells can achieve high extraction efficiency. For efficient bottom light extraction, parallel polarized light is preferred, because it propagates predominately perpendicular to the QW plane and into the typical and more efficient light escape cones. This is favored over perpendicular polarized light that propagates along the QW plane which requires multiple, lossy bounces before extraction. The thickness and carrier density of AlGaN QW layers have a strong influence on the valence subband structure, and the resulting optical polarization and light extraction of ultraviolet light-emitting diodes. At Al>0.3, thinner QW layers (<2.5 nm are preferred) result in light preferentially polarized parallel to the QW plane. Also, active regions consisting of six or more QWs, to reduce carrier density, and with thin barriers, to efficiently inject carriers in all the QWs, are preferred.

  16. Superhydrophobic anti-ultraviolet films by doctor blade coating

    SciTech Connect (OSTI)

    Cai, Chang-Yun; Yang, Hongta; Lin, Kun-Yi Andrew

    2014-11-17

    This article reports a scalable technology for fabricating polymer films with excellent water-repelling and anti-ultraviolet properties. A roll-to-roll compatible doctor blade coating technology is utilized to prepare silica colloidal crystal-polymer composites. The silica microspheres can then be selectively removed to create flexible self-standing macroporous polymer films with crystalline arrays of pores. The void sizes are controlled by tuning the duration of a reactive ion etching process prior to the removal of the templating silica microspheres. After surface modification, superhydrophobic surface can be achieved. This study further demonstrates that the as-prepared transparent porous films with 200?nm of pores exhibit diffraction of ultraviolet lights originated from the Bragg's diffractive of light from the three-dimensional highly ordered air cavities.

  17. Magnetic fluorescent lamp having reduced ultraviolet self-absorption

    DOE Patents [OSTI]

    Berman, Samuel M.; Richardson, Robert W.

    1985-01-01

    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.

  18. Durable Corrosion and Ultraviolet-Resistant Silver Mirror

    DOE Patents [OSTI]

    Jorgensen, G. J.; Gee, R.

    2006-01-24

    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.

  19. Amplitudes and Ultraviolet Behavior of N = 8 Supergravity

    SciTech Connect (OSTI)

    Bern, Zvi; Carrasco, John Joseph; Dixon, Lance J.; Johansson, Henrik; Roiban, Radu; /Penn State U.

    2011-05-20

    In this contribution we describe computational tools that permit the evaluation of multi-loop scattering amplitudes in N = 8 supergravity, in terms of amplitudes in N = 4 super-Yang-Mills theory. We also discuss the remarkable ultraviolet behavior of N = 8 supergravity, which follows from these amplitudes, and is as good as that of N = 4 super-Yang-Mills theory through at least four loops.

  20. Inorganic volumetric light source excited by ultraviolet light

    DOE Patents [OSTI]

    Reed, Scott; Walko, Robert J.; Ashley, Carol S.; Brinker, C. Jeffrey

    1994-01-01

    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.

  1. Inorganic volumetric light source excited by ultraviolet light

    DOE Patents [OSTI]

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

    1994-04-26

    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.

  2. Optical Design for Extremely Large Telescope Adaptive Optics...

    Office of Scientific and Technical Information (OSTI)

    ThesisDissertation: Optical Design for Extremely Large Telescope Adaptive Optics Systems Citation Details In-Document Search Title: Optical Design for Extremely Large Telescope ...

  3. Evolution of extreme resistance to ionizing radiation via genetic...

    Office of Scientific and Technical Information (OSTI)

    Published Article: Evolution of extreme resistance to ionizing radiation via genetic adaptation of DNA repair Prev Next Title: Evolution of extreme resistance to ionizing ...

  4. Extreme dynamic compression with a low energy laser pulse (Conference...

    Office of Scientific and Technical Information (OSTI)

    Conference: Extreme dynamic compression with a low energy laser pulse Citation Details In-Document Search Title: Extreme dynamic compression with a low energy laser pulse You ...

  5. Extremely stable bare hematite photoanode for solar water splitting...

    Office of Scientific and Technical Information (OSTI)

    Extremely stable bare hematite photoanode for solar water splitting Prev Next Title: Extremely stable bare hematite photoanode for solar water splitting Authors: Dias, Paula ; ...

  6. Extreme Temperature Energy Storage and Generation, for Cost and...

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

    Extreme Temperature Energy Storage and Generation, for Cost and Risk Reduction in Geothermal Exploration Extreme Temperature Energy Storage and Generation, for Cost and Risk ...

  7. Extreme_SeaState_Contour_v1

    Energy Science and Technology Software Center (OSTI)

    2015-10-19

    This software generates environmental contours of extreme sea states using buoy observations of significant wave height and energy period or peak period. The code transforms these observations using principal component analysis (PCA) to create an uncorrelated representation of the data. The subsequent components are modeled using probability distributions and parameter fitting functions. The inverse first-order reliability method (I-FORM) is then applied to these models in order to generate an extreme event contour based on amore » given return period (i.e., 100 years).The subsequent contour is then transformed back into the original input space defined by the variables of interest in order to create an environmental contour of extreme sea states.« less

  8. Extreme_SeaState_Contour_v1

    SciTech Connect (OSTI)

    2015-10-19

    This software generates environmental contours of extreme sea states using buoy observations of significant wave height and energy period or peak period. The code transforms these observations using principal component analysis (PCA) to create an uncorrelated representation of the data. The subsequent components are modeled using probability distributions and parameter fitting functions. The inverse first-order reliability method (I-FORM) is then applied to these models in order to generate an extreme event contour based on a given return period (i.e., 100 years).The subsequent contour is then transformed back into the original input space defined by the variables of interest in order to create an environmental contour of extreme sea states.

  9. Matter-Radiation Interactions in Extremes

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

    Matter-Radiation Interactions in Extremes (MaRIE) Matter-Radiation Interactions in Extremes (MaRIE) MaRIE will provide a capability to address the control of performance and production of materials at the mesoscale. MaRIE fills a critical gap in length scale between studies conducted at the integral scale at DARHT and U1a, and at the atomic scale at NIF and Z. MaRIE Why MaRIE NNSA does not currently have a capability to understand and test materials response regimes at resolution necessary to

  10. Extreme Science (LBNL Science at the Theater)

    SciTech Connect (OSTI)

    Ajo-Franklin, Caroline; Klein, Spencer; Minor, Andrew; Torok, Tamas

    2012-02-27

    On Feb. 27, 2012 at the Berkeley Repertory Theatre, four Berkeley Lab scientists presented talks related to extreme science - and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel.

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

    DOE Patents [OSTI]

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

    1996-12-17

    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.

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

    DOE Patents [OSTI]

    Sze, Robert C.; Quigley, Gerard P.

    1996-01-01

    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.

  13. 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)

    2014-08-18

    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.

  14. ULTRAVIOLET RADIATION INSIDE INTERSTELLAR GRAIN AGGREGATES. III. FLUFFY GRAINS

    SciTech Connect (OSTI)

    Cacciola, Adriano; Saija, Rosalba; Borghese, Ferdinando; Denti, Paolo; Cecchi-Pestellini, Cesare; Iati, Maria Antonia

    2009-08-20

    We study the problem of light depolarization within fluffy interstellar dust grains, in which coagulation generates interstitial cavities partly filled with icy condensed gas. A significant amount of elliptical polarized ultraviolet radiation may be generated in situ by geometry-induced depolarization within the cavities. The behavior of the depolarization is studied both by changing the orientation of the aggregates and by changing chemical composition and size of the subunits forming the aggregate. We found that a considerable amount of depolarization occurs within the ice mantles of the subunits, provided their thickness is not too large. We discuss the implications of these results for chiral selection in space.

  15. Ultraviolet Free Electron Laser Facility preliminary design report

    SciTech Connect (OSTI)

    Ben-Zvi, I.

    1993-02-01

    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).

  16. Materials Science in Radiation and Dynamics Extremes

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

    8 Materials Science in Radiation and Dynamics Extremes Our combination of modeling and experimental testing capabilities opens up unparalleled opportunities to do fundamental research leading to physics-based predictive models. Contact Us Group Leader Ellen Cerreta Email Deputy Group Leader Christopher Stanek Email Group Office (505) 665-4735 We predict structure/property relationships of materials, perform computational materials modeling, characterize thermophysical properties, and measure the

  17. Extreme Scale Computing, Co-Design

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

    Information Science, Computing, Applied Math » Extreme Scale Computing, Co-design » Publications Publications Ramon Ravelo, Qi An, Timothy C. Germann, and Brad Lee Holian, "Large-scale molecular dynamics simulations of shock induced plasticity in tantalum single crystals," AIP Conference Proceedings 1426, 1263-1266 (2012). Frank J. Cherne, Guy Dimonte, and Timothy C. Germann, "Richtymer-Meshkov instability examined with large-scale molecular dynamics simulations," AIP

  18. Gamma ray bursts and extreme energy cosmic rays

    SciTech Connect (OSTI)

    Scarsi, Livio

    1998-06-15

    Extreme Energy Cosmic Ray particles (EECR) with E>10{sup 20} eV arriving on Earth with very low flux ({approx}1 particle/Km{sup 2}-1000yr) require for their investigation very large detecting areas, exceeding values of 1000 km{sup 2} sr. Projects with these dimensions are now being proposed: Ground Arrays ('Auger' with 2x3500 km{sup 2} sr) or exploiting the Earth Atmosphere as seen from space ('AIR WATCH' and OWL,'' with effective area reaching 1 million km{sup 2} sr). In this last case, by using as a target the 10{sup 13} tons of air viewed, also the high energy neutrino flux can be investigated conveniently. Gamma Rays Bursts are suggested as a possible source for EECR and the associated High Energy neutrino flux.

  19. Investigator Award

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

    Investigations Investigations Investigations The Office of Investigations performs investigations into allegations of fraud, waste, and abuse in programs and operations of the Department, NNSA and FERC. Priority is given to investigations of suspected violations of criminal and civil statutes, as well as serious administrative misconduct. Particular focus is placed on the prevention and detection of contract and grant fraud; environmental, health and safety violations; computer crimes; and

  20. General Investigator

    Broader source: Energy.gov [DOE]

    A successful candidate in this position will: Serve as a investigator in the Counterintelligence (CI) Investigations Division and will develop, lead, conduct, and otherwise oversee CI...

  1. HST-COS observations of AGNs. II. Extended survey of ultraviolet composite spectra from 159 active galactic nuclei

    SciTech Connect (OSTI)

    Stevans, Matthew L.; Shull, J. Michael; Danforth, Charles W.; Tilton, Evan M. E-mail: michael.shull@colorado.edu E-mail: evan.tilton@colorado.edu

    2014-10-10

    The ionizing fluxes from quasars and other active galactic nuclei (AGNs) are critical for interpreting their emission-line spectra and for photoionizing and heating the intergalactic medium. Using far-ultraviolet (FUV) spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), we directly measure the rest-frame ionizing continua and emission lines for 159 AGNs at redshifts 0.001 < z {sub AGN} < 1.476 and construct a composite spectrum from 475 to 1875 Å. We identify the underlying AGN continuum and strong extreme ultraviolet (EUV) emission lines from ions of oxygen, neon, and nitrogen after masking out absorption lines from the H I Lyα forest, 7 Lyman-limit systems (N{sub H} {sub I}≥10{sup 17.2} cm{sup –2}) and 214 partial Lyman-limit systems (14.5

  2. Method for detection of extremely low concentration

    DOE Patents [OSTI]

    Andresen, Brian D.; Miller, Fred S.

    2002-01-01

    An ultratrace detector system for hand-held gas chromatography having high sensitivity, for example, to emissions generated during production of weapons, biological compounds, drugs, etc. The detector system is insensitive to water, air, helium, argon, oxygen, and CO.sub.2. The detector system is basically composed of a hand-held capillary gas chromatography (GC), an insulated heated redox-chamber, a detection chamber, and a vapor trap. For example, the detector system may use gas phase redox reactions and spectral absorption of mercury vapor. The gas chromatograph initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica--or other metal--aerogel material which acts as an insulator. Compounds easily oxidized by HgO liberate atomic mercury that subsequently pass through a detection chamber which includes a detector cell, such as quartz, that is illuminated with a 254 nm ultra-violet (UV) mercury discharge lamp which generates the exact mercury absorption bands that are used to detect the liberated mercury atoms. Atomic mercury strongly absorbs 254 nm energy is therefore a specific signal for reducing compounds eluting from the capillary GC, whereafter the atomic mercury is trapped for example, in a silicon-aerogel trap.

  3. Investigations Memorandum

    Broader source: Energy.gov [DOE]

    Investigation of Allegations Involving False Statements and False Claims at the Yucca Mountain Project

  4. Impact of plasma jet vacuum ultraviolet radiation on reactive oxygen species generation in bio-relevant liquids

    SciTech Connect (OSTI)

    Jablonowski, H.; Hammer, M. U.; Reuter, S.; Bussiahn, R.; Weltmann, K.-D.; Woedtke, Th. von

    2015-12-15

    Plasma medicine utilizes the combined interaction of plasma produced reactive components. These are reactive atoms, molecules, ions, metastable species, and radiation. Here, ultraviolet (UV, 100–400 nm) and, in particular, vacuum ultraviolet (VUV, 10–200 nm) radiation generated by an atmospheric pressure argon plasma jet were investigated regarding plasma emission, absorption in a humidified atmosphere and in solutions relevant for plasma medicine. The energy absorption was obtained for simple solutions like distilled water (dH{sub 2}O) or ultrapure water and sodium chloride (NaCl) solution as well as for more complex ones, for example, Rosewell Park Memorial Institute (RPMI 1640) cell culture media. As moderate stable reactive oxygen species, hydrogen peroxide (H{sub 2}O{sub 2}) was studied. Highly reactive oxygen radicals, namely, superoxide anion (O{sub 2}{sup •−}) and hydroxyl radicals ({sup •}OH), were investigated by the use of electron paramagnetic resonance spectroscopy. All species amounts were detected for three different treatment cases: Plasma jet generated VUV and UV radiation, plasma jet generated UV radiation without VUV part, and complete plasma jet including all reactive components additionally to VUV and UV radiation. It was found that a considerable amount of radicals are generated by the plasma generated photoemission. From the experiments, estimation on the low hazard potential of plasma generated VUV radiation is discussed.

  5. Multifunctional optical correlator for picosecond ultraviolet laser pulse measurement

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

    Rakhman, Abdurahim; Wang, Yang; Garcia, Frances; Long, Cary D.; Huang, Chunning; Takeda, Yasuhiro; Liu, Yun

    2014-01-01

    A compact optical correlator system that measures both the autocorrelation between two infrared (IR) lights and the cross-correlation between an IR and an ultraviolet (UV) light using a single nonlinear optical crystal has been designed and experimentally demonstrated. The rapid scanning of optical delay line, switching between auto and cross-correlations, crystal angle tuning, and data acquisition and processing are all computer controlled. Pulse widths of an IR light from a mode-locked laser are measured by the correlator and the results are compared with a direct measurement using a high-speed photodetector system. The correlator has been used to study the parametermore » dependence of the pulse width of a macropulse UV laser designed for laser-assisted hydrogen ion (H-) beam stripping for the Spallation Neutron Source at Oak Ridge National Laboratory.« less

  6. Tunnel junction enhanced nanowire ultraviolet light emitting diodes

    SciTech Connect (OSTI)

    Sarwar, A. T. M. Golam; May, Brelon J.; Deitz, Julia I.; Grassman, Tyler J.; McComb, David W.; Myers, Roberto C.

    2015-09-07

    Polarization engineered interband tunnel junctions (TJs) are integrated in nanowire ultraviolet (UV) light emitting diodes (LEDs). A ∼6 V reduction in turn-on voltage is achieved by the integration of tunnel junction at the base of polarization doped nanowire UV LEDs. Moreover, efficient hole injection into the nanowire LEDs leads to suppressed efficiency droop in TJ integrated nanowire LEDs. The combination of both reduced bias voltage and increased hole injection increases the wall plug efficiency in these devices. More than 100 μW of UV emission at ∼310 nm is measured with external quantum efficiency in the range of 4–6 m%. The realization of tunnel junction within the nanowire LEDs opens a pathway towards the monolithic integration of cascaded multi-junction nanowire LEDs on silicon.

  7. North American extreme temperature events and related large scale meteorological patterns: A review of statistical methods, dynamics, modeling, and trends

    SciTech Connect (OSTI)

    Grotjahn, Richard; Black, Robert; Leung, Ruby; Wehner, Michael F.; Barlow, Mathew; Bosilovich, Michael; Gershunov, Alexander; Gutowski, Jr., William J.; Gyakum, John R.; Katz, Richard W.; Lee, Yun -Young; Lim, Young -Kwon; Prabhat, -

    2015-05-22

    This paper reviews research approaches and open questions regarding data, statistical analyses, dynamics, modeling efforts, and trends in relation to temperature extremes. Our specific focus is upon extreme events of short duration (roughly less than 5 days) that affect parts of North America. These events are associated with large scale meteorological patterns (LSMPs). Methods used to define extreme events statistics and to identify and connect LSMPs to extreme temperatures are presented. Recent advances in statistical techniques can connect LSMPs to extreme temperatures through appropriately defined covariates that supplements more straightforward analyses. A wide array of LSMPs, ranging from synoptic to planetary scale phenomena, have been implicated as contributors to extreme temperature events. Current knowledge about the physical nature of these contributions and the dynamical mechanisms leading to the implicated LSMPs is incomplete. There is a pressing need for (a) systematic study of the physics of LSMPs life cycles and (b) comprehensive model assessment of LSMP-extreme temperature event linkages and LSMP behavior. Generally, climate models capture the observed heat waves and cold air outbreaks with some fidelity. However they overestimate warm wave frequency and underestimate cold air outbreaks frequency, and underestimate the collective influence of low-frequency modes on temperature extremes. Climate models have been used to investigate past changes and project future trends in extreme temperatures. Overall, modeling studies have identified important mechanisms such as the effects of large-scale circulation anomalies and land-atmosphere interactions on changes in extreme temperatures. However, few studies have examined changes in LSMPs more specifically to understand the role of LSMPs on past and future extreme temperature changes. Even though LSMPs are resolvable by global and regional climate models, they are not necessarily well simulated so more

  8. North American extreme temperature events and related large scale meteorological patterns: A review of statistical methods, dynamics, modeling, and trends

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

    Grotjahn, Richard; Black, Robert; Leung, Ruby; Wehner, Michael F.; Barlow, Mathew; Bosilovich, Michael; Gershunov, Alexander; Gutowski, Jr., William J.; Gyakum, John R.; Katz, Richard W.; et al

    2015-05-22

    This paper reviews research approaches and open questions regarding data, statistical analyses, dynamics, modeling efforts, and trends in relation to temperature extremes. Our specific focus is upon extreme events of short duration (roughly less than 5 days) that affect parts of North America. These events are associated with large scale meteorological patterns (LSMPs). Methods used to define extreme events statistics and to identify and connect LSMPs to extreme temperatures are presented. Recent advances in statistical techniques can connect LSMPs to extreme temperatures through appropriately defined covariates that supplements more straightforward analyses. A wide array of LSMPs, ranging from synoptic tomore » planetary scale phenomena, have been implicated as contributors to extreme temperature events. Current knowledge about the physical nature of these contributions and the dynamical mechanisms leading to the implicated LSMPs is incomplete. There is a pressing need for (a) systematic study of the physics of LSMPs life cycles and (b) comprehensive model assessment of LSMP-extreme temperature event linkages and LSMP behavior. Generally, climate models capture the observed heat waves and cold air outbreaks with some fidelity. However they overestimate warm wave frequency and underestimate cold air outbreaks frequency, and underestimate the collective influence of low-frequency modes on temperature extremes. Climate models have been used to investigate past changes and project future trends in extreme temperatures. Overall, modeling studies have identified important mechanisms such as the effects of large-scale circulation anomalies and land-atmosphere interactions on changes in extreme temperatures. However, few studies have examined changes in LSMPs more specifically to understand the role of LSMPs on past and future extreme temperature changes. Even though LSMPs are resolvable by global and regional climate models, they are not necessarily well simulated so

  9. PREDICTING Lyα AND Mg II FLUXES FROM K AND M DWARFS USING GALAXY EVOLUTION EXPLORER ULTRAVIOLET PHOTOMETRY

    SciTech Connect (OSTI)

    Shkolnik, Evgenya L.; Rolph, Kristina A.; Peacock, Sarah; Barman, Travis S. E-mail: kristina.rolph@fandm.edu E-mail: barman@lpl.arizona.edu

    2014-11-20

    A star's ultraviolet (UV) emission can greatly affect the atmospheric chemistry and physical properties of closely orbiting planets with the potential for severe mass loss. In particular, the Lyα emission line at 1216 Å, which dominates the far-ultraviolet (FUV) spectrum, is a major source of photodissociation of important atmospheric molecules such as water and methane. The intrinsic flux of Lyα, however, cannot be directly measured due to the absorption of neutral hydrogen in the interstellar medium and contamination by geocoronal emission. To date, reconstruction of the intrinsic Lyα line based on Hubble Space Telescope spectra has been accomplished for 46 FGKM nearby stars, 28 of which have also been observed by the Galaxy Evolution Explorer (GALEX). Our investigation provides a correlation between published intrinsic Lyα and GALEX far- and near-ultraviolet (NUV) chromospheric fluxes for K and M stars. The negative correlations between the ratio of the Lyα to the GALEX fluxes reveal how the relative strength of Lyα compared to the broadband fluxes weakens as the FUV and NUV excess flux increase. We also correlate GALEX fluxes with the strong NUV Mg II h+k spectral emission lines formed at lower chromospheric temperatures than Lyα. The reported correlations provide estimates of intrinsic Lyα and Mg II fluxes for the thousands of K and M stars in the archived GALEX all-sky surveys. These will constrain new stellar upper atmosphere models for cool stars and provide realistic inputs to models describing exoplanetary photochemistry and atmospheric evolution in the absence of UV spectroscopy.

  10. Radiation stability of graphene under extreme conditions

    SciTech Connect (OSTI)

    Kumar, Sunil, E-mail: kumar.sunil092@gmail.com; Tripathi, Ambuj; Khan, Saif A.; Pannu, Compesh; Avasthi, Devesh K. [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2014-09-29

    In this letter, we report radiation stability of graphene under extreme condition of high energy density generated by 150?MeV Au ion irradiation. The experiment reveals that graphene is radiation resistant for irradiation at 10{sup 14?}ions/cm{sup 2} of 150?MeV Au ions. It is significant to note that annealing effects are observed at lower fluences whereas defect production occurs at higher fluences but significant crystallinity is retained. Our results demonstrate applicability of graphene based devices in radiation environment and space applications.

  11. Extremely compliant and highly stretchable patterned graphene

    SciTech Connect (OSTI)

    Zhu, Shuze; Huang, Yinjun; Li, Teng, E-mail: LiT@umd.edu [Department of Mechanical Engineering and Maryland NanoCenter, University of Maryland, College Park, Maryland 20742 (United States)

    2014-04-28

    Graphene is intrinsically ultra-stiff in its plane. Its huge mechanical mismatch when interfacing with ultra-compliant biological tissues and elastomers (79 orders of magnitude difference in stiffness) poses significant challenge in its application to functional devices such as epidermal electronics and sensing prosthesis. We offer a feasible and promising solution to this significant challenge by suitably patterning graphene into a nanomesh. Through systematic coarse-grained simulations, we show that graphene nanomesh can be made extremely compliant with nearly zero stiffness up to about 20% elongation and then remain highly compliant up to about 50% elongation.

  12. Development of an Extreme Environment Materials Research Facility at Princeton

    SciTech Connect (OSTI)

    Cohen, A B; Tully, C G; Austin, R; Calaprice, F; McDonald, K; Ascione, G; Baker, G; Davidson, R; Dudek, L; Grisham, L; Kugel, H; Pagdon, K; Stevenson, T; Woolley, R

    2010-11-17

    The need for a fundamental understanding of material response to a neutron and/or high heat flux environment can yield development of improved materials and operations with existing materials. Such understanding has numerous applications in fields such as nuclear power (for the current fleet and future fission and fusion reactors), aerospace, and other research fields (e.g., high-intensity proton accelerator facilities for high energy physics research). A proposal has been advanced to develop a facility for testing various materials under extreme heat and neutron exposure conditions at Princeton. The Extreme Environment Materials Research Facility comprises an environmentally controlled chamber (48 m^3) capable of high vacuum conditions, with extreme flux beams and probe beams accessing a central, large volume target. The facility will have the capability to expose large surface areas (1 m^2) to 14 MeV neutrons at a fluence in excess of 10^13 n/s. Depending on the operating mode. Additionally beam line power on the order of 15-75 MW/m2 for durations of 1-15 seconds are planned... The multi-second duration of exposure can be repeated every 2-10 minutes for periods of 10-12 hours. The facility will be housed in the test cell that held the Tokamak Fusion Test Reactor (TFTR), which has the desired radiation and safety controls as well as the necessary loading and assembly infrastructure. The facility will allow testing of various materials to their physical limit of thermal endurance and allow for exploring the interplay between radiation-induced embrittlement, swelling and deformation of materials, and the fatigue and fracturing that occur in response to thermal shocks. The combination of high neutron energies and intense fluences will enable accelerated time scale studies. The results will make contributions for refining predictive failure modes (modeling) in extreme environments, as well as providing a technical platform for the development of new alloys, new

  13. Tribal Energy System Vulnerabilities to Climate Change and Extreme Weather

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

    | Department of Energy System Vulnerabilities to Climate Change and Extreme Weather Tribal Energy System Vulnerabilities to Climate Change and Extreme Weather This U.S. Department of Energy Office of Indian Energy report assesses climate change and extreme weather vulnerabilities specific to tribal energy infrastructure and systems in the contiguous United States and Alaska. It includes information about the impacts from climate change and extreme weather events on both onsite and offsite

  14. Daily HMS Extremes in Met Data - Hanford Site

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

    Hanford Meteorological Station Daily HMS Extremes in Met Data Hanford Meteorological Station Real Time Met Data from Around the Site Current and Past 48 Hours HMS Observations Daily HMS Extremes in Met Data Met and Climate Data Summary Products Contacts / Hours Current NWS Forecast for the Tri-Cities NWS Windchill Chart Daily HMS Extremes in Met Data Email Email Page | Print Print Page | Text Increase Font Size Decrease Font Size This table shows the daily extremes at each of the remote stations

  15. Funding Opportunity Announcement: Enabling Extreme Real-Time Grid

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

    Integration of Solar Energy (ENERGISE) | Department of Energy Enabling Extreme Real-Time Grid Integration of Solar Energy (ENERGISE) Funding Opportunity Announcement: Enabling Extreme Real-Time Grid Integration of Solar Energy (ENERGISE) Funding Opportunity Announcement: Enabling Extreme Real-Time Grid Integration of Solar Energy (ENERGISE) Funding Number: DE-FOA-0001495 Funding Amount: $25,000,000 Description The Enabling Extreme Real-Time Grid Integration of Solar Energy (ENERGISE) funding

  16. LANL Shock Tube Kathy Prestridge Extreme Fluids Team

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

    Header image FLUID DYNAMICS at Los Alamos Extreme Fluids Team in Physics Division home the team research publications pictures diversity contact The Extreme Fluids Team On the P-23 Extreme Fluids Team at Los Alamos National Laboratory, we apply high-resolution diagnostics to study fluid dynamics problems in extreme environments, such as shock-driven mixing, multiphase flows, and variable-density turbulence. The team is composed of Los Alamos staff, postdocs, and students. EXPERIMENTAL FACILITIES

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

    DOE Patents [OSTI]

    MacGowan, Brian J.; Matthews, Dennis L.; Trebes, James E.

    1988-01-01

    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).

  18. 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.

    1987-05-05

    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.

  19. Tunnel-injection quantum dot deep-ultraviolet light-emitting diodes with polarization-induced doping in III-nitride heterostructures

    SciTech Connect (OSTI)

    Verma, Jai Islam, S. M.; Protasenko, Vladimir; Kumar Kandaswamy, Prem; Xing, Huili; Jena, Debdeep

    2014-01-13

    Efficient semiconductor optical emitters in the deep-ultraviolet spectral window are encountering some of the most deep rooted problems of semiconductor physics. In III-Nitride heterostructures, obtaining short-wavelength photon emission requires the use of wide bandgap high Al composition AlGaN active regions. High conductivity electron (n-) and hole (p-) injection layers of even higher bandgaps are necessary for electrical carrier injection. This approach requires the activation of very deep dopants in very wide bandgap semiconductors, which is a difficult task. In this work, an approach is proposed and experimentally demonstrated to counter the challenges. The active region of the heterostructure light emitting diode uses ultrasmall epitaxially grown GaN quantum dots. Remarkably, the optical emission energy from GaN is pushed from 365?nm (3.4?eV, the bulk bandgap) to below 240?nm (>5.2?eV) because of extreme quantum confinement in the dots. This is possible because of the peculiar bandstructure and band alignments in the GaN/AlN system. This active region design crucially enables two further innovations for efficient carrier injection: Tunnel injection of carriers and polarization-induced p-type doping. The combination of these three advances results in major boosts in electroluminescence in deep-ultraviolet light emitting diodes and lays the groundwork for electrically pumped short-wavelength lasers.

  20. Left-Wing Extremism: The Current Threat

    SciTech Connect (OSTI)

    Karl A. Seger

    2001-04-30

    Left-wing extremism is ''alive and well'' both in the US and internationally. Although the current domestic terrorist threat within the U. S. is focused on right-wing extremists, left-wing extremists are also active and have several objectives. Leftist extremists also pose an espionage threat to U.S. interests. While the threat to the U.S. government from leftist extremists has decreased in the past decade, it has not disappeared. There are individuals and organizations within the U.S. who maintain the same ideology that resulted in the growth of left-wing terrorism in this country in the 1970s and 1980s. Some of the leaders from that era are still communicating from Cuba with their followers in the U.S., and new leaders and groups are emerging.

  1. A Road Map to Extreme High Vacuum

    SciTech Connect (OSTI)

    Ganapati Rao Myneni

    2007-06-20

    Ultimate pressure of a well-designed vacuum system very much depends on pretreatments, processing and the procedures [1,2]. Until now much attention has been paid in minimizing hydrogen outgassing from the chamber material. However, procedures and processing deserves further scrutiny than hitherto given so far. For reducing the gas load, high sensitivity helium leak detection techniques with sensitivities better than 1 10-12 Torr l/sec need to be used. Effects that are induced by vacuum instrumentation need to be reduced in order to obtain accurate pressure measurements. This presentation will discuss: clean assembly procedures, metal sponges for cryosorption pumping of hydrogen to extreme high vacuum, low cost surface diffusion barriers for reducing the hydrogen gas load, cascade pumping, sensitive helium leak detection techniques and the use of modified extractor and residual gas analyzers. Further, alternative back up pumping systems based on active NEGs [3] for turbo molecular pumps will be presented.

  2. Monitoring Extreme-scale Lustre Toolkit

    SciTech Connect (OSTI)

    Brim, Michael J; Lothian, Josh

    2015-01-01

    We discuss the design and ongoing development of the Monitoring Extreme-scale Lustre Toolkit (MELT), a unified Lustre performance monitoring and analysis infrastructure that provides continuous, low-overhead summary information on the health and performance of Lustre, as well as on-demand, in-depth problem diagnosis and root-cause analysis. The MELT infrastructure leverages a distributed overlay network to enable monitoring of center-wide Lustre filesystems where clients are located across many network domains. We preview interactive command-line utilities that help administrators and users to observe Lustre performance at various levels of resolution, from individual servers or clients to whole filesystems, including job-level reporting. Finally, we discuss our future plans for automating the root-cause analysis of common Lustre performance problems.

  3. The far-ultraviolet UPS and downs of Alpha Centauri (Journal...

    Office of Scientific and Technical Information (OSTI)

    Centauri have yielded a detailed time history of far-ultraviolet (FUV: 1150-1700 ) emissions of the solarlike primary (A: G2 V) and the cooler but more active secondary (B: K1...

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

    DOE Patents [OSTI]

    Vogl, O.; Li, S.

    1983-10-06

    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.

  5. Ultraviolet reflector materials for solar detoxification of hazardous waste

    SciTech Connect (OSTI)

    Jorgensen, G.; Govindarajan, R.

    1991-07-01

    Organic waste detoxification requires cleavage of carbon bonds. Such reactions can be photo-driven by light that is energetic enough to disrupt such bonds. Alternately, light can be used to activate catalyst materials, which in turn can break organic bonds. In either case, photons with wavelengths less than 400 nm are required. Because the terrestrial solar resource below 400 nm is so small (roughly 3% of the available spectrum), highly efficient optical concentrators are needed that can withstand outdoor service conditions. In the past, optical elements for solar application have been designed to prevent ultraviolet (uv) radiation from reaching the reflective layer to avoid the potentially harmful effects of such light on the collector materials themselves. This effectively forfeits the uv part of the spectrum in return for some measure of protection against optical degradation. To optimize the cost/performance benefit of photochemical reaction systems, optical materials must be developed that are not only highly efficient but also inherently stable against the radiation they are designed to concentrate. The requirements of uv optical elements in terms of appropriate spectral bands and level of reflectance are established based upon the needs of photochemical applications. Relevant literature on uv reflector materials is reviewed which, along with discussions with industrial contacts, allows the establishment of a data base of currently available materials. Although a number of related technologies exist that require uv reflectors, to date little attention has been paid to achieving outdoor durability required for solar applications. 49 refs., 3 figs.

  6. Ultraviolet photodissociation of OCS: Product energy and angular distributions

    SciTech Connect (OSTI)

    McBane, G. C. [Department of Chemistry, Grand Valley State University, Allendale, Michigan 49401 (United States); Schmidt, J. A.; Johnson, M. S. [Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen O (Denmark); Schinke, R. [Max-Planck-Institut fuer Dynamik und Selbstorganisation (MPIDS), D-37077 Goettingen (Germany)

    2013-03-07

    The ultraviolet photodissociation of carbonyl sulfide (OCS) was studied using three-dimensional potential energy surfaces and both quantum mechanical dynamics calculations and classical trajectory calculations including surface hopping. The transition dipole moment functions used in an earlier study [J. A. Schmidt, M. S. Johnson, G. C. McBane, and R. Schinke, J. Chem. Phys. 137, 054313 (2012)] were improved with more extensive treatment of excited electronic states. The new functions indicate a much larger contribution from the 1 {sup 1}A{sup Double-Prime} state ({sup 1}{Sigma}{sup -} in linear OCS) than was found in the previous work. The new transition dipole functions yield absorption spectra that agree with experimental data just as well as the earlier ones. The previously reported potential energy surfaces were also empirically modified in the region far from linearity. The resulting product state distributions P{sub v,j}, angular anisotropy parameters {beta}(j), and carbon monoxide rotational alignment parameters A{sub 0}{sup (2)}(j) agree reasonably well with the experimental results, while those computed from the earlier transition dipole and potential energy functions do not. The higher-j peak in the bimodal rotational distribution is shown to arise from nonadiabatic transitions from state 2 {sup 1}A{sup Prime} to the OCS ground state late in the dissociation.

  7. 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

    2008-05-12

    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.

  8. On the role of chemical reactions in initiating ultraviolet laser ablation in poly(methyl methacrylate)

    SciTech Connect (OSTI)

    Prasad, Manish; Conforti, Patrick F.; Garrison, Barbara J.

    2007-05-15

    The role of chemical reactions is investigated versus the thermal and mechanical processes occurring in a polymer substrate during irradiation by a laser pulse and subsequent ablation. Molecular dynamics simulations with an embedded Monte Carlo based reaction scheme were used to study ultraviolet ablation of poly(methyl methacrylate) at 157 nm. We discuss the onset of ablation, the mechanisms leading to ablation, and the role of stress relaxation of the polymer matrix during ablation. Laser induced heating and chemical decomposition of the polymer substrate are considered as ablation pathways. It is shown that heating the substrate can set off ablation via mechanical failure of the material only for very short laser pulses. For longer pulses, the mechanism of ejection is thermally driven limited by the critical number of bonds broken in the substrate. Alternatively, if the photon energy goes towards direct bond breaking, it initiates chemical reactions, polymer unzipping, and formation of gaseous products, leading to a nearly complete decomposition of the top layers of substrates. The ejection of small molecules has a hollowing out effect on the weakly connected substrates which can lead to lift-off of larger chunks. Excessive pressure buildup upon the creation of gaseous molecules does not lead to enhanced yield. The larger clusters are thermally ejected, and an entrainment of larger polymer fragments in gaseous molecules is not observed.

  9. INTENSITY ENHANCEMENT OF OVI ULTRAVIOLET EMISSION LINES IN SOLAR SPECTRA DUE TO OPACITY

    SciTech Connect (OSTI)

    Keenan, F. P.; Mathioudakis, M.; Doyle, J. G.; Madjarska, M. S.; Rose, S. J.; Bowler, L. A.; Britton, J.; McCrink, L.

    2014-04-01

    Opacity is a property of many plasmas. It is normally expected that if an emission line in a plasma becomes optically thick, then its intensity ratio to that of another transition that remains optically thin should decrease. However, radiative transfer calculations undertaken both by ourselves and others predict that under certain conditions the intensity ratio of an optically thick to an optically thin line can show an increase over the optically thin value, indicating an enhancement in the former. These conditions include the geometry of the emitting plasma and its orientation to the observer. A similar effect can take place between lines of differing optical depths. While previous observational studies have focused on stellar point sources, here we investigate the spatially resolved solar atmosphere using measurements of the I(1032 )/I(1038 ) intensity ratio of OVI in several regions obtained with the Solar Ultraviolet Measurements of Emitted Radiation instrument on board the Solar and Heliospheric Observatory satellite. We find several I(1032 )/I(1038 ) ratios observed on the disk to be significantly larger than the optically thin value of 2.0, providing the first detection (to our knowledge) of intensity enhancement in the ratio arising from opacity effects in the solar atmosphere. The agreement between observation and theory is excellent and confirms that the OVI emission originates from a slab-like geometry in the solar atmosphere, rather than from cylindrical structures.

  10. 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

    2012-06-27

    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.

  11. Oxygen isotope fractionation in the vacuum ultraviolet photodissociation of carbon monoxide: Wavelength, pressure and temperature dependency.

    SciTech Connect (OSTI)

    Chakraborty, Subrata; Davis, Ryan; Ahmed, Musahid; Jackson, Teresa L.; Thiemens, Mark H.

    2012-01-03

    Several absorption bands exist in the VUV region of Carbon monoxide (CO). Emission spectra indicate that these bands are all predissociative. An experimental investigation of CO photodissociation by vacuum ultraviolet photons (90 to 108 nm; ~13 to 11 eV) from the Advanced Light Source Synchrotron and direct measurement of the associated oxygen isotopic composition of the products are presented here. A wavelength dependency of the oxygen isotopic composition in the photodissociation product was observed. Slope values (δ'{sup 18}O/ δ'{sup 17}O) ranging from 0.76 to 1.32 were observed in oxygen three-isotope space (δ'{sup 18}O vs. δ'{sup 17}O) which correlated with increasing synchrotron photon energy, and indicate a dependency of the upper electronic state specific dissociation dynamics (e.g., perturbation and coupling associated with a particular state). An unprecedented magnitude in isotope separation was observed for photodissociation at the 105 and 107 nm synchrotron bands and are found to be associated with accidental predissociation of the vibrational states ({nu} = 0 and 1) of the upper electronic state E{sup 1}Π. For each synchrotron band, a large (few hundred per mil) extent of isotopic fractionation was observed and the range of fractionation is a combination of column density and exposure time. A significant temperature dependency in oxygen isotopic fractionation was observed, indicating a rotational level dependency in the predissociation process.

  12. THE NEAR-ULTRAVIOLET LUMINOSITY FUNCTION OF YOUNG, EARLY M-TYPE DWARF STARS

    SciTech Connect (OSTI)

    Ansdell, Megan; Baranec, Christoph; Gaidos, Eric; Mann, Andrew W.; Lpine, Sebastien; James, David; Buccino, Andrea; Mauas, Pablo; Petrucci, Romina; Law, Nicholas M.; Riddle, Reed

    2015-01-01

    Planets orbiting within the close-in habitable zones of M dwarf stars will be exposed to elevated high-energy radiation driven by strong magnetohydrodynamic dynamos during stellar youth. Near-ultraviolet (NUV) irradiation can erode and alter the chemistry of planetary atmospheres, and a quantitative description of the evolution of NUV emission from M dwarfs is needed when modeling these effects. We investigated the NUV luminosity evolution of early M-type dwarfs by cross-correlating the Lpine and Gaidos catalog of bright M dwarfs with the Galaxy Evolution Explorer (GALEX) catalog of NUV (1771-2831 ) sources. Of the 4805 sources with GALEX counterparts, 797 have NUV emission significantly (>2.5?) in excess of an empirical basal level. We inspected these candidate active stars using visible-wavelength spectra, high-resolution adaptive optics imaging, time-series photometry, and literature searches to identify cases where the elevated NUV emission is due to unresolved background sources or stellar companions; we estimated the overall occurrence of these ''false positives'' (FPs) as ?16%. We constructed an NUV luminosity function that accounted for FPs, detection biases of the source catalogs, and GALEX upper limits. We found the NUV luminosity function to be inconsistent with predictions from a constant star-formation rate and simplified age-activity relation defined by a two-parameter power law.

  13. Facilitating Co-Design for Extreme-Scale Systems Through Lightweight Simulation

    SciTech Connect (OSTI)

    Engelmann, Christian; Lauer, Frank

    2010-01-01

    This work focuses on tools for investigating algorithm performance at extreme scale with millions of concurrent threads and for evaluating the impact of future architecture choices to facilitate the co-design of high-performance computing (HPC) architectures and applications. The approach focuses on lightweight simulation of extreme-scale HPC systems with the needed amount of accuracy. The prototype presented in this paper is able to provide this capability using a parallel discrete event simulation (PDES), such that a Message Passing Interface (MPI) application can be executed at extreme scale, and its performance properties can be evaluated. The results of an initial prototype are encouraging as a simple 'hello world' MPI program could be scaled up to 1,048,576 virtual MPI processes on a four-node cluster, and the performance properties of two MPI programs could be evaluated at up to 16,384 virtual MPI processes on the same system.

  14. Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel

    SciTech Connect (OSTI)

    Tesler, Alexander B.; Kim, Philseok; Kolle, Stefan; Howell, Caitlin; Ahanotu, Onye; Aizenberg, Joanna

    2015-10-20

    Formation of unwanted deposits on steels during their interaction with liquids is an inherent problem that often leads to corrosion, biofouling and results in reduction in durability and function. Here we report a new route to form anti-fouling steel surfaces by electrodeposition of nanoporous tungsten oxide (TO) films. TO-modified steels are as mechanically durable as bare steel and highly tolerant to compressive and tensile stresses due to chemical bonding to the substrate and island-like morphology. When inherently superhydrophilic TO coatings are converted to superhydrophobic, they remain non-wetting even after impingement with yttria-stabilized-zirconia particles, or exposure to ultraviolet light and extreme temperatures. Upon lubrication, these surfaces display omniphobicity against highly contaminating media retaining hitherto unseen mechanical durability. Furthermore, to illustrate the applicability of such a durable coating in biofouling conditions, we modified naval construction steels and surgical instruments and demonstrated significantly reduced marine algal film adhesion, Escherichia coli attachment and blood staining.

  15. The formation of IRIS diagnostics. III. Near-ultraviolet spectra and images

    SciTech Connect (OSTI)

    Pereira, T. M. D.; Leenaarts, J.; De Pontieu, B.; Carlsson, M.; Uitenbroek, H. E-mail: jorritl@astro.uio.no E-mail: mats.carlsson@astro.uio.no

    2013-12-01

    The Mg II h and k lines are the prime chromospheric diagnostics of NASA's Interface Region Imaging Spectrograph (IRIS). In the previous papers of this series, we used a realistic three-dimensional radiative magnetohydrodynamics model to calculate the h and k lines in detail and investigated how their spectral features relate to the underlying atmosphere. In this work, we employ the same approach to investigate how the h and k diagnostics fare when taking into account the finite resolution of IRIS and different noise levels. In addition, we investigate the diagnostic potential of several other photospheric lines and near-continuum regions present in the near-ultraviolet (NUV) window of IRIS and study the formation of the NUV slit-jaw images. We find that the instrumental resolution of IRIS has a small effect on the quality of the h and k diagnostics; the relations between the spectral features and atmospheric properties are mostly unchanged. The peak separation is the most affected diagnostic, but mainly due to limitations of the simulation. The effects of noise start to be noticeable at a signal-to-noise ratio (S/N) of 20, but we show that with noise filtering one can obtain reliable diagnostics at least down to a S/N of 5. The many photospheric lines present in the NUV window provide velocity information for at least eight distinct photospheric heights. Using line-free regions in the h and k far wings, we derive good estimates of photospheric temperature for at least three heights. Both of these diagnostics, in particular the latter, can be obtained even at S/Ns as low as 5.

  16. Accident Investigations

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2011-03-04

    This Order prescribes organizational responsibilities, authorities, and requirements for conducting investigations of certain accidents occurring at DOE sites, facilities, areas, operations, and activities. Supersedes DOE O 225.1A. Cancels DOE G 225.1A-1.

  17. Paving the Way to Nanoelectronics 16 nm and Smaller

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

    Science Highlight Investigating Extreme Ultraviolet Lithography Mask Defects), and the development of ultrahigh-resolution photoresist-a light-sensitive material used to form a...

  18. AN EXTREMELY CARBON-RICH, EXTREMELY METAL-POOR STAR IN THE SEGUE 1 SYSTEM

    SciTech Connect (OSTI)

    Norris, John E.; Yong, David; Gilmore, Gerard; Wyse, Rosemary F. G.; Frebel, Anna

    2010-10-10

    We report the analysis of high-resolution, high signal-to-noise ratio, spectra of an extremely metal-poor, extremely C-rich red giant, Seg 1-7, in Segue 1-described in the literature alternatively as an unusually extended globular cluster or an ultra-faint dwarf galaxy. The radial velocity of Seg 1-7 coincides precisely with the systemic velocity of Segue 1, and its chemical abundance signature of [Fe/H] = -3.52, [C/Fe] = +2.3, [N/Fe] = +0.8, [Na/Fe] = +0.53, [Mg/Fe] = +0.94, [Al/Fe] = +0.23, and [Ba/Fe] < -1.0 is similar to that of the rare and enigmatic class of Galactic halo objects designated CEMP-no (carbon-rich, extremely metal-poor with no enhancement (over solar ratios) of heavy neutron-capture elements). This is the first star in a Milky Way 'satellite' that unambiguously lies on the metal-poor, C-rich branch of the Aoki et al. bimodal distribution of field halo stars in the ([C/Fe], [Fe/H])-plane. Available data permit us only to identify Seg 1-7 as a member of an ultra-faint dwarf galaxy or as debris from the Sgr dwarf spheroidal galaxy. In either case, this demonstrates that at extremely low abundance, [Fe/H ] <-3.0, star formation and associated chemical evolution proceeded similarly in the progenitors of both the field halo and satellite systems. By extension, this is consistent with other recent suggestions that the most metal-poor dwarf spheroidal and ultra-faint dwarf satellites were the building blocks of the Galaxy's outer halo.

  19. Extreme Temperature Energy Storage and Generation, for Cost and Risk

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

    Reduction in Geothermal Exploration | Department of Energy Extreme Temperature Energy Storage and Generation, for Cost and Risk Reduction in Geothermal Exploration Extreme Temperature Energy Storage and Generation, for Cost and Risk Reduction in Geothermal Exploration Extreme Temperature Energy Storage and Generation, for Cost and Risk Reduction in Geothermal Exploration presentation at the April 2013 peer review meeting held in Denver, Colorado. fast_cap_sys_peer2013.pdf (1.51 MB) More

  20. 'Extreme Makeover: Home Edition' Builds Efficiently | Department of Energy

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

    'Extreme Makeover: Home Edition' Builds Efficiently 'Extreme Makeover: Home Edition' Builds Efficiently February 12, 2010 - 9:30am Addthis Joshua DeLung You may recall this post on Energy Empowers, which previewed an upcoming episode of ABC's "Extreme Makeover: Home Edition" where the U.S. Department of Energy collaborated with builders to incorporate energy-efficiency and renewable energy technologies at The Fishing School, one of two such collaborative projects in an episode that was

  1. OBSERVATIONS AND MODELING OF THE EMERGING EXTREME-ULTRAVIOLET LOOPS IN THE QUIET SUN AS SEEN WITH THE SOLAR DYNAMICS OBSERVATORY

    SciTech Connect (OSTI)

    Chitta, L. P.; Van Ballegooijen, A. A.; DeLuca, E. E.; Kariyappa, R.; Hasan, S. S.; Hanslmeier, A.

    2013-05-01

    We used data from the Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) to study coronal loops at small scales, emerging in the quiet Sun. With HMI line-of-sight magnetograms, we derive the integrated and unsigned photospheric magnetic flux at the loop footpoints in the photosphere. These loops are bright in the EUV channels of AIA. Using the six AIA EUV filters, we construct the differential emission measure (DEM) in the temperature range 5.7-6.5 in log T (K) for several hours of observations. The observed DEMs have a peak distribution around log T Almost-Equal-To 6.3, falling rapidly at higher temperatures. For log T < 6.3, DEMs are comparable to their peak values within an order of magnitude. The emission-weighted temperature is calculated, and its time variations are compared with those of magnetic flux. We present two possibilities for explaining the observed DEMs and temperatures variations. (1) Assuming that the observed loops are composed of a hundred thin strands with certain radius and length, we tested three time-dependent heating models and compared the resulting DEMs and temperatures with the observed quantities. This modeling used enthalpy-based thermal evolution of loops (EBTEL), a zero-dimensional (0D) hydrodynamic code. The comparisons suggest that a medium-frequency heating model with a population of different heating amplitudes can roughly reproduce the observations. (2) We also consider a loop model with steady heating and non-uniform cross-section of the loop along its length, and find that this model can also reproduce the observed DEMs, provided the loop expansion factor {gamma} {approx} 5-10. More observational constraints are required to better understand the nature of coronal heating in the short emerging loops on the quiet Sun.

  2. Constraining UV continuum slopes of active galactic nuclei with cloudy models of broad-line region extreme-ultraviolet emission lines

    SciTech Connect (OSTI)

    Moloney, Joshua [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Michael Shull, J., E-mail: joshua.moloney@colorado.edu, E-mail: michael.shull@colorado.edu [Also at Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK. (United Kingdom)

    2014-10-01

    Understanding the composition and structure of the broad-line region (BLR) of active galactic nuclei (AGNs) is important for answering many outstanding questions in supermassive black hole evolution, galaxy evolution, and ionization of the intergalactic medium. We used single-epoch UV spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope to measure EUV emission-line fluxes from four individual AGNs with 0.49 ? z ? 0.64, two AGNs with 0.32 ? z ? 0.40, and a composite of 159 AGNs. With the CLOUDY photoionization code, we calculated emission-line fluxes from BLR clouds with a range of density, hydrogen ionizing flux, and incident continuum spectral indices. The photoionization grids were fit to the observations using single-component and locally optimally emitting cloud (LOC) models. The LOC models provide good fits to the measured fluxes, while the single-component models do not. The UV spectral indices preferred by our LOC models are consistent with those measured from COS spectra. EUV emission lines such as N IV ?765, O II ?833, and O III ?834 originate primarily from gas with electron temperatures between 37,000 K and 55,000 K. This gas is found in BLR clouds with high hydrogen densities (n {sub H} ? 10{sup 12} cm{sup 3}) and hydrogen ionizing photon fluxes (?{sub H} ? 10{sup 22} cm{sup 2} s{sup 1}).

  3. Excitation of helium Rydberg states and doubly excited resonances in strong extreme ultraviolet fields: Full-dimensional quantum dynamics using exponentially tempered Gaussian basis sets

    SciTech Connect (OSTI)

    Kaprlov-?nsk, Petra Ruth; mydke, Jan; Department of Radiation and Chemical Physics, Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8 ; Civi, Svatopluk

    2013-09-14

    Recently optimized exponentially tempered Gaussian basis sets [P. R. Kapralova-Zdanska and J. Smydke, J. Chem. Phys. 138, 024105 (2013)] are employed in quantitative simulations of helium absorption cross-sections and two-photon excitation yields of doubly excited resonances. Linearly polarized half-infinite and Gaussian laser pulses at wavelengths 3858 nm and large intensities up to 100 TW/cm{sup 2} are considered. The emphasis is laid on convergence of the results with respect to the quality of the Gaussian basis sets (typically limited by a number of partial waves, density, and spatial extent of the basis functions) as well as to the quality of the basis set of field-free states (typically limited by the maximum rotational quantum number and maximum excitation of the lower electron). Particular attention is paid to stability of the results with respect to varying complex scaling parameter. Moreover, the study of the dynamics is preceded by a thorough check of helium energies and oscillator strengths as they are obtained with the exponentially tempered Gaussian basis sets, being also compared with yet unpublished emission wavelengths measured in electric discharge experiments.

  4. Optical Design for Extremely Large Telescope Adaptive Optics...

    Office of Scientific and Technical Information (OSTI)

    Large Telescope Adaptive Optics Systems Citation Details In-Document Search Title: Optical Design for Extremely Large Telescope Adaptive Optics Systems You are accessing a ...

  5. Impact of Extreme Injection Pressure and EGR on the Combustion...

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

    Impact of Extreme Injection Pressure and EGR on the Combustion System of a HD Single Cylinder Engine Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research ...

  6. Extreme dynamic compression with a low energy laser pulse (Conference...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: Presented at: Extreme dynamic compression with a low energy laser pulse, Tampa, FL, United States, Jun 15 - Jun 19, 2015 Research Org: Lawrence ...

  7. Center for Materials at Irradiation and Mechanical Extremes:...

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

    a Cu 10 nm nanocrystalline sample being uni-axial compressed to strain of 20% and then stress released. Irradiation Extremes Thrust Traditional structural materials degrade and...

  8. SUMMARY OF REVISED TORNADO, HURRICANE AND EXTREME STRAIGHT WIND...

    Office of Environmental Management (EM)

    Summary of Revised Tornado, Hurricane and Extreme Straight Wind Characteristics at Nuclear Facility Sites BY: John D. Stevenson Consulting Engineer PDF icon Summary of Revised ...

  9. LDRD symposium focuses on materials in extremes, big data, and...

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

    LDRD symposium focuses on materials in extremes, big data, and energy use impacts | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission...

  10. Extreme Adaptive Optics for the Thirty Meter Telescope (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Extreme Adaptive Optics for the Thirty Meter Telescope Direct detection of extrasolar Jovian planets is a major scientific motivation for the construction of future ...

  11. SUMMARY OF REVISED TORNADO, HURRICANE AND EXTREME STRAIGHT WIND...

    Office of Environmental Management (EM)

    N E T SUMMARY OF REVISED TORNADO, HURRICANE AND EXTREME STRAIGHT WIND CHARACTERISTICS AT ... (1) natural hazard phenomenon (earthquake, wind, flooding and precipitation) and ...

  12. Best Practices in Literature Research for the 10-Year Extreme...

    Office of Environmental Management (EM)

    Analysis?? * Data Collection - 33 feet elevation - 3 second gust Analysis of Wind Data Fisher-Tippett Type I (Gumbel) distribution shall be used * Generalized Extreme Value ...

  13. Tribal Energy System Vulnerabilities to Climate Change and Extreme...

    Broader source: Energy.gov (indexed) [DOE]

    Tribal Energy System Vulnerabilities to Climate Change and Extreme Weather ii NOTICE This ... States government or any agency thereof. energy.govindianenergy | indianenergy@hq.doe.go...

  14. Extreme Temperature Energy Storage and Generation, for Cost and...

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

    Geothermal Technologies Program 2013 Peer Review Extreme Temperature Energy Storage and ... generator A (250C) energy storage system A (250C) converter to manage and ...

  15. Asking the right questions: benchmarking fault-tolerant extreme...

    Office of Scientific and Technical Information (OSTI)

    Title: Asking the right questions: benchmarking fault-tolerant extreme-scale systems. Abstract not provided. Authors: Widener, Patrick ; Ferreira, Kurt Brian ; Levy, Scott N. ; ...

  16. Attributing Changes in the Risk of Extreme Weather and Climate...

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

    150 Million Year: 2013 Research Domain: Earth Science The climate system is a naturally ... Modeling of the statistics of extreme weather is exceedingly computationally intensive. ...

  17. Recovery from ultraviolet-induced threshold voltage shift in indium gallium zinc oxide thin film transistors by positive gate bias

    SciTech Connect (OSTI)

    Liu, P.; Chen, T. P.; Li, X. D.; Wong, J. I.; Liu, Z.; Liu, Y.; Leong, K. C.

    2013-11-11

    The effect of short-duration ultraviolet (UV) exposure on the threshold voltage (V{sub th}) of amorphous indium gallium zinc oxide thin film transistors (TFTs) and its recovery characteristics were investigated. The V{sub th} exhibited a significant negative shift after UV exposure. The V{sub th} instability caused by UV illumination is attributed to the positive charge trapping in the dielectric layer and/or at the channel/dielectric interface. The illuminated devices showed a slow recovery in threshold voltage without external bias. However, an instant recovery can be achieved by the application of positive gate pulses, which is due to the elimination of the positive trapped charges as a result of the presence of a large amount of field-induced electrons in the interface region.

  18. Accident Investigations

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1996-04-26

    To prescribe requirements for conducting investigations of certain accidents occurring at Department of Energy (DOE) operations and sites; to improve the environment, safety and health for DOE, contractors, and the public; and to prevent the recurrence of such accidents. Chg 2, 4-26-96

  19. Accident Investigations

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-10-26

    To prescribe requirements for conducting investigations of certain accidents occurring at Department of Energy (DOE) operations and sites; to improve the environment , safety and health for DOE, contractors, and the public; and to prevent the recurrence of such accidents. Chg 1, 10-26-95. Cancels parts of DOE 5484.1

  20. Ultraviolet radiation as disinfection for fish surgical tools

    SciTech Connect (OSTI)

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

    2013-04-04

    Telemetry is frequently used to examine the behavior of fish, and the transmitters used are normally surgically implanted into the coelomic cavity of fish. Implantation requires the use of surgical tools such as scalpels, forceps, needle holders, and sutures. When fish are implanted consecutively, as in 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. To determine the efficacy for this application, ultraviolet (UV) radiation was used to disinfect surgical tools 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, causative agents of furunculosis, coldwater disease, bacterial kidney disease, and saprolegniasis (water mold), respectively. Four experiments were conducted to address the question of UV efficacy. In the first experiment, forceps were exposed to the three bacteria at three varying concentrations. 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. UV radiation exposures at all durations were effective at killing all three bacteria on forceps at the highest bacteria concentrations. In the second experiment, stab scalpels, sutures, and needle holders were exposed to A. salmonicida using the same methodology as used in Experiment 1. UV radiation exposure at 5 and 15 min was effective at killing A. salmonicida on stab scalpels and sutures but not needle holders. In the third experiment, S. parasitica, a water mold, was tested using an agar plate method and forceps-pinch method. UV radiation was effective at killing the water mold at all three exposure durations. Collectively, this study shows that UV

  1. LITHIUM ABUNDANCES OF EXTREMELY METAL-POOR TURNOFF STARS

    SciTech Connect (OSTI)

    Aoki, Wako; Inoue, Susumu; Barklem, Paul S.; Beers, Timothy C.; Christlieb, Norbert; Perez, Ana E. GarcIa; Norris, John E.; Carollo, Daniela E-mail: Paul.Barklem@physics.uu.se E-mail: N.Christlieb@lsw.uni-heidelberg.de E-mail: jen@mso.anu.edu.au E-mail: inoue@tap.scphys.kyoto-u.ac.jp

    2009-06-20

    We have determined Li abundances for eleven metal-poor turnoff stars, among which eight have [Fe/H] <-3, based on LTE analyses of high-resolution spectra obtained with the High Dispersion Spectrograph on the Subaru Telescope. The Li abundances for four of these eight stars are determined for the first time by this study. Effective temperatures are determined by a profile analysis of H{alpha} and H{beta}. While seven stars have Li abundances as high as the Spite Plateau value, the remaining four objects with [Fe/H] <-3 have A(Li) =log (Li/H)+ 12 {approx}< 2.0, confirming the existence of extremely metal-poor (EMP) turnoff stars having low Li abundances, as reported by previous work. The average of the Li abundances for stars with [Fe/H]<-3 is lower by 0.2 dex than that of the stars with higher metallicity. No clear constraint on the metallicity dependence or scatter of the Li abundances is derived from our measurements for the stars with [Fe/H]<-3. Correlations of the Li abundance with effective temperatures, with abundances of Na, Mg, and Sr, and with the kinematical properties are investigated, but no clear correlation is seen in the EMP star sample.

  2. Focusing adaptive-optics for neutron spectroscopy at extreme conditions

    SciTech Connect (OSTI)

    Simeoni, G. G.; Valicu, R. G.; Borchert, G.; Böni, P.; Rasmussen, N. G.; Yang, F.; Kordel, T.; Holland-Moritz, D.; Kargl, F.; Meyer, A.

    2015-12-14

    Neutron Spectroscopy employing extreme-conditions sample environments is nowadays a crucial tool for the understanding of fundamental scientific questions as well as for the investigation of materials and chemical-physical properties. For all these kinds of studies, an increased neutron flux over a small sample area is needed. The prototype of a focusing neutron guide component, developed and produced completely at the neutron source FRM II in Garching (Germany), has been installed at the time-of-flight (TOF) disc-chopper neutron spectrometer TOFTOF and came into routine-operation. The design is based on the compressed Archimedes' mirror concept for finite-size divergent sources. It represents a unique device combining the supermirror technology with Adaptive Optics, suitable for broad-bandwidth thermal-cold TOF neutron spectroscopy (here optimized for 1.4–10 Å). It is able to squeeze the beam cross section down to a square centimeter, with a more than doubled signal-to-background ratio, increased efficiency at high scattering angles, and improved symmetry of the elastic resolution function. We present a comparison between the simulated and measured beam cross sections, as well as the performance of the instrument within real experiments. This work intends to show the unprecedented opportunities achievable at already existing instruments, along with useful guidelines for the design and construction of next-generation neutron spectrometers.

  3. Atmospheric Moisture Budget and Spatial Resolution Dependence of Precipitation Extremes in Aquaplanet Simulations

    SciTech Connect (OSTI)

    Yang, Qing; Leung, Lai-Yung R.; Rauscher, Sara; Ringler, Todd; Taylor, Mark

    2014-05-01

    This study investigates the resolution dependency of precipitation extremes in an aqua-planet framework. Strong resolution dependency of precipitation extremes is seen over both tropics and extra-tropics, and the magnitude of this dependency also varies with dynamical cores. Moisture budget analyses based on aqua-planet simulations with the Community Atmosphere Model (CAM) using the Model for Prediction Across Scales (MPAS) and High Order Method Modeling Environment (HOMME) dynamical cores but the same physics parameterizations suggest that during precipitation extremes moisture supply for surface precipitation is mainly derived from advective moisture convergence. The resolution dependency of precipitation extremes mainly originates from advective moisture transport in the vertical direction. At most vertical levels over the tropics and in the lower atmosphere over the subtropics, the vertical eddy transport of mean moisture field dominates the contribution to precipitation extremes and its resolution dependency. Over the subtropics, the source of moisture, its associated energy, and the resolution dependency during extremes are dominated by eddy transport of eddies moisture at the mid- and upper-troposphere. With both MPAS and HOMME dynamical cores, the resolution dependency of the vertical advective moisture convergence is mainly explained by dynamical changes (related to vertical velocity or omega), although the vertical gradients of moisture act like averaging kernels to determine the sensitivity of the overall resolution dependency to the changes in omega at different vertical levels. The natural reduction of variability with coarser resolution, represented by areal data averaging (aggregation) effect, largely explains the resolution dependency in omega. The thermodynamic changes, which likely result from non-linear feedback in response to the large dynamical changes, are small compared to the overall changes in dynamics (omega). However, after excluding the

  4. Method for the detection of nitro-containing compositions using ultraviolet photolysis

    DOE Patents [OSTI]

    Reagen, William K.; Lancaster, Gregory D.; Partin, Judy K.; Moore, Glenn A.

    2000-01-01

    A method for detecting nitro-containing compositions (e.g. nitrate/nitrite materials) in water samples and on solid substrates. In a water sample, ultraviolet light is applied to the sample so that dissolved nitro compositions therein will photolytically dissociate into gaseous nitrogen oxides (NO.sub.2(g) and/or NO.sub.(g)). A carrier gas is then introduced into the sample to generate a gaseous stream which includes the carrier gas combined with any gaseous nitrogen oxides. The carrier gas is thereafter directed into a detector. To detect nitro-compositions on solid substrates, ultraviolet light is applied thereto. A detector is then used to detect any gaseous nitrogen oxides which are photolytically generated during ultraviolet illumination. An optional carrier gas may be applied to the substrate during illumination to produce a gaseous stream which includes the carrier gas and any gaseous nitrogen oxides. The gaseous stream is then supplied to the detector.

  5. A new facility for the synchrotron radiation-based calibration of transfer radiation sources in the ultraviolet and vacuum ultraviolet spectral range

    SciTech Connect (OSTI)

    Thornagel, Reiner; Fliegauf, Rolf; Klein, Roman Kroth, Simone; Paustian, Wolfgang; Richter, Mathias

    2015-01-15

    The Physikalisch-Technische Bundesanstalt (PTB) has a long tradition in the calibration of radiation sources in the ultraviolet and vacuum ultraviolet spectral range, with traceability to calculable synchrotron radiation. Within this context, new instrumentation in the PTB laboratory at the Metrology Light Source (MLS) has been put into operation that opens up extended and improved calibration possibilities. A new facility for radiation source calibrations has been set up in the spectral range from 7 nm to 400 nm based on a combined normal incidence-grazing incidence monochromator. The facility can be used for the calibration of transfer sources in terms of spectral radiant intensity or mean spectral radiance, with traceability to the MLS primary source standard. We describe the design and performance of the experimental station and give examples of some commissioning results.

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

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

    Spectroscopy | Department of Energy 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 Analyzer allows simultaneous and separate measurement of NO and NO2 for on-road and non-raod applications p-11_ensfield.pdf (194.58 KB) More Documents & Publications On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption Laser Spectroscopy Combined with

  7. 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.

    2013-12-15

    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.

  8. Transition state region in the A-Band photodissociation of allyl...

    Office of Scientific and Technical Information (OSTI)

    extreme ultraviolet transient absorption study Citation Details In-Document ... extreme ultraviolet transient absorption study Authors: Bhattacherjee, Aditi 1 ...

  9. Impact of horizontal resolution on simulation of precipitation extremes in an aqua-planet version of the Community Atmosphere Model (CAM)

    SciTech Connect (OSTI)

    Li, F.; Collins, W.D.; Wehner, M.F.; Williamson, D.L.; Olson, J.G.; Algieri, C.

    2011-03-01

    One key question regarding current climate models is whether the projection of climate extremes converges to a realistic representation as the spatial and temporal resolutions of the model are increased. Ideally the model extreme statistics should approach a fixed distribution once the resolutions are commensurate with the characteristic length and time scales of the processes governing the formation of the extreme phenomena of interest. In this study, a series of AGCM runs with idealized 'aquaplanet-steady-state' boundary conditions have been performed with the Community Atmosphere Model CAM3 to investigate the effect of horizontal resolution on climate extreme simulations. The use of the aquaplanet framework highlights the roles of model physics and dynamics and removes any apparent convergence in extreme statistics due to better resolution of surface boundary conditions and other external inputs. Assessed at a same large spatial scale, the results show that the horizontal resolution and time step have strong effects on the simulations of precipitation extremes. The horizontal resolution has a much stronger impact on precipitation extremes than on mean precipitation. Updrafts are strongly correlated with extreme precipitation at tropics at all the resolutions, while positive low-tropospheric temperature anomalies are associated with extreme precipitation at mid-latitudes.

  10. HPSS in the Extreme Scale Era (2018-2022)

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

    Computing (NERSC) Facility in Oakland, CA, on July 14-15, 2009, is a report on the feasibility of using HPSS into the Extreme Scale era of storage (2018 - 2022). Workshop...

  11. SNL-ESSC (Sandia National Laboratories - Extreme Sea State Contour...

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

    Test Centers Scaled Wind Farm Technology Facility ... HomeStationary PowerEnergy Conversion EfficiencyWater ... State Contour) Code admin 2016-02-03T19:54:53+00:00 Extreme ...

  12. New analogies between extreme QCD and cold atoms

    SciTech Connect (OSTI)

    Nishida, Yusuke

    2012-08-15

    We discuss two new analogies between extreme QCD and cold atoms. One is the analogue of 'hard probes' in cold atoms. The other is the analogue of 'quark-hadron continuity' in cold atoms.

  13. Preservation of an extreme transient geotherm in the Raft River...

    Open Energy Info (EERE)

    of an extreme transient geotherm in the Raft River detachment shear zone Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Preservation of an...

  14. DOE Zero Energy Ready Home Case Study: Green Extreme Homes &...

    Broader source: Energy.gov (indexed) [DOE]

    Green Extreme Homes & Carl Franklin Homes, Garland, TX Case study of a DOE Zero Energy Ready affordable home in Garland, TX, that was the first retrofit home certified to the DOE ...

  15. Evolution of Grain Boundary Networks in Extreme Radiation Environments

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

    of the Evolution of Grain Boundary Networks in Extreme Radiation Environments. Evolution of Grain Boundary Networks in Extreme Radiation Environments Research Our objective is to understand the characteristics of an "optimal" grain boundary (GB) network that minimizes microstructural evolution in radiation environments. Through our research we have elucidated that this optimal network requires a balance between two populations of grain boundaries: low free volume (low free energy)

  16. Supercomputers: Extreme Computing at the National Labs | Department of

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

    Energy Supercomputers: Extreme Computing at the National Labs Supercomputers: Extreme Computing at the National Labs September 4, 2013 - 1:08pm Addthis Titan 1 of 5 Titan Oak Ridge National Laboratory's Titan has a theoretical peak performance of more than 20 petaflops, or more than 20 quadrillion calculations per second. This will enable researchers across the scientific arena, from materials to climate change to astrophysics, to acquire unparalleled accuracy in their simulations and

  17. Inventors in Action: Extreme Subsea Machines | GE Global Research

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

    Inventors in Action: Extreme Subsea Machines Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) Inventors in Action: Extreme Subsea Machines GE Researchers Oliver Astley, Power Conversion and Delivery Technology Leader, Konrad Weeber, Chief Engineer, Electrical Technologies and Systems, and Sergio Sabedotti, Offshore and

  18. Cardiovascular Flow Simulations at Extreme Scale | Argonne Leadership

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

    Computing Facility Cardiovascular Flow Simulations at Extreme Scale Authors: Zhou, M., Sahni, O., Kim, H.J., Figueroa, C.A., Taylor, C.A., Shephard, M.S., Jansen, K.E. As cardiovascular models grow more sophisticated in terms of the geometry considered, and more physiologically realistic boundary conditions are applied, and fluid flow is coupled to structural models, the computational complexity grows. Massively parallel adaptivity and flow solvers with extreme scalability enable

  19. Scientists use world's fastest computer to model materials under extreme

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

    conditions Materials under extreme conditions Scientists use world's fastest computer to model materials under extreme conditions Materials scientists are for the first time attempting to create atomic-scale models that describe how voids are created, grow, and merge. October 30, 2009 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable

  20. Energy Storage and Generation for Extreme Temperature and Pressure and

    Office of Scientific and Technical Information (OSTI)

    Directional Measurement While Drilling Applications (Technical Report) | SciTech Connect Technical Report: Energy Storage and Generation for Extreme Temperature and Pressure and Directional Measurement While Drilling Applications Citation Details In-Document Search Title: Energy Storage and Generation for Extreme Temperature and Pressure and Directional Measurement While Drilling Applications FastCAP Systems Corporation has successfully completed all milestones defined by the award

  1. Persisting cold extremes under 21st-century warming scenarios

    SciTech Connect (OSTI)

    Kodra, Evan A; Steinhaeuser, Karsten J K; Ganguly, Auroop R

    2011-01-01

    Analyses of climate model simulations and observations reveal that extreme cold events are likely to persist across each land-continent even under 21st-century warming scenarios. The grid-based intensity, duration and frequency of cold extreme events are calculated annually through three indices: the coldest annual consecutive three-day average of daily maximum temperature, the annual maximum of consecutive frost days, and the total number of frost days. Nine global climate models forced with a moderate greenhouse-gas emissions scenario compares the indices over 2091 2100 versus 1991 2000. The credibility of model-simulated cold extremes is evaluated through both bias scores relative to reanalysis data in the past and multi-model agreement in the future. The number of times the value of each annual index in 2091 2100 exceeds the decadal average of the corresponding index in 1991 2000 is counted. The results indicate that intensity and duration of grid-based cold extremes, when viewed as a global total, will often be as severe as current typical conditions in many regions, but the corresponding frequency does not show this persistence. While the models agree on the projected persistence of cold extremes in terms of global counts, regionally, inter-model variability and disparity in model performance tends to dominate. Our findings suggest that, despite a general warming trend, regional preparedness for extreme cold events cannot be compromised even towards the end of the century.

  2. Lubricating bacteria model for the growth of bacterial colonies exposed to ultraviolet radiation

    SciTech Connect (OSTI)

    Zhang Shengli; Zhang Lei; Liang Run; Zhang Erhu; Liu Yachao; Zhao Shumin

    2005-11-01

    In this paper, we study the morphological transition of bacterial colonies exposed to ultraviolet radiation by modifying the bacteria model proposed by Delprato et al. Our model considers four factors: the lubricant fluid generated by bacterial colonies, a chemotaxis initiated by the ultraviolet radiation, the intensity of the ultraviolet radiation, and the bacteria's two-stage destruction rate with given radiation intensities. Using this modified model, we simulate the ringlike pattern formation of the bacterial colony exposed to uniform ultraviolet radiation. The following is shown. (1) Without the UV radiation the colony forms a disklike pattern and reaches a constant front velocity. (2) After the radiation is switched on, the bacterial population migrates to the edge of the colony and forms a ringlike pattern. As the intensity of the UV radiation is increased the ring forms faster and the outer velocity of the colony decreases. (3) For higher radiation intensities the total population decreases, while for lower intensities the total population increases initially at a small rate and then decreases. (4) After the UV radiation is switched off, the bacterial population grows both outward as well as into the inner region, and the colony's outer front velocity recovers to a constant value. All these results agree well with the experimental observations [Phys. Rev. Lett. 87, 158102 (2001)]. Along with the chemotaxis, we find that lubricant fluid and the two-stage destruction rate are critical to the dynamics of the growth of the bacterial colony when exposed to UV radiation, and these were not previously considered.

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

    DOE Patents [OSTI]

    Vogl, Otto; Li, Shanjun

    1988-05-17

    Ultraviolet light absorbing compounds having two different chromophors in the same molecule, particularly the benzotriazole chromophor and either the dihydroxybenzophenone or dihydroxyacetophenone chromophor; specifically, the two compounds 3,5-[di(2H-benzotriazole-2-yl)]-2,4-dihydroxyacetophenone and 3,5-[di(2H-benzotriazole-2-yl)]2,4-dihydroxybenzophenone.

  4. Nuclei at extreme conditions. A relativistic study

    SciTech Connect (OSTI)

    Afanasjev, Anatoli

    2014-11-14

    The major goals of the current project were further development of covariant density functional theory (CDFT), better understanding of its features, its application to different nuclear structure and nuclear astrophysics phenomena and training of graduate and undergraduate students. The investigations have proceeded in a number of directions which are discussed in detail in the part “Accomplishments” of this report. We have studied the role of isovector and isoscalar proton-neutron pairings in rotating nuclei; based on available experimental data it was concluded that there are no evidences for the existence of isoscalar proton-neutron pairing. Generalized theoretical approach has been developed for pycnonuclear reaction rates in the crust of neutron stars and interior of white dwarfs. Using this approach, extensive database for considerable number of pycnonuclear reactions involving stable and neutron-rich light nuclei has been created; it can be used in future for the study of various nuclear burning phenomena in different environments. Time-odd mean fields and their manifestations in terminating states, non-rotating and rotating nuclei have been studied in the framework of covariant density functional theory. Contrary to non-relativistic density functional theories these fields, which are important for a proper description of nuclear systems with broken time-reversal symmetry, are uniquely defined in the CDFT framework. Hyperdeformed nuclear shapes (with semi-axis ratio 2.5:1 and larger) have been studied in the Z = 40-58 part of nuclear chart. We strongly believe that such shapes could be studied experimentally in the future with full scale GRETA detector.

  5. Organizing the Extremely Large LSST Database forReal-Time Astronomical...

    Office of Scientific and Technical Information (OSTI)

    Organizing the Extremely Large LSST Database forReal-Time Astronomical Processing Citation Details In-Document Search Title: Organizing the Extremely Large LSST Database ...

  6. Intensification of hot extremes in the United States

    SciTech Connect (OSTI)

    Diffenbaugh, Noah [Stanford University; Ashfaq, Moetasim [ORNL

    2010-01-01

    Governments are currently considering policies that will limit greenhouse gas concentrations, including negotiation of an international treaty to replace the expiring Kyoto Protocol. Existing mitigation targets have arisen primarily from political negotiations, and the ability of such policies to avoid dangerous impacts is still uncertain. Using a large suite of climate model experiments, we find that substantial intensification of hot extremes could occur within the next 3 decades, below the 2 C global warming target currently being considered by policy makers. We also find that the intensification of hot extremes is associated with a shift towards more anticyclonic atmospheric circulation during the warm season, along with warm-season drying over much of the U.S. The possibility that intensification of hot extremes could result from relatively small increases in greenhouse gas concentrations suggests that constraining global warming to 2 C may not be sufficient to avoid dangerous climate change.

  7. TECA: A Parallel Toolkit for Extreme Climate Analysis

    SciTech Connect (OSTI)

    Prabhat, Mr; Ruebel, Oliver; Byna, Surendra; Wu, Kesheng; Li, Fuyu; Wehner, Michael; Bethel, E. Wes

    2012-03-12

    We present TECA, a parallel toolkit for detecting extreme events in large climate datasets. Modern climate datasets expose parallelism across a number of dimensions: spatial locations, timesteps and ensemble members. We design TECA to exploit these modes of parallelism and demonstrate a prototype implementation for detecting and tracking three classes of extreme events: tropical cyclones, extra-tropical cyclones and atmospheric rivers. We process a modern TB-sized CAM5 simulation dataset with TECA, and demonstrate good runtime performance for the three case studies.

  8. Climate, extreme heat, and electricity demand in California

    SciTech Connect (OSTI)

    Miller, N.L.; Hayhoe, K.; Jin, J.; Auffhammer, M.

    2008-04-01

    Climate projections from three atmosphere-ocean climate models with a range of low to mid-high temperature sensitivity forced by the Intergovernmental Panel for Climate Change SRES higher, middle, and lower emission scenarios indicate that, over the 21st century, extreme heat events for major cities in heavily air-conditioned California will increase rapidly. These increases in temperature extremes are projected to exceed the rate of increase in mean temperature, along with increased variance. Extreme heat is defined here as the 90 percent exceedance probability (T90) of the local warmest summer days under the current climate. The number of extreme heat days in Los Angeles, where T90 is currently 95 F (32 C), may increase from 12 days to as many as 96 days per year by 2100, implying current-day heat wave conditions may last for the entire summer, with earlier onset. Overall, projected increases in extreme heat under the higher A1fi emission scenario by 2070-2099 tend to be 20-30 percent higher than those projected under the lower B1 emission scenario, ranging from approximately double the historical number of days for inland California cities (e.g. Sacramento and Fresno), up to four times for previously temperate coastal cities (e.g. Los Angeles, San Diego). These findings, combined with observed relationships between high temperature and electricity demand for air-conditioned regions, suggest potential shortfalls in transmission and supply during T90 peak electricity demand periods. When the projected extreme heat and peak demand for electricity are mapped onto current availability, maintaining technology and population constant only for demand side calculations, we find the potential for electricity deficits as high as 17 percent. Similar increases in extreme heat days are suggested for other locations across the U.S. southwest, as well as for developing nations with rapidly increasing electricity demands. Electricity response to recent extreme heat events, such

  9. Argonne National Laboratory Develops Extreme-Scale Wind Farm Simulation

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

    Capabilities | Department of Energy Develops Extreme-Scale Wind Farm Simulation Capabilities Argonne National Laboratory Develops Extreme-Scale Wind Farm Simulation Capabilities October 1, 2013 - 3:42pm Addthis A wake of a wind turbine modeled by the actuator line model in Nek5000 A wake of a wind turbine modeled by the actuator line model in Nek5000 This is an excerpt from the Third Quarter 2013 edition of the Wind Program R&D Newsletter. Researchers at the U.S. Department of Energy's

  10. Extreme high-head portables provide more pumping options

    SciTech Connect (OSTI)

    Fiscor, S.

    2006-10-15

    Three years ago, Godwin Pumps, one of the largest manufacturers of portable pumps, introduced its Extreme Duty High Lift (HL) series of pumps and more mines are finding unique applications for these pumps. The Extreme HL series is a range single-stage Dri-Prime pumps with heads up to 600 feet and flows up to 5,000 gallons per minute. The American Coal Co.'s Galatia mine, an underground longwall mine in southern Illinois, used an HL 160 to replace a multiple-staged centrifugal pump. It provided Galatia with 1,500 gpm at 465 ft. 3 photos.

  11. COLLOQUIUM: Extreme Global Warming: Examples from the Past | Princeton

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

    Plasma Physics Lab April 16, 2014, 4:00pm to 5:30pm MBG Auditorium COLLOQUIUM: Extreme Global Warming: Examples from the Past Professor Mark Pagani Yale University Earth's climate 50 million years ago was the warmest time of the Cenozoic and characterized by expansive high-latitude warmth and low meridional temperature gradients. Starting at about 55 million years ago, a series of rapid and extreme carbon-induced global warming events, known as hyperthermals, are evident. This presentation

  12. Ultraviolet and white photon avalanche upconversion in Ho{sup 3+}-doped nanophase glass ceramics

    SciTech Connect (OSTI)

    Lahoz, F.; Martin, I.R.; Calvilla-Quintero, J.M.

    2005-01-31

    Ho{sup 3+}-doped fluoride nanophase glass ceramics have been synthesized from silica-based oxyfluoride glass. An intense white emission light is observed by the naked eye under near infrared excitation at 750 nm. This visible upconversion is due to three strong emission bands in the primary color components, red, green, and blue. Besides, ultraviolet signals are also recorded upon the same excitation wavelength. The excitation mechanism of both the ultraviolet and the visible emissions is a photon avalanche process with a relatively low pump power threshold at about 20 mW. The total upconverted emission intensity has been estimated to increase by about a factor of 20 in the glass ceramic compared to the precursor glass, in which an avalanche type mechanism is not generated.

  13. Improved energy efficiency by use of the new ultraviolet light radiation paint curing process

    SciTech Connect (OSTI)

    Grosset, A.M.; Su, W.-F.A.

    1984-08-01

    In product finishing lines, ultraviolet radiation curing of paints on prefabricated structures is more energy efficient than curing by natural gas fired ovens, and could eliminate solvent emission. The replacement of a conventional natural gas fired oven by an ultraviolet radiation curing line for paint curing could save quadrillions of joules per year for each finishing line. In this program sponsored by the U.S. Department of Energy, Office of Industrial Programs, two photoinduced polymerizations, via free radical or cationic mechanisms, were considered in the formulation of UV curable paints. The spectral output of radiation sources was chosen so as to complement the absorption spectra of pigments and photoactive agents; thus highly pigmented thick films could be cured fully by UV radiation. One coat enamels, topcoats, and primers have been developed which can be applied on three dimensional objects by spraying and can be cured by passing through a tunnel containing UV lamps.

  14. Ultraviolet high-spectral-resolution Doppler lidar for measuring wind field and aerosol optical properties

    SciTech Connect (OSTI)

    Imaki, Masaharu; Kobayashi, Takao

    2005-10-01

    An ultraviolet incoherent Doppler lidar that incorporates the high-spectral-resolution (HSR) technique has been developed for measuring the wind field and aerosol optical properties in the troposphere. An injection seeded and tripled Nd:YAG laser at an ultraviolet wavelength of 355 nm was used in the lidar system. The HRS technique can resolve the aerosol Mie backscatter and the molecular Rayleigh backscatter to derive the signal components. By detecting the Mie backscatter, a great increase in the Doppler filter sensitivity was realized compared to the conventional incoherent Doppler lidars that detected the Rayleigh backscatter. The wind velocity distribution in a two-dimensional cross section was measured. By using the HSR technique, multifunction and absolute value measurements were realized for aerosol extinction, and volume backscatter coefficients; the laser beam transmittance, the lidar ratio, and the backscatter ratio are derived from these measurements.

  15. The Reactivity of Energetic Materials At Extreme Conditions

    SciTech Connect (OSTI)

    Fried, L E

    2006-10-23

    shock conditions, for example, energetic materials undergo rapid heating to a few thousand degrees and are subjected to a compression of hundreds of kilobars, resulting in almost 30% volume reduction. Complex chemical reactions are thus initiated, in turn releasing large amounts of energy to sustain the detonation process. Clearly, understanding of the various chemical events at these extreme conditions is essential in order to build predictive material models. Scientific investigations into the reactive process have been undertaken over the past two decades. However, the sub-{micro}s time scale of explosive reactions, in addition to the highly exothermic conditions of an explosion, make experimental investigation of the decomposition pathways difficult at best. More recently, new computational approaches to investigate condensed-phase reactivity in energetic materials have been developed. Here we focus on two different approaches to condensed-phase reaction modeling: chemical equilibrium methods and atomistic modeling of condensed-phase reactions. These are complementary approaches to understanding the chemical reactions of high explosives. Chemical equilibrium modeling uses a highly simplified thermodynamic picture of the reaction process, leading to a convenient and predictive model of detonation and other decomposition processes. Chemical equilibrium codes are often used in the design of new materials, both at the level of synthesis chemistry and formulation. Atomistic modeling is a rapidly emerging area. The doubling of computational power approximately every 18 months has made atomistic condensed-phase modeling more feasible. Atomistic calculations employ far fewer empirical parameters than chemical equilibrium calculations. Nevertheless, the atomistic modeling of chemical reactions requires an accurate global Born-Oppenheimer potential energy surface. Traditionally, such a surface is constructed by representing the potential energy surface with an analytical fit

  16. Interaction of extremely-low-frequency electromagnetic fields with living systems

    SciTech Connect (OSTI)

    Tenforde, T.S.

    1991-11-01

    The sources and physical properties of extremely-low-frequency (ELF) electromagnetic fields are described in this paper. Biological effects and mechanisms through which ELF fields interact with humans and other organisms are discussed, including several aspects of this subject that are presently under active laboratory investigation. Studies on the potential health effects of ELF fields present in the home and workplace are also summarized, including a critical evaluation of evidence for a possible linkage between exposure to ELF fields and cancer risk. 53 refs.

  17. Enhanced multicolor fluorescence in bioimaging using deep-ultraviolet surface plasmon resonance

    SciTech Connect (OSTI)

    Kikawada, Masakazu; Ono, Atsushi; Inami, Wataru; Kawata, Yoshimasa

    2014-06-02

    Enhanced multicolor fluorescence has been achieved using deep-ultraviolet surface plasmon resonance (DUV-SPR) on an aluminum thin film using the Kretschmann configuration. The film thickness and the incident angle of the light were optimized by calculations using the Fresnel equations. The presence of a surface oxide layer was also considered in the calculations. Experimental measurements showed that DUV-SPR led to a strong enhancement of the fluorescence intensity from both quantum dots and dye-labeled cells.

  18. Ultraviolet and electron irradiation of DC-704 siloxane oil in zinc orthotitanate paint

    SciTech Connect (OSTI)

    Mossman, D.L.; Barsh, M.K.; Greenberg, S.A.

    1982-01-01

    Discrepancies exist between accelerated laboratory simulation and geosynchronous orbit flight data for zinc orthotitanate (ZOT) paint degradation. The effects of ultraviolet and electron irradiation on ZOT contaminated with DC-704 silicone oil are reported. In-situ solar absorptance and emittance changes for contaminated and clean specimens are discussed with reference to post-test surface morphology, determined by scanning electron microscope analysis. Features of the contaminated ZOT degradation kinetics correlate with orbital performance.

  19. Characterizing ultraviolet and infrared observational properties for galaxies. II. Features of attenuation law

    SciTech Connect (OSTI)

    Mao, Ye-Wei; Kong, Xu; Lin, Lin E-mail: xkong@ustc.edu.cn

    2014-07-01

    Variations in the attenuation law have a significant impact on observed spectral energy distributions for galaxies. As one important observational property for galaxies at ultraviolet and infrared wavelength bands, the correlation between infrared-to-ultraviolet luminosity ratio and ultraviolet color index (or ultraviolet spectral slope), i.e., the IRX-UV relation (or IRX-β relation), offered a widely used formula for correcting dust attenuation in galaxies, but the usability appears to be in doubt now because of considerable dispersion in this relation found by many studies. In this paper, on the basis of spectral synthesis modeling and spatially resolved measurements of four nearby spiral galaxies, we provide an interpretation of the deviation in the IRX-UV relation with variations in the attenuation law. From both theoretical and observational viewpoints, two components in the attenuation curve, the linear background and the 2175 Å bump, are suggested to be the parameters in addition to the stellar population age (addressed in the first paper of this series) in the IRX-UV function; different features in the attenuation curve are diagnosed for the galaxies in our sample. Nevertheless, it is often difficult to ascertain the attenuation law for galaxies in actual observations. Possible reasons for preventing the successful detection of the parameters in the attenuation curve are also discussed in this paper, including the degeneracy of the linear background and the 2175 Å bump in observational channels, the requirement for young and dust-rich systems to study, and the difficulty in accurate estimates of dust attenuations at different wavelength bands.

  20. The Ultraviolet Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas

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

    Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; et al

    2015-12-04

    High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength ultraviolet driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams inmore » the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.« less

  1. The Ultraviolet Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas

    SciTech Connect (OSTI)

    Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; Tarazkar, Maryam; Romanov, Dmitri A.; Levis, Robert J.; Gaffney, Jim A.; Foord, Mark; Libby, Stephen B.; Jaron-Becker, Agnieskzka; Becker, Andreas; Plaja, Luis; Muranane, Margaret M.; Kapteyn, Henry C.; Popmintchev, Tenio

    2015-12-04

    High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength ultraviolet driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams in the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.

  2. An extremal $${\\mathcal{N}}=2$$ superconformal field theory

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

    Benjamin, Nathan; Dyer, Ethan; Fitzpatrick, A. Liam; Kachru, Shamit

    2015-11-16

    Here, we provide an example of an extremal chiralmore » $${\\mathcal{N}}$$ = 2 superconformal field theory at c = 24. The construction is based on a $${{\\mathbb{Z}}}_{2}$$ orbifold of the theory associated to the $${A}_{1}^{24}$$ Niemeier lattice. The statespace is governed by representations of the sporadic group M 23.« less

  3. Quantum Chromodynamics and Nuclear Physics at Extreme Energy Density

    SciTech Connect (OSTI)

    Mueller, B.; Bass, S.A.; Chandrasekharan, S.; Mehen, T.; Springer, R.P.

    2005-11-07

    The report describes research in theoretical quantum chromodynamics, including effective field theories of hadronic interactions, properties of strongly interacting matter at extreme energy density, phenomenology of relativistic heavy ion collisions, and algorithms and numerical simulations of lattice gauge theory and other many-body systems.

  4. ITEP Webinar: Extreme Weather Events and Climate Change

    Broader source: Energy.gov [DOE]

    Attend this Institute for Tribal Environmental Professionals (ITEP) webinar and hear about the known variability in extreme weather such as excessive heat, cold waves, floods, droughts, hurricanes, severe thunderstorms and tornadoes. Projections and uncertainties of how these hazards might change due to global warming will be reviewed.

  5. Causal Analysis of the Unanticipated Extremity Exposure at HFEF

    SciTech Connect (OSTI)

    David E. James; Charles R. Posegate; Thomas P. Zahn; Alan G. Wagner

    2011-11-01

    This report covers the unintended extremity exposure to an operator while handling a metallurgical mount sample of irradiated fuel following an off-scale high beta radiation reading of the sample. The decision was made to continue working after the meter indicated high off-scale by the HPT Supervisor, which resulted in the operator at the next operation being exposed.

  6. The efficacy of post porosity plasma protection against vacuum-ultraviolet damage in porous low-k materials

    SciTech Connect (OSTI)

    Lionti, K.; Volksen, W.; Darnon, M.; Magbitang, T.; Dubois, G.

    2015-03-21

    As of today, plasma damage remains as one of the main challenges to the reliable integration of porous low-k materials into microelectronic devices at the most aggressive node. One promising strategy to limit damage of porous low-k materials during plasma processing is an approach we refer to as post porosity plasma protection (P4). In this approach, the pores of the low-k material are filled with a sacrificial agent prior to any plasma treatment, greatly minimizing the total damage by limiting the physical interactions between plasma species and the low-k material. Interestingly, the contribution of the individual plasma species to the total plasma damage is not fully understood. In this study, we investigated the specific damaging effect of vacuum-ultraviolet (v-UV) photons on a highly porous, k = 2.0 low-k material and we assessed the P4 protective effect against them. It was found that the impact of the v-UV radiation varied depending upon the v-UV emission lines of the plasma. More importantly, we successfully demonstrated that the P4 process provides excellent protection against v-UV damage.

  7. Tuning the plasmon band number of aluminum nanorod within the ultraviolet-visible region by gold coating

    SciTech Connect (OSTI)

    Zhu, Jian E-mail: nanoptzhao@163.com; Li, Jian-Jun; Zhao, Jun-Wu E-mail: nanoptzhao@163.com

    2014-11-15

    The localized surface plasmon (LSP) properties of Al nanorod with Au coating have been investigated by using the quasi-static calculation. Because of the anisotropic plasmon splitting and the plasmon coupling between the Al and Au surfaces, the band number of LSP in the Al-Au core-shell nanorod could be tuned from 2 to 4 continuously in the ultraviolet-visible region. Due to the non-spherical symmetry and the dielectric polarization-induced plasmon energy fading, the Au coating-dependent plasmon shift and split are further affected by the aspect ratio and the dielectric surrounding. When the aspect ratio or the surrounding dielectric constant has a small value, the band number of LSP could only be tuned from 2 to 3. However, the band number of LSP could only be tuned from 3 to 4 when the aspect ratio or the surrounding dielectric constant has a large value. This tunable band number of LSP in the Au-coated Al nanorod provides potential application for multichannel plasmonic nanosensors.

  8. ASU EFRC - Principal investigators

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

    Principal investigators Ana Moore Principal Investigator Subtask 4 Leader Anne Jones Principal Investigator Devens Gust Director of the Center Principal Investigator Don Seo...

  9. Conceptual Design Report for the Extreme Ecosystems Test Chambers

    SciTech Connect (OSTI)

    C. Barnes; J. Beller; K. Caldwell; K. Croft; R. Cherry; W. Landman

    1998-12-01

    This conceptual design supports the creation of Extreme Ecosystems Test Chambers, which will replicate deep subsurface and subocean environments characterized by high pressure (2,000 psi) and subfreezing to high temperature (-4 to 300 degrees F) with differing chemical and saturation conditions. The design provides a system to support research and development that includes heat transfer, phase change issues in porous media, microbiology in extreme environments, and carbon sequestration and extraction. The initial system design is based on the research needs to support the commercial production of methane hydrates from subsurface sediments. The design provides for three pressure vessels: a Down Hole Test Vessel, a Vertical Multi-phase Test Vessel, and a Horizontal Multi-phase Test Vessel.

  10. Science at the Theatre - Extreme Science - Promo Video

    ScienceCinema (OSTI)

    Klein, Spencer

    2013-05-29

    On Feb. 27 at 7 pm at the Berkeley Repertory Theatre, join four Berkeley Lab scientists as they discuss extreme science -- and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel. Go here for more information and to view videos of previous Science at the Theater events: http://www.lbl.gov/LBL-PID/fobl/

  11. Science at the Theatre - Extreme Science - Promo Video

    SciTech Connect (OSTI)

    Klein, Spencer

    2012-01-01

    On Feb. 27 at 7 pm at the Berkeley Repertory Theatre, join four Berkeley Lab scientists as they discuss extreme science -- and what it means to you. Topics include: Neutrino hunting in Antarctica. Learn why Spencer Klein goes to the ends of the Earth to search for these ghostly particles. From Chernobyl to Central Asia, Tamas Torok travels the globe to study microbial diversity in extreme environments. Andrew Minor uses the world's most advanced electron microscopes to explore materials at ultrahigh stresses and in harsh environments. And microbes that talk to computers? Caroline Ajo-Franklin is pioneering cellular-electrical connections that could help transform sunlight into fuel. Go here for more information and to view videos of previous Science at the Theater events: http://www.lbl.gov/LBL-PID/fobl/

  12. QUENCHING DEPENDS ON MORPHOLOGIES: IMPLICATIONS FROM THE ULTRAVIOLET-OPTICAL RADIAL COLOR DISTRIBUTIONS IN GREEN VALLEY GALAXIES

    SciTech Connect (OSTI)

    Pan, Zhizheng; Lin, Weipeng; Li, Jinrong; Kong, Xu; Wang, Jing E-mail: linwp@shao.ac.cn

    2014-09-01

    In this Letter, we analyze the radial ultraviolet-optical color distributions in a sample of low redshift green valley galaxies, with the Galaxy Evolution Explorer (GALEX)+Sloan Digital Sky Survey (SDSS) images, to investigate how the residual recent star formation is distributed in these galaxies. We find that the dust-corrected u r colors of early-type galaxies (ETGs) are flat out to R {sub 90}, while the colors monotonously turn blue when r > 0.5 R {sub 50} for late-type galaxies (LTGs). More than half of the ETGs are blue-cored and have remarkable positive NUV r color gradients, suggesting that their star formations are centrally concentrated. The rest have flat color distributions out to R {sub 90}. The centrally concentrated star formation activity in a large portion of ETGs is confirmed by the SDSS spectroscopy, showing that ?50% of the ETGs have EW(H?)>6.0 . Of the LTGs, 95% show uniform radial color profiles, which can be interpreted as a red bulge plus an extended blue disk. The links between the two kinds of ETGs, e.g., those objects having remarkable ''blue-cores'' and those having flat color gradients, are less known and require future investigations. It is suggested that the LTGs follow a general model by which quenching first occurs in the core regions, and then finally extend to the rest of the galaxy. Our results can be re-examined and have important implications for the IFU surveys, such as MaNGA and SAMI.

  13. Historical trends and extremes in boreal Alaska river basins

    SciTech Connect (OSTI)

    Bennett, Katrina E.; Cannon, Alex J.; Hinzman, Larry

    2015-05-12

    Climate change will shift the frequency, intensity, duration and persistence of extreme hydroclimate events and have particularly disastrous consequences in vulnerable systems such as the warm permafrost-dominated Interior region of boreal Alaska. This work focuses on recent research results from nonparametric trends and nonstationary generalized extreme value (GEV) analyses at eight Interior Alaskan river basins for the past 50/60 years (1954/642013). Trends analysis of maximum and minimum streamflow indicates a strong (>+50%) and statistically significant increase in 11-day flow events during the late fall/winter and during the snowmelt period (late April/mid-May), followed by a significant decrease in the 11-day flow events during the post-snowmelt period (late May and into the summer). The AprilMayJune seasonal trends show significant decreases in maximum streamflow for snowmelt dominated systems (<50%) and glacially influenced basins (24% to 33%). Annual maximum streamflow trends indicate that most systems are experiencing declines, while minimum flow trends are largely increasing. Nonstationary GEV analysis identifies time-dependent changes in the distribution of spring extremes for snowmelt dominated and glacially dominated systems. Temperature in spring influences the glacial and high elevation snowmelt systems and winter precipitation drives changes in the snowmelt dominated basins. The Pacific Decadal Oscillation was associated with changes occurring in snowmelt dominated systems, and the Arctic Oscillation was linked to one lake dominated basin, with half of the basins exhibiting no change in response to climate variability. The paper indicates that broad scale studies examining trend and direction of change should employ multiple methods across various scales and consider regime dependent shifts to identify and understand changes in extreme streamflow within boreal forested watersheds of Alaska.

  14. Extreme Scale Unstructured Adaptive CFD: From Multiphase Flow to

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

    Aerodynamic Flow Control | Argonne Leadership Computing Facility Isosurface of instantaneous Q criterion colored by speed over a vertical tail Isosurface of instantaneous Q criterion colored by speed over a vertical tail at Re=3.5\ 10^5 of a DES simulation with a rudder deflection angle of 30 degrees and 12 unsteady jets active. Kenneth Jansen, University of Colorado at Boulder Extreme Scale Unstructured Adaptive CFD: From Multiphase Flow to Aerodynamic Flow Control PI Name: Kenneth Jansen

  15. Historical trends and extremes in boreal Alaska river basins

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

    Bennett, Katrina E.; Cannon, Alex J.; Hinzman, Larry

    2015-05-12

    Climate change will shift the frequency, intensity, duration and persistence of extreme hydroclimate events and have particularly disastrous consequences in vulnerable systems such as the warm permafrost-dominated Interior region of boreal Alaska. This work focuses on recent research results from nonparametric trends and nonstationary generalized extreme value (GEV) analyses at eight Interior Alaskan river basins for the past 50/60 years (1954/64–2013). Trends analysis of maximum and minimum streamflow indicates a strong (>+50%) and statistically significant increase in 11-day flow events during the late fall/winter and during the snowmelt period (late April/mid-May), followed by a significant decrease in the 11-day flowmore » events during the post-snowmelt period (late May and into the summer). The April–May–June seasonal trends show significant decreases in maximum streamflow for snowmelt dominated systems (<–50%) and glacially influenced basins (–24% to –33%). Annual maximum streamflow trends indicate that most systems are experiencing declines, while minimum flow trends are largely increasing. Nonstationary GEV analysis identifies time-dependent changes in the distribution of spring extremes for snowmelt dominated and glacially dominated systems. Temperature in spring influences the glacial and high elevation snowmelt systems and winter precipitation drives changes in the snowmelt dominated basins. The Pacific Decadal Oscillation was associated with changes occurring in snowmelt dominated systems, and the Arctic Oscillation was linked to one lake dominated basin, with half of the basins exhibiting no change in response to climate variability. The paper indicates that broad scale studies examining trend and direction of change should employ multiple methods across various scales and consider regime dependent shifts to identify and understand changes in extreme streamflow within boreal forested watersheds of Alaska.« less

  16. VALIDATION OF HANFORD PERSONNEL AND EXTREMITY DOSIMETERS IN PLUTONIUM ENVIRONMENTS

    SciTech Connect (OSTI)

    Scherpelz, Robert I.; Fix, John J.; Rathbone, Bruce A.

    2000-02-10

    A study was performed in the Plutonium Finishing Plant to assess the performance of Hanford personnel neutron dosimetry. The study was assessed whole body dosimetry and extremity dosimetry performance. For both parts of the study, the TEPC was used as the principle instrument for characterizing workplace neutron fields. In the whole body study, 12.7-cm-diameter TEPCs were used in ten different locations in the facility. TLD and TED personnel dosimeters were exposed on a water-filled phantom to enable a comparison of TEPC and dosimeter response. In the extremity study, 1.27-cm-diameter TEPCs were exposed inside the fingers of a gloveboxe glove. Extremity dosimeters were wrapped around the TEPCs. The glove was then exposed to six different cans of plutonium, simulating the exposure that a worker's fingers would receive in a glovebox. The comparison of TEPC-measured neutron dose equivalent to TLD-measured gamma dose equivalent provided neutron-to-gamma ratios that can be used to estimate the neutron dose equivalent received by a worker's finger based on the gamma readings of an extremity dosimeter. The study also utilized a Snoopy and detectors based on bubble technology for assessing neutron exposures, providing a comparison of the effectiveness of these instruments for workplace monitoring. The study concludes that the TLD component of the HCND performs adequately overall, with a positive bias of 30%, but exhibits excessive variability in individual results due to instabilities in the algorithm. The TED response was less variable but only 20% of the TEPC reference dose on average because of the low neutron energies involved. The neutron response of the HSD was more variable than the TLD component of the HCND and biased high by a factor of 8 overall due to its calibration to unmoderated 252Cf. The study recommends further work to correct instabilities in the HCND algorithm and to explore the potential shown by the bubble-based dosimeters.

  17. Historical trends and extremes in boreal Alaska river basins

    SciTech Connect (OSTI)

    Bennett, Katrina E.; Cannon, Alex J.; Hinzman, Larry

    2015-05-12

    Climate change will shift the frequency, intensity, duration and persistence of extreme hydroclimate events and have particularly disastrous consequences in vulnerable systems such as the warm permafrost-dominated Interior region of boreal Alaska. This work focuses on recent research results from nonparametric trends and nonstationary generalized extreme value (GEV) analyses at eight Interior Alaskan river basins for the past 50/60 years (1954/64–2013). Trends analysis of maximum and minimum streamflow indicates a strong (>+50%) and statistically significant increase in 11-day flow events during the late fall/winter and during the snowmelt period (late April/mid-May), followed by a significant decrease in the 11-day flow events during the post-snowmelt period (late May and into the summer). The April–May–June seasonal trends show significant decreases in maximum streamflow for snowmelt dominated systems (<–50%) and glacially influenced basins (–24% to –33%). Annual maximum streamflow trends indicate that most systems are experiencing declines, while minimum flow trends are largely increasing. Nonstationary GEV analysis identifies time-dependent changes in the distribution of spring extremes for snowmelt dominated and glacially dominated systems. Temperature in spring influences the glacial and high elevation snowmelt systems and winter precipitation drives changes in the snowmelt dominated basins. The Pacific Decadal Oscillation was associated with changes occurring in snowmelt dominated systems, and the Arctic Oscillation was linked to one lake dominated basin, with half of the basins exhibiting no change in response to climate variability. The paper indicates that broad scale studies examining trend and direction of change should employ multiple methods across various scales and consider regime dependent shifts to identify and understand changes in extreme streamflow within boreal forested watersheds of Alaska.

  18. Kinetic Simulations of Fusion Energy Dynamics at the Extreme Scale |

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

    Argonne Leadership Computing Facility Kinetic Simulations of Fusion Energy Dynamics at the Extreme Scale PI Name: William Tang PI Email: tang@pppl.gov Institution: Princeton Plasma Physics Laboratory Allocation Program: INCITE Allocation Hours at ALCF: 40 Million Year: 2013 Research Domain: Physics To build the scientific foundations needed to develop fusion power as a clean and sustainable energy source, the timely development of a high-physics-fidelity predictive simulation capability for

  19. Extreme Scale Quantum Chemistry with Sparse Eigensolvers and

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

    Parameterization | Argonne Leadership Computing Facility Extreme Scale Quantum Chemistry with Sparse Eigensolvers and Parameterization Event Sponsor: Argonne Leadership Computing Facility Seminar Start Date: Sep 15 2016 - 11:00am Building/Room: Building 240/Room 4301 Location: Argonne National Laboratory Speaker(s): Murat Keçeli Speaker(s) Title: Argonne National Laboratory, CSE Host: Alvaro Vazquez Mayagoitia Hartree-Fock (HF), density functional theory (DFT) and their parameterized

  20. Preliminary Wave Energy Converters Extreme Load Analysis: Preprint

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

    Preliminary Wave Energy Converters Extreme Load Analysis Preprint Y-H. Yu, J. Van Rij, and M. Lawson National Renewable Energy Laboratory R. Coe Sandia National Laboratories To be presented at the 34 th International Conference on Ocean, Offshore and Arctic Engineering (OMAE 2015) St. John's, Newfoundland, Canada May 31-June 5, 2015 Conference Paper NREL/CP-5000-63677 March 2015 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC

  1. Tribal Energy System Vulnerabilities to Climate Change and Extreme Weather

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

    Tribal Energy System Vulnerabilities to Climate Change and Extreme Weather ii NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use

  2. Hig Resolution Seismometer Insensitive to Extremely Strong Magnetic Fields

    SciTech Connect (OSTI)

    Abramovich, Igor A

    2009-07-14

    A highly sensitive broadband seismic sensor has been developed successfully to be used in beam focusing systems of particale accelerators. The sensor is completely insensitive to extremely strong magnetic fields and to hard radiation conditions that exist at the place of their installation. A unique remote sensor calibration method has been invented and implemented. Several such sensors were sold to LAPP (LAPP-IN2P3/CNRS-Universit de Savoie; Laboratoire d'Annecy-le-Vieux de Physique des Particules)

  3. COLLOQUIUM: Exploring the Physical Properties of Matter in Extreme

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

    Conditions | Princeton Plasma Physics Lab May 7, 2014, 4:00pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Exploring the Physical Properties of Matter in Extreme Conditions Siegfried Glenzer SLAC National Accelerator Laboratory One of the great challenges of this century is to determine if nuclear fusion of hydrogen isotopes can be demonstrated in the laboratory and developed into an unlimited carbon-free energy source. Recently, experiments on laser-driven targets have begun on the

  4. Global extreme events and their regional economic impact: 1996 update

    SciTech Connect (OSTI)

    Shen, S.

    1996-12-31

    The meaning of global warming and its relevance to everyday life is explained. Simple thermodynamics is used to predict an oscillatory nature of the change in climate due to global warming. The regional economic impacts of global extreme events are what mankind needs to focus on in government and private sector policy and planning. The economic impact of global warming has been tracked by the Extreme Event Index (EEI) established by the Global Warming International Center (GWIC). This review will update the overall trend and the components of the EEI from 1960 to 1996. The regional components of the global EEI have provided an excellent gauge for measuring the statistical vulnerability of any geographical locality in climate related economic disasters. The author further explains why we no longer fully understand the nature and magnitudes of common phenomena such as storms and wind speeds because of these extreme events, precipitation and temperature oscillations, atmospheric thermal unrest, as well as the further stratification of clouds, and changes in the absorptive properties of clouds. Hurricane strength winds are increasingly common even in continental areas. The author links the increase in duration of the El Nino to global warming, and further predicts a high public health risk as a result of the earth`s transition to another equilibrium state in its young history.

  5. Fabrication of diamond based sensors for use in extreme environments

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

    Samudrala, Gopi K.; Moore, Samuel L.; Vohra, Yogesh K.

    2015-04-23

    Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This methodmore » can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. Here, we demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.« less

  6. Fabrication of diamond based sensors for use in extreme environments

    SciTech Connect (OSTI)

    Samudrala, Gopi K.; Moore, Samuel L.; Vohra, Yogesh K.

    2015-04-23

    Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This method can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. Here, we demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.

  7. Exascale Co-design for Modeling Materials in Extreme Environments

    SciTech Connect (OSTI)

    Germann, Timothy C.

    2014-07-08

    Computational materials science has provided great insight into the response of materials under extreme conditions that are difficult to probe experimentally. For example, shock-induced plasticity and phase transformation processes in single-crystal and nanocrystalline metals have been widely studied via large-scale molecular dynamics simulations, and many of these predictions are beginning to be tested at advanced 4th generation light sources such as the Advanced Photon Source (APS) and Linac Coherent Light Source (LCLS). I will describe our simulation predictions and their recent verification at LCLS, outstanding challenges in modeling the response of materials to extreme mechanical and radiation environments, and our efforts to tackle these as part of the multi-institutional, multi-disciplinary Exascale Co-design Center for Materials in Extreme Environments (ExMatEx). ExMatEx has initiated an early and deep collaboration between domain (computational materials) scientists, applied mathematicians, computer scientists, and hardware architects, in order to establish the relationships between algorithms, software stacks, and architectures needed to enable exascale-ready materials science application codes within the next decade. We anticipate that we will be able to exploit hierarchical, heterogeneous architectures to achieve more realistic large-scale simulations with adaptive physics refinement, and are using tractable application scale-bridging proxy application testbeds to assess new approaches and requirements. Such current scale-bridging strategies accumulate (or recompute) a distributed response database from fine-scale calculations, in a top-down rather than bottom-up multiscale approach.

  8. Cooperative effect of ultraviolet and near-infrared beams in laser-induced condensation

    SciTech Connect (OSTI)

    Matthews, M.; Henin, S.; Pomel, F.; Kasparian, J.; Wolf, J.-P.; Thberge, F.; Daigle, J.-F.; Lassonde, P.; Kieffer, J.-C.

    2013-12-23

    We demonstrate the cooperative effect of near infrared (NIR) and ultraviolet (UV) beams on laser-induced condensation. Launching a UV laser after a NIR pulse yields up to a 5-fold increase in the production of nanoparticles (25300 nm) as compared to a single NIR beam. This cooperative effect exceeds the sum of those from the individual beams and occurs for delays up to 1 ?s. We attribute it to the UV photolysis of ozone created by the NIR pulses. The resulting OH radicals oxidize NO{sub 2} and volatile organic compounds, producing condensable species.

  9. Vacuum ultraviolet and infrared spectra of condensed methyl acetate on cold astrochemical dust analogs

    SciTech Connect (OSTI)

    Sivaraman, B.; Nair, B. G.; Mason, N. J.; Lo, J.-I.; Cheng, B.-M.; Kundu, S.; Davis, D.; Prabhudesai, V.; Krishnakumar, E.; Raja Sekhar, B. N.

    2013-12-01

    Following the recent report of the first identification of methyl acetate (CH{sub 3}COOCH{sub 3}) in the interstellar medium (ISM), we have carried out vacuum ultraviolet (VUV) and infrared (IR) spectroscopy studies on methyl acetate from 10 K until sublimation in an ultrahigh vacuum chamber simulating astrochemical conditions. We present the first VUV and IR spectra of methyl acetate relevant to ISM conditions. Spectral signatures clearly showed molecular reorientation to have started in the ice by annealing the amorphous ice formed at 10 K. An irreversible phase change from amorphous to crystalline methyl acetate ice was found to occur between 110 K and 120 K.

  10. A simplified scheme for generating narrow-band mid-ultraviolet laser radiation

    SciTech Connect (OSTI)

    Almog, G.; Scholz, M. Weber, W.; Leisching, P.; Kaenders, W.; Udem, Th.

    2015-03-15

    We report on the development and characterization of continuous, narrow-band, and tunable laser systems that use direct second-harmonic generation from blue and green diode lasers with an output power level of up to 11.1 mW in the mid-ultraviolet. One of our laser systems was tuned to the mercury 6{sup 1}S{sub 0} → 6{sup 3}P{sub 1} intercombination line at 253.7 nm. We could perform Doppler-free saturation spectroscopy on this line and were able to lock our laser to the transition frequency on long time scales.

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

    SciTech Connect (OSTI)

    Baghapour, Sh.; Parvin, P. Mokhtari, S.; Reyhani, A.; Mortazavi, S. Z.; Amjadi, A.

    2014-08-07

    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.

  12. 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)

    2014-03-21

    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.

  13. Segmented Ultralight Pre-Aligned Rotor for Extreme-Scale Wind Turbines

    SciTech Connect (OSTI)

    Loth, E.; Steele, A.; Ichter, B.; Selig, M.; Moriarty, P.

    2012-01-01

    To alleviate the mass-scaling issues associated with conventional upwind rotors of extreme-scale turbines, a downwind rotor concept is proposed which employs fixed blade curvature based on force alignment at rated conditions. For a given peak stress constraint, the reduction in downwind cantilever loads allows reduced shell and spar thickness, and thus a reduced blade mass as compared with a conventional upwind rotor, especially as rotor sizes approach extreme-scales. To quantify this mass reduction, a Finite Element Analysis was conducted for a 10 MW rated rotor based on the NREL offshore 5 MW baseline wind turbine. The results show that this 'pre-alignment' yields a net downstream deflection of 32 deg, a downward hub-pitch angle of 6 deg, a 20% increase in blade length (to maintain the same radius as the conventional blade), and a net mass savings of about 50% through decreased shell and spar thicknesses. The pre-alignment may also allow a more straightforward and efficient segmentation of the blade since shear stresses near joints are substantially reduced. Segmenting, in turn, can dramatically reduce costs associated with fabrication, transport and assembly for extreme-scale off-shore systems. The pre-aligned geometric curvature can also help alleviate tower wake effects on the blades since blade tips (where shadow effects can be most problematic) are shifted downstream where the tower wake is weaker. In addition, the portion of the tower that is upstream of the blade tips can be faired with an externally-rotating aerodynamic shroud. Furthermore, the downwind rotor can allow a floating off-shore tri-pod platform to reduce tower weight and yaw-control requirements. A simple economic analysis of the segmented ultralight pre-aligned rotor (SUPAR) concept suggests that the overall system cost savings can be as much as 25%, indicating that more detailed (numerical and experimental) investigations are warranted.

  14. Solidification at the High and Low Rate Extreme

    SciTech Connect (OSTI)

    Halim Meco

    2004-12-19

    The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt

  15. Method for synthesizing extremely high-temperature melting materials

    DOE Patents [OSTI]

    Saboungi, Marie-Louise (Chicago, IL); Glorieux, Benoit (Perpignan, FR)

    2007-11-06

    The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as carbides and transition-metal, lanthanide and actinide oxides, using an aerodynamic levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

  16. Method For Synthesizing Extremely High-Temperature Melting Materials

    DOE Patents [OSTI]

    Saboungi, Marie-Louise; Glorieux, Benoit

    2005-11-22

    The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as borides, carbides and transition-metal, lanthanide and actinide oxides, using an Aerodynamic Levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.

  17. Extreme nonlinear optics of two-level systems

    SciTech Connect (OSTI)

    Tritschler, T.; Muecke, O. D.; Wegener, M.

    2003-09-01

    For Rabi frequencies comparable to, or even larger than, the transition frequency of a two-level system, the regime of extreme nonlinear optics is reached. Here, we give an overview of the radiated light intensity as a function of carrier frequency of light, transition frequency, Rabi frequency, spectrometer frequency, as well as of the shape and duration of the exciting optical pulses. The graphical representations reveal an amazing complexity and beauty of the nonlinear optical response. Analytical results within the ''square-wave approximation'' qualitatively reproduce many of the intricate features of the exact numerical calculations.

  18. 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

    2010-08-04

    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.

  19. Measurement of the solar ultraviolet radiation at ground level in Bangi, Malaysia

    SciTech Connect (OSTI)

    Aljawi, Ohoud; Gopir, Geri; Duay, Abdul Basit

    2015-04-24

    Understanding the amount of ultraviolet (UV) radiation received by human, plant, and animal organisms near the earth’s surface is important to a wide range of fields such as cancer research, agriculture and forestry. The solar ultraviolet spectral irradiance at ground level was measured using the Avantes spectrometer for the period of January to March 2014 at Bangi (2°55´N, 101°46´E, 50 m above sea level) in Malaysia. These data were used to estimate the diurnal variation of UV irradiance (300 – 400 nm). The maximum irradiance of UV radiation was 45 W m{sup −2} on horizontal surface. The maximum irradiance of UV received in the local noon time, and the minimum values of UV irradiance was received in the local morning time. It is found a bigger value of UV radiation was observed on clear sky in January. The estimation of daily flux average of UV irradiance was (921± 91) kJ m{sup −2}.

  20. Ultraviolet relaxation dynamics of aniline, N, N-dimethylaniline and 3,5-dimethylaniline at 250 nm

    SciTech Connect (OSTI)

    Thompson, James O. F.; Saalbach, Lisa; Crane, Stuart W.; Paterson, Martin J.; Townsend, Dave

    2015-03-21

    Time-resolved photoelectron imaging was used to investigate the electronic relaxation dynamics of gas-phase aniline, N, N-dimethylaniline, and 3,5-dimethylaniline following ultraviolet excitation at 250 nm. Our analysis was supported by ab initio coupled-cluster calculations evaluating excited state energies and (in aniline) the evolution of a range of excited state physical properties as a function of N–H bond extension. Due to a lack of consistency between several earlier studies undertaken in aniline, the specific aim of this present work was to gain new insight into the previously proposed non-adiabatic coupling interaction between the two lowest lying singlet excited states S{sub 1}(ππ{sup ∗}) and S{sub 2}(3s/πσ{sup ∗}). The methyl-substituted systems N, N-dimethylaniline and 3,5-dimethylaniline were included in order to obtain more detailed dynamical information about the key internal molecular coordinates that drive the S{sub 1}(ππ{sup ∗})/S{sub 2}(3s/πσ{sup ∗}) coupling mechanism. Our findings suggest that in all three systems, both electronic states are directly populated during the initial excitation, with the S{sub 2}(3s/πσ{sup ∗}) state then potentially decaying via either direct dissociation along the N–X stretching coordinate (X = H or CH{sub 3}) or internal conversion to the S{sub 1}(ππ{sup ∗}) state. In aniline and N, N-dimethylaniline, both pathways most likely compete in the depletion of S{sub 2}(3s/πσ{sup ∗}) state population. However, in 3,5-dimethylaniline, only the direct dissociation mechanism appears to be active. This is rationalized in terms of changes in the relative rates of the two decay pathways upon methylation of the aromatic ring system.

  1. How Do You Stay Warm While Saving Money and Energy in Extreme...

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

    Stay Warm While Saving Money and Energy in Extreme Weather? How Do You Stay Warm While Saving Money and Energy in Extreme Weather? February 3, 2011 - 6:30am Addthis Many states are ...

  2. Approaching isotropy in the vortex system of SmFeAs(O,F) at extreme...

    Office of Scientific and Technical Information (OSTI)

    vortex system of SmFeAs(O,F) at extreme magnetic fields Citation Details In-Document Search Title: Approaching isotropy in the vortex system of SmFeAs(O,F) at extreme magnetic ...

  3. Best Practices in Literature Review for the 10 Year Extreme Wind...

    Office of Environmental Management (EM)

    Best Practices in Literature Review for the 10 Year Extreme Wind Update at the DOE Pantex Site Best Practices in Literature Review for the 10 Year Extreme Wind Update at the DOE...

  4. Rod-shaped Nuclei at Extreme Spin and Isospin (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Rod-shaped Nuclei at Extreme Spin and Isospin Citation Details In-Document Search Title: Rod-shaped Nuclei at Extreme Spin and Isospin Authors: Zhao, P. W. ; Itagaki, N. ; Meng, J. ...

  5. Rod-shaped Nuclei at Extreme Spin and Isospin (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Rod-shaped Nuclei at Extreme Spin and Isospin Title: Rod-shaped Nuclei at Extreme Spin and Isospin Authors: Zhao, P. W. ; Itagaki, N. ; Meng, J. Publication Date: 2015-07-08 OSTI ...

  6. Special Report: Graphics Processing Units Speed Results in Extreme-Scale

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

    Supercomputers | Princeton Plasma Physics Lab Special Report: Graphics Processing Units Speed Results in Extreme-Scale Supercomputers American Fusion News Category: U.S. Universities Link: Special Report: Graphics Processing Units Speed Results in Extreme-Scale Supercomputers

  7. Basic Research Needs for Materials Under Extreme Environments. Report of the Basic Energy Sciences Workshop on Materials Under Extreme Environments, June 11-13, 2007

    SciTech Connect (OSTI)

    Wadsworth, J.; Crabtree, G. W.; Hemley, R. J.; Falcone, R.; Robertson, I.; Stringer, J.; Tortorelli, P.; Gray, G. T.; Nicol, M.; Lehr, J.; Tozer, S. W.; Diaz de la Rubia, T.; Fitzsimmons, T.; Vetrano, J. S.; Ashton, C. L.; Kitts, S.; Landson, C.; Campbell, B.; Gruzalski, G.; Stevens, D.

    2008-02-01

    To evaluate the potential for developing revolutionary new materials that will meet demanding future energy requirements that expose materials to environmental extremes.

  8. SUMMARY OF REVISED TORNADO, HURRICANE AND EXTREME STRAIGHT WIND CHARACTERISTICS AT NUCLEAR FACILITY SITES

    Office of Energy Efficiency and Renewable Energy (EERE)

    Summary of Revised Tornado, Hurricane and Extreme Straight Wind Characteristics at Nuclear Facility Sites BY: John D. Stevenson Consulting Engineer

  9. Extreme behavior: New national security facility will open its doors to

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

    study materials at extreme conditions | Argonne National Laboratory Extreme behavior: New national security facility will open its doors to study materials at extreme conditions August 4, 2016 Tweet EmailPrint A new, first-of-its-kind-worldwide research capability will help unravel the mysteries of material behavior at extreme conditions and short time scales in support of the National Nuclear Security Administration's (NNSA's) vital national security missions. NNSA, the Department of

  10. Phase Transformation in Tantalum under Extreme Laser Deformation

    SciTech Connect (OSTI)

    Lu, C. -H.; Hahn, E. N.; Remington, B. A.; Maddox, B. R.; Bringa, E. M.; Meyers, M. A.

    2015-10-19

    The structural and mechanical response of metals is intimately connected to phase transformations. For instance, the product of a phase transformation (martensite) is responsible for the extraordinary range of strength and toughness of steel, making it a versatile and important structural material. Although abundant in metals and alloys, the discovery of new phase transformations is not currently a common event and often requires a mix of experimentation, predictive computations, and luck. High-energy pulsed lasers enable the exploration of extreme pressures and temperatures, where such discoveries may lie. The formation of a hexagonal (omega) phase was observed in recovered monocrystalline body-centered cubic tantalum of four crystallographic orientations subjected to an extreme regime of pressure, temperature, and strain-rate. This was accomplished using high-energy pulsed lasers. The omega phase and twinning were identified by transmission electron microscopy at 70 GPa (determined by a corresponding VISAR experiment). It is proposed that the shear stresses generated by the uniaxial strain state of shock compression play an essential role in the transformation. Lastly, molecular dynamics simulations show the transformation of small nodules from body-centered cubic to a hexagonal close-packed structure under the same stress state (pressure and shear).

  11. Characterization of Polarizing Splitter Optics in Extreme Environments

    SciTech Connect (OSTI)

    Tucker, Ryand; Olson, Matthew; Morelli, Gregg

    2013-01-04

    Development of laser systems capable of surviving extreme conditions experienced in military applications requires mounts and components that are able to survive these conditions. The characterization of mounted and/or bonded optical assemblies in harsh environments is critical for the development of laser and optical systems for functionality in these extreme conditions. Customized mounts, bonding assemblies and packaging strategies are utilized to develop and field reliable and robust optical subassemblies. Thin film polarizers operating at 45o and polarizing beam splitter cubes were chosen for initial testing based on past experiences, advancements in optical coating and construction technologies and material properties. Shock, vibration, shear strength, tensile strength and temperature testing are performed on mounted polarizing beam splitter cubes and thin film polarizers from two manufacturers. Previous testing showed that polarizing beam splitter cubes constructed using epoxy would become damaged in the laser resonator. The cubes being tested in this report are constructed using epoxy- free direct optical contact bonding. Thin film polarizers operating at 45o are chosen opposed to Brewster’s angle thin film polarizers to reduce the size and simplify design and construction since an optical wedge is not required. The components and mounts are each environmentally tested beyond the manufacturers’ specifications for shock, vibration, and temperature. Component functionality is monitored during and after the environmental testing. Experimental results from the testing will be discussed as will the impact on future laser resonator designs.

  12. Radiography Capabilities for Matter-Radiation Interactions in Extremes

    SciTech Connect (OSTI)

    Walstrom, Peter Lowell; Garnett, Robert William; Chapman, Catherine A. B; Salazar, Harry Richard; Otoole, Joseph Alfred; Barber, Ronald L.; Gomez, Tony Simon

    2015-04-28

    The Matter-Radiation Interactions in Extremes (MaRIE) experimental facility will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges. This new facility will provide the new tools scientists need to develop next-generation materials that will perform predictably and on-demand for currently unattainable lifetimes in extreme environments. The MaRIE facility is based on upgrades to the existing LANSCE 800-MeV proton linac and a new 12-GeV electron linac and associated X-ray FEL to provide simultaneous multiple probe beams, and new experimental areas. In addition to the high-energy photon probe beam, both electron and proton radiography capabilities will be available at the MaRIE facility. Recently, detailed radiography system studies have been performed to develop conceptual layouts of high-magnification electron and proton radiography systems that can meet the experimental requirements for the expected first experiments to be performed at the facility. A description of the radiography systems, their performance requirements, and a proposed facility layout are presented.

  13. Phase Transformation in Tantalum under Extreme Laser Deformation

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

    Lu, C. -H.; Hahn, E. N.; Remington, B. A.; Maddox, B. R.; Bringa, E. M.; Meyers, M. A.

    2015-10-19

    The structural and mechanical response of metals is intimately connected to phase transformations. For instance, the product of a phase transformation (martensite) is responsible for the extraordinary range of strength and toughness of steel, making it a versatile and important structural material. Although abundant in metals and alloys, the discovery of new phase transformations is not currently a common event and often requires a mix of experimentation, predictive computations, and luck. High-energy pulsed lasers enable the exploration of extreme pressures and temperatures, where such discoveries may lie. The formation of a hexagonal (omega) phase was observed in recovered monocrystalline body-centeredmore » cubic tantalum of four crystallographic orientations subjected to an extreme regime of pressure, temperature, and strain-rate. This was accomplished using high-energy pulsed lasers. The omega phase and twinning were identified by transmission electron microscopy at 70 GPa (determined by a corresponding VISAR experiment). It is proposed that the shear stresses generated by the uniaxial strain state of shock compression play an essential role in the transformation. Lastly, molecular dynamics simulations show the transformation of small nodules from body-centered cubic to a hexagonal close-packed structure under the same stress state (pressure and shear).« less

  14. Phase transformation in tantalum under extreme laser deformation

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

    Lu, C. -H.; Hahn, E. N.; Remington, B. A.; Maddox, B. R.; Bringa, E. M.; Meyers, M. A.

    2015-10-19

    The structural and mechanical response of metals is intimately connected to phase transformations. For instance, the product of a phase transformation (martensite) is responsible for the extraordinary range of strength and toughness of steel, making it a versatile and important structural material. Although abundant in metals and alloys, the discovery of new phase transformations is not currently a common event and often requires a mix of experimentation, predictive computations, and luck. High-energy pulsed lasers enable the exploration of extreme pressures and temperatures, where such discoveries may lie. The formation of a hexagonal (omega) phase was observed in recovered monocrystalline body-centeredmore » cubic tantalum of four crystallographic orientations subjected to an extreme regime of pressure, temperature, and strain-rate. This was accomplished using high-energy pulsed lasers. The omega phase and twinning were identified by transmission electron microscopy at 70 GPa (determined by a corresponding VISAR experiment). It is proposed that the shear stresses generated by the uniaxial strain state of shock compression play an essential role in the transformation. In conclusion, molecular dynamics simulations show the transformation of small nodules from body-centered cubic to a hexagonal close-packed structure under the same stress state (pressure and shear).« less

  15. Luminescent properties of Eu{sup 2+}-doped BaGdF{sub 5} glass ceramics a potential blue phosphor for ultra-violet light-emitting diode

    SciTech Connect (OSTI)

    Zhang, Weihuan; Zhang, Yuepin Ouyang, Shaoye; Zhang, Zhixiong; Wang, Qian; Xia, Haiping

    2015-01-14

    Eu{sup 2+} doped transparent oxyfluoride glass ceramics containing BaGdF{sub 5} nanocrystals were successfully fabricated by melt-quenching technique under a reductive atmosphere. The structure of the glass and glass ceramics were investigated by differential scanning calorimetry, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The luminescent properties were investigated by transmission, excitation, and emission spectra. The decay time of the Gd{sup 3+} ions at 312?nm excited with 275?nm were also investigated. The results of XRD and TEM indicated the existence of BaGdF5 nanocrystals in the transparent glass ceramics. The excitation spectra of Eu{sup 2+} doped glass ceramics showed an excellent overlap with the main emission region of an ultraviolet light-emitting diode (UV-LED). Compared with the as-made glass, the emission of glass ceramics is much stronger by a factor of increasing energy transfer efficiency from Gd{sup 3+} to Eu{sup 2+} ions, the energy transfer efficiency from Gd{sup 3+} to Eu{sup 2+} ions was discussed. In addition, the chromaticity coordinates of glass and glass ceramics specimens were also discussed, which indicated that the Eu{sup 2+} doped BaGdF{sub 5} glass ceramics may be used as a potential blue-emitting phosphor for UV-LED.

  16. Investigations | Department of Energy

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

    Investigations Investigations Investigations The Office of Investigations performs investigations into allegations of fraud, waste, and abuse in programs and operations of the Department, NNSA and FERC. Priority is given to investigations of suspected violations of criminal and civil statutes, as well as serious administrative misconduct. Particular focus is placed on the prevention and detection of contract and grant fraud; environmental, health and safety violations; computer crimes; and

  17. Accident Investigation Handbook

    Broader source: Energy.gov (indexed) [DOE]

    Accident Investigations (AI) and Operational Safety Reviews (OSR) are valuable for ... in conducting Department of Energy (DOE) accident investigations over the past many years. ...

  18. Accident Investigation Handbook

    Office of Environmental Management (EM)

    ... investigator to think in terms other than causal series, ... backwards, it is easy to oversimplify the search for causes. ... may have as they enter the investigation process ...

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

    SciTech Connect (OSTI)

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

    2013-10-29

    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.

  20. Reducing Waste in Extreme Scale Systems through Introspective Analysis

    SciTech Connect (OSTI)

    Bautista-Gomez, Leonardo; Gainaru, Ana; Perarnau, Swann; Engelmann, Christian; Cappello, Franck; Snir, Marc

    2016-01-01

    Resilience is an important challenge for extreme- scale supercomputers. Today, failures in supercomputers are assumed to be uniformly distributed in time. However, recent studies show that failures in high-performance computing systems are partially correlated in time, generating periods of higher failure density. Our study of the failure logs of multiple supercomputers show that periods of higher failure density occur with up to three times more than the average. We design a monitoring system that listens to hardware events and forwards important events to the runtime to detect those regime changes. We implement a runtime capable of receiving notifications and adapt dynamically. In addition, we build an analytical model to predict the gains that such dynamic approach could achieve. We demonstrate that in some systems, our approach can reduce the wasted time by over 30%.

  1. Amplitude variations on the Extreme Adaptive Optics testbed

    SciTech Connect (OSTI)

    Evans, J; Thomas, S; Dillon, D; Gavel, D; Phillion, D; Macintosh, B

    2007-08-14

    High-contrast adaptive optics systems, such as those needed to image extrasolar planets, are known to require excellent wavefront control and diffraction suppression. At the Laboratory for Adaptive Optics on the Extreme Adaptive Optics testbed, we have already demonstrated wavefront control of better than 1 nm rms within controllable spatial frequencies. Corresponding contrast measurements, however, are limited by amplitude variations, including those introduced by the micro-electrical-mechanical-systems (MEMS) deformable mirror. Results from experimental measurements and wave optic simulations of amplitude variations on the ExAO testbed are presented. We find systematic intensity variations of about 2% rms, and intensity variations with the MEMS to be 6%. Some errors are introduced by phase and amplitude mixing because the MEMS is not conjugate to the pupil, but independent measurements of MEMS reflectivity suggest that some error is introduced by small non-uniformities in the reflectivity.

  2. Extremely strong tubular stacking of aromatic oligoamide macrocycles

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

    Kline, Mark A.; Wei, Xiaoxi; Horner, Ian J.; Liu, Rui; Chen, Shuang; Chen, Si; Yung, Ka Yi; Yamato, Kazuhiro; Cai, Zhonghou; Bright, Frank V.; et al

    2014-09-16

    As the third-generation rigid macrocycles evolved from progenitor 1, cyclic aromatic oligoamides 3, with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of K-dimer > 1013 M-1 in CHCl3), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (-49.77 kcal mol-1) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of 3. In the solid-state, X-ray diffraction (XRD) confirms that the aggregation of 3 results in well-aligned tubular stacks. Furthermore, themore » persistent tubular assemblies of 3, with their non-deformable sub-nm pore, are expected to possess many interesting functions. One such function, transmembrane ion transport, is observed for 3.« less

  3. Extremely strong tubular stacking of aromatic oligoamide macrocycles

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

    Kline, Mark A.; Wei, Xiaoxi; Horner, Ian J.; Liu, Rui; Chen, Shuang; Chen, Si; Yung, Ka Yi; Yamato, Kazuhiro; Cai, Zhonghou; Bright, Frank V.; et al

    2015-01-01

    As the third-generation rigid macrocycles evolved from progenitor 1, cyclic aromatic oligoamides 3, with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of Kdimer > 1013 M-1 in CHCl3), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (-49.77 kcal mol-1) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of 3. In the solid-state, X-ray diffraction (XRD) confirms that the aggregation of 3 results in well-aligned tubular stacks. The persistentmore » tubular assemblies of 3, with their non-deformable sub-nm pore, are expected to possess many interesting functions. One such function, transmembrane ion transport, is observed for 3.« less

  4. Extremely strong tubular stacking of aromatic oligoamide macrocycles

    SciTech Connect (OSTI)

    Kline, Mark A.; Wei, Xiaoxi; Horner, Ian J.; Liu, Rui; Chen, Shuang; Chen, Si; Yung, Ka Yi; Yamato, Kazuhiro; Cai, Zhonghou; Bright, Frank V.; Zeng, Xiao Cheng; Gong, Bing

    2015-01-01

    As the third-generation rigid macrocycles evolved from progenitor 1, cyclic aromatic oligoamides 3, with a backbone of reduced constraint, exhibit extremely strong stacking with an astoundingly high affinity (estimated lower limit of Kdimer > 1013 M-1 in CHCl3), which leads to dispersed tubular stacks that undergo further assembly in solution. Computational study reveals a very large binding energy (-49.77 kcal mol-1) and indicates highly cooperative local dipole interactions that account for the observed strength and directionality for the stacking of 3. In the solid-state, X-ray diffraction (XRD) confirms that the aggregation of 3 results in well-aligned tubular stacks. The persistent tubular assemblies of 3, with their non-deformable sub-nm pore, are expected to possess many interesting functions. One such function, transmembrane ion transport, is observed for 3.

  5. BAL QSOs AND EXTREME UFOs: THE EDDINGTON CONNECTION

    SciTech Connect (OSTI)

    Zubovas, Kastytis; King, Andrew

    2013-05-20

    We suggest a common physical origin connecting the fast, highly ionized winds (UFOs) seen in nearby active galactic nuclei (AGNs), and the slower and less ionized winds of broad absorption line (BAL) QSOs. The primary difference is the mass-loss rate in the wind, which is ultimately determined by the rate at which mass is fed toward the central supermassive black hole (SMBH) on large scales. This is below the Eddington accretion rate in most UFOs, and slightly super-Eddington in extreme UFOs such as PG1211+143, but ranges up to {approx}10-50 times this in BAL QSOs. For UFOs this implies black hole accretion rates and wind mass-loss rates which are at most comparable to Eddington, giving fast, highly ionized winds. In contrast, BAL QSO black holes have mildly super-Eddington accretion rates, and drive winds whose mass-loss rates are significantly super-Eddington, and so are slower and less ionized. This picture correctly predicts the velocities and ionization states of the observed winds, including the recently discovered one in SDSS J1106+1939. We suggest that luminous AGNs may evolve through a sequence from BAL QSO through LoBAL to UFO-producing Seyfert or quasar as their Eddington factors drop during the decay of a bright accretion event. LoBALs correspond to a short-lived stage in which the AGN radiation pressure largely evacuates the ionization cone, but before the large-scale accretion rate has dropped to the Eddington value. We show that sub-Eddington wind rates would produce an M-{sigma} relation lying above that observed. We conclude that significant SMBH mass growth must occur in super-Eddington phases, either as BAL QSOs, extreme UFOs, or obscured from direct observation.

  6. 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.; Afram, N.; Unruh, Y. C.; Berdyugina, S. V.; Berkefeld, T.; Schmidt, W.; Bonet, J. A.; MartInez Pillet, V.; Knoelker, M.; Title, A. M.

    2010-11-10

    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.

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

    SciTech Connect (OSTI)

    Gulati, P.; Prakash, R.; Pal, U. N.; Kumar, M.; Vyas, V.

    2014-07-07

    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.

  8. Stability of vacuum-ultraviolet radiometric transfer standards: Electron cyclotron resonance versus hollow cathode source

    SciTech Connect (OSTI)

    Gottwald, Alexander; Richter, Mathias; Ulm, Gerhard; Schuehle, Udo

    2005-02-01

    Established transfer standards such as Penning and hollow cathode discharge sources suffer from limited spectral range and, in particular, a limited lifetime and stability due to electrode erosion. The development of a vacuum-ultraviolet radiation source based on an electron cyclotron resonance (ECR)-created plasma might overcome these limitations. To test such a source with regard to its usefulness as radiometric transfer standard, the emission intensity of a Ne plasma was monitored over an operation period of 180 days, with regard to stability and reproducibility in the 50-75 nm wavelength range. For comparison and calibration, a hollow cathode was used as transfer standard traceable to the electron storage ring BESSY II as primary standard. It was found that the ECR source exceeded the lifetime of the hollow cathode source by far, offering a more balanced spectral emission line variety with similar stability.

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

    SciTech Connect (OSTI)

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

    1991-01-01

    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.

  10. 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)

    2012-07-15

    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}.

  11. Ultraviolet Absorption Spectrum of Malonaldehyde in Water Is Dominated by Solvent-Stabilized Conformations

    SciTech Connect (OSTI)

    Xu, Xuefei; Zheng, Jingjing; Truhlar, Donald G.

    2015-07-01

    Free energy calculations for eight enol isomers of malonaldehyde (MA) and simulation of the ultraviolet (UV) absorption spectrum in both the gas phase and water (pH = 3, where the molecule exists in neutral undeprotonated form) show that in water the two s-trans nonchelated enol conformers of MA become thermodynamically more stable than the internally hydrogen-bonded (“chelated enol”) conformer (CE). The pure CE conformer in water has a slightly red-shifted UV spectrum with respect to that in the gas phase, but the blue-shifted spectrum observed in water at pH 3 is dominated by solvent-stabilized conformations that have negligible populations in the gas phase. Density functional calculations with the solvation model based on density (SMD) and an ensemble-averaged vertical excitation model explain the experimental observations in detail.

  12. Far-ultraviolet observations of comet C/2001 Q4 (NEAT) with FIMS/SPEAR

    SciTech Connect (OSTI)

    Lim, Y.-M.; Min, K.-W.; Feldman, P. D.; Han, W.; Edelstein, J.

    2014-02-01

    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}Π-X{sup 1}Σ{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.

  13. Foreign-national Investigators

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

    foreign national investigators Foreign-national Investigators Foreign National Investigators must have access to B174 shown on their badge. Foreign National Investigators must notify Beth Mariotti by e-mail of their first intended presence in B174. By September 2009, it is expected that there will be no restrictions on computer use by Foreign National Investigators at JLF. However, LLNL prohibits the use of personally-owned computers on-site

  14. Molecular basis of the structural stability of a Top7-based scaffold at extreme pH and temperature conditions

    SciTech Connect (OSTI)

    Soares, Thereza A.; Boschek, Curt B.; Apiyo, David O.; Baird, Cheryl L.; Straatsma, TP

    2010-07-01

    The development of stable scaffolds that can tolerate environmental extremes has an immense potential for applications in industry and defense. Recently, we have engineered an eight-residue loop into the de novo designed Top7 protein, which specifically binds the glycoprotein CD4. The robust properties of the Top7, coupled with the ease in production, make it a robust scaffold to design novel functionalities for use under extreme environmental conditions. In the present work, a series of explicit-solvent molecular dynamics simulations are reported which investigates the effect of mutations and extreme conditions of temperature and pH on the structure, stability, and dynamics of the native and engineered Top7. These simulations indicate that i. The structural dynamics of the engineered and native Top7 in solution are equivalent under corresponding conditions of pH and temperature. Ensemble-averaged structures of the native and engineered Top7 maintain the overall tertiary structure pattern, albeit with loss of helical content when at low pH and high-temperature conditions. Mutations of residues E43A, D46A, E67A, E69A, EA81A along the ?-helices of the engineered Top7 did not lead to significant changes in the native fold under pH 2 and 400 K, suggesting that the helices can accommodate varying sequences. iii. The anti-parallel ?-sheet is the structural core responsible for the stability of the native and engineered Top7 and is well maintained under extreme pH and temperature conditions. These findings indicate that the insertion of an eight-residue loop into the structure of Top7 does not adversely affect the global fold or the structural stability of the Top7 scaffold.

  15. Manus Water Isotope Investigation

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

    9 Manus Water Isotope Investigation Field Campaign Report JL Conroy D Noone KM Cobb March ... DOESC-ARM-15-079 Manus Water Isotope Investigation Field Campaign Report JL Conroy, ...

  16. Manus Water Isotope Investigation

    Office of Scientific and Technical Information (OSTI)

    ENERGY Office of Science DOESC-ARM-15-079 Manus Water Isotope Investigation Field ... DOESC-ARM-15-079 Manus Water Isotope Investigation Field Campaign Report JL Conroy, ...

  17. FBP Notice to Investigate

    Broader source: Energy.gov (indexed) [DOE]

    to support the investigation will be sent separately via email. Under the Major Fraud Act (MFA), as amended, 41 U.S.C. 4310, this investigation may be a proceeding...

  18. Extreme argon purity in a large, non-evacuated cryostat

    SciTech Connect (OSTI)

    Tope, Terry; Adamowski, Mark; Carls, B.; Hahn, A.; Jaskierny, W.; Jostlein, H.; Kendziora, C.; Lockwitz, S.; Pahlka, B.; Plunkett, R.; Pordes, S.; Rebel, B.; Schmitt, R.; Skup, E.; Stancari, M.; Yang, T.

    2014-01-29

    Liquid Argon Time Projection Chambers (LArTPCs) show promise as scalable devices for the large detectors needed for long-baseline neutrino oscillation physics. Over the last several years at Fermilab a staged approach to developing the technology for large detectors has been developed. The TPC detectors require ultra-pure liquid argon with respect to electronegative contaminants such as oxygen and water. The tolerable electronegative contamination level may be as pure as 60 parts per trillion of oxygen. Three liquid argon cryostats operated at Fermilab have achieved the extreme purity required by TPCs. These three cryostats used evacuation to remove atmospheric contaminants as the first purification step prior to filling with liquid argon. Future physics experiments may require very large detectors with tens of kilotonnes of liquid argon mass. The capability to evacuate such large cryostats adds significant cost to the cryostat itself in addition to the cost of a large scale vacuum pumping system. This paper describes a 30 ton liquid argon cryostat at Fermilab which uses purging to remove atmospheric contaminants instead of evacuation as the first purification step. This cryostat has achieved electronegative contamination levels better than 60 parts per trillion of oxygen equivalent. The results of this liquid argon purity demonstration will strongly influence the design of future TPC cryostats.

  19. Secretary Chu to Appear This Sunday on ABC's Extreme Makeover: Home Edition

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

    | Department of Energy Appear This Sunday on ABC's Extreme Makeover: Home Edition Secretary Chu to Appear This Sunday on ABC's Extreme Makeover: Home Edition February 12, 2010 - 12:00am Addthis Washington - This Sunday, February 14th, Energy Secretary Steven Chu will appear on the show Extreme Makeover: Home Edition. The Department of Energy and Oak Ridge National Laboratory worked with the builders to offer technical assistance as they designed and built a super high efficiency home and a

  20. On the use of Extreme Value Theory in analyses of continuum gamma decay

    SciTech Connect (OSTI)

    Garcia-Ruiz, R. F.; Cristancho, F.

    2010-08-04

    Extreme Value theory seems to be a promising tool for analysing experimental continuum gamma decay spectra in order to obtain physical parameters at high excitation energy.

  1. Single-crystal X-ray diffraction at extreme conditions: a review...

    Office of Scientific and Technical Information (OSTI)

    Title: Single-crystal X-ray diffraction at extreme conditions: a review Authors: Ballaran, Tiziana Boffa ; Kurnosov, Alexander ; Trots, Dmytro 1 + Show Author Affiliations ...

  2. Approaching isotropy in the vortex system of SmFeAs(O,F) at extreme...

    Office of Scientific and Technical Information (OSTI)

    Approaching isotropy in the vortex system of SmFeAs(O,F) at extreme magnetic fields ... Sponsoring Org: NSF Country of Publication: United States Language: English Subject: ...

  3. Fibre Diffraction Analysis of Skin Offers a Very Early and Extremely...

    Office of Scientific and Technical Information (OSTI)

    Test for Prostate Cancer Citation Details In-Document Search Title: Fibre Diffraction Analysis of Skin Offers a Very Early and Extremely Accurate Diagnostic Test for ...

  4. Fibre Diffraction Analysis of Skin Offers a Very Early and Extremely...

    Office of Scientific and Technical Information (OSTI)

    Accurate Diagnostic Test for Prostate Cancer Title: Fibre Diffraction Analysis of Skin Offers a Very Early and Extremely Accurate Diagnostic Test for Prostate Cancer Double ...

  5. The role of the carbon-silicon complex in eliminating deep ultraviolet absorption in AlN

    SciTech Connect (OSTI)

    Gaddy, BE; Bryan, Z; Bryan, I; Xie, JQ; Dalmau, R; Moody, B; Kumagai, Y; Nagashima, T; Kubota, Y; Kinoshita, T; Koukitu, A; Kirste, R; Sitar, Z; Collazo, R; Irving, DL

    2014-05-19

    Co-doping AlN crystals with Si is found to suppress the unwanted 4.7 eV (265 nm) deep ultraviolet absorption associated with isolated carbon acceptors common in materials grown by physical vapor transport. Density functional theory calculations with hybrid functionals demonstrate that silicon forms a stable nearest-neighbor defect complex with carbon. This complex is predicted to absorb at 5.5 eV and emit at or above 4.3 eV. Absorption and photoluminescence measurements of co-doped samples confirm the presence of the predicted C-N-Si-Al complex absorption and emission peaks and significant reduction of the 4.7 eV absorption. Other sources of deep ultraviolet absorption in AlN are also discussed. (C) 2014 AIP Publishing LLC.

  6. Effects of solar ultraviolet photons on mammalian cell DNA. [UVA (320-400 nm):a2

    SciTech Connect (OSTI)

    Peak, M.J.; Peak, J.G.

    1991-01-01

    This document presents information on the possible mechanisms of carcinogenesis caused by UVA (ultraviolet radiation in the 320--400 nm region). Most studies showing the carcinogenic effects of ultraviolet light have concentrated on UVB (280--320 nm). UVA had been considered harmless even though it penetrates biological tissues better than UVB. Recently, it has become apparent that UVA is also capable of causing damage to cellular DNA. This was unexpected because the DNA UV absorption spectrum indicates a negligible probability that photons of wavelengths longer than 320 nm will be directly absorbed. The most common defects induced in DNA by UVB are pyrimidine photoproducts, such as thymidine dimers. UVA photons produce defects resembling those caused by ionizing radiations: single- and double-strand breaks, and DNA-protein crosslinks. This paper also discusses the role of DNA repair mechanisms in UVA-induced defects and the molecular mechanisms of UVA damage induction. 38 refs. (MHB)

  7. 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)

    2014-02-03

    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.

  8. Final Report for Project. Quark matter under extreme conditions

    SciTech Connect (OSTI)

    Incera, Vivian; Ferrer, Efrain

    2015-12-31

    The results obtained in the two years of the grant have served to shine new light on several important questions about the phases of quantum chromodynamics (QCD) under extreme conditions that include quark matter at high density, as well quark-gluon plasma at high temperatures, both in the presence of strong magnetic fields. The interest in including an external magnetic field on these studies is motivated by the generation of large magnetic fields in off-central heavy-ion collisions and by their common presence in astrophysical compact objects, the two scenarios where the physics of quark matter becomes relevant. The tasks carried out in this DOE project led us, among other things, to discover the first connection between the physics of very dense quark matter and novel materials as for instance topological insulators and Weyl semimetals; they allowed us to find a physical explanation for and a solution to a standing puzzle in the apparent effect of a magnetic field on the critical temperature of the QCD chiral transition; and they led us to establish by the first time that the core of the observed two-solar-mass neutron stars could be made up of quark matter in certain inhomogeneous chiral phases in a magnetic field and that this was consistent with current astrophysical observations. A major goal established by the Nuclear Science Advisory committee in its most recent report “Reaching for the Horizon” has been “to truly understand how nuclei and strongly interacting matter in all its forms behave and can predict their behavior in new settings.” The results found in this DOE project have all contributed to address this goal, and thus they are important for advancing fundamental knowledge in the area of nuclear physics and for enhancing our understanding of the role of strong magnetic fields in the two settings where they are most relevant, neutron stars and heavy-ion collisions.

  9. Detection of Coherent Structures in Extreme-Scale Simulations

    SciTech Connect (OSTI)

    Kamath, C; Iverson, J; Kirk, R; Karypis, G

    2012-03-24

    The analysis of coherent structures is a common problem in many scientific domains ranging from astrophysics to combustion, fusion, and materials science. The data from three-dimensional simulations are analyzed to detect the structures, extract statistics on them, and track them over time to gain insights into the phenomenon being modeled. This analysis is typically done off-line, using data that have been written out by the simulations. However, the move towards extreme scale architectures, with multi-core processors and graphical processing units, will affect how such analysis is done as it is unlikely that the systems will support the I/O bandwidth required for off-line analysis. Moving the analysis in-situ is a solution only if we know a priori what analysis will be done, as well as the algorithms used and their parameter settings. Even then, we need to ensure that this will not substantially increase the memory requirements or the data movement as the former will be limited and the latter will be expensive. In the Exa-DM project, a collaboration between Lawrence Livermore National Laboratory and University of Minnesota, we are exploring ways in which we can address the conflicting demands of coherent structure analysis of simulation data and the architecture of modern parallel systems, while enabling scientific discovery at the exascale. In this paper, we describe our work in two areas: the in situ implementation of an existing algorithm for coherent structure analysis and the use of graph-based techniques to efficiently compress the data.

  10. Removal of pollutant compounds from water supplies using ozone, ultraviolet light, and a counter, current packed column. Master's thesis

    SciTech Connect (OSTI)

    Kelly, E.L.

    1991-01-01

    Many water pollutants are determined to be carcinogenic and often appear in very low concentrations and still pose a health risk. Conventional water treatment processes cannot remove these contaminants and there is a great demand for the development of alternative removal technologies. The use of ozone and ultraviolet light in a counter current packed column could prove to be an effective treatment process to remove these contaminants.

  11. Nanostructured High Performance Ultraviolet and Blue Light Emitting Diodes for Solid State Lighting

    SciTech Connect (OSTI)

    Arto V. Nurmikko; Jung Han

    2005-09-30

    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.

  12. NANOSTRUCTURED HIGH PERFORMANCE ULTRAVIOLET AND BLUE LIGHT EMITTING DIODES FOR SOLID STATE LIGHTING

    SciTech Connect (OSTI)

    Arto V. Nurmikko; Jung Han

    2004-10-01

    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.

  13. Distinguishing Unfolding and Functional Conformational Transitions of Calmodulin Using Ultraviolet Resonance Raman Spectroscopy

    SciTech Connect (OSTI)

    Jones, Eric M.; Balakrishnan, G.; Squier, Thomas C.; Spiro, Thomas

    2014-06-14

    Calmodulin (CaM) is a ubiquitous moderator protein for calcium signaling in all eukaryotic cells. This small calcium-binding protein exhibits a broad range of structural transitions, including domain opening and folding-unfolding, that allow it to recognize a wide variety of binding partners in vivo. While the static structures of CaM associated with its various binding activities are fairly well known, it has been challenging to examine the dynamics of transition between these structures in real-time, due to a lack of suitable spectroscopic probes of CaM structure. In this paper, we examine the potential of ultraviolet resonance Raman (UVRR) spectroscopy for clarifying the nature of structural transitions in CaM. We find that the UVRR spectral change (with 229 nm excitation) due to thermal unfolding of CaM is qualitatively different from that associated with opening of the C-terminal domain in response to Ca2+ binding. This spectral difference is entirely due to differences in teritary contacts at the inter-domain tyrosine residue Tyr138, toward which other spectroscopic methods are not sensitive. We conclude that UVRR is ideally suited to identifying the different types of structural transitions in CaM and other proteins with conformation-sensitive tyrosine residues, opening a path to time-resolved studies of CaM dynamics using Raman spectroscopy.

  14. Effective interface state effects in hydrogenated amorphous-crystalline silicon heterostructures using ultraviolet laser photocarrier radiometry

    SciTech Connect (OSTI)

    Melnikov, A.; Mandelis, A.; Halliop, B.; Kherani, N. P.

    2013-12-28

    Ultraviolet photocarrier radiometry (UV-PCR) was used for the characterization of thin-film (nanolayer) intrinsic hydrogenated amorphous silicon (i-a-Si:H) on c-Si. The small absorption depth (approximately 10?nm at 355?nm laser excitation) leads to strong influence of the nanolayer parameters on the propagation and recombination of the photocarrier density wave (CDW) within the layer and the substrate. A theoretical PCR model including the presence of effective interface carrier traps was developed and used to evaluate the transport parameters of the substrate c-Si as well as those of the i-a-Si:H nanolayer. Unlike conventional optoelectronic characterization methods such as photoconductance, photovoltage, and photoluminescence, UV-PCR can be applied to more complete quantitative characterization of a-Si:H/c-Si heterojunction solar cells, including transport properties and defect structures. The quantitative results elucidate the strong effect of a front-surface passivating nanolayer on the transport properties of the entire structure as the result of effective a-Si:H/c-Si interface trap neutralization through occupation. A further dramatic improvement of those properties with the addition of a back-surface passivating nanolayer is observed and interpreted as the result of the interaction of the increased excess bulk CDW with, and more complete occupation and neutralization of, effective front interface traps.

  15. High-performance deep ultraviolet photodetectors based on ZnO quantum dot assemblies

    SciTech Connect (OSTI)

    Xu, Xiaoyong; Xu, Chunxiang E-mail: jghu@yzu.edu.cn; Hu, Jingguo E-mail: jghu@yzu.edu.cn

    2014-09-14

    A high-performance ZnO quantum dots (QDs)-based ultraviolet (UV) photodetector has been successfully fabricated via the self-assembly of QDs on the Au interdigital electrode. The broadened band gap in ZnO QDs makes the device has the highly selective response for the deep UV detection. The unique QD-QD junction barriers similar to back-to-back Schottky barriers dominate the conductance of the QD network and the UV light-induced barrier-height modulation plays a crucial role in enhancing the photoresponsivity and the response speed. Typically, the as-fabricated device exhibits the fast response and recovery times of within 1 s, the deep UV selectivity of less than 340 nm, and the stable repeatability with on/off current ratio over 10, photoresponsivity of 5.0410A/W, and photocurrent gain of 1.910, demonstrating that the ZnO QD network is a superior building block for deep UV photodetectors.

  16. Narrowband filter radiometer for ground-based measurements of global ultraviolet solar irradiance and total ozone

    SciTech Connect (OSTI)

    Petkov, Boyan; Vitale, Vito; Tomasi, Claudio; Bonafe, Ubaldo; Scaglione, Salvatore; Flori, Daniele; Santaguida, Riccardo; Gausa, Michael; Hansen, Georg; Colombo, Tiziano

    2006-06-20

    The ultraviolet narrowband filter radiometer (UV-RAD) designed by the authors to take ground-based measurements of UV solar irradiance, total ozone, and biological dose rate is described, together with the main characteristics of the seven blocked filters mounted on it, all of which have full widths at half maxima that range 0.67 to 0.98 nm. We have analyzed the causes of cosine response and calibration errors carefully to define the corresponding correction terms, paying particular attention to those that are due to the spectral displacements of the filter transmittance peaks from the integer wavelength values. The influence of the ozone profile on the retrieved ozone at large solar zenith angles has also been examined by means of field measurements. The opportunity of carrying out nearly monochromatic irradiance measurements offered by the UV-RAD allowed us to improve the procedure usually followed to reconstruct the solar spectrum at the surface by fitting the computed results, using radiative transfer models with field measurements of irradiance. Two long-term comparison campaigns took place, showing that a mean discrepancy of+0.3% exists between the UV-RAD total ozone values and those given by the Brewer no. 63 spectroradiometer and that mean differences of+0.3% and-0.9% exist between the erythemal dose rates determined with the UV-RAD and those obtained with the Brewer no. 63 and the Brewer no. 104 spectroradiometers, respectively.

  17. Characterizing mid-ultraviolet to optical light curves of nearby type IIn supernovae

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

    de la Rosa, Janie; Roming, Pete; Pritchard, Tyler; Fryer, Chris

    2016-03-21

    Here, we present early mid-ultraviolet and optical observations of Type IIn supernovae (SNe IIn) observed from 2007 to 2013. Our results focus on the properties of UV light curves: peak absolute magnitudes, temporal decay, and color evolution. During early times, this sample demonstrates that UV light decays faster than optical, and each event transitions from a predominantly UV-bright phase to an optically bright phase. In order to understand early UV behavior, we generate and analyze the sample's blackbody luminosity, temperature, and radius as the SN ejecta expand and cool. Since most of our observations were detected post maximum luminosity, wemore » introduce a method for estimating the date of peak magnitude. When our observations are compared based on filter, we find that even though these SNe IIn vary in peak magnitudes, there are similarities in UV decay rates. We use a simple semi-analytical SN model in order to understand the effects of the explosion environment on our UV observations. Understanding the UV characteristics of nearby SNe IIn during an early phase can provide valuable information about the environment surrounding these explosions, leading us to evaluating the diversity of observational properties in this subclass.« less

  18. Gold nanoparticles formed directly on a membrane by ultraviolet light irradiation

    SciTech Connect (OSTI)

    Qian, Hui Chen, Jian; Shen, Wei-Zheng; Kawasaki, Masahiro; Egerton, Ray F.

    2015-06-08

    There have been numerous research efforts directed towards the synthesis of gold (Au) nanoparticles (NPs) and the understanding of their formation, so that their size, shape, and stability can be well controlled for desired applications. Here, we report a dry photo-reduced method of Au NP formation directly on a membrane, such as a carbon thin film or a quartz slide. The evolution of Au NP formation was revealed by ex-situ experiments in an aberration-corrected scanning transmission electron microscope. The membranes were immersed in Au{sup 3+} solution before being taken out and quickly dried in ambient air at room temperature, then irradiated with ultraviolet (UV) light with wavelengths of 189 nm and 254 nm in a low-pressure chamber. The results show that Au{sup 3+} ions and ion clusters self-assembled on the membrane surface before UV irradiation and that solid Au NPs with sizes of 3 nm–12 nm were formed after UV irradiation. Annealing at 40 °C for about 30 min helped to further stabilize the nanoparticles. The Au NPs were uniform and well dispersed, and should find applications in the electron microscopy field, for example.

  19. The WFPC2 ultraviolet survey: The blue straggler population in NGC 5824

    SciTech Connect (OSTI)

    Sanna, N.; Dalessandro, E.; Ferraro, F. R.; Lanzoni, B.; Miocchi, P.

    2014-01-01

    We have used a combination of high-resolution Hubble Space Telescope Wide Field Planetary Camera 2 and wide-field ground-based observations, in ultraviolet and optical bands, to study the blue straggler star population of the massive outer halo globular cluster NGC 5824 over its entire radial extent. We have computed the center of the cluster and constructed the radial density profile from detailed star counts. The profile is well reproduced by a Wilson model with a small core (r{sub c} ? 4.''4) and a concentration parameter c ? 2.74. We also present the first age determination for this cluster. From a comparison with isochrones, we find t = 13 0.5 Gyr. We discuss this result in the context of the observed age-metallicity relation of Galactic globular clusters. A total of 60 bright blue stragglers has been identified. Their radial distribution is found to be bimodal, with a central peak, a well-defined minimum at r ? 20'', and an upturn at large radii. In the framework of the dynamical clock recently defined by Ferraro et al., this feature suggests that NGC 5824 is a cluster of intermediate dynamical age.

  20. Development of substrate-removal-free vertical ultraviolet light-emitting diode (RefV-LED)

    SciTech Connect (OSTI)

    Kurose, N. Aoyagi, Y.; Shibano, K.; Araki, T.

    2014-02-15

    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.

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

    DOE Patents [OSTI]

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

    1982-06-29

    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.

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

    DOE Patents [OSTI]

    Glownia, James H.; Sander, Robert K.

    1985-01-01

    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.

  3. 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

    2013-01-28

    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.

  4. Control of the polarization of a vacuum-ultraviolet, high-gain, free-electron laser

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

    Allaria, Enrico; Diviacco, Bruno; Callegari, Carlo; Finetti, Paola; Mahieu, Benoît; Viefhaus, Jens; Zangrando, Marco; De Ninno, Giovanni; Lambert, Guillaume; Ferrari, Eugenio; et al

    2014-12-02

    The two single-pass, externally seeded free-electron lasers (FELs) of the FERMI user facility are designed around Apple-II-type undulators that can operate at arbitrary polarization in the vacuum ultraviolet-to-soft x-ray spectral range. Furthermore, within each FEL tuning range, any output wavelength and polarization can be set in less than a minute of routine operations. We report the first demonstration of the full output polarization capabilities of FERMI FEL-1 in a campaign of experiments where the wavelength and nominal polarization are set to a series of representative values, and the polarization of the emitted intense pulses is thoroughly characterized by three independentmore » instruments and methods, expressly developed for the task. The measured radiation polarization is consistently >90% and is not significantly spoiled by the transport optics; differing, relative transport losses for horizontal and vertical polarization become more prominent at longer wavelengths and lead to a non-negligible ellipticity for an originally circularly polarized state. The results from the different polarimeter setups validate each other, allow a cross-calibration of the instruments, and constitute a benchmark for user experiments.« less

  5. Characterization of a radio frequency carbon nanotube growth plasma by ultraviolet absorption and optical emission spectroscopy

    SciTech Connect (OSTI)

    Cruden, Brett A.; Meyyappan, M.

    2005-04-15

    Radio frequency driven methane/hydrogen plasmas for carbon nanotube growth at pressures between 0.5 and 20 Torr, bias power from 0 to 110 W, and inductive coil power from 0 to 200 W are characterized via optical diagnostics. Ultraviolet absorption spectroscopy is used for quantitative determination of CH{sub 3} radical density for these systems, giving densities on the order of 10{sup 13} cm{sup -3}, accounting for approximately 0.1% of the plasma neutral content. Emission data are also analyzed to extract neutral gas temperatures from the H{sub 2} spectrum and electron densities and temperatures and approximate atomic H densities in the system. Neutral temperature is estimated between 700 and 1100 K, though the lower electrode is heated to 1273 K. Electron temperature is estimated to be between 2.5 and 3.5 eV in the high-energy (>12 eV) portion of the electron energy distribution, and the data suggest an overall non-Maxwellian distribution of electrons. The dissociation of hydrogen is estimated at around 0.1%. Dependencies on power and pressure are explored, indicating more efficient ionization, dissociation, and electron heating at lower pressure and higher power. The absence of any dependency on coil power suggests the plasma is operating in a noninductive mode for these conditions.

  6. Control of the polarization of a vacuum-ultraviolet, high-gain, free-electron laser

    SciTech Connect (OSTI)

    Allaria, Enrico; Diviacco, Bruno; Callegari, Carlo; Finetti, Paola; Mahieu, Benoît; Viefhaus, Jens; Zangrando, Marco; De Ninno, Giovanni; Lambert, Guillaume; Ferrari, Eugenio; Buck, Jens; Ilchen, Markus; Vodungbo, Boris; Mahne, Nicola; Svetina, Cristian; Spezzani, Carlo; Di Mitri, Simone; Penco, Giuseppe; Trovó, Mauro; Fawley, William M.; Rebernik, Primoz R.; Gauthier, David; Grazioli, Cesare; Coreno, Marcello; Ressel, Barbara; Kivimäki, Antti; Mazza, Tommaso; Glaser, Leif; Scholz, Frank; Seltmann, Joern; Gessler, Patrick; Grünert, Jan; De Fanis, Alberto; Meyer, Michael; Knie, André; Moeller, Stefan P.; Raimondi, Lorenzo; Capotondi, Flavio; Pedersoli, Emanuele; Plekan, Oksana; Danailov, Miltcho B.; Demidovich, Alexander; Nikolov, Ivaylo; Abrami, Alessandro; Gautier, Julien; Lüning, Jan; Zeitoun, Philippe; Giannessi, Luca

    2014-12-02

    The two single-pass, externally seeded free-electron lasers (FELs) of the FERMI user facility are designed around Apple-II-type undulators that can operate at arbitrary polarization in the vacuum ultraviolet-to-soft x-ray spectral range. Furthermore, within each FEL tuning range, any output wavelength and polarization can be set in less than a minute of routine operations. We report the first demonstration of the full output polarization capabilities of FERMI FEL-1 in a campaign of experiments where the wavelength and nominal polarization are set to a series of representative values, and the polarization of the emitted intense pulses is thoroughly characterized by three independent instruments and methods, expressly developed for the task. The measured radiation polarization is consistently >90% and is not significantly spoiled by the transport optics; differing, relative transport losses for horizontal and vertical polarization become more prominent at longer wavelengths and lead to a non-negligible ellipticity for an originally circularly polarized state. The results from the different polarimeter setups validate each other, allow a cross-calibration of the instruments, and constitute a benchmark for user experiments.

  7. Exploratory Data analysis ENvironment eXtreme scale (EDENx)

    SciTech Connect (OSTI)

    Steed, Chad Allen

    2015-07-01

    EDENx is a multivariate data visualization tool that allows interactive user driven analysis of large-scale data sets with high dimensionality. EDENx builds on our earlier system, called EDEN to enable analysis of more dimensions and larger scale data sets. EDENx provides an initial overview of summary statistics for each variable in the data set under investigation. EDENx allows the user to interact with graphical summary plots of the data to investigate subsets and their statistical associations. These plots include histograms, binned scatterplots, binned parallel coordinate plots, timeline plots, and graphical correlation indicators. From the EDENx interface, a user can select a subsample of interest and launch a more detailed data visualization via the EDEN system. EDENx is best suited for high-level, aggregate analysis tasks while EDEN is more appropriate for detail data investigations.

  8. Exploratory Data analysis ENvironment eXtreme scale (EDENx)

    Energy Science and Technology Software Center (OSTI)

    2015-07-01

    EDENx is a multivariate data visualization tool that allows interactive user driven analysis of large-scale data sets with high dimensionality. EDENx builds on our earlier system, called EDEN to enable analysis of more dimensions and larger scale data sets. EDENx provides an initial overview of summary statistics for each variable in the data set under investigation. EDENx allows the user to interact with graphical summary plots of the data to investigate subsets and their statisticalmore » associations. These plots include histograms, binned scatterplots, binned parallel coordinate plots, timeline plots, and graphical correlation indicators. From the EDENx interface, a user can select a subsample of interest and launch a more detailed data visualization via the EDEN system. EDENx is best suited for high-level, aggregate analysis tasks while EDEN is more appropriate for detail data investigations.« less

  9. Accident Investigation Handbook

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

    ... as shown in Figure 2-2. Investigation Electronic File Structure Assessments Timeline ... Lessons to be Learned Evidence Files (log books, training, etc.) Tasking Letter Deep ...

  10. Electrical Current Leakage and Open-Core Threading Dislocations in AlGaN-Based Deep Ultraviolet Light-Emitting Diodes.

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

    Moseley, Michael William; Allerman, Andrew A.; Crawford, Mary H.; Wierer, Jonathan; Smith, Michael L.; Biedermann, Laura

    2014-08-04

    Electrical current transport through leakage paths in AlGaN-based deep ultraviolet (DUV) lightemitting diodes (LEDs) and their effect on LED performance are investigated. Open-core threading dislocations, or nanopipes, are found to conduct current through nominally insulating Al0.7Ga0.3N layers and limit the performance of DUV-LEDs. A defect-sensitive phosphoric acid etch reveals these opencore threading dislocations in the form of large, micron-scale hexagonal etch pits visible with optical microscopy, while closed-core screw-, edge-, and mixed-type threading dislocations are represented by smaller and more numerous nanometer-scale pits visible by atomic-force microscopy. The electrical and optical performances of DUV-LEDs fabricated on similar Si-doped Al0.7Ga0.3N templatesmore » are found to have a strong correlation to the density of these nanopipes, despite their small fraction (<0.1% in this study) of the total density of threading dislocations.« less

  11. Temperature-dependent Raman and ultraviolet photoelectron spectroscopy studies on phase transition behavior of VO{sub 2} films with M1 and M2 phases

    SciTech Connect (OSTI)

    Okimura, Kunio Hanis Azhan, Nurul; Hajiri, Tetsuya; Kimura, Shin-ichi; Zaghrioui, Mustapha; Sakai, Joe

    2014-04-21

    Structural and electronic phase transitions behavior of two polycrystalline VO{sub 2} films, one with pure M1 phase and the other with pure M2 phase at room temperature, were investigated by temperature-controlled Raman spectroscopy and ultraviolet photoelectron spectroscopy (UPS). We observed characteristic transient dynamics in which the Raman modes at 195 cm{sup −1} (V-V vibration) and 616 cm{sup −1} (V-O vibration) showed remarkable hardening along the temperature in M1 phase film, indicating the rearrangements of V-V pairs and VO{sub 6} octahedra. It was also shown that the M1 Raman mode frequency approached those of invariant M2 peaks before entering rutile phase. In UPS spectra with high energy resolution of 0.03 eV for the M2 phase film, narrower V{sub 3d} band was observed together with smaller gap compared to those of M1 phase film, supporting the nature of Mott insulator of M2 phase even in the polycrystalline film. Cooperative behavior of lattice rearrangements and electronic phase transition was suggested for M1 phase film.

  12. Electrical current leakage and open-core threading dislocations in AlGaN-based deep ultraviolet light-emitting diodes

    SciTech Connect (OSTI)

    Moseley, Michael Allerman, Andrew; Crawford, Mary; Wierer, Jonathan J.; Smith, Michael; Biedermann, Laura

    2014-08-07

    Electrical current transport through leakage paths in AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) and their effect on LED performance are investigated. Open-core threading dislocations, or nanopipes, are found to conduct current through nominally insulating Al{sub 0.7}Ga{sub 0.3}N layers and limit the performance of DUV-LEDs. A defect-sensitive phosphoric acid etch reveals these open-core threading dislocations in the form of large, micron-scale hexagonal etch pits visible with optical microscopy, while closed-core screw-, edge-, and mixed-type threading dislocations are represented by smaller and more numerous nanometer-scale pits visible by atomic-force microscopy. The electrical and optical performances of DUV-LEDs fabricated on similar Si-doped Al{sub 0.7}Ga{sub 0.3}N templates are found to have a strong correlation to the density of these nanopipes, despite their small fraction (<0.1% in this study) of the total density of threading dislocations.

  13. A Fault-Oblivious Extreme-Scale Execution Environment (FOX)

    SciTech Connect (OSTI)

    Van Hensbergen, Eric; Speight, William; Xenidis, Jimi

    2013-03-15

    IBM Research’s contribution to the Fault Oblivious Extreme-scale Execution Environment (FOX) revolved around three core research deliverables: ● collaboration with Boston University around the Kittyhawk cloud infrastructure which both enabled a development and deployment platform for the project team and provided a fault-injection testbed to evaluate prototypes ● operating systems research focused on exploring role-based operating system technologies through collaboration with Sandia National Labs on the NIX research operating system and collaboration with the broader IBM Research community around a hybrid operating system model which became known as FusedOS ● IBM Research also participated in an advisory capacity with the Boston University SESA project, the core of which was derived from the K42 operating system research project funded in part by DARPA’s HPCS program. Both of these contributions were built on a foundation of previous operating systems research funding by the Department of Energy’s FastOS Program. Through the course of the X-stack funding we were able to develop prototypes, deploy them on production clusters at scale, and make them available to other researchers. As newer hardware, in the form of BlueGene/Q, came online, we were able to port the prototypes to the new hardware and release the source code for the resulting prototypes as open source to the community. In addition to the open source coded for the Kittyhawk and NIX prototypes, we were able to bring the BlueGene/Q Linux patches up to a more recent kernel and contribute them for inclusion by the broader Linux community. The lasting impact of the IBM Research work on FOX can be seen in its effect on the shift of IBM’s approach to HPC operating systems from Linux and Compute Node Kernels to role-based approaches as prototyped by the NIX and FusedOS work. This impact can be seen beyond IBM in follow-on ideas being incorporated into the proposals for the Exasacale Operating

  14. Matter in Extreme Conditions Instrument - Conceptual Design Report

    SciTech Connect (OSTI)

    Boyce, R.F.; Boyce, R.M.; Haller, G.; Hastings, J.B.; Hays, G.; Lee, H.J.; Lee, R.W.; Nagler, B.; Scharfenstein, M.; Marsh, D.; White, W.E.; /SLAC

    2009-12-09

    The SLAC National Accelerator Laboratory (SLAC), in collaboration with Argonne National Laboratory (ANL), Lawrence Livermore National Laboratory (LLNL), and the University of California at Los Angeles (UCLA), is constructing a Free-Electron Laser (FEL) research facility. The FEL has already met its performance goals in the wavelength range 1.5 nm - 0.15 nm. This facility, the Linac Coherent Light Source (LCLS), utilizes the SLAC 2-Mile Linear Accelerator (linac) and will produce sub-picosecond pulses of short wavelength X-rays with very high peak brightness and almost complete transverse coherence. The final one-third of the SLAC linac is used as the source of electrons for the LCLS. The high energy electrons are transported across the SLAC Research Yard, into a tunnel which houses a long undulator. In passing through the undulator, the electrons are bunched by the force of their own synchrotron radiation and produce an intense, monochromatic, spatially coherent beam of X-rays. By varying the electron energy, the FEL X-ray wavelength is tunable from 1.5 nm to 0.15 nm. The LCLS includes two experimental halls as well as X-ray optics and infrastructure necessary to create a facility that can be developed for research in a variety of disciplines such as atomic physics, materials science, plasma physics and biosciences. This Conceptual Design Report, the authors believe, confirms the feasibility of designing and constructing an X-ray instrument in order to exploit the unique scientific capability of LCLS by creating extreme conditions and study the behavior of plasma under those controlled conditions. This instrument will address the Office of Science, Fusion Energy Sciences, mission objective related to study of Plasma and Warm Dense Matter as described in the report titled LCLS, the First Experiments, prepared by the LCLS Scientific Advisory Committee (SAC) in September 2000. The technical objective of the LCLS Matter in Extreme Conditions (MEC) Instrument project is

  15. Durable silver mirror with ultra-violet thru far infra-red reflection

    DOE Patents [OSTI]

    Wolfe, Jesse D.

    2010-11-23

    A durable highly reflective silver mirror characterized by high reflectance in a broad spectral range of about 300 nm in the UV to the far infrared (.about.10000 nm), as well as exceptional environmental durability. A high absorptivity metal underlayer is used which prevents the formation of a galvanic cell with a silver layer while increasing the reflectance of the silver layer. Environmentally durable overcoat layers are provided to enhance mechanical and chemical durability and protect the silver layer from corrosion and tarnishing, for use in a wide variety of surroundings or climates, including harsh or extreme environments.

  16. 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; Kuin, Paul; De Pasquale, Massimiliano; Scalzo, Richard; Holland, Stephen; Milne, Peter

    2014-05-20

    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.

  17. ACTUAL-WASTE TESTING OF ULTRAVIOLET LIGHT TO AUGMENT THE ENHANCED CHEMICAL CLEANING OF SRS SLUDGE

    SciTech Connect (OSTI)

    Martino, C.; King, W.; Ketusky, E.

    2012-07-10

    In support of Savannah River Site (SRS) tank closure efforts, the Savannah River National Laboratory (SRNL) conducted Real Waste Testing (RWT) to evaluate Enhanced Chemical Cleaning (ECC), an alternative to the baseline 8 wt% oxalic acid (OA) chemical cleaning technology for tank sludge heel removal. ECC utilizes a more dilute OA solution (2 wt%) and an oxalate destruction technology using ozonolysis with or without the application of ultraviolet (UV) light. SRNL conducted tests of the ECC process using actual SRS waste material from Tanks 5F and 12H. The previous phase of testing involved testing of all phases of the ECC process (sludge dissolution, OA decomposition, product evaporation, and deposition tank storage) but did not involve the use of UV light in OA decomposition. The new phase of testing documented in this report focused on the use of UV light to assist OA decomposition, but involved only the OA decomposition and deposition tank portions of the process. Compared with the previous testing at analogous conditions without UV light, OA decomposition with the use of UV light generally reduced time required to reach the target of <100 mg/L oxalate. This effect was the most pronounced during the initial part of the decomposition batches, when pH was <4. For the later stages of each OA decomposition batch, the increase in OA decomposition rate with use of the UV light appeared to be minimal. Testing of the deposition tank storage of the ECC product resulted in analogous soluble concentrations regardless of the use or non-use of UV light in the ECC reactor.

  18. Infrared lessons for ultraviolet gravity: the case of massive gravity and Born-Infeld

    SciTech Connect (OSTI)

    Jimnez, Jose Beltrn; Heisenberg, Lavinia; Olmo, Gonzalo J. E-mail: Lavinia.Heisenberg@unige.ch

    2014-11-01

    We generalize the ultraviolet sector of gravitation via a Born-Infeld action using lessons from massive gravity. The theory contains all of the elementary symmetric polynomials and is treated in the Palatini formalism. We show how the connection can be solved algebraically to be the Levi-Civita connection of an effective metric. The non-linearity of the algebraic equations yields several branches, one of which always reduces to General Relativity at low curvatures. We explore in detail a minimal version of the theory, for which we study solutions in the presence of a perfect fluid with special attention to the cosmological evolution. In vacuum we recover Ricci-flat solutions, but also an additional physical solution corresponding to an Einstein space. The existence of two physical branches remains for non-vacuum solutions and, in addition, the branch that connects to the Einstein space in vacuum is not very sensitive to the specific value of the energy density. For the branch that connects to the General Relativity limit we generically find three behaviours for the Hubble function depending on the equation of state of the fluid, namely: either there is a maximum value for the energy density that connects continuously with vacuum, or the energy density can be arbitrarily large but the Hubble function saturates and remains constant at high energy densities, or the energy density is unbounded and the Hubble function grows faster than in General Relativity. The second case is particularly interesting because it could offer an interesting inflationary epoch even in the presence of a dust component. Finally, we discuss the possibility of avoiding certain types of singularities within the minimal model.

  19. Director, Division of Investigations

    Broader source: Energy.gov [DOE]

    The Federal Energy Regulatory Commission is looking for an experienced, highly skilled executive to serve as Director of the Division of Investigations (DOI) in the Office of Enforcement (OE). The...

  20. Intrinsic relationship between electronic structures and phase transition of SrBi{sub 2?x}Nd{sub x}Nb{sub 2}O{sub 9} ceramics from ultraviolet ellipsometry at elevated temperatures

    SciTech Connect (OSTI)

    Duan, Z. H.; Jiang, K.; Xu, L. P.; Li, Y. W.; Hu, Z. G. Chu, J. H.

    2014-02-07

    The ferroelectric orthorhombic to paraelectric tetragonal phase transition of SrBi{sub 2?x}Nd{sub x}Nb{sub 2}O{sub 9} (x?=?0, 0.05, 0.1, and 0.2) layer-structured ceramics has been investigated by temperature-dependent spectroscopic ellipsometry. Based on the analysis of dielectric functions from 0 to 500?C with double Tauc-Lorentz dispersion model, the interband transitions located at ultraviolet region have shown an abrupt variation near the Curie temperature. The changes of dielectric functions are mainly due to the thermal-optical and/or photoelastic effect. Moreover, the characteristic alteration in interband transitions can be ascribed to distortion of NbO{sub 6} octahedron and variation of hybridization between Bi 6s and O 2p states during the structure transformation.

  1. Effects of Mg-doped AlN/AlGaN superlattices on properties of p-GaN contact layer and performance of deep ultraviolet light emitting diodes

    SciTech Connect (OSTI)

    Al tahtamouni, T. M.; Lin, J. Y.; Jiang, H. X.

    2014-04-15

    Mg-doped AlN/AlGaN superlattice (Mg-SL) and Mg-doped AlGaN epilayers have been investigated in the 284 nm deep ultraviolet (DUV) light emitting diodes (LEDs) as electron blocking layers. It was found that the use of Mg-SL improved the material quality of the p-GaN contact layer, as evidenced in the decreased density of surface pits and improved surface morphology and crystalline quality. The performance of the DUV LEDs fabricated using Mg-SL was significantly improved, as manifested by enhanced light intensity and output power, and reduced turn-on voltage. The improved performance is attributed to the enhanced blocking of electron overflow, and enhanced hole injection.

  2. X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy investigation of Al-related dipole at the HfO{sub 2}/Si interface

    SciTech Connect (OSTI)

    Zhu, L. Q.; Barrett, N.; Jegou, P.

    2009-01-15

    The presence of an ultrathin oxide layer at the high-k/SiO{sub 2} interface may result in an interfacial dipole related to the specific high-k dielectric used for the gate stacks. 1 nm HfO{sub 2}/x nmAl{sub 2}O{sub 3}/SiO{sub 2}/Si stacks with different x values (x=0, 0.4, 0.8, 1.2) have been prepared by atomic layer deposition. Using photoelectron spectroscopy, an Al-related interfacial dipole in the HfO{sub 2}/Al{sub 2}O{sub 3}/SiO{sub 2} gate stack has been identified. X-ray photoelectron spectroscopy analysis shows that the dipole is correlated with the formation of an interfacial Al-silicate. The dipole is located at the Al-silicate interface between Al{sub 2}O{sub 3} and SiO{sub 2}, and its strength increases with the increase in Al{sub 2}O{sub 3} thickness because of Al silicate growth. Such Al-related interfacial dipole should have potential applications in future positive metal-oxide-semiconductor devices.

  3. Intensity, duration, and frequency of precipitation extremes under 21st-century warming scenarios

    SciTech Connect (OSTI)

    Kao, Shih-Chieh; Ganguly, Auroop R

    2011-01-01

    Recent research on the projection of precipitation extremes has either focused on conceptual physical mechanisms that generate heavy precipitation or rigorous statistical methods that extrapolate tail behavior. However, informing both climate prediction and impact assessment requires concurrent physically and statistically oriented analysis. A combined examination of climate model simulations and observation-based reanalysis data sets suggests more intense and frequent precipitation extremes under 21st-century warming scenarios. Utilization of statistical extreme value theory and resampling-based uncertainty quantification combined with consideration of the Clausius-Clapeyron relationship reveals consistently intensifying trends for precipitation extremes at a global-average scale. However, regional and decadal analyses reveal specific discrepancies in the physical mechanisms governing precipitation extremes, as well as their statistical trends, especially in the tropics. The intensifying trend of precipitation extremes has quantifiable impacts on intensity-duration-frequency curves, which in turn have direct implications for hydraulic engineering design and water-resources management. The larger uncertainties at regional and decadal scales suggest the need for caution during regional-scale adaptation or preparedness decisions. Future research needs to explore the possibility of uncertainty reduction through higher resolution global climate models, statistical or dynamical downscaling, as well as improved understanding of precipitation extremes processes.

  4. Optimization of an on-board imaging system for extremely rapid radiation therapy

    SciTech Connect (OSTI)

    Cherry Kemmerling, Erica M.; Wu, Meng Yang, He; Fahrig, Rebecca; Maxim, Peter G.; Loo, Billy W.

    2015-11-15

    Purpose: Next-generation extremely rapid radiation therapy systems could mitigate the need for motion management, improve patient comfort during the treatment, and increase patient throughput for cost effectiveness. Such systems require an on-board imaging system that is competitively priced, fast, and of sufficiently high quality to allow good registration between the image taken on the day of treatment and the image taken the day of treatment planning. In this study, three different detectors for a custom on-board CT system were investigated to select the best design for integration with an extremely rapid radiation therapy system. Methods: Three different CT detectors are proposed: low-resolution (all 4 × 4 mm pixels), medium-resolution (a combination of 4 × 4 mm pixels and 2 × 2 mm pixels), and high-resolution (all 1 × 1 mm pixels). An in-house program was used to generate projection images of a numerical anthropomorphic phantom and to reconstruct the projections into CT datasets, henceforth called “realistic” images. Scatter was calculated using a separate Monte Carlo simulation, and the model included an antiscatter grid and bowtie filter. Diagnostic-quality images of the phantom were generated to represent the patient scan at the time of treatment planning. Commercial deformable registration software was used to register the diagnostic-quality scan to images produced by the various on-board detector configurations. The deformation fields were compared against a “gold standard” deformation field generated by registering initial and deformed images of the numerical phantoms that were used to make the diagnostic and treatment-day images. Registrations of on-board imaging system data were judged by the amount their deformation fields differed from the corresponding gold standard deformation fields—the smaller the difference, the better the system. To evaluate the registrations, the pointwise distance between gold standard and realistic registration

  5. MaRIE 1.0: The Matter-Radiation Interactions in Extremes Project, and the

    Office of Scientific and Technical Information (OSTI)

    Challenge of Dynamic Mesoscale Imaging (Conference) | SciTech Connect Conference: MaRIE 1.0: The Matter-Radiation Interactions in Extremes Project, and the Challenge of Dynamic Mesoscale Imaging Citation Details In-Document Search Title: MaRIE 1.0: The Matter-Radiation Interactions in Extremes Project, and the Challenge of Dynamic Mesoscale Imaging The Matter-Radiation Interactions in Extremes project will build the experimental facility for the time-dependent control of dynamic material

  6. DOE Tour of Zero: McKinley Project by Carl Franklin Homes and Green Extreme

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

    Homes | Department of Energy McKinley Project by Carl Franklin Homes and Green Extreme Homes DOE Tour of Zero: McKinley Project by Carl Franklin Homes and Green Extreme Homes 1 of 9 Carl Franklin Homes and Green Extreme Homes Community Development Corporation built this 1,594-square-foot two-story home in Garland, Texas, to the performance criteria of the U.S. Department of Energy Zero Energy Ready Home (ZERH) program. 2 of 9 This affordable energy-efficient home was built for a husband and

  7. Assessing Regional Scale Variability in Extreme Value Statistics Under Altered Climate Scenarios

    SciTech Connect (OSTI)

    Brunsell, Nathaniel; Mechem, David; Ma, Chunsheng

    2015-02-20

    Recent studies have suggested that low-frequency modes of climate variability can significantly influence regional climate. The climatology associated with extreme events has been shown to be particularly sensitive. This has profound implications for droughts, heat waves, and food production. We propose to examine regional climate simulations conducted over the continental United States by applying a recently developed technique which combines wavelet multi–resolution analysis with information theory metrics. This research is motivated by two fundamental questions concerning the spatial and temporal structure of extreme events. These questions are 1) what temporal scales of the extreme value distributions are most sensitive to alteration by low-frequency climate forcings and 2) what is the nature of the spatial structure of variation in these timescales? The primary objective is to assess to what extent information theory metrics can be useful in characterizing the nature of extreme weather phenomena. Specifically, we hypothesize that (1) changes in the nature of extreme events will impact the temporal probability density functions and that information theory metrics will be sensitive these changes and (2) via a wavelet multi–resolution analysis, we will be able to characterize the relative contribution of different timescales on the stochastic nature of extreme events. In order to address these hypotheses, we propose a unique combination of an established regional climate modeling approach and advanced statistical techniques to assess the effects of low-frequency modes on climate extremes over North America. The behavior of climate extremes in RCM simulations for the 20th century will be compared with statistics calculated from the United States Historical Climatology Network (USHCN) and simulations from the North American Regional Climate Change Assessment Program (NARCCAP). This effort will serve to establish the baseline behavior of climate extremes, the

  8. FAR-ULTRAVIOLET SPECTROSCOPY OF THE NOVA-LIKE VARIABLE KQ MONOCEROTIS: A NEW SW SEXTANTIS STAR?

    SciTech Connect (OSTI)

    Wolfe, Aaron; Sion, Edward M.; Bond, Howard E. E-mail: edward.sion@villanova.edu

    2013-06-01

    New optical spectra obtained with the SMARTS 1.5 m telescope and archival International Ultraviolet Explorer (IUE) far-ultraviolet (FUV) spectra of the nova-like variable KQ Mon are discussed. The optical spectra reveal Balmer lines in absorption as well as He I absorption superposed on a blue continuum. The 2011 optical spectrum is similar to the KPNO 2.1 m IIDS spectrum we obtained 33 years earlier except that the Balmer and He I absorption is stronger in 2011. Far-ultraviolet IUE spectra reveal deep absorption lines due to C II, Si III, Si IV, C IV, and He II, but no P Cygni profiles indicative of wind outflow. We present the results of the first synthetic spectral analysis of the IUE archival spectra of KQ Mon with realistic optically thick, steady-state, viscous accretion-disk models with vertical structure and high-gravity photosphere models. We find that the photosphere of the white dwarf (WD) contributes very little FUV flux to the spectrum and is overwhelmed by the accretion light of a steady disk. Disk models corresponding to a WD mass of {approx}0.6 M {sub Sun }, with an accretion rate of order 10{sup -9} M {sub Sun} yr{sup -1} and disk inclinations between 60 Degree-Sign and 75 Degree-Sign , yield distances from the normalization in the range of 144-165 pc. KQ Mon is discussed with respect to other nova-like variables. Its spectroscopic similarity to the FUV spectra of three definite SW Sex stars suggests that it is likely a member of the SW Sex class and lends support to the possibility that the WD is magnetic.

  9. ULTRAVIOLET EMISSION-LINE CORRELATIONS IN HST/COS SPECTRA OF ACTIVE GALACTIC NUCLEI: SINGLE-EPOCH BLACK HOLE MASSES

    SciTech Connect (OSTI)

    Tilton, Evan M.; Shull, J. Michael, E-mail: evan.tilton@colorado.edu, E-mail: michael.shull@colorado.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States)

    2013-09-01

    Effective methods of measuring supermassive black hole masses in active galactic nuclei (AGNs) are of critical importance to studies of galaxy evolution. While there has been much success in obtaining masses through reverberation mapping, the extensive observing time required by this method has limited the practicality of applying it to large samples at a variety of redshifts. This limitation highlights the need to estimate these masses using single-epoch spectroscopy of ultraviolet (UV) emission lines. We use UV spectra of 44 AGNs from HST/COS, the International Ultraviolet Explorer, and the Far Ultraviolet Spectroscopic Explorer of the C IV {lambda}1549, O VI {lambda}1035, O III] {lambda}1664, He II {lambda}1640, C II {lambda}1335, and Mg II {lambda}2800 emission lines and explore their potential as tracers of the broad-line region and supermassive black hole mass. The higher signal-to-noise ratio and better spectral resolution of the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) resolve AGN intrinsic absorption and produce more accurate line widths. From these, we test the viability of mass-scaling relationships based on line widths and luminosities and carry out a principal component analysis based on line luminosities, widths, skewness, and kurtosis. At L{sub 1450} {<=} 10{sup 45} erg s{sup -1}, the UV line luminosities correlate well with H{beta}, as does the 1450 A continuum luminosity. We find that C IV, O VI, and Mg II can be used as reasonably accurate estimators of AGN black hole masses, while He II and C II are uncorrelated.

  10. EXTREME STAR FORMATION IN THE HOST GALAXIES OF THE FASTEST GROWING SUPERMASSIVE BLACK HOLES AT z = 4.8

    SciTech Connect (OSTI)

    Mor, Rivay; Netzer, Hagai; Trakhtenbrot, Benny; Shemmer, Ohad; Lira, Paulina

    2012-04-20

    We report new Herschel observations of 25 z {approx_equal} 4.8 extremely luminous optically selected active galactic nuclei (AGNs). Five of the sources have extremely large star-forming (SF) luminosities, L{sub SF}, corresponding to SF rates (SFRs) of 2800-5600 M{sub Sun} yr{sup -1} assuming a Salpeter initial mass function. The remaining sources have only upper limits on their SFRs, but stacking their Herschel images results in a mean SFR of 700 {+-} 150 M{sub Sun} yr{sup -1}. The higher SFRs in our sample are comparable to the highest observed values so far at any redshift. Our sample does not contain obscured AGNs, which enables us to investigate several evolutionary scenarios connecting supermassive black holes and SF activity in the early universe. The most probable scenario is that we are witnessing the peak of SF activity in some sources and the beginning of the post-starburst decline in others. We suggest that all 25 sources, which are at their peak AGN activity, are in large mergers. AGN feedback may be responsible for diminishing the SF activity in 20 of them, but is not operating efficiently in 5 others.

  11. Extreme solid state refrigeration using nanostructured Bi-Te alloys.

    SciTech Connect (OSTI)

    Lima Sharma, Ana L.; Spataru, Dan Catalin; Medlin, Douglas L.; Sharma, Peter Anand; Morales, Alfredo Martin

    2009-09-01

    Materials are desperately needed for cryogenic solid state refrigeration. We have investigated nanostructured Bi-Te alloys for their potential use in Ettingshausen refrigeration to liquid nitrogen temperatures. These alloys form alternating layers of Bi{sub 2} and Bi{sub 2}Te{sub 3} blocks in equilibrium. The composition Bi{sub 4}Te{sub 3} was identified as having the greatest potential for having a high Ettingshausen figure of merit. Both single crystal and polycrystalline forms of this material were synthesized. After evaluating the Ettingshausen figure of merit for a large, high quality polycrystal, we simulated the limits of practical refrigeration in this material from 200 to 77 K using a simple device model. The band structure was also computed and compared to experiments. We discuss the crystal growth, transport physics, and practical refrigeration potential of Bi-Te alloys.

  12. Deep Chandra , HST-COS, and megacam observations of the Phoenix cluster: Extreme star formation and AGN feedback on hundred kiloparsec scales

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

    McDonald, Michael; McNamara, Brian R.; Perimeter Institute for Theoretical Physics, Waterloo; van Weeren, Reinout J.; Applegate, Douglas E.; Bayliss, Matthew; Harvard Univ., Cambridge, MA; Bautz, Marshall W.; Benson, Bradford A.; Univ. of Chicago, Chicago, IL; et al

    2015-09-28

    In this study, we present new ultraviolet, optical, and X-ray data on the Phoenix galaxy cluster (SPT-CLJ2344-4243). Deep optical imaging reveals previously undetected filaments of star formation, extending to radii of ~50–100 kpc in multiple directions. Combined UV-optical spectroscopy of the central galaxy reveals a massive (2 × 109 M⊙), young (~4.5 Myr) population of stars, consistent with a time-averaged star formation rate of 610 ± 50 M⊙ yr–1. We report a strong detection of O vi λλ1032,1038, which appears to originate primarily in shock-heated gas, but may contain a substantial contribution (>1000 M⊙ yr–1) from the cooling intracluster mediummore » (ICM). We confirm the presence of deep X-ray cavities in the inner ~10 kpc, which are among the most extreme examples of radio-mode feedback detected to date, implying jet powers of 2 – 7 × 1045 erg s–1. We provide evidence that the active galactic nucleus inflating these cavities may have only recently transitioned from "quasar-mode" to "radio-mode," and may currently be insufficient to completely offset cooling. A model-subtracted residual X-ray image reveals evidence for prior episodes of strong radio-mode feedback at radii of ~100 kpc, with extended "ghost" cavities indicating a prior epoch of feedback roughly 100 Myr ago. This residual image also exhibits significant asymmetry in the inner ~200 kpc (0.15R500), reminiscent of infalling cool clouds, either due to minor mergers or fragmentation of the cooling ICM. Taken together, these data reveal a rapidly evolving cool core which is rich with structure (both spatially and in temperature), is subject to a variety of highly energetic processes, and yet is cooling rapidly and forming stars along thin, narrow filaments.« less

  13. Extreme Balance of System Hardware Cost Reduction (BOS-X) Funding Opportunity

    Broader source: Energy.gov [DOE]

    Under the Extreme Balance of System Hardware Cost Reduction (BOS-X) program, DOE is funding new components and system designs to overcome scientific, technological, and engineering barriers to...

  14. COLLOQUIUM: The MaRIE (Matter-Radiation Interactions in Extremes...

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

    January 27, 2016, 4:15pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: The MaRIE (Matter-Radiation Interactions in Extremes) Project Dr. Cris Barnes Los Alamos National Laboratory...

  15. A Better Way to ID Extreme Weather Events in Climate Models

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

    develop ever-more sophisticated computer models to predict the effects of climate change, one of the things they'll look for are changes in the frequency of extreme weather...

  16. Extremal covariant positive operator valued measures: The case of a compact symmetry group

    SciTech Connect (OSTI)

    Carmeli, Claudio; Heinosaari, Teiko; Pellonpaeae, Juha-Pekka; Toigo, Alessandro

    2008-06-15

    Given a unitary representation U of a compact group G and a transitive G-space {omega}, we characterize the extremal elements of the convex set of all U-covariant positive operator valued measures.

  17. Northeast Climate Science Center: Transposing Extreme Rainfall to Assess Climate Vulnerability

    Broader source: Energy.gov [DOE]

    Climate models predict significant increases in the magnitude and frequency of extreme rainfalls.  However, climate model projections of precipitation vary greatly across models.  For communities...

  18. MaRIE 1.0: The Matter-Radiation Interactions in Extremes Project...

    Office of Scientific and Technical Information (OSTI)

    MaRIE 1.0: The Matter-Radiation Interactions in Extremes Project, and the Challenge of Dynamic Mesoscale Imaging Citation Details In-Document Search Title: MaRIE 1.0: The Matter-Ra...

  19. MaRIE 1.0 -- The Matter-Radiation Interactions in Extremes Project...

    Office of Scientific and Technical Information (OSTI)

    MaRIE 1.0 -- The Matter-Radiation Interactions in Extremes Project: Accelerating Qualification, Certification, and Assessment Citation Details In-Document Search Title: MaRIE 1.0 ...

  20. 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.

    2013-02-28

    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

  1. Ultraviolet photodissociation dynamics of the n-propyl and i-propyl radicals

    SciTech Connect (OSTI)

    Song, Yu; Zheng, Xianfeng; Zhou, Weidong; Lucas, Michael; Zhang, Jingsong

    2015-06-14

    Ultraviolet (UV) photodissociation dynamics of jet-cooled n-propyl (n-C{sub 3}H{sub 7}) radical via the 3s Rydberg state and i-propyl (i-C{sub 3}H{sub 7}) radical via the 3p Rydberg states are studied in the photolysis wavelength region of 230260 nm using high-n Rydberg atom time-of-flight and resonance enhanced multiphoton ionization techniques. The H-atom photofragment yield spectra of the n-propyl and i-propyl radicals are broad and in good agreement with the UV absorption spectra. The H + propene product translational energy distributions, P(E{sub T})s, of both n-propyl and i-propyl are bimodal, with a slow component peaking around 5-6 kcal/mol and a fast one peaking at ?50 kcal/mol (n-propyl) and ?45 kcal/mol (i-propyl). The fraction of the average translational energy in the total excess energy, ?f{sub T}?, is 0.3 for n-propyl and 0.2 for i-propyl, respectively. The H-atom product angular distributions of the slow components of n-propyl and i-propyl are isotropic, while that of the fast component of n-propyl is anisotropic (with an anisotropy parameter ?0.8) and that of i-propyl is nearly isotropic. Site-selective loss of the ? hydrogen atom is confirmed using the partially deuterated CH{sub 3}CH{sub 2}CD{sub 2} and CH{sub 3}CDCH{sub 3} radicals. The bimodal translational energy and angular distributions indicate two dissociation pathways to the H + propene products in the n-propyl and i-propyl radicals: (i) a unimolecular dissociation pathway from the hot ground-state propyl after internal conversion from the 3s and 3p Rydberg states and (ii) a direct, prompt dissociation pathway coupling the Rydberg excited states to a repulsive part of the ground-state surface, presumably via a conical intersection.

  2. SIMULTANEOUS X-RAY AND ULTRAVIOLET OBSERVATIONS OF THE SW SEXTANTIS STAR DW URSAE MAJORIS

    SciTech Connect (OSTI)

    Hoard, D. W.; Wachter, S.; Lu, Ting-Ni; Knigge, Christian; Homer, Lee; Szkody, Paula; Still, M.; Long, Knox S.; Dhillon, V. S.

    2010-11-15

    We present the first pointed X-ray observation of DW Ursae Majoris, a novalike cataclysmic variable (CV) and one of the archetype members of the SW Sextantis class, obtained with the XMM-Newton satellite. These data provide the first detailed look at an SW Sex star in the X-ray regime (with previous X-ray knowledge of the SW Sex stars limited primarily to weak or non-detections in the ROSAT All Sky Survey). It is also one of only a few XMM-Newton observations (to date) of any high mass transfer rate novalike CV, and the only one in the evolutionarily important 3-4 hr orbital period range. The observed X-ray spectrum of DW UMa is very soft, with {approx}95% of the detected X-ray photons at energies <2 keV. The spectrum can be fit equally well by a one-component cooling flow model, with a temperature range of 0.2-3.5 keV, or a two-component, two-temperature thermal plasma model, containing hard ({approx}5-6 keV) and soft ({approx}0.8 keV) components. The X-ray light curve of DW UMa shows a likely partial eclipse, implying X-ray reprocessing in a vertically extended region, and an orbital modulation, implying a structural asymmetry in the X-ray reprocessing site (e.g., it cannot be a uniform corona). We also obtained a simultaneous near-ultraviolet light curve of DW UMa using the Optical Monitor on XMM-Newton. This light curve is similar in appearance to published optical-UV light curves of DW UMa and shows a prominent deep eclipse. Regardless of the exact nature of the X-ray reprocessing site in DW UMa, the lack of a prominent hard X-ray total eclipse and very low fraction of high energy X-rays point to the presence of an optically and geometrically thick accretion disk that obscures the boundary layer and modifies the X-ray spectrum emitted near the white dwarf.

  3. THE GALEX TIME DOMAIN SURVEY. I. SELECTION AND CLASSIFICATION OF OVER A THOUSAND ULTRAVIOLET VARIABLE SOURCES

    SciTech Connect (OSTI)

    Gezari, S.; Martin, D. C.; Forster, K.; Neill, J. D.; Morrissey, P.; Wyder, T. K.; Huber, M.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Magnier, E. A.; Tonry, J. L.; Heckman, T.; Bianchi, L.; Neff, S. G.; Seibert, M.; Schiminovich, D.; Price, P. A.

    2013-03-20

    We present the selection and classification of over a thousand ultraviolet (UV) variable sources discovered in {approx}40 deg{sup 2} of GALEX Time Domain Survey (TDS) NUV images observed with a cadence of 2 days and a baseline of observations of {approx}3 years. The GALEX TDS fields were designed to be in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey, which provides deep optical imaging and simultaneous optical transient detections via image differencing. We characterize the GALEX photometric errors empirically as a function of mean magnitude, and select sources that vary at the 5{sigma} level in at least one epoch. We measure the statistical properties of the UV variability, including the structure function on timescales of days and years. We report classifications for the GALEX TDS sample using a combination of optical host colors and morphology, UV light curve characteristics, and matches to archival X-ray, and spectroscopy catalogs. We classify 62% of the sources as active galaxies (358 quasars and 305 active galactic nuclei), and 10% as variable stars (including 37 RR Lyrae, 53 M dwarf flare stars, and 2 cataclysmic variables). We detect a large-amplitude tail in the UV variability distribution for M-dwarf flare stars and RR Lyrae, reaching up to |{Delta}m| = 4.6 mag and 2.9 mag, respectively. The mean amplitude of the structure function for quasars on year timescales is five times larger than observed at optical wavelengths. The remaining unclassified sources include UV-bright extragalactic transients, two of which have been spectroscopically confirmed to be a young core-collapse supernova and a flare from the tidal disruption of a star by dormant supermassive black hole. We calculate a surface density for variable sources in the UV with NUV < 23 mag and |{Delta}m| > 0.2 mag of {approx}8.0, 7.7, and 1.8 deg{sup -2} for quasars, active galactic nuclei, and RR Lyrae stars, respectively. We also calculate a surface density rate in the

  4. Professor and Director of the Fusion Science Center of Extreme States of

    National Nuclear Security Administration (NNSA)

    Matter and Fast Ignition, University of Rochester | National Nuclear Security Administration | (NNSA) Professor and Director of the Fusion Science Center of Extreme States of Matter and Fast Ignition, University of Rochester Edward Moses congratulates fellow award winner Riccardo Betti Riccardo Betti September 2009 Edward Teller Medal Riccardo Betti of the University of Rochester's Fusion Science Center of Extreme State fo Matter and Fast Ignition was recently awarded with the 2009 Edward

  5. U.S. Energy Sector Vulnerabilities to Climate Change and Extreme Weather |

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

    Department of Energy U.S. Energy Sector Vulnerabilities to Climate Change and Extreme Weather U.S. Energy Sector Vulnerabilities to Climate Change and Extreme Weather This report-part of the Administration's efforts to support national climate change adaptation planning through the Interagency Climate Change Adaptation Task Force and Strategic Sustainability Planning process established under Executive Order 13514 and to advance the U.S. Department of Energy's goal of promoting energy

  6. 2012 Scientific Collaborations at Extreme-Scale | U.S. DOE Office of

    Office of Science (SC) Website

    Science (SC) 2 Scientific Collaborations at Extreme-Scale Advanced Scientific Computing Research (ASCR) ASCR Home About Research Applied Mathematics Computer Science Next Generation Networking 2012 Scientific Collaborations at Extreme-Scale Scientific Discovery through Advanced Computing (SciDAC) ASCR SBIR-STTR Facilities Science Highlights Benefits of ASCR Funding Opportunities Advanced Scientific Computing Advisory Committee (ASCAC) Community Resources Contact Information Advanced

  7. Energy Frontier Research in Extreme Environments (EFree) | U.S. DOE Office

    Office of Science (SC) Website

    of Science (SC) Frontier Research in Extreme Environments (EFree) Energy Frontier Research Centers (EFRCs) EFRCs Home Centers EFRC External Websites Research Science Highlights News & Events Publications History Contact BES Home Centers Energy Frontier Research in Extreme Environments (EFree) Print Text Size: A A A FeedbackShare Page EFree Header Director Russell Hemley Lead Institution Carnegie Institution of Washington Year Established 2009 Mission To accelerate the discovery and

  8. First-of-its-Kind NNSA Capability to Support Study of Materials at Extreme

    National Nuclear Security Administration (NNSA)

    Conditions for Stockpile Stewardship | National Nuclear Security Administration | (NNSA) First-of-its-Kind NNSA Capability to Support Study of Materials at Extreme Conditions for Stockpile Stewardship August 04, 2016 WASHINGTON - A new first-of-its-kind-worldwide research capability will help unravel the mysteries of material behavior at extreme conditions and short time scales in support of the Department of Energy's National Nuclear Security Administration's (DOE/NNSA's) vital national

  9. The matter in extreme conditions instrument at the Linac Coherent Light Source

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

    Nagler, Bob; Arnold, Brice; Bouchard, Gary; Boyce, Richard F.; Boyce, Richard M.; Callen, Alice; Campell, Marc; Curiel, Ruben; Galtier, Eric; Garofoli, Justin; et al

    2015-04-21

    The LCLS beam provides revolutionary capabilities for studying the transient behavior of matter in extreme conditions. The particular strength of the Matter in Extreme Conditions instrument is that it combines the unique LCLS beam with high-power optical laser beams, and a suite of dedicated diagnostics tailored for this field of science. In this paper an overview of the beamline, the capabilities of the instrumentation, and selected highlights of experiments and commissioning results are presented.

  10. Extreme Weather Events and Interconnected Infrastructures: Toward More Comprehensive Climate Change Planning

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

    Wilbanks, Thomas J.; Fernandez, Steven J.; Allen, Melissa R.

    2015-06-23

    The President s Climate Change Action Plan calls for the development of better science, data, and tools for climate preparedness. Many of the current questions about preparedness for extreme weather events in coming decades are, however, difficult to answer with assets that have been developed by climate science to answer longer-term questions about climate change. Capacities for projecting exposures to climate-related extreme events, along with their implications for interconnected infrastructures, are now emerging.

  11. Impact of Extreme Injection Pressure and EGR on the Combustion System of a

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

    HD Single Cylinder Engine | Department of Energy Extreme Injection Pressure and EGR on the Combustion System of a HD Single Cylinder Engine Impact of Extreme Injection Pressure and EGR on the Combustion System of a HD Single Cylinder Engine Poster presentation at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of FreedomCAR and Vehicle Technologies (OFCVT).

  12. Lack of uniform trends but increasing spatial variability in observed Indian rainfall extremes

    SciTech Connect (OSTI)

    Ghosh, Subimal [ORNL; Das, Debasish [ORNL; Kao, Shih-Chieh [ORNL; Ganguly, Auroop R [ORNL

    2012-01-01

    Recent studies disagree on how rainfall extremes over India have changed in space and time over the past half century, as well as on whether the changes observed are due to global warming or regional urbanization. Although a uniform and consistent decrease in moderate rainfall has been reported, a lack of agreement about trends in heavy rainfall may be due in part to differences in the characterization and spatial averaging of extremes. Here we use extreme value theory to examine trends in Indian rainfall over the past half century in the context of long-term, low-frequency variability.We show that when generalized extreme value theory is applied to annual maximum rainfall over India, no statistically significant spatially uniform trends are observed, in agreement with previous studies using different approaches. Furthermore, our space time regression analysis of the return levels points to increasing spatial variability of rainfall extremes over India. Our findings highlight the need for systematic examination of global versus regional drivers of trends in Indian rainfall extremes, and may help to inform flood hazard preparedness and water resource management in the region.

  13. Best Practice -- Subsurface Investigations

    SciTech Connect (OSTI)

    Clark Scott

    2010-03-01

    These best practices for Subsurface Survey processes were developed at the Idaho National Laboratory (INL) and later shared and formalized by a sub-committee, under the Electrical Safety Committee of EFCOG. The developed best practice is best characterized as a Tier II (enhanced) survey process for subsurface investigations. A result of this process has been an increase in the safety and lowering of overall cost, when utility hits and their related costs are factored in. The process involves improving the methodology and thoroughness of the survey and reporting processes; or improvement in tool use rather than in the tools themselves. It is hoped that the process described here can be implemented at other sites seeking to improve their Subsurface Investigation results with little upheaval to their existing system.

  14. Appendix HYDRO: Hydrological Investigations

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

    HYDRO-2014 Hydrological Investigations United States Department of Energy Waste Isolation Pilot Plant Carlsbad Field Office Carlsbad, New Mexico Compliance Recertification Application 2014 Appendix HYDRO-2014 Table of Contents HYDRO-1.0 Hydrological Studies HYDRO-2.0 Optimization of Culebra Monitoring Well Network HYDRO-3.0 Geochemical Analyses HYDRO-4.0 Steel-Cased Well Reconfiguration and Replacement HYDRO-5.0 Geological Information HYDRO-6.0 Hydraulic Test Interpretation HYDRO-7.0 Monitoring

  15. High performance organic integrated device with ultraviolet photodetective and electroluminescent properties consisting of a charge-transfer-featured naphthalimide derivative

    SciTech Connect (OSTI)

    Wang, Hanyu; Wang, Xu; Yu, Junsheng E-mail: jsyu@uestc.edu.cn; Zhou, Jie; Lu, Zhiyun E-mail: jsyu@uestc.edu.cn

    2014-08-11

    A high performance organic integrated device (OID) with ultraviolet photodetective and electroluminescent (EL) properties was fabricated by using a charge-transfer-featured naphthalimide derivative of 6-(3,5-bis-[9-(4-t-butylphenyl)-9H-carbazol-3-yl]-phenoxy)-2- (4-t-butylphenyl)-benzo[de]isoquinoline-1,3-dione (CzPhONI) as the active layer. The results showed that the OID had a high detectivity of 1.5 × 10{sup 11} Jones at −3 V under the UV-350 nm illumination with an intensity of 0.6 mW/cm{sup 2}, and yielded an exciplex EL light emission with a maximum brightness of 1437 cd/m{sup 2}. Based on the energy band diagram, both the charge transfer feature of CzPhONI and matched energy level alignment were responsible for the dual ultraviolet photodetective and EL functions of OID.

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

    SciTech Connect (OSTI)

    Laity, George; Fierro, Andrew; Dickens, James; Neuber, Andreas; Frank, Klaus

    2014-03-28

    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.

  17. Temperature dependent dielectric function in the near-infrared to vacuum-ultraviolet ultraviolet spectral range of alumina and yttria stabilized zirconia thin films

    SciTech Connect (OSTI)

    Schmidt-Grund, R. Lhmann, T.; Bntgen, T.; Franke, H.; Lorenz, M.; Grundmann, M.; Opper, D.

    2013-12-14

    The dielectric function of nano-/polycrystalline alumina and yttria stabilised zirconia thin films has been investigated in a wide spectral range from 1.0?eV to 7.5?eV and temperatures between 10?K and room temperature. In the near band-edge spectral range, we found a broad distribution of optical transitions within the band gap, the so-called Urbach absorption tail which is typical for amorphous or polycrystalline materials due to the lack of long range order in the crystal structure. The coupling properties of the electronic system to the optical phonon bath and thermal lattice vibrations strongly depend on the ratio of the spectral extent of these disorder states to the main phonon energy, which we correlate with the different crystalline structure of our samples. The films have been grown at room temperature and 650?C by pulsed laser deposition.

  18. ULTRAVIOLET+INFRARED STAR FORMATION RATES: HICKSON COMPACT GROUPS WITH SWIFT AND SPITZER

    SciTech Connect (OSTI)

    Tzanavaris, P.; Hornschemeier, A. E.; Immler, S.; Johnson, K. E.; Reines, A. E.; Gronwall, C.; Hoversten, E.; Charlton, J. C.

    2010-06-10

    We present Swift UVOT ultraviolet (UV; 1600-3000 A) data with complete three-band UV photometry for a sample of 41 galaxies in 11 nearby (<4500 km s{sup -1}) Hickson Compact Groups (HCGs) of galaxies. We use UVOT uvw2-band (2000 A) photometry to estimate the dust-unobscured component, SFR{sub UV}, of the total star formation rate, SFR{sub TOTAL}. We use Spitzer MIPS 24 {mu}m photometry to estimate SFR{sub IR}, the component of SFR{sub TOTAL} that suffers dust extinction in the UV and is re-emitted in the IR. By combining the two components, we obtain SFR{sub TOTAL} estimates for all HCG galaxies. We obtain total stellar mass, M {sub *}, estimates by means of Two Micron All Sky Survey K{sub s} -band luminosities, and use them to calculate specific star formation rates, SSFR {identical_to} SFR{sub TOTAL}/M {sub *}. SSFR values show a clear and significant bimodality, with a gap between low ({approx}<3.2 x 10{sup -11} yr{sup -1}) and high-SSFR ({approx_gt}1.2 x 10{sup -10} yr{sup -1}) systems. We compare this bimodality to the previously discovered bimodality in {alpha}{sub IRAC}, the MIR activity index from a power-law fit to the Spitzer IRAC 4.5-8 {mu}m data for these galaxies. We find that all galaxies with {alpha}{sub IRAC} {<=} 0 ( >0) are in the high- (low-) SSFR locus, as expected if high levels of star-forming activity power MIR emission from polycyclic aromatic hydrocarbon molecules and a hot dust continuum. Consistent with this finding, all elliptical/S0 galaxies are in the low-SSFR locus, while 22 out of 24 spirals/irregulars are in the high-SSFR locus, with two borderline cases. We further divide our sample into three subsamples (I, II, and III) according to decreasing H I richness of the parent galaxy group to which a galaxy belongs. Consistent with the SSFR and {alpha}{sub IRAC} bimodality, 12 out of 15 type I (11 out of 12 type III) galaxies are in the high- (low-) SSFR locus, while type II galaxies span almost the full range of SSFR values. We use the

  19. Response of snow-dependent hydrologic extremes to continued global warming

    SciTech Connect (OSTI)

    Diffenbaugh, Noah; Scherer, Martin; Ashfaq, Moetasim

    2012-01-01

    Snow accumulation is critical for water availability in the Northern Hemisphere1,2, raising concern that global warming could have important impacts on natural and human systems in snow-dependent regions1,3. Although regional hydrologic changes have been observed (for example, refs 1,3 5), the time of emergence of extreme changes in snow accumulation and melt remains a key unknown for assessing climate- change impacts3,6,7. We find that the CMIP5 global climate model ensemble exhibits an imminent shift towards low snow years in the Northern Hemisphere, with areas of western North America, northeastern Europe and the Greater Himalaya showing the strongest emergence during the near- termdecadesandat2 Cglobalwarming.Theoccurrenceof extremely low snow years becomes widespread by the late twenty-first century, as do the occurrences of extremely high early-season snowmelt and runoff (implying increasing flood risk), and extremely low late-season snowmelt and runoff (implying increasing water stress). Our results suggest that many snow-dependent regions of the Northern Hemisphere are likely to experience increasing stress from low snow years within the next three decades, and from extreme changes in snow-dominated water resources if global warming exceeds 2 C above the pre-industrial baseline.

  20. Modified Inverse First Order Reliability Method (I-FORM) for Predicting Extreme Sea States.

    SciTech Connect (OSTI)

    Eckert-Gallup, Aubrey Celia; Sallaberry, Cedric Jean-Marie; Dallman, Ann Renee; Neary, Vincent Sinclair

    2014-09-01

    Environmental contours describing extreme sea states are generated as the input for numerical or physical model simulation s as a part of the stand ard current practice for designing marine structure s to survive extreme sea states. Such environmental contours are characterized by combinations of significant wave height ( ) and energy period ( ) values calculated for a given recurrence interval using a set of data based on hindcast simulations or buoy observations over a sufficient period of record. The use of the inverse first - order reliability method (IFORM) i s standard design practice for generating environmental contours. In this paper, the traditional appli cation of the IFORM to generating environmental contours representing extreme sea states is described in detail and its merits and drawbacks are assessed. The application of additional methods for analyzing sea state data including the use of principal component analysis (PCA) to create an uncorrelated representation of the data under consideration is proposed. A reexamination of the components of the IFORM application to the problem at hand including the use of new distribution fitting techniques are shown to contribute to the development of more accurate a nd reasonable representations of extreme sea states for use in survivability analysis for marine struc tures. Keywords: In verse FORM, Principal Component Analysis , Environmental Contours, Extreme Sea State Characteri zation, Wave Energy Converters

  1. A Better Way to ID Extreme Weather Events in Climate Models

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

    A Better Way to ID Extreme Weather Events in Climate Models A Better Way to ID Extreme Weather Events in Climate Models Berkeley Lab scientists help automate the search for hurricanes and other storms in huge datasets December 7, 2011 Dan Krotz, dakrotz@lbl.gov, +1 510-486-4019 You'd think that spotting a category 5 hurricane would never be difficult. But when the hurricane is in a global climate model that spans several decades, it becomes a fleeting wisp among mountains of data. That's a

  2. Hydrologic Extremes in a changing climate: how much information can regional climate models provide?

    SciTech Connect (OSTI)

    Lettenmaier, Dennis P.

    2012-08-14

    We proposed to identify a set of about 10 urban areas across the western U.S., and hourly precipitation data within each of these areas, which were extracted from the NCDC TD 3240. We also proposed to analyze the annual maximum series of precipitation extremes simulated for NARCCAP (using Reanalysis boundary forcing) for the grid cells close to station data, and to compare the distributions of annual maximum precipitation for accumulation intervals ranging from one to 28 hours. Recognizing that there may inevitably be differences between the station data and RCM grid cell values, we proposed to examine the scale dependence in the distributions of extremes.

  3. #LabChat: Extreme Circumstances, Unique Solutions, June 28 at 1pm EDT |

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

    Department of Energy Extreme Circumstances, Unique Solutions, June 28 at 1pm EDT #LabChat: Extreme Circumstances, Unique Solutions, June 28 at 1pm EDT June 27, 2012 - 2:31pm Addthis The simple, portable device identifies materials through their characteristic energy signals as unique as fingerprints. The three detectors are housed in a thermos-sized container that is connected to a laptop computer. The device issues a signal turning the laptop display bright red when nuclear material of

  4. ISABELA-QA: query-driven analytics with ISABELA-compressed extreme-scale

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

    scientific data | Argonne Leadership Computing Facility ISABELA-QA: query-driven analytics with ISABELA-compressed extreme-scale scientific data Authors: Lakshminarasimhan,S., Jenkins, J., Latham,R., Samatova, N.F., Arkatkar, I., Gong, Z., Kolla, H., Chen, J., Ku, S.H. Chang, C.S., Ethier, S., Klasky, S. Efficient analytics of scientific data from extreme-scale simulations is quickly becoming a top-notch priority. The increasing simulation output data sizes demand for a paradigm shift in how

  5. High blue-near ultraviolet photodiode response of vertically stacked graphene-MoS{sub 2}-metal heterostructures

    SciTech Connect (OSTI)

    Wi, Sungjin; Chen, Mikai; Nam, Hongsuk; Liu, Amy C.; Meyhofer, Edgar; Liang, Xiaogan

    2014-06-09

    We present a study on the photodiode response of vertically stacked graphene/MoS{sub 2}/metal heterostructures in which MoS{sub 2} layers are doped with various plasma species. In comparison with undoped heterostructures, such doped ones exhibit significantly improved quantum efficiencies in both photovoltaic and photoconductive modes. This indicates that plasma-doping-induced built-in potentials play an important role in photocurrent generation. As compared to indium-tin-oxide/ MoS{sub 2}/metal structures, the presented graphene/MoS{sub 2}/metal heterostructures exhibit greatly enhanced quantum efficiencies in the blue-near ultraviolet region, which is attributed to the low density of recombination centers at graphene/MoS{sub 2} heterojunctions. This work advances the knowledge for making photo-response devices based on layered materials.

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

    SciTech Connect (OSTI)

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

    2015-02-02

    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 at ultralow (<1??A) forward current, does not exhibit any shifts when the forward current is increased. External quantum efficiency (EQE) as high as 0.9% is achieved at 25??A current at room temperature. Experiments and simulation analysis show that devices fabricated with thinner Ag NWs have higher EQE. However, for very thin Ag NWs (diameter?

  7. Effects of various kitchen heat treatments, ultraviolet light, and gamma irradiation on mirex insecticide residues in fish

    SciTech Connect (OSTI)

    Cin, D.A.; Kroger, M.

    1982-03-01

    Concentrations of the chlorinated hydrocarbon insecticide mirex (C/sub 10/Cl/sub 12/) were determined in brown trout from a defined contaminated area of Spring Creek, Centre County, PA, using electron-capture gas chromatography. Conventional heat treatments, namely, baking, frying, poaching, and baking without skin, did not cause significant decreases of the contaminant. Ultraviolet irradiation led to significant reductions (p < 0.05) in mirex concentration in muscle tissue. Exposures of 24, 48, and 72 hr led to degradations of 30.0%, and 45.6%, respectively, of the initial mirex concentration. Gamma irradiation also led to significant reductions (p < 0.05) in mirex concentration in muscle tissue. Following absorption of 1, 3, and 5 Mrad, degradations of 9.8%, 23,1%, and 37.5%, respectively, of the initial mirex concentration were observed.

  8. Compositionally graded relaxed AlGaN buffers on semipolar GaN for mid-ultraviolet emission

    SciTech Connect (OSTI)

    Young, Erin C.; Wu Feng; Haeger, Daniel A.; Nakamura, Shuji; Denbaars, Steven P.; Cohen, Daniel A.; Speck, James S.; Romanov, Alexey E.

    2012-10-01

    In this Letter, we report on the growth and properties of relaxed, compositionally graded Al{sub x}Ga{sub 1-x}N buffer layers on freestanding semipolar (2021) GaN substrates. Continuous and step compositional grades with Al concentrations up to x = 0.61 have been achieved, with emission wavelengths in the mid-ultraviolet region as low as 265 nm. Coherency stresses were relaxed progressively throughout the grades by misfit dislocation generation via primary (basal) slip and secondary (non-basal) slip systems. Threading dislocation densities in the final layers of the grades were less than 10{sup 6}/cm{sup 2} as confirmed by plan-view transmission electron microscopy and cathodoluminescence studies.

  9. Notification of Investigation at BWCS

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

    The investigation will include an onsite visit and interviews with contractor personnel. A request for documents to support the investigation will be provided separately via e-mail...

  10. Accident Investigation Report- Fire Report

    Broader source: Energy.gov [DOE]

    On February 7, 2014, Deputy Assistant Secretary, Safety, Security, and Quality Programs Environmental Management, DOE, formally appointed an Accident Investigation Board to investigate an...

  11. Overspinning a nearly extreme black hole and the weak cosmic censorship conjecture

    SciTech Connect (OSTI)

    Richartz, Mauricio; Saa, Alberto

    2008-10-15

    We revisit here the recent proposal for overspinning a nearly extreme black hole by means of a quantum tunneling process. We show that electrically neutral massless fermions evade possible backreaction effects related to superradiance, confirming the view that it would be indeed possible to form a naked singularity due to quantum effects.

  12. Draft Genome Sequence of Brevibacterium linens AE038-8, an Extremely Arsenic-Resistant Bacterium

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

    Maizel, Daniela; Utturkar, Sagar M.; Brown, Steven D.; Ferrero, Marcela; Rosen, Barry

    2015-04-16

    To understand the arsenic biogeocycles in the groundwaters at Tucumán, Argentina, we isolated Brevibacterium linens sp. strain AE38-8, obtained from arsenic-contaminated well water. This strain is extremely resistant to arsenicals and has arsenic resistance (ars) genes in its genome. Here, we report the draft genome sequence of B. linens AE38-8.

  13. Approaching the exa-scale: a real-world evaluation of rendering extremely large data sets

    SciTech Connect (OSTI)

    Patchett, John M; Ahrens, James P; Lo, Li - Ta; Browniee, Carson S; Mitchell, Christopher J; Hansen, Chuck

    2010-10-15

    Extremely large scale analysis is becoming increasingly important as supercomputers and their simulations move from petascale to exascale. The lack of dedicated hardware acceleration for rendering on today's supercomputing platforms motivates our detailed evaluation of the possibility of interactive rendering on the supercomputer. In order to facilitate our understanding of rendering on the supercomputing platform, we focus on scalability of rendering algorithms and architecture envisioned for exascale datasets. To understand tradeoffs for dealing with extremely large datasets, we compare three different rendering algorithms for large polygonal data: software based ray tracing, software based rasterization and hardware accelerated rasterization. We present a case study of strong and weak scaling of rendering extremely large data on both GPU and CPU based parallel supercomputers using Para View, a parallel visualization tool. Wc use three different data sets: two synthetic and one from a scientific application. At an extreme scale, algorithmic rendering choices make a difference and should be considered while approaching exascale computing, visualization, and analysis. We find software based ray-tracing offers a viable approach for scalable rendering of the projected future massive data sizes.

  14. Preliminary Results of a RANS Simulation for a Floating Point Absorber Wave Energy System Under Extreme Wave Conditions

    SciTech Connect (OSTI)

    Yu, Y.; Li, Y.

    2011-10-01

    This paper presents the results of a preliminary study on the hydrodynamics of a moored floating-point absorber (FPA) wave energy system under extreme wave conditions.

  15. Criminal Investigator | Department of Energy

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

    Criminal Investigator Criminal Investigator Special Agent Responsibilities The Office of Investigations conducts investigations of DOE personnel, contractors, and others receiving DOE funds concerning alleged violations of law that impact DOE programs, operations, facilities, and personnel. Examples of issues investigated by the OIG include soliciting and/or accepting a bribe, overcharging the Government on contracts and grants, providing false data and information, supplying defective or

  16. Ionospheric total electron content, and far ultraviolet, near infrared oxygen emission

    SciTech Connect (OSTI)

    Aghanajafi, C.

    1988-01-01

    The purpose of this investigation is to calculate the total electron content and four oxygen emissions for solar cycle maximum at equinox season. The investigation shows that the total electron content reaches its maximum development at 2100 LT with the crest nearest to the equator being the greatest. This asymmetry reverses at 0200 LT when the crest farthest from the equator is smallest. In spite of the fact that while N{sub max} decreases at noon, and the layer becomes greater in altitude under the influence of the upward drift, the noon bite out occurs at the equator around 1200 Lt. The behavior of OI 6300 {angstrom}, the brightest dayglow source is investigated. The oxygen at 6300 {angstrom} is strongly a function of N{sub max} and h{sub max}. The data for the OI 6300 {angstrom} reveal that the latitudinal asymmetry is associated with the asymmetry in altitude of F{sub 2} peak. The maximum electron density height is strongly affected by vertical E {times} B drift velocity. The emission at 1356 {angstrom} and 7774 {angstrom} is calculated using the radiative recombination and ion-ion recombination processes. The ion-ion recombination has substantial effect in total emission rates. The intensity of OI 911 {angstrom} due to direct recombination to the ground state is obtained. These emissions can be used as a way of remotely sensing the F region and exosphere plasma properties, and the winds responsible for plasma transport.

  17. Deep Chandra , HST-COS, and megacam observations of the Phoenix cluster: Extreme star formation and AGN feedback on hundred kiloparsec scales

    SciTech Connect (OSTI)

    McDonald, Michael; McNamara, Brian R.; van Weeren, Reinout J.; Applegate, Douglas E.; Bayliss, Matthew; Bautz, Marshall W.; Benson, Bradford A.; Carlstrom, John E.; Bleem, Lindsey E.; Chatzikos, Marios; Edge, Alastair C.; Fabian, Andrew C.; Garmire, Gordon P.; Hlavacek-Larrondo, Julie; Jones-Forman, Christine; Mantz, Adam B.; Miller, Eric D.; Stalder, Brian; Veilleux, Sylvain; ZuHone, John A.

    2015-09-28

    In this study, we present new ultraviolet, optical, and X-ray data on the Phoenix galaxy cluster (SPT-CLJ2344-4243). Deep optical imaging reveals previously undetected filaments of star formation, extending to radii of ~50–100 kpc in multiple directions. Combined UV-optical spectroscopy of the central galaxy reveals a massive (2 × 109 M), young (~4.5 Myr) population of stars, consistent with a time-averaged star formation rate of 610 ± 50 M yr–1. We report a strong detection of O vi λλ1032,1038, which appears to originate primarily in shock-heated gas, but may contain a substantial contribution (>1000 M yr–1) from the cooling intracluster medium (ICM). We confirm the presence of deep X-ray cavities in the inner ~10 kpc, which are among the most extreme examples of radio-mode feedback detected to date, implying jet powers of 2 – 7 × 1045 erg s–1. We provide evidence that the active galactic nucleus inflating these cavities may have only recently transitioned from "quasar-mode" to "radio-mode," and may currently be insufficient to completely offset cooling. A model-subtracted residual X-ray image reveals evidence for prior episodes of strong radio-mode feedback at radii of ~100 kpc, with extended "ghost" cavities indicating a prior epoch of feedback roughly 100 Myr ago. This residual image also exhibits significant asymmetry in the inner ~200 kpc (0.15R500), reminiscent of infalling cool clouds, either due to minor mergers or fragmentation of the cooling ICM. Taken together, these data reveal a rapidly evolving cool core which is rich with structure (both spatially and in temperature), is subject to a variety of highly energetic processes, and yet is cooling rapidly and forming stars along thin, narrow filaments.

  18. An electrically injected AlGaN nanowire laser operating in the ultraviolet-C band

    SciTech Connect (OSTI)

    Zhao, S.; Liu, X.; Kang, J.; Mi, Z.; Woo, S. Y.; Botton, G. A.

    2015-07-27

    We have investigated the molecular beam epitaxial growth and characterization of nearly defect-free AlGaN nanowire heterostructures grown directly on Si substrate. By exploiting the Anderson localization of light, we have demonstrated electrically injected AlGaN nanowire lasers that can operate at 262.1 nm. The threshold current density is 200 A/cm{sup 2} at 77 K. The relatively low threshold current is attributed to the high Q-factor of the random cavity and the three-dimensional quantum confinement offered by the atomic-scale composition modulation in self-organized AlGaN nanowires.

  19. New red phosphor for near-ultraviolet light-emitting diodes with high color-purity

    SciTech Connect (OSTI)

    Wang, Zhengliang; He, Pei; Wang, Rui; Zhao, Jishou; Gong, Menglian

    2010-02-15

    New red phosphors, Na{sub 5}Eu(MoO{sub 4}){sub 4} doped with boron oxide were prepared by the solid-state reaction. Their structure and photo-luminescent properties were investigated. With the introduction of boron oxide, the red emission intensity of the phosphors under 395 nm excitation is strengthened, with high color-purity (x = 0.673, y = 0.327). The single red light-emitting diode was obtained by combining InGaN chip with the red phosphor, bright red light can be observed by naked eyes from the red light-emitting diodes under a forward bias of 20 mA.

  20. Charged annular disks and Reissner-Nordstroem type black holes from extremal dust

    SciTech Connect (OSTI)

    Lora-Clavijo, F. D.; Ospina-Henao, P. A.; Pedraza, J. F.

    2010-10-15

    We present the first analytical superposition of a charged black hole with an annular disk of extremal dust. In order to obtain the solutions, we first solve the Einstein-Maxwell field equations for sources that represent disklike configurations of matter in confomastatic spacetimes by assuming a functional dependence among the metric function, the electric potential, and an auxiliary function, which is taken as a solution of the Laplace equation. We then employ the Lord Kelvin inversion method applied to models of finite extension in order to obtain annular disks. The structures obtained extend to infinity, but their total masses are finite and all the energy conditions are satisfied. Finally, we observe that the extremal Reissner-Nordstroem black hole can be embedded into the center of the disks by adding a boundary term in the inversion.