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Sample records for 60-beam omega laser

  1. High-Energy Petawatt Capability for the Omega Laser

    SciTech Connect

    Waxer, L.J.; Maywar, D.N.; Kelly, J.H.; Kessler, T.J.; Kruschwitz, B.E.; Loucks, S.J.; McCrory, R.L.; Meyerhofer, D.D.; Morse, S.F.B.; Stoeckl, C.; Zuegel, J.D.

    2005-07-25

    The 60-beam Omega laser system at the University of Rochester's Laboratory for Laser Energetics (LLE) has been a workhorse on the frontier of laser fusion and high-energy-density physics for more than a decade. LLE scientists are currently extending the performance of this unique, direct-drive laser system by adding high-energy petawatt capabilities.

  2. A picosecond beam-timing system for the OMEGA laser

    SciTech Connect

    Donaldson, W. R.; Katz, J.; Huff, R.; Hill, E. M.; Kelly, J. H.; Kwaitkowski, J.; Brannon, R. B.; Boni, R.

    2016-05-27

    Here, a timing system is demonstrated for the OMEGA Laser System that guarantees all 60 beams will arrive on target simultaneously with a root mean square variability of 4 ps. The system relies on placing a scattering sphere at the target position to couple the UV light from each beam into a single photodetector.

  3. A picosecond beam-timing system for the OMEGA laser

    SciTech Connect

    Donaldson, W. R.; Katz, J.; Huff, R.; Hill, E. M.; Kelly, J. H.; Kwiatkowski, J.; Brannon, R. B.; Boni, R.

    2016-05-15

    A timing system is demonstrated for the OMEGA Laser System that guarantees all 60 beams will arrive on target simultaneously with a root mean square variability of 4 ps. The system relies on placing a scattering sphere at the target position to couple the ultraviolet light from each beam into a single photodetector.

  4. A picosecond beam-timing system for the OMEGA laser

    DOE PAGES

    Donaldson, W. R.; Katz, J.; Huff, R.; ...

    2016-05-27

    Here, a timing system is demonstrated for the OMEGA Laser System that guarantees all 60 beams will arrive on target simultaneously with a root mean square variability of 4 ps. The system relies on placing a scattering sphere at the target position to couple the UV light from each beam into a single photodetector.

  5. OMEGA EP: High-Energy Petawatt Capability for the OMEGA Laser Facility

    SciTech Connect

    Kelly, J.H.; Waxer, L.J.; Bagnoud, V.; Begishev, I.A.; Bromage, J.; Kruschwitz, B.E.; Kessler, T.J.; Loucks, S.J.; Maywar, D.N.; McCrory, R.L.; Meyerhofer, D.D.; Morse, S.F.B.; Oliver, J.B.; Rigatti, A.L.; Schmid, A.W.; Stoeckl, C.; Dalton, S.; Folnsbee, L.; Guardalben, M.J.; Jungquist, R.; Puth, J.; Shoup III, M.J.; Weiner, D.; Zuegel, J.D.

    2006-06-28

    OMEGA EP (Extended Performance) is a petawatt-class addition to the existing 30-kJ, 60-beam OMEGA Laser Facility at the University of Rochester. When completed, it will consist of four beamlines, each capable of producing up to 6.5 kJ at 351 nm in a 1 to 10 ns pulse. Two of the beamlines will produce up to 2.6 kJ in a pulse-width range of 1 to 100 ps at 1053 nm using chirped-pulse amplification (CPA). This paper reviews both the OMEGA EP performance objectives and the enabling technologies required to meet these goals.

  6. Laser scattering from long scalelength plasmas on Omega. Final report

    SciTech Connect

    Drake, R.P.; Seka, W.; Craxton, R.S.; Bauer, B.S.

    1998-12-31

    In this project, the authors accomplished the tasks called for in the revised statement of work associated with this grant. Specifically, they accomplished: (1) active participation in the design of long-scalelength plasmas for Omega and in experiments to characterize these plasmas; (2) development of software that permits the rapid evaluation of laser-scattering diagnostic possibilities involving the standard parametric instabilities. It must be able to account for all 60 beams in Omega in addition to a probe beam and variable detector locations; and (3) design, purchase of components for, and assembly of instrumentation to make such measurements, providing for long-term versatility in the type of measurement. The project background and these accomplishments are discussed.

  7. High-yield bang time detector for the OMEGA laser

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Stoeckl, C.; Sangster, T. C.; Mileham, C.; Roberts, S.; Lerche, R. A.

    2006-10-01

    A simple, low-cost, high-yield neutron bang time (HYNBT) detector has been developed and implemented on the 60-beam, 30kJ OMEGA Laser Facility at the University of Rochester's Laboratory for Laser Energetics. The HYNBT consists of three chemical-vapor deposition diamond detectors of different sizes and sensitivities placed in a lead-shielded housing. The HYNBT is located in a reentrant tube 50cm from the center of the target chamber. The HYNBT has been temporally cross calibrated against the streak-camera-based neutron temporal diagnostic (NTD) for both D2 and DT implosions. The HYNBT has an internal time resolution better than 20ps and is able to measure bang time for yields above 1010 for DT and 5×1010 for D2 implosions. The implementation of the HYNBT on the National Ignition Facility will be discussed.

  8. Design of the OMEGA Laser Target Chamber Tritium Removal System

    SciTech Connect

    Nobile, Arthur; Reichert, Heidi; Janezic, Roger T.; Harding, David R.; Lund, Lance D.; Shmayda, Walter T.

    2003-06-15

    Preparations are currently underway at the OMEGA laser at the University of Rochester Laboratory for Laser Energetics (UR/LLE) to conduct direct drive laser implosion campaigns with inertial confinement fusion targets containing deuterium-tritium (DT) cryogenic ice layers. The OMEGA Cryogenic Target Handling System will fill plastic targets with high-pressure DT (150 MPa) at 300 to 500 K, cool them down to cryogenic temperature (<25 K), form the DT ice layer, and transport the targets to the OMEGA laser target chamber. Targets will then be shot with the 60-beam 30-kJ OMEGA laser. A tritium removal system has been designed to remove tritium from effluents associated with operation of the target chamber and its associated diagnostic antechambers, vacuum pumping systems, and target insertion systems. The design of the target chamber tritium removal system (TCTRS) is based on catalytic oxidation of DT and tritiated methane to tritiated water (DTO), followed by immobilization of DTO on molecular sieves. The design of the TCTRS presented a challenge due to the low tritium release limits dictated by the tritium license at UR/LLE. Aspen Plus, a commercial software package intended for the simulation and design of chemical processing systems operating at steady state, was used to simulate and design the TCTRS. A second commercial software package, Aspen ADSIM, was used to simulate and design the TCTRS molecular sieve beds, which operate at unsteady state. In this paper, we describe the design of the TCTRS and the benefits that were realized by use of the Aspen Plus and Aspen ADSIM software packages.

  9. Transmitted Laser Beam Diagnostic at the Omega Laser Facility

    SciTech Connect

    Niemann, C; Antonini, G; Compton, S; Glenzer, S; Hargrove, D; Moody, J; Kirkwood, R; Rekow, V; Sorce, C; Armstrong, W; Bahr, R; Keck, R; Pien, G; Seka, W; Thorp, K

    2004-04-01

    We have developed and commissioned a transmitted beam diagnostic (TBD) for the 2{omega} high intensity interaction beam at the Omega laser facility. The TBD consists of a bare-surface reflector mounted near the target, which collects and reflects 4% of the transmitted light to a detector assembly outside the vacuum chamber. The detector includes a time integrating near-field camera that measures beam spray, deflection and the absolute transmitted power. We present a detailed description of the instrument and the calibration method and include first measurements on laser heated gasbag targets to demonstrate the performance of the diagnostic.

  10. The Fifth Omega Laser Facility Users Group Workshop

    SciTech Connect

    Petrasso, R. D.

    2015-10-01

    A capacity gathering of over 100 researchers from 25 universities and laboratories met at the Laboratory for Laser Energetics (LLE) for the Fifth Omega Laser Facility Users Group (OLUG) workshop. The purpose of the 2.5-day workshop was to facilitate communications and exchanges among individual Omega users and between users and the LLE management; to present ongoing and proposed research; to encourage research opportunities and collaborations that could be undertaken at the Omega Laser Facility and in a complementary fashion at other facilities [such as the National Ignition Facility (NIF) or the Laboratoire pour l’Utilisation des Lasers Intenses (LULI)]; to provide an opportunity for students, postdoctoral fellows, and young researchers to present their research in an informal setting; and to provide feedback to LLE management from the users about ways to improve the facility and future experimental campaigns.

  11. The Sixth Omega Laser Facility Users Group Workshop

    SciTech Connect

    Petrasso, R. D.

    2014-10-01

    A capacity gathering of over 100 researchers from 25 universities and laboratories met at the Laboratory for Laser Energetics (LLE) for the Sixth Omega Laser Facility Users Group (OLUG) workshop. The purpose of the 2.5-day workshop was to facilitate communications and exchanges among individual OMEGA users, and between users and the LLE management; to present ongoing and proposed research; to encourage research opportunities and collaborations that could be undertaken at the Omega Laser Facility and in a complementary fashion at other facilities [such as the National Ignition Facility (NIF) or the Laboratoire pour l’Utilisation des Lasers Intenses (LULI)]; to provide an opportunity for students, postdoctoral fellows, and young researchers to present their research in an informal setting; and to provide feedback from the users to LLE management about ways to improve and keep the facility and future experimental campaigns at the cutting edge.

  12. Recent Developments in Fabrication of Direct Drive Cylinder Targets for Hydrodynamics Experiments at the OMEGA Laser

    SciTech Connect

    Nobile, A.; Balkey, M.M.; Bartos, J.J.; Batha, S.H.; Day, R.D.; Elliott, J.E.; Elliott, N.E.; Gomez, V.M.; Hatch, D.J.; Lanier, N.E.; Fincke, J.R.; Manzanares, R.; Pierce, T.H.; Sandoval, D.L.; Schmidt, D.W.; Steckle, W.P.

    2004-03-15

    Experimental campaigns are being conducted at the 60 beam OMEGA laser at the University of Rochester's Laboratory for Laser Energetics to acquire data to validate hydrodynamic models in the high energy-density regime. This paper describes targets that have been developed and constructed for these experimental campaigns. Targets are 860 {mu}m inner diameter by 2.2 mm length cylinders with 70 {mu}m thick polymer ablator. On the ablator inner surface and located halfway along the axis of the cylinder is a 500 {mu}m wide Al marker band. Band thicknesses in the range 8-16 microns are used. CH foam with densities in the range 30-90 mg/cc fills the inside of the cylinder. While these targets have been fabricated for years, several new improvements and features have recently been developed. Improvements include the use of epoxy instead of polystyrene for the ablator, and the use of electrodeposited Al for the marker band. A critical feature of the target is the surface feature that is placed on the marker band. Experiments are aimed at understanding the hydrodynamic behavior of imploding cylinders as a function of this surface feature. Recent development work has focused on production of engineered surface features on the target marker band. Using a fast tool servo on a diamond turning lathe, a wide range of specified surface features have been produced. This paper will address improvements to the cylinder targets as well as current development efforts.

  13. 3w Transmitted Beam Diagnostic at the Omega Laser Facility

    SciTech Connect

    Froula, D H; Rekow, V; Sorce, C; Piston, K; Knight, R; Alvarez, S; Griffith, R; Hargrove, D; Ross, J S; Dixit, S; Pollock, B; Divol, L; Glenzer, S H; Armstrong, W; Bahr, R; Thorp, K; Pien, G

    2006-04-24

    A 3{omega} transmitted beam diagnostic has been commissioned on the Omega Laser at the Laboratory for Laser Energetics, University of Rochester [Soures et.al., Laser Part. Beams 11 (1993)]. Transmitted light from one beam is collected by a large focusing mirror and directed onto a diagnostic platform. The near field of the transmitted light is imaged; the system collects information from twice the original f-cone of the beam. Two gated optical cameras capture the near field image of the transmitted light. Thirteen spatial positions around the measurement region are temporally resolved using fast photodiodes to allow a measure of the beam spray evolution. The Forward stimulated Raman scattering and forward simulated Brillion scattering are spectrally and temporally resolved at 5 independent locations within twice the original f-cone. The total transmitted energy is measured in two spectral bands ({delta}{lambda} < 400 nm and {delta}{lambda} > 400 nm).

  14. Laser-driven magnetized liner inertial fusion on OMEGA

    NASA Astrophysics Data System (ADS)

    Barnak, D. H.; Davies, J. R.; Betti, R.; Bonino, M. J.; Campbell, E. M.; Glebov, V. Yu.; Harding, D. R.; Knauer, J. P.; Regan, S. P.; Sefkow, A. B.; Harvey-Thompson, A. J.; Peterson, K. J.; Sinars, D. B.; Slutz, S. A.; Weis, M. R.; Chang, P.-Y.

    2017-05-01

    Magneto-inertial fusion (MIF) combines the compression of fusion fuel, a hallmark of inertial confinement fusion (ICF), with strongly magnetized plasmas that suppress electron heat losses, a hallmark of magnetic fusion. It can reduce the traditional velocity, pressure, and convergence ratio requirements of ICF. The magnetized liner inertial fusion (MagLIF) concept being studied at the Z Pulsed-Power Facility is a key target concept in the U.S. ICF Program. Laser-driven MagLIF is being developed on OMEGA to test the scaling of MagLIF over a range of absorbed energy of the order of 1 kJ on OMEGA to 500 kJ on Z. It is also valuable as a platform for studying the key physics of MIF. An energy-scaled point design has been developed for OMEGA that is roughly 10 × smaller in linear dimensions than Z MagLIF targets. A 0.6-mm-outer-diameter plastic cylinder filled with 2.4 mg/cm3 of D2 is placed in a ˜10-T axial magnetic field, generated by a Magneto-inertial fusion electrical discharge system, the cylinder is compressed by 40 OMEGA beams, and the gas fill is preheated by a single OMEGA beam propagating along the axis. Preheating to >100 eV and axially uniform compression over 0.7 mm have been demonstrated, separately, in a series of preparatory experiments that meet our initial expectations. The preliminary results from the first integrated experiments combining magnetization, compression, and preheat demonstrating a roughly 2 x increase in the neutron yield will be reported here for the first time.

  15. Laser-Driven Magnetized Liner Inertial Fusion on OMEGA

    NASA Astrophysics Data System (ADS)

    Barnak, D. H.

    2016-10-01

    Magneto-inertial fusion (MIF) is an approach that combines the implosion and compression of fusion fuel (a hallmark of inertial fusion) with strongly magnetized plasmas that suppress electron heat losses (a hallmark of magnetic fusion). It is of interest because it could potentially reduce some of the traditional velocity, pressure, and convergence ratio requirements of inertial confinement fusion (ICF). The magnetized liner inertial fusion (MagLIF) concept being studied at the Z Pulsed-Power Facility is a key target concept in the U.S. ICF Program. Laser-driven MagLIF is being developed to enable a test of the scaling of MagLIF over a range of absorbed energy from of the order of 20 kJ (on OMEGA) to 500 kJ (on Z). It is also valuable as a platform for studying the key physics of MIF. An energy-scaled point design has been developed for the Omega Laser Facility that is roughly 10 × smaller in linear dimensions than Z MagLIF targets. A 0.6-mm-outer-diam plastic cylinder filled with 2.4 mg/cm3 of D2 is placed in a 10-T axial magnetic field, generated by MIFEDS (magneto-inertial fusion electrical discharge system), the cylinder is compressed by 40 OMEGA beams, and the gas fill is preheated by a single OMEGA beam propagating along the axis. Preheating to >100 eV and axially uniform compression over a 0.7-mm height have been demonstrated, separately, in a series of preparatory experiments that meet our initial expectations. Preliminary results from the first integrated experiments combining magnetization, compression, and preheat will be reported for the first time. The scaling of laser-driven MagLIF from OMEGA up to the 1800 kJ available on the NIF (National Ignition Facility) will also be described briefly. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  16. A pulsed-laser calibration system for the laser backscatter diagnostics at the Omega laser

    SciTech Connect

    Neumayer, P; Sorce, C; Froula, D H; Rekow, V; Loughman, K; Knight, R; Glenzer, S H; Bahr, R; Seka, W

    2008-04-29

    A calibration system has been developed that allows a direct determination of the sensitivity of the laser backscatter diagnostics at the Omega laser. A motorized mirror at the target location redirects individual pulses of a mJ-class laser onto the diagnostic to allow the in-situ measurement of the local point response of the backscatter diagnostics. Featuring dual wavelength capability at the 2nd and 3rd harmonic of the Nd:YAG laser, both spectral channels of the backscatter diagnostics can be directly calibrated. In addition, channel cross-talk and polarization sensitivity can be determined. The calibration system has been employed repeatedly over the last two years and has enabled precise backscatter measurements of both stimulated Brillouin scattering and stimulated Raman scattering in gas-filled hohlraum targets that emulate conditions relevant to those in inertial confinement fusion targets.

  17. A pulsed-laser calibration system for the laser backscatter diagnostics at the Omega laser

    SciTech Connect

    Neumayer, P; Sorce, C; Froula, D H; Rekow, V; Loughman, K; Knight, R; Glenzer, S H; Bahr, R; Seka, W

    2009-10-09

    A calibration system has been developed that allows a direct determination of the sensitivity of the laser backscatter diagnostics at the Omega laser. A motorized mirror at the target location redirects individual pulses of a mJ-class laser onto the diagnostic to allow the in-situ measurement of the local point response of the backscatter diagnostics. Featuring dual wavelength capability at the 2nd and 3rd harmonic of the Nd:YAG laser, both spectral channels of the backscatter diagnostics can be directly calibrated. In addition, channel cross-talk and polarization sensitivity can be determined. The calibration system has been employed repeatedly over the last two years and has enabled precise backscatter measurements of both stimulated Brillouin scattering and stimulated Raman scattering in gas-filled hohlraum targets that emulate conditions relevant to those in inertial confinement fusion targets.

  18. PIC Simulations of direct laser accelerated electron from underdense plasmas using the OMEGA EP Laser

    NASA Astrophysics Data System (ADS)

    Hussein, Amina; Batson, Thomas; Krushelnick, Karl; Willingale, Louise; Arefiev, Alex; Wang, Tao; Nilson, Phil; Froula, Dustin; Haberberger, Dan; Davies, Andrew; Theobald, Wolfgang; Williams, Jackson; Chen, Hui

    2016-10-01

    The OMEGA EP laser system is used to study channeling phenomena and direct laser acceleration (DLA) through an underdense plasma. The interaction of a ps laser pulse with a subcritical density CH plasma plume results in the expulsion of electron along the laser axis, forming a positively charged channel. Electrons confined within this channel are subject to the action of the laser field as well as the transverse electric field of the channel, resulting the DLA of these electrons and the formation of a high energy electron beam. We have performed 2D simulations of ultra-intense laser radiation with underdense plasma using the PIC code EPOCH to investigate electron densities and self-consistently generated electric fields, as well as electron trajectories. This work was supported by the National Laser Users' Facility (NLUF), DOE.

  19. Green (2(omega)) Laser Beam propagation in high-temperature Hohlraum Plasmas

    SciTech Connect

    Niemann, C; Berger, R; Divol, L; Froula, D H; Jones, O S; Kirkwood, R K; Meezan, N; Moody, J; Ross, J S; Suter, L; Glenzer, S H

    2007-10-26

    We demonstrate propagation and small backscatter losses of a frequency-doubled (2{omega}) laser beam interacting with inertial confinement fusion hohlraum plasmas. The electron temperature of 3.3 keV, approximately a factor of two higher than achieved in previous experiments with open geometry targets, approaches plasma conditions of high-fusion yield hohlraums. In this new temperature regime, we measure 2{omega} laser beam transmission approaching 80% with simultaneous backscattering losses of less than 10%. These findings suggests that good laser coupling into fusion hohlraums using 2{omega} light is possible.

  20. Collapsing Radiative Shocks in Argon Gas on the Omega Laser

    SciTech Connect

    Reighard, A B; Drake, R P; Dannenberg, K; Perry, T S; Robey, H A; Remington, B A; Wallace, R J; Ryutov, D D; Greenough, J; Knauer, J; Boehly, T; Bouquet, S; Calder, A; Rosner, R; Fryxell, B; Arnett, D; Koenig, M; Stone, J

    2003-11-01

    A number of astrophysical systems involve radiative shocks that collapse spatially in response to energy lost through radiation. Supernova remnants are an example of systems that cool enough to radiatively collapse. This is believed to produce thin, dense shells that are Vishniac unstable. This type of instability may be responsible for the convoluted structure of supernova remnants such as the Cygnus Loop. We are conducting experiments on the Omega laser intended to produce such collapsing shocks and to study their evolution. The experiments use the laser to accelerate a thin slab of driving material (beryllium) through 1.1 ATM of argon gas ({approx}2 mg/cc) at {approx}100 km/sec. The simulations also predict that the dense layer will be pushed ahead of the dense beryllium by the leading edge of the expansion of this material. The experiment is diagnosed in two ways. X-ray radiography has detected the presence of the dense shocked layer. These data indicate that the shock velocity is {approx}100 km/s. A unique, side-on application of the VISAR (Velocity Interferometer System for Any Reflector) technique is used to detect frequency shifts from ionization and any reflections from the edge of the dense shocked layer.

  1. Plasma interpenetration study on the Omega laser facility

    NASA Astrophysics Data System (ADS)

    Le Pape, Sebastien; Divol, Laurent; Ross, Steven; Wilks, Scott; Amendt, Peter; Berzak Hopkins, Laura; Huser, Gael; Moody, John; MacKinnon, Andy; Meezan, Nathan

    2016-10-01

    The Near Vacuum Campaign on the National Ignition Facility has sparked an interest on the nature of the gold/carbon interface at high velocity, high electron temperature, low-electron density. Indeed radiation-hydrodynamic simulations have been unable to accurately reproduce the experimental shape of the hot spot resulting from implosion driven in Near Vacuum Holhraum. The experimental data are suggesting that the inner beams are freely propagating to the waist of the hohlraum when simulations predict that a density ridge at the gold/carbon interface blocks the inner beams. The discrepancy between experimental data and simulation might be explained by the fluid description of the plasma interface in a rad-hydro code which is probably not valid in when two plasma at high velocity, high temperature are meeting. To test our assumption, we went to the Omega laser facility to study gold/carbon interface in the relevant regime. Time resolved images of the self-emission as well as Thomson scattering data will be presented. For the first time, a transition from a multifluid to a single fluid is observed as plasmas are interacting. This work was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  2. Summaries of FY16 LANL experimental campaigns at the OMEGA and EP Laser Facilities

    SciTech Connect

    Loomis, Eric Nicholas; Merritt, Elizabeth Catherine; Montgomery, David; Kim, Yong Ho; Murphy, Thomas Joseph; Johns, Heather Marie; Kline, John L.; Shah, Rahul C.; Zylstra, Alex; Herrmann, Hans W.; Schmitt, Mark J.; Flippo, Kirk Adler; Rasmus, Alexander Martin

    2016-10-25

    In FY16, Los Alamos National Laboratory carried out 22 shot days on the OMEGA and OMEGA- EP laser facilities in the areas of High Energy Density (HED) Science and Inertial Confinement Fusion (ICF). In HED our focus areas were on radiation flow, hydrodynamic turbulent mix and burn, warm dense matter equations of state, and coupled Kelvin-­Helmholtz (KH)/Richtmyer-­ Meshkov (RM) instability growth. For ICF our campaigns focused on the Priority Research Directions (PRD) of implosion phase mix and stagnation and burn, specifically as they pertain to Laser Direct Drive (LDD). We also had several focused shot days on transport properties in the kinetic regime. We continue to develop advanced diagnostics such as Neutron Imaging, Gamma Reaction History, and Gas Cherenkov Detectors. Below are a summary of our campaigns, their motivation, and main results from this year.

  3. X-ray Thomson scattering measurements from hohlraum-driven spheres on the OMEGA laser

    NASA Astrophysics Data System (ADS)

    Saunders, A. M.; Jenei, A.; Döppner, T.; Falcone, R. W.; Kraus, D.; Kritcher, A.; Landen, O. L.; Nilsen, J.; Swift, D.

    2016-11-01

    X-ray Thomson scattering (XRTS) is a powerful diagnostic for probing warm and hot dense matter. We present the design and results of the first XRTS experiments with hohlraum-driven CH2 targets on the OMEGA laser facility at the Laboratory for Laser Energetics in Rochester, NY. X-rays seen directly from the XRTS x-ray source overshadow the elastic scattering signal from the target capsule but can be controlled in future experiments. From the inelastic scattering signal, an average plasma temperature is inferred that is in reasonable agreement with the temperatures predicted by simulations. Knowledge gained in this experiment shows a promising future for further XRTS measurements on indirectly driven OMEGA targets.

  4. X-ray Thomson scattering measurements from hohlraum-driven spheres on the OMEGA laser.

    PubMed

    Saunders, A M; Jenei, A; Döppner, T; Falcone, R W; Kraus, D; Kritcher, A; Landen, O L; Nilsen, J; Swift, D

    2016-11-01

    X-ray Thomson scattering (XRTS) is a powerful diagnostic for probing warm and hot dense matter. We present the design and results of the first XRTS experiments with hohlraum-driven CH2 targets on the OMEGA laser facility at the Laboratory for Laser Energetics in Rochester, NY. X-rays seen directly from the XRTS x-ray source overshadow the elastic scattering signal from the target capsule but can be controlled in future experiments. From the inelastic scattering signal, an average plasma temperature is inferred that is in reasonable agreement with the temperatures predicted by simulations. Knowledge gained in this experiment shows a promising future for further XRTS measurements on indirectly driven OMEGA targets.

  5. A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited)

    NASA Astrophysics Data System (ADS)

    Nilson, P. M.; Ehrne, F.; Mileham, C.; Mastrosimone, D.; Jungquist, R. K.; Taylor, C.; Stillman, C. R.; Ivancic, S. T.; Boni, R.; Hassett, J.; Lonobile, D. J.; Kidder, R. W.; Shoup, M. J.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Froula, D. H.; Hill, K. W.; Gao, L.; Bitter, M.; Efthimion, P.; Meyerhofer, D. D.

    2016-11-01

    A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with a radius of curvature of 330 mm and a Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated x-ray emission spectra in the 7.97- to 8.11-keV range, centered on the Cu Kα1 line. To demonstrate the performance of the spectrometer under high-power conditions, Kα1,2 emission spectra were measured from Cu foils irradiated by the OMEGA EP laser with 100-J, 1-ps pulses at focused intensities above 1018 W/cm2. The ultimate goal is to couple the spectrometer to a picosecond x-ray streak camera and measure temperature-equilibration dynamics inside rapidly heated materials. The plan for these ultrafast streaked x-ray spectroscopy studies is discussed.

  6. A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited).

    PubMed

    Nilson, P M; Ehrne, F; Mileham, C; Mastrosimone, D; Jungquist, R K; Taylor, C; Stillman, C R; Ivancic, S T; Boni, R; Hassett, J; Lonobile, D J; Kidder, R W; Shoup, M J; Solodov, A A; Stoeckl, C; Theobald, W; Froula, D H; Hill, K W; Gao, L; Bitter, M; Efthimion, P; Meyerhofer, D D

    2016-11-01

    A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with a radius of curvature of 330 mm and a Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated x-ray emission spectra in the 7.97- to 8.11-keV range, centered on the Cu Kα1 line. To demonstrate the performance of the spectrometer under high-power conditions, Kα1,2 emission spectra were measured from Cu foils irradiated by the OMEGA EP laser with 100-J, 1-ps pulses at focused intensities above 10(18) W/cm(2). The ultimate goal is to couple the spectrometer to a picosecond x-ray streak camera and measure temperature-equilibration dynamics inside rapidly heated materials. The plan for these ultrafast streaked x-ray spectroscopy studies is discussed.

  7. Design and operation of the multiple-pulse driver line on the OMEGA laser

    NASA Astrophysics Data System (ADS)

    Kosc, T. Z.; Kelly, J. H.; Hill, E. M.; Waxer, L. J.

    2016-05-01

    The multiple-pulse driver line (MPD) provides on-shot co-propagation of two separately generated pulse shapes in all 60 OMEGA beams at the Laboratory for Laser Energetics. Smoothing by spectral dispersion (SSD), which increases the laser bandwidth, can be applied to either one of the two pulse shapes, thereby enabling dynamic bandwidth reduction. The design of the MPD required careful consideration of beam combination as well as the minimum pulse separation for two pulses generated by two separate seed sources. A new combined-pulse-shape diagnostic needed to be designed and installed after the last SSD grating. The capability of MPD to reduce dynamic bandwidth has been used on a series of campaigns on OMEGA and the performance data are presented.

  8. Planar hydrodynamic instability computations and experiments with rugby-shaped hohlraums at the Omega laser

    NASA Astrophysics Data System (ADS)

    Vandenboomgaerde, M.; Liberatore, S.; Galmiche, D.; Casner, A.; Huser, G.; Jadaud, J. P.; Villette, B.

    2008-05-01

    Implosion of inertial confinement fusion (ICF) capsule is very sensitive to the growth of sphericity perturbations. The control of the feeding of such perturbations and their transport ('feedthrough') through the ablator is a key point to reach ignition. Since 2002 [1, 2], experiments have been designed and performed on the Omega laser facility in order to study these phenomena in planar geometry. A new 'rugby shaped' hohlraum was used [3, 4]. We present experimental results and comparisons with numerical simulations.

  9. High Energy Electron Acceleration from Underdense Plasma Channeling Using the OMEGA EP Laser

    NASA Astrophysics Data System (ADS)

    Batson, Thomas; Raymond, Anthony; Hussein, Amina; Krushelnick, Karl; Willingale, Louise; Nilson, Phil; Froula, Dustin; Harberberger, Dan; Davies, Andrew; Theobald, Wolfgang; Williams, Jackson; Chen, Hui; Arefiev, Alexey

    2016-10-01

    For intense, ps scale lasers, propagation through underdense plasmas results in forces which expel electrons from along the laser axis, resulting in the formation of channels. Electrons can then be injected from the channel walls into the laser path, which results in the direct laser acceleration (DLA) of these electrons and the occurrence of an electron beam of 100's of MeV. Experiments performed at the OMEGA EP laser studied the formation of a laser channel in an underdense CH plasma, as well as the spatial properties and energy of an electron beam created via DLA mechanisms. The 4 omega optical probe diagnostic was used to characterize the density of the plasma plume, while proton radiography was used to observe the electromagnetic fields of the channel formation. These electric fields as well as the spectra of the accelerated electrons have been studied across different plasma density profiles. The channel behavior and electron spectra are compared to 2D particle-in-cell simulations.

  10. Gigabar Spherical Shock Generation on the OMEGA Laser

    SciTech Connect

    Nora, R.; Theobald, W.; Betti, R.; Marshall, F. J.; Michel, D. T.; Seka, W.; Yaakobi, B.; Lafon, M.; Stoeckl, C.; Delettrez, J.; Solodov, A. A.; Casner, A.; Reverdin, C.; Ribeyre, X.; Vallet, A.; Peebles, J.; Beg, F. N.; Wei, M. S.

    2015-01-01

    This Letter presents the first experimental demonstration of the capability to launch shocks of several hundred Mbar in spherical targets - a milestone for shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)]. Using the temporal delay between the launching of the strong shock at the outer surface of the spherical target and the time when the shock converges at the center, the shock-launching pressure can be inferred using radiation-hydrodynamic simulations. Peak ablation pressures exceeding 300 Mbar are inferred at absorbed laser intensities of ~3 × 1015 W/cm2. The shock strength is shown to be significantly enhanced by the coupling of suprathermal electrons with a total converted energy of up to 8% of the incident laser energy. At the end of the laser pulse, the shock pressure is estimated to exceed ~1 Gbar because of convergence effects.

  11. OPCPA front end and contrast optimization for the OMEGA EP kilojoule, picosecond laser

    SciTech Connect

    Dorrer, C.; Consentino, A.; Irwin, D.; Qiao, J.; Zuegel, J. D.

    2015-09-01

    OMEGA EP is a large-scale laser system that combines optical parametric amplification and solid-state laser amplification on two beamlines to deliver high-intensity, high-energy optical pulses. The temporal contrast of the output pulse is limited by the front-end parametric fluorescence and other features that are specific to parametric amplification. The impact of the two-crystal parametric preamplifier, pump-intensity noise, and pump-signal timing is experimentally studied. The implementation of a parametric amplifier pumped by a short pump pulse before stretching, further amplification, and recompression to enhance the temporal contrast of the high-energy short pulse is described.

  12. OPCPA front end and contrast optimization for the OMEGA EP kilojoule, picosecond laser

    DOE PAGES

    Dorrer, C.; Consentino, A.; Irwin, D.; ...

    2015-09-01

    OMEGA EP is a large-scale laser system that combines optical parametric amplification and solid-state laser amplification on two beamlines to deliver high-intensity, high-energy optical pulses. The temporal contrast of the output pulse is limited by the front-end parametric fluorescence and other features that are specific to parametric amplification. The impact of the two-crystal parametric preamplifier, pump-intensity noise, and pump-signal timing is experimentally studied. The implementation of a parametric amplifier pumped by a short pump pulse before stretching, further amplification, and recompression to enhance the temporal contrast of the high-energy short pulse is described.

  13. Understanding Laser-Imprint Effects on Plastic-Target Implosions on OMEGA with New Physics Models

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Michel, D. T.; Davis, A. K.; Betti, R.; Radha, P. B.; Campbell, E. M.; Froula, D. H.; Stoeckl, C.

    2016-10-01

    Using the state-of-the-art physics models (nonlocal thermal transport, cross-beam energy transfer, and first-principles equation of state) recently implemented in our two-dimensional hydrocode DRACO, we have performed a systematic study of laser-imprint effects on plastic-target implosions on OMEGA by both simulations and experiments. Through varying the laser picket intensity, the imploding shells were set at different adiabats ranging from α = 2 to α = 6 . As the shell adiabat α decreases, we observed: (1) the measured shell thickness at the hot spot emission becomes larger than the uniform prediction; (2) the hot-spot core emits and neutron burn starts earlier than the corresponding 1-D prediction; and (3) the measured neutron yields are significantly reduced from their 1-D designs. Most of these experimental observations are well reproduced by our DRACO simulations with laser imprints. These studies clearly identify that laser imprint is the major cause for target performance degradation of OMEGA implosions of α <= 3 . Mitigating laser imprints must be an essential effort to improve low- α target performance in direct-drive inertial confinement fusion ignition attempts. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  14. Understanding the effects of laser imprint on plastic-target implosions on OMEGA

    SciTech Connect

    Hu, S. X.; Michel, D. T.; Davis, A. K.; Betti, R.; Radha, P. B.; Campbell, E. M.; Froula, D. H.; Stoeckl, C.

    2016-10-03

    Understanding the effects of laser imprint on target performance is critical to the success of direct-drive inertial confinement fusion. Directly measuring the disruption caused by laser imprints to the imploding shell and hot-spot formation, in comparison with multidimensional radiation–hydrodynamic simulations, can provide a clear picture of how laser nonuniformities cause target performance to degrade. With the recently developed x-ray self-emission imaging technique and the state-of-the-art physics models recently implemented in the two-dimensional hydrocode DRACO, a systematic study of laser-imprint effects on warm target implosions on OMEGA has been performed using both experimental results and simulations. By varying the laser-picket intensity, the imploding shells were set at different adiabats (from α = 2 to α = 6). As the shell adiabats decreased, it was observed that (1) the measured shell thickness at the time the hot spot lit up became larger than the uniform one-dimensional (1-D) predictions; (2) the hot-spot core emitted earlier than the corresponding 1-D predictions; (3) the measured neutron yield first increased then decreased as the shell adiabat α was reduced; and (4) the hot-spot size reduced as α decreased for cases where SSD (smoothing by spectral dispersion) was on but became larger for low-α shots in cases where SSD was off. Most of these experimental observations are well reproduced by DRACO simulations with laser imprints including modes up to λmax = 200. In addition, these studies identify the importance of laser imprint as the major source of degrading target performance for OMEGA implosions of adiabat α ≤ 3. Mitigating laser imprints is required to improve low-α target performance.

  15. Understanding the effects of laser imprint on plastic-target implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Michel, D. T.; Davis, A. K.; Betti, R.; Radha, P. B.; Campbell, E. M.; Froula, D. H.; Stoeckl, C.

    2016-10-01

    Understanding the effects of laser imprint on target performance is critical to the success of direct-drive inertial confinement fusion. Directly measuring the disruption caused by laser imprints to the imploding shell and hot-spot formation, in comparison with multidimensional radiation-hydrodynamic simulations, can provide a clear picture of how laser nonuniformities cause target performance to degrade. With the recently developed x-ray self-emission imaging technique and the state-of-the-art physics models recently implemented in the two-dimensional hydrocode DRACO, a systematic study of laser-imprint effects on warm target implosions on OMEGA has been performed using both experimental results and simulations. By varying the laser-picket intensity, the imploding shells were set at different adiabats (from α = 2 to α = 6). As the shell adiabats decreased, it was observed that (1) the measured shell thickness at the time the hot spot lit up became larger than the uniform one-dimensional (1-D) predictions; (2) the hot-spot core emitted earlier than the corresponding 1-D predictions; (3) the measured neutron yield first increased then decreased as the shell adiabat α was reduced; and (4) the hot-spot size reduced as α decreased for cases where SSD (smoothing by spectral dispersion) was on but became larger for low-α shots in cases where SSD was off. Most of these experimental observations are well reproduced by DRACO simulations with laser imprints including modes up to λmax = 200. These studies identify the importance of laser imprint as the major source of degrading target performance for OMEGA implosions of adiabat α ≤ 3. Mitigating laser imprints is required to improve low-α target performance.

  16. Understanding the effects of laser imprint on plastic-target implosions on OMEGA

    DOE PAGES

    Hu, S. X.; Michel, D. T.; Davis, A. K.; ...

    2016-10-03

    Understanding the effects of laser imprint on target performance is critical to the success of direct-drive inertial confinement fusion. Directly measuring the disruption caused by laser imprints to the imploding shell and hot-spot formation, in comparison with multidimensional radiation–hydrodynamic simulations, can provide a clear picture of how laser nonuniformities cause target performance to degrade. With the recently developed x-ray self-emission imaging technique and the state-of-the-art physics models recently implemented in the two-dimensional hydrocode DRACO, a systematic study of laser-imprint effects on warm target implosions on OMEGA has been performed using both experimental results and simulations. By varying the laser-picket intensity,more » the imploding shells were set at different adiabats (from α = 2 to α = 6). As the shell adiabats decreased, it was observed that (1) the measured shell thickness at the time the hot spot lit up became larger than the uniform one-dimensional (1-D) predictions; (2) the hot-spot core emitted earlier than the corresponding 1-D predictions; (3) the measured neutron yield first increased then decreased as the shell adiabat α was reduced; and (4) the hot-spot size reduced as α decreased for cases where SSD (smoothing by spectral dispersion) was on but became larger for low-α shots in cases where SSD was off. Most of these experimental observations are well reproduced by DRACO simulations with laser imprints including modes up to λmax = 200. In addition, these studies identify the importance of laser imprint as the major source of degrading target performance for OMEGA implosions of adiabat α ≤ 3. Mitigating laser imprints is required to improve low-α target performance.« less

  17. Understanding the effects of laser imprint on plastic-target implosions on OMEGA

    SciTech Connect

    Hu, S. X.; Michel, D. T.; Davis, A. K.; Betti, R.; Radha, P. B.; Campbell, E. M.; Froula, D. H.; Stoeckl, C.

    2016-10-03

    Understanding the effects of laser imprint on target performance is critical to the success of direct-drive inertial confinement fusion. Directly measuring the disruption caused by laser imprints to the imploding shell and hot-spot formation, in comparison with multidimensional radiation–hydrodynamic simulations, can provide a clear picture of how laser nonuniformities cause target performance to degrade. With the recently developed x-ray self-emission imaging technique and the state-of-the-art physics models recently implemented in the two-dimensional hydrocode DRACO, a systematic study of laser-imprint effects on warm target implosions on OMEGA has been performed using both experimental results and simulations. By varying the laser-picket intensity, the imploding shells were set at different adiabats (from α = 2 to α = 6). As the shell adiabats decreased, it was observed that (1) the measured shell thickness at the time the hot spot lit up became larger than the uniform one-dimensional (1-D) predictions; (2) the hot-spot core emitted earlier than the corresponding 1-D predictions; (3) the measured neutron yield first increased then decreased as the shell adiabat α was reduced; and (4) the hot-spot size reduced as α decreased for cases where SSD (smoothing by spectral dispersion) was on but became larger for low-α shots in cases where SSD was off. Most of these experimental observations are well reproduced by DRACO simulations with laser imprints including modes up to λmax = 200. In addition, these studies identify the importance of laser imprint as the major source of degrading target performance for OMEGA implosions of adiabat α ≤ 3. Mitigating laser imprints is required to improve low-α target performance.

  18. High-Resolving-Power, Streaked X-Ray Spectroscopy on the OMEGA EP Laser System

    NASA Astrophysics Data System (ADS)

    Nilson, P. M.; Ehrne, F.; Mileham, C.; Mastrosimone, D.; Jungquist, R. K.; Taylor, C.; Boni, R.; Hassett, J.; Stillman, C. R.; Ivancic, S. T.; Lonobile, D. J.; Kidder, R. W.; Shoup, M. J., III; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Froula, D. H.; Hill, K. W.; Gao, L.; Bitter, M.; Efthimion, P.; Meyerhofer, D. D.

    2016-10-01

    A high-resolving-power, streaked x-ray spectrometer is being developed and tested on the OMEGA EP Laser System to study temperature-equilibration dynamics in rapidly heated solid matter. Temporal spectral shifts of the Cu Kα line in isochorically heated solid targets provide a fairly simple system where the spectrometer performance will be validated. The goal is to achieve a resolving power of several thousand and 2-ps temporal resolution. A time-integrating survey spectrometer has been developed and deployed on OMEGA EP to evaluate the throughput, focusing fidelity, and spectral resolution of two different crystal geometries. The results from these measurements will be presented and used to justify the down-selected time-resolved spectrometer design. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  19. Hydrodynamics simulations of 2 (omega) laser propagation in underdense gasbag plasmas

    SciTech Connect

    Meezan, N B; Divol, L; Marinak, M M; Kerbel, G D; Suter, L J; Stevenson, R M; Slark, G E; Oades, K

    2004-04-05

    Recent 2{omega} laser propagation and stimulated Raman backscatter (SRS) experiments performed on the Helen laser have been analyzed using the radiation-hydrodynamics code hydra. These experiments utilized two diagnostics sensitive to the hydrodynamics of gasbag targets: a fast x-ray framing camera (FXI) and an SRS streak spectrometer. With a newly implemented nonlocal thermal transport model, hydra is able to reproduce many features seen in the FXI images and the SRS streak spectra. Experimental and simulated side-on FXI images suggest that propagation can be explained by classical laser absorption and the resulting hydrodynamics. Synthetic SRS spectra generated from the hydra results reproduce the details of the experimental SRS streak spectra. Most features in the synthetic spectra can be explained solely by axial density and temperature gradients. The total SRS backscatter increases with initial gasbag fill density up to {approx} 0.08 times the critical density, then decreases. Images from a near-backscatter camera (NBI) show that severe beam spray is not responsible for the trend in total backscatter. Filamentation does not appear to be a significant factor in gasbag hydrodynamics. The simulation and analysis techniques established here can be used in upcoming experimental campaigns on the Omega laser facility and the National Ignition Facility.

  20. Hydrodynamics simulations of 2{omega} laser propagation in underdense gasbag plasmas

    SciTech Connect

    Meezan, N.B.; Divol, L.; Marinak, M.M.; Kerbel, G.D.; Suter, L.J.; Stevenson, R.M.; Slark, G.E.; Oades, K.

    2004-12-01

    Recent 2{omega} laser propagation and stimulated Raman backscatter (SRS) experiments performed on the Helen laser have been analyzed using the radiation-hydrodynamics code HYDRA [M. M. Marinak, G. D. Kerbel, N. A. Gentile, O. Jones, D. Munro, S. Pollaine, T. R. Dittrich, and S. W. Haan, Phys. Plasmas 8, 2275 (2001)]. These experiments utilized two diagnostics sensitive to the hydrodynamics of gasbag targets: a fast x-ray framing camera (FXI) and a SRS streak spectrometer. With a newly implemented nonlocal thermal transport model, HYDRA is able to reproduce many features seen in the FXI images and the SRS streak spectra. Experimental and simulated side-on FXI images suggest that propagation can be explained by classical laser absorption and the resulting hydrodynamics. Synthetic SRS spectra generated from the HYDRA results reproduce the details of the experimental SRS streak spectra. Most features in the synthetic spectra can be explained solely by axial density and temperature gradients. The total SRS backscatter increases with initial gasbag fill density up to {approx_equal}0.08 times the critical density, then decreases. Data from a near-backscatter imaging camera show that severe beam spray is not responsible for the trend in total backscatter. Filamentation does not appear to be a significant factor in gasbag hydrodynamics. The simulation and analysis techniques established here can be used in ongoing experimental campaigns on the Omega laser facility and the National Ignition Facility.

  1. Accretion Shocks in the Laboratory: Using the OMEGA Laser to Study Star Formation

    NASA Astrophysics Data System (ADS)

    Young, R. P.; Kuranz, C. C.; Li, C. K.; Hartigan, P.; Froula, D.; Fiksel, G.; Ross, J. S.; Chang, P. Y.; Klein, S.; Zylstra, A.; Sio, H. W.; Liao, A.; Barnak, D.

    2016-10-01

    We present an on-going series of experiments using the OMEGA laser (Laboratory for Laser Energetics) to study star formation. Spectra of young stars show evidence of hotspots created when streams of accreting material impact at the surface of the star to create accretion shocks. These accretion shocks are poorly understood, as the surfaces of young stars cannot be spatially resolved. Our experiment series creates a scaled ``accretion shock'' on the OMEGA laser by driving a plasma jet (the ``accretion stream'') into a solid block (the ``stellar surface''), in the presence of a parallel magnetic field analogous to the star's local field. Thus far, visible image data from this experimental series either shows very thin accretion shocks forming or does not show them forming at all. We intend to present this data, provide possible explanations for why shocks may not have formed, and discuss potential improvements to the experimental design. This work is funded by the U.S. Department of Energy, through the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956, and the National Laser User Facility Program, Grant Number DE-NA0002719.

  2. Measurements and Calculations of Halfraum Radiation Drives at the Omega Laser

    SciTech Connect

    MacLaren, S A; Back, C A; Hammer, J H

    2005-01-06

    Thin walled gold halfraums are a common choice for producing x-ray drives in experiments at high-power laser facilities. At the Omega Laser, we use 10 kJ of laser energy in a two-pulse sequence to generate halfraum drive temperatures of 160-190 eV for {approx}3ns. This type of drive is well characterized and reproducible, with characterization of the drive radiation temperature typically performed using the Dante diagnostic. Additionally, calibrated Photoconductive Diamond Detectors (PCDs) are used to measure the drive when it is desirable to utilize the Dante elsewhere in the experiment. Measurements of halfraum drives from both Dante and PCDs are compared with calculations, with good agreement. This agreement lends the calculations a predictive capability in designing further experiments utilizing halfraum drives.

  3. Experimental configuration of direct drive cylindrical implosions on the Omega Laser

    SciTech Connect

    Barnes, C.W.; Tubbs, D.L.; Beck, J.B.

    1998-12-31

    Details about the cylindrical implosions using direct-drive irradiation on the OMEGA Laser facility are provided. The experimental configuration, including orientation, construction, and mounting of the targets is described. An attempt to characterize the modulation transfer function of the primary x-ray framing camera diagnostic results in insufficient exposure contrast but relative agreement with other determinations. The x-ray intensity of the titanium backlighter driven by the 2.5-nsec linear ramp of the laser beams is described, and the relative intensity on film is compared to similar Nova experiments. The parallax effects of different length marker layers of high-opacity dichloropolystyrene is measured, resulting in the conclusion that the marker layer length should be matched to the laser drive illumination profile.

  4. Designing symmetric polar direct drive implosions on the Omega laser facility

    SciTech Connect

    Krasheninnikova, Natalia S.; Cobble, James A.; Murphy, Thomas J.; Tregillis, Ian L.; Bradley, Paul A.; Hakel, Peter; Hsu, Scott C.; Kyrala, George A.; Obrey, Kimberly A.; Schmitt, Mark J.; Baumgaertel, Jessica A.; Batha, Steven H.

    2014-04-15

    Achieving symmetric capsule implosions with Polar Direct Drive [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004); R. S. Craxton et al., Phys. Plasmas 12, 056304 (2005); F. J. Marshall et al., J. Phys. IV France 133, 153–157 (2006)] has been explored during recent Defect Induced Mix Experiment campaign on the Omega facility at the Laboratory for Laser Energetics. To minimize the implosion asymmetry due to laser drive, optimized laser cone powers, as well as improved beam pointings, were designed using 3D radiation-hydrodynamics code HYDRA [M. M. Marinak et al., Phys. Plasmas 3, 2070 (1996)]. Experimental back-lit radiographic and self-emission images revealed improved polar symmetry and increased neutron yield which were in good agreement with 2D HYDRA simulations. In particular, by reducing the energy in Omega's 21.4° polar rings by 16.75%, while increasing the energy in the 58.9° equatorial rings by 8.25% in such a way as to keep the overall energy to the target at 16 kJ, the second Legendre mode (P{sub 2}) was reduced by a factor of 2, to less than 4% at bang time. At the same time the neutron yield increased by 62%. The polar symmetry was also improved relative to nominal DIME settings by a more radical repointing of OMEGA's 42.0° and 58.9° degree beams, to compensate for oblique incidence and reduced absorption at the equator, resulting in virtually no P{sub 2} around bang time and 33% more yield.

  5. Damage in fused-silica spatial-filter lenses on the OMEGA laser system

    NASA Astrophysics Data System (ADS)

    Rigatti, Amy L.; Smith, Douglas J.; Schmid, Ansgar W.; Papernov, Semyon; Kelly, John H.

    1999-04-01

    Vacuum surface damage to fused-silica, spatial-filter lenses is the most prevalent laser-damage problem occurring on the OMEGA laser system. Approximately one-half of the stage C- input and output, D-input, E-input, and F-input spatial- filter lenses are currently damaged with millimeter-scale fracture sites. With the establishment of safe operational damage criteria, laser operation has not been impeded. These sol-gel-coated lenses see an average fluence of 2 to 4 J/cm2 at 1053 nm/1 ns. Sol-gel coatings on fused-silica glass have small-spot damage thresholds at least a factor of 2 higher than this peak operational fluence. It is now known that the vacuum surface of OMEGA's spatial-filter lenses are contaminated with vacuum pump oils and machine oils used in the manufacture of the tubes; however, development-phase damage tests were conducted on uncontaminated witness samples. Possible explanations for the damage include absorbing defects originating form ablated pinhole materials, contamination nucleated at surface defects on the coating, or subsurface defects from the polishing process. The damage does not correlate with hot spots in the beam, and the possibility of damage from ghost reflections has been eliminated. Experiments have been initiated to investigate the long-term benefits of ion etching to remove subsurface damage and to replace sol-gel layers by dielectric oxide coatings, which do not degrade with oil contamination.

  6. Enhanced Performance of Large 3(omega) Optics Using UV and IR Lasers

    SciTech Connect

    Prasad, R R; Bruere, J; Peterson, J; Halpin, J; Borden, M; Hackel, R P

    2003-11-01

    We have developed techniques using small-beam raster scanning to laser-condition fused silica optics to increase their damage threshold. Further, we showed that CO{sub 2} lasers could be used to mitigate and stabilize damage sites while still on the order of a few tens of microns in size, thereby greatly increasing the lifetime of an optic. We recently activated the Phoenix pre-production facility to condition and mitigate optics as large as 43 cm x 43 cm. Several full-scale optics have been processed in Phoenix. The optics were first photographed using a damage mapping system to identify scratches, digs, or other potential sites for initiation of laser damage. We then condition the optic, raster scanning with the excimer laser. The first scan is performed at a low fluence. A damage map is then acquired and any new damage sites or any sites that have grown in size are mitigated using the CO{sub 2} laser. The process is repeated at successively higher fluences until a factor of 1.7 above the nominal operating fluence is reached. After conditioning, optics were tested in a large beam 3{omega} laser and showed no damage at fluences of 8 J/cm{sup 2} average.

  7. A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited)

    SciTech Connect

    Nilson, P. M. Ehrne, F.; Mileham, C.; Mastrosimone, D.; Jungquist, R. K.; Taylor, C.; Stillman, C. R.; Ivancic, S. T.; Boni, R.; Hassett, J.; Lonobile, D. J.; Kidder, R. W.; Shoup, M. J.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Froula, D. H.; Hill, K. W.; Gao, L.; Bitter, M.; and others

    2016-11-15

    A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with a radius of curvature of 330 mm and a Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated x-ray emission spectra in the 7.97- to 8.11-keV range, centered on the Cu K{sub α1} line. To demonstrate the performance of the spectrometer under high-power conditions, K{sub α1,2} emission spectra were measured from Cu foils irradiated by the OMEGA EP laser with 100-J, 1-ps pulses at focused intensities above 10{sup 18} W/cm{sup 2}. The ultimate goal is to couple the spectrometer to a picosecond x-ray streak camera and measure temperature-equilibration dynamics inside rapidly heated materials. The plan for these ultrafast streaked x-ray spectroscopy studies is discussed.

  8. High performance capsule implosions on the OMEGA Laser facility with rugby hohlraumsa)

    NASA Astrophysics Data System (ADS)

    Robey, H. F.; Amendt, P.; Park, H.-S.; Town, R. P. J.; Milovich, J. L.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Sorce, C.; Strozzi, D. J.; Philippe, F.; Casner, A.; Caillaud, T.; Landoas, O.; Liberatore, S.; Monteil, M.-C.; Séguin, F.; Rosenberg, M.; Li, C. K.; Petrasso, R.; Glebov, V.; Stoeckl, C.; Nikroo, A.; Giraldez, E.

    2010-05-01

    Rugby-shaped hohlraums have been proposed as a method for x-ray drive enhancement for indirectly driven capsule implosions. This concept has recently been tested in a series of shots on the OMEGA laser facility [T. R. Boehly, D. L. Brown, R. S. Craxton et al., Opt. Commun. 133, 495 (1997)]. In this paper, experimental results are presented comparing the performance of D2-filled capsules between standard cylindrical Au hohlraums and rugby-shaped hohlraums. The rugby hohlraums demonstrated 18% more x-ray drive energy as compared with the cylinders, and the high-performance design of these implosions (both cylinder and rugby) also provided ≈20× more deuterium (DD) neutrons than any previous indirectly driven campaign on OMEGA and ≈3× more than ever achieved on NOVA [E. M. Campbell, Laser Part. Beams 9, 209 (1991)] implosions driven with nearly twice the laser energy. This increase in performance enables, for the first time, a measurement of the neutron burn history and imaging of the neutron core shapes in an indirectly driven implosion. Previous DD neutron yields had been too low to register this key measurement of capsule performance and the effects of dynamic mix. A wealth of additional data on the fuel areal density from the suite of charged particle diagnostics was obtained on a subset of the shots that used D H3e rather than D2 fuel. Comparisons of the experimental results with numerical simulations are shown to be in very good agreement. The design techniques employed in this campaign, e.g., smaller laser entrance holes and hohlraum case-to-capsule ratios, provide added confidence in the pursuit of ignition on the National Ignition Facility [J. D. Lindl, P. Amendt, R. L. Berger et al., Phys. Plasmas 11, 339 (2004)].

  9. High Performance Capsule Implosions on the Omega Laser Facility with Rugby Hohlraums

    NASA Astrophysics Data System (ADS)

    Robey, Harry F.

    2009-11-01

    Rugby-shaped hohlraums have been proposed as a method for x-ray drive enhancement for indirectly-driven capsule implosions [1]. This concept has recently been tested in a series of shots on the OMEGA laser facility at the Laboratory for Laser Energetics at the University of Rochester. In this talk, experimental results are presented comparing the performance of D2-filled capsules between standard cylindrical Au hohlraums and rugby-shaped hohlraums. Not only did the rugby hohlraums demonstrate 18% more x-ray drive energy as compared with the cylinders, but the high-performance design of these implosions (both cylinder and rugby) also provided 20X more DD neutrons than any previous indirectly-driven campaign on Omega (and 3X more than ever achieved on Nova implosions driven with nearly twice the laser energy). This increase in performance enables, for the first time, a measurement of the neutron burn history of an indirectly-driven implosion. Previous DD neutron yields had been too low to register this key measurement of capsule performance and the effects of dynamic mix. A wealth of additional data on the fuel areal density from the suite of charged particle diagnostics was obtained on a subset of the shots that used D^3He rather than D2 fuel. Comparisons of the experimental results with numerical simulations are shown to be in excellent agreement. The design techniques employed in this campaign, e.g., smaller NIF-like laser entrance holes and hohlraum case-to-capsule ratios, provide added confidence in the pursuit of ignition on the National Ignition Facility. [4pt] [1] P. Amendt, C. Cerjan, D. E. Hinkel, J. L. Milovich, H.-S. Park, and H. F. Robey, ``Rugby-like hohlraum experimental designs for demonstrating x-ray drive enhancement'', Phys. Plasmas 15, 012702 (2008).

  10. Spatially and spectrally resolved filamentary structures in the (3/2)omega 0 emission from laser produced plasmas

    NASA Astrophysics Data System (ADS)

    Lin, Z.; Willi, O.; Rumsby, P. T.

    This study was conducted to explore the problem of filamentation of laser light in the underdense plasma corona surrounding ablatively imploded spherical targets, a phenomenon which may prevent the realization of laser-driven fusion schemes. Preliminary observations were made of filamentary structures in the (3/2)(omega sub 0) emission from microballoon targets irradiated in the ablative mode. Time integrated spectroscopy showed double and single peaked (3/2)(omega sub 0) emission spectra. A simple model for the growth and collapse of filaments was based on the movement of the density contours at the bottom of the filament with large velocity. Here the laser intensity was high and various decay instabilities and scattering processes took place. In particular the two plasmon decay instability occurred where the electron density was nc/4, a region of (3/2)(omega sub 0) emission. The model was consistent with the experimentally observed spectra and predicted the type of omega sub 0 and 2 omega sub 0 that should be observed in future experiments.

  11. High pressure, quasi-isentropic compression experiments on the Omega laser

    SciTech Connect

    Lorenz, K; Edwards, M; Jankowski, A; Pollaine, S; Smith, R; Remington, B

    2006-05-26

    The high energy density of pulsed lasers can be used to generate shockless loading in solids to high pressures and compressions but low temperatures. We have used the Omega laser to extend the capabilities of this technique to multi-Mbar pressures and compressions approaching a factor of 2 in aluminum foils. The energy from a 3.7 ns laser pulse is used to drive a strong shock through a 200 {micro}m polystyrene disc. The disc material unloads from a high-pressure state and expands across a 300 {micro}m vacuum gap where it stagnates against the sample to produce a smooth, monotonically increasing load with rise times from a few to {approx} 20 ns. Ramped compression reasing waves having peak pressures of 14-200 GPa (0.14-2.0 Mbar) and peak compressions {rho}/{rho}{sub 0} of 1.1-2.0 were generated in the aluminum samples using laser pulse energies of 400 J to 2 kJ. Wave profiles from a series of successively thicker targets loaded to 120 GPa show the evolution of the high-pressure compression wave within the sample. The initial loading in the sample is shockless, and develops into a shock at a depth of 20-25 {micro}m. We compare these wave profiles with hydrodynamic simulations from which we extract material temperatures and plastic strain rates behind the compression wave. Limitations and future prospects for this new shockless loading technique are discussed.

  12. Advanced-Ignition-Concept Exploration on OMEGA

    SciTech Connect

    Theobald, W; Anderson, K S; Betti, R; Craxton, R S; Delettrez, J A; Frenje, J A; Glebov, V Yu; Gotchev, O V; Kelly, J H; Li, C K; Mackinnon, A J; Marshall, F J; McCrory, R L; Meyerhofer, D D; Myatt, J F; Norreys, P A; Nilson, P M; Patel, P K; Petrasso, R D; Radha, P B; Ren, C; Sangster, T C; Seka, W; Smalyuk, V A; Solodov, A A; Stephens, R B; Stoeckl, C; Yaakobi, B

    2009-11-24

    Advanced ignition concepts, such as fast ignition and shock ignition, are being investigated at the Omega Laser Facility. Integrated fast-ignition experiments with room-temperature re-entrant cone targets have begun, using 18 kJ of 351 nm drive energy to implode empty 40μm thick CD shells, followed by 1.0 kJ of 1053 nm wavelength, short-pulse energy. Short pulses of 10 ps width have irradiated the inside of a hollow gold re-entrant cone at the time of peak compression. A threefold increase in the time-integrated, 2 to 7 keV x-ray emission was observed with x-ray pinhole cameras, indicating that energy is coupled from the short-pulse laser into the core by fast electrons. In shock-ignition experiments, spherical plastic-shell targets were compressed to high areal densities on a low adiabat, and a strong shock wave was sent into the converging, compressed capsule. In one experiment, 60 beams were used with an intensity spike at the end of the laser pulse, and the implosion performance was studied through neutron-yield and areal-density measurements. In a second experiment, the 60 OMEGA beams were split into a 40+20 configuration, with 40 low-intensity beams used for fuel assembly and 20 delayed beams with a short, high-intensity pulse shape (up to 1×1016 Wcm^-2) for shock generation.

  13. Advanced-Ignition-Concept Exploration on OMEGA

    SciTech Connect

    Theobald, W; Anderson, K S; Betti, R; Craxton, R S; Delettrez, J A; Frenje, J A; Glebov, V Yu; Gotchev, O V; Kelly, J H; Li, C K; Mackinnon, A J; Marshall, F J; McCrory, R L; Meyerhofer, D D; Myatt, J F; Norreys, P A; Nilson, P M; Patel, P K; Petrasso, R D; Radha, P B; Ren, C; Sangster, T C; Seka, W; Smalyuk, V A; Solodov, A A; Stephens, R B; Stoeckl, C; Yaakobi, B

    2009-11-24

    Advanced ignition concepts, such as fast ignition and shock ignition, are being investigated at the Omega Laser Facility. Integrated fast-ignition experiments with room-temperature re-entrant cone targets have begun, using 18 kJ of 351 nm drive energy to implode empty 40μm thick CD shells, followed by 1.0 kJ of 1053 nm wavelength, short-pulse energy. Short pulses of 10 ps width have irradiated the inside of a hollow gold re-entrant cone at the time of peak compression. A threefold increase in the time-integrated, 2 to 7 keV x-ray emission was observed with x-ray pinhole cameras, indicating that energy is coupled from the short-pulse laser into the core by fast electrons. In shock-ignition experiments, spherical plastic-shell targets were compressed to high areal densities on a low adiabat, and a strong shock wave was sent into the converging, compressed capsule. In one experiment, 60 beams were used with an intensity spike at the end of the laser pulse, and the implosion performance was studied through neutron-yield and areal-density measurements. In a second experiment, the 60 OMEGA beams were split into a 40+20 configuration, with 40 low-intensity beams used for fuel assembly and 20 delayed beams with a short, high-intensity pulse shape (up to 1×1016 Wcm-2) for shock generation.

  14. Multipurpose 10 in. manipulator-based optical telescope for Omega and the Trident laser facilities

    NASA Astrophysics Data System (ADS)

    Oertel, J. A.; Murphy, T. J.; Berggren, R. R.; Faulkner, J.; Schmell, R.; Little, D.; Archuleta, T.; Lopez, J.; Velarde, J.; Horton, R. F.

    1999-01-01

    We have recently designed and are building a telescope which acts as an imaging light collector relaying the image to an optical table for experiment dependent analysis and recording. The expected primary use of this instrument is a streaked optical pyrometer for witness plate measurements of the hohlraum drive temperature. The telescope is based on the University of Rochester's 10 in. manipulator (TIM) which allows compatibility between Omega, Trident, and the NIF lasers. The optics capture a f/7 cone of light, have a field of view of 6 mm, have a spatial resolution of 5-7 μm per line pair at the object plane, and are optimized for operation at 280 nm. The image is at a magnification of 11.7×, which is convenient for many experiments, but can be changed using additional optics that reside outside the TIM.

  15. A multipurpose TIM-based optical telescope for Omega and the Trident laser facilities

    SciTech Connect

    Oertel, J.A.; Murphy, T.J.; Berggren, R.R.

    1998-12-31

    The authors have recently designed and are building a telescope which acts as an imaging light collector relaying the image to an optical table for experiment dependent analysis and recording. The expected primary use of this instrument is a streaked optical pyrometer for witness plate measurements of Hohlraum drive temperature. The telescope is based on University of Rochester`s Ten-Inch Manipulator (TIM) which allows compatibility between Omega, Trident, and the NIF lasers. The optics capture a f/7 cone of light, have a field of view of 6-mm, have a spatial resolution of 5 to 7-{micro}m per line pair at the object plane, and are optimized for operation at 280-nm. The image is at a magnification of 11.7x, which is convenient for many experiments, but can be changed using additional optics that reside outside the TIM.

  16. Single-mode Rayleigh-Taylor growth-rate measurements with the OMEGA laser system

    SciTech Connect

    Knauer, J. P.; Verdon, C. P.; Meyerhofer, D. D.; Boehly, T. R.; Bradley, D. K.; Smalyuk, V. A.; Ofer, D.; McKenty, P. W.; Glendinning, S. G.; Kalantar, D. H.; Watt, R. G.; Gobby, P. L.; Willi, O.; Taylor, R. J.

    1997-04-15

    The results from a series of single-mode Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five to six 351-nm laser beams overlapped with total intensities up to 2.5x10{sup 14} W/cm{sup 2}. Experiments were performed with both 3-ns ramp and 3-ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%-7% over a 600-{mu}m-diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using through-foil radiography and was detected with an x-ray framing camera for CH targets with and without a foam buffer. The growth of both 31-{mu}m and 60-{mu}m wavelength perturbations was found to be in good agreement with ORCHID simulations when the experimental details, including noise, were included. The addition of a 30-mg/cc, 100-{mu}m-thick polystyrene foam buffer layer resulted in reduced growth of the 31-{mu}m perturbation and essentially unchanged growth for the 60-{mu}m case when compared to targets without foam.

  17. Single-mode Rayleigh-Taylor growth-rate measurements with the OMEGA laser system

    NASA Astrophysics Data System (ADS)

    Knauer, J. P.; Verdon, C. P.; Meyerhofer, D. D.; Boehly, T. R.; Bradley, D. K.; Smalyuk, V. A.; Ofer, D.; McKenty, P. W.; Glendinning, S. G.; Kalantar, D. H.; Watt, R. G.; Gobby, P. L.; Willi, O.; Taylor, R. J.

    1997-04-01

    The results from a series of single-mode Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five to six 351-nm laser beams overlapped with total intensities up to 2.5×1014W/cm2. Experiments were performed with both 3-ns ramp and 3-ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%-7% over a 600-μm-diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using through-foil radiography and was detected with an x-ray framing camera for CH targets with and without a foam buffer. The growth of both 31-μm and 60-μm wavelength perturbations was found to be in good agreement with ORCHID simulations when the experimental details, including noise, were included. The addition of a 30-mg/cc, 100-μm-thick polystyrene foam buffer layer resulted in reduced growth of the 31-μm perturbation and essentially unchanged growth for the 60-μm case when compared to targets without foam.

  18. Single-mode Rayleigh-Taylor growth-rate measurements with the OMEGA laser system

    SciTech Connect

    Knauer, J.P.; Verdon, C.P.; Meyerhofer, D.D.; Boehly, T.R.; Bradley, D.K.; Smalyuk, V.A.; Ofer, D.; McKenty, P.W.; Glendinning, S.G.; Kalantar, D.H.; Watt, R.G.; Gobby, P.L.; Willi, O.; Taylor, R.J.

    1997-04-01

    The results from a series of single-mode Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five to six 351-nm laser beams overlapped with total intensities up to 2.5{times}10{sup 14}W/cm{sup 2}. Experiments were performed with both 3-ns ramp and 3-ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4{percent}{endash}7{percent} over a 600-{mu}m-diam region defined by the 90{percent} intensity contour. The temporal growth of the modulation in optical depth was measured using through-foil radiography and was detected with an x-ray framing camera for CH targets with and without a foam buffer. The growth of both 31-{mu}m and 60-{mu}m wavelength perturbations was found to be in good agreement with {ital ORCHID} simulations when the experimental details, including noise, were included. The addition of a 30-mg/cc, 100-{mu}m-thick polystyrene foam buffer layer resulted in reduced growth of the 31-{mu}m perturbation and essentially unchanged growth for the 60-{mu}m case when compared to targets without foam. {copyright} {ital 1997 American Institute of Physics.}

  19. Initial Single-Mode Rayleigh-Taylor Growth Rates Measured with the OMEGA Laser System

    NASA Astrophysics Data System (ADS)

    Knauer, J. P.; Meyerhofer, D. D.; Boehly, T. R.; Ofer, D.; Verdon, C. P.; Bradley, D. K.; McKenty, P. W.; Smalyuk, V. A.

    1996-11-01

    A series of single-mode growth measurements done with the OMEGA laser system are reported. These measurements were done to qualify the laser irradiation and diagnostic suite for future experiments that will use the growth of perturbations at the ablation interface to quantify improvements in irradiation uniformity, reduced growth due to increased ablation velocities, and the effect of increased density scale lengths on the growth rate at the ablation interface. This series of measurements used a laser intensity of 2 × 10^14 W/cm^2 over a spot size of 700 μm for both Gaussian and non-Gaussian shaped pulses with an rms irradiation nonuniformity of 7%. Data were collected with a gated x-ray framing camera with a 10-μm spatial resolution and a 40-ps temporal resolution. This work was supported by the U. S. Department of Energy Office of Inertial Confinement Fusion under cooperative Agreement No. DE-FC03-92SF19460.

  20. High pressure, quasi-isentropic compression experiments on the Omega laser

    NASA Astrophysics Data System (ADS)

    Lorenz, K. T.; Edwards, M. J.; Jankowski, A. F.; Pollaine, S. M.; Smith, R. F.; Remington, B. A.

    2006-10-01

    The high energy density of pulsed lasers can be used to generate shockless loading in solids to high pressures and compressions but low temperatures. [J. Edwards, K.T. Lorenz, B.A. Remington, S. Pollaine, J. Colvin, D. Braun, B.F. Lasinski, D. Reisman, J.M. McNaney, J.A. Greenough, R.Wallace, H. Louis, D. Kalantar, Laser-driven plasma loader for shockless compression and acceleration of samples in the solid state, Phys. Rev. Lett. 92 (2004) 075002.] We have used the Omega laser to extend the capabilities of this technique to multi-Mbar pressures and compressions approaching a factor of 2 in aluminum foils. The energy from a 3.7 ns laser pulse is used to drive a strong shock through a 200 μm polystyrene disc. The disc material unloads from a high-pressure state and expands across a 300 μm vacuum gap where it stagnates against the sample to produce a smooth, monotonically increasing load with rise times from a few to ˜20 ns. Ramped compression waves having peak pressures of 14-200 GPa (0.14-2.0 Mbar) and peak compressions ρ/ ρ0 of 1.1-2.0 were generated in the aluminum samples using laser pulse energies of 400 J to 2 kJ. Wave profiles from a series of successively thicker targets loaded to 120 GPa show the evolution of the high-pressure compression wave within the sample. The initial loading in the sample is shockless, and develops into a shock at a depth of 20-25 μm. We compare these wave profiles with hydrodynamic simulations from which we extract material temperatures and plastic strain rates behind the compression wave. Limitations and future prospects for this new shockless loading technique are discussed.

  1. A versatile high-resolution x-ray imager (HRXI) for laser-plasma experiments on OMEGA

    SciTech Connect

    Bourgade, J. L.; Troussel, P.; Casner, A.; Huser, G.; Fariaud, J.; Remond, C.; Gontier, D.; Chollet, C.; Zuber, C.; Reverdin, C.; Richard, A.; Maroni, R.; Aubard, F.; Angelier, B.

    2008-10-15

    A high-resolution x-ray imager (HRXI) devoted to laser-plasma experiments combines two state-of-the-art technologies developed in France: a high-resolution x-ray microscope and a high-speed x-ray streak camera. The resulting streaked imager achieves spatial and temporal resolutions of {approx}5 {mu}m and {approx}10 ps, respectively. The HXRI has recorded enhanced spatial and temporal resolution radiographs of indirectly driven targets on OMEGA. This paper describes the main features of the instrument and details the activation process on OMEGA (particularly the alignment). Recent results obtained on joint CEA/LLE radiographic OMEGA experiments will also be presented.

  2. Numerical Modeling of LLNL's Au-Sphere experiments on the OMEGA Laser

    NASA Astrophysics Data System (ADS)

    Ma, K. H.; Raicher, E.; Frank, Y.; Fraenkel, M.; Johnsen, E.; Drake, R. P.; Shvarts, D.

    2016-10-01

    Experiments performed by LLNL on OMEGA studying X-ray conversion efficiencies for high-Z materials, aimed to confirm hohlraum modeling, resulted in a''liberal'' flux limiter value of 0.15 to match simulations with these measurements. This conclusion was re-examined and another model accounting for the effect of Ion Acoustic Turbulence on the thermal electron flux limitation was proposed. Our work continues to explore relevant physical parameters in modeling these experiments using the HYADES and FLORENCE codes. The sensitivity of laser absorption, X-ray emission and corona electron temperature to the electron flux limiter, inverse bremsstrahlung coefficient, resonant absorption in the critical layer, LTE and NLTE atomic physics and a numerical convergence study due to steep density and electron temperature profiles at the critical layer will be discussed. Additionally, alternative experimental designs, such as an ``onion'' configuration of plastic and gold as well as different laser illumination patterns, were studied. Supported by the LLNL under subcontract B614207 to DE-AC52-07NA27344.

  3. Experimental observations of turbulent mixing due to Kelvin-Helmholtz instability on the OMEGA Laser Facility

    SciTech Connect

    Smalyuk, V. A.; Hansen, J. F.; Hurricane, O. A.; Langstaff, G.; Martinez, D.; Park, H.-S.; Raman, K.; Remington, B. A.; Robey, H. F.; Schilling, O.; Wallace, R.; Elbaz, Y.; Shimony, A.; Shvarts, D.; Di Stefano, C.; Drake, R. P.; Marion, D.; Krauland, C. M.; Kuranz, C. C.

    2012-09-15

    Shear-flow, Kelvin-Helmholtz (KH) turbulent mixing experiments were performed on the OMEGA Laser Facility [Boehly et al., Opt. Commun. 133, 495 (1997)] in which laser-driven shock waves propagated through a low-density plastic foam placed on top of a higher-density plastic foil. The plastic foil was comprised a thin iodine-doped plastic tracer layer bonded on each side to an undoped density-matched polyamide-imide plastic. Behind the shock front, lower-density foam plasma flowed over the higher-density plastic plasma, such that the interface between the foam and plastic was KH unstable. The initial perturbations consisted of pre-imposed, sinusoidal 2D perturbations, and broadband 3D perturbations due to surface roughness at the interface between the plastic and foam. KH instability growth was measured using side-on radiography with a point-projection 5-keV vanadium backlighter. Time-integrated images were captured on D-8 x-ray film. Spatial density profiles of iodine-doped plastic mixed with foam were inferred using x-ray radiographs. The mixing layer ensuing from the KH instability with layer width up to {approx}100 {mu}m was observed at a location {approx}1 mm behind the shock front. The measured mixing layer width was in good agreement with predictions based on a simple self-similar model of KH instability growth using an estimate of the shear velocity obtained from numerical simulations of the experiments.

  4. Exploring Astrophysically Relevant Bow Shocks Using MIFEDS and the OMEGA Laser

    NASA Astrophysics Data System (ADS)

    Levesque, Joseph; Kuranz, Carolyn; Young, Rachel; Fiksel, Gennady; Manuel, Mario; Trantham, Matthew; Klein, Sallee; Hartigan, Patrick; Liao, Andy; Li, Chikang

    2016-10-01

    We present current experiments using the Omega Laser Facility and their magneto-inertial fusion electrical discharge system (MIFEDS) to observe the effect of magnetic pressure on bow shock dynamics in an astrophysically relevant regime. Astrophysical bow shocks are an interesting phenomenon in which a shock forms when incident supersonic flow encounters a sufficiently magnetized medium surrounding an object. The most well-known example of this phenomena is the interaction of the solar wind with the Earth's magnetic field, which creates our magnetosphere. In our experiment the magnetosphere will be emulated by a current flowing through a curved wire to create an azimuthal magnetic field. To create the analogous solar wind, lasers rear-irradiate two opposing graphite targets so the plasma outflows collide and then expand along the collision plane toward the magnetized wires. We use the UV Thomson scattering diagnostic technique to determine plasma parameters along with optical imaging and proton radiography to characterize the plasma flow and the bow shock that forms. This work is supported by the U.S. DOE, through NNSA Grants DE-NA0002956 (SSAA) and DE-NA0002719 (NLUF), by the LLE under DE-NA0001944, and by the LLNL under subcontract B614207 to DE-AC52-07NA27344.

  5. New results on the laser produced positrons using the TITAN and OMEGA EP lasers

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Wilks, S.; Meyerhofer, D. D.; Beiersdorfer, P.; Dollar, F.; Falk, K.; Hazi, A.; Link, A.; Murphy, C. D.; Park, J.; Seely, J.; Szabo, C. I.; Shepherd, R.; Tommasini, R.; Welch, D.; Zulick, K.

    2010-11-01

    We performed new experiments and simulations on generating positrons with intense lasers [1]. A cone shaped positron jet is produced by irradiating a gold target with an intense picosecond duration laser pulse. The jet has ˜20 degree angular divergence and a quasi-monochromatic energy distribution with energy 4 to 20 MeV. The conversion efficiency from laser energy to positrons in the jet is ˜ 2x10-4. The positron angular and energy distributions are controlled by the laser and target conditions. The positron acceleration mechanism is identified experimentally as the sheath electric field on the rear surface of target. This talk will present the details of these new experimental and simulation results.[4pt] [1] Hui Chen, S. C. Wilks, D. D. Meyerhofer et al., PRL 105,015003 (2010)

  6. Numerical simulatin of supernova-relevant laser-driven hydro experiments on OMEGA

    SciTech Connect

    Leibrandt, D; Robey, H F; Edwards, M J; Braun, D G; Miles, A R; Drake, R P

    2004-02-10

    In ongoing experiments performed on the OMEGA laser [J. M. Soures et al., Phys. Plasmas 5, 2108 (1996)] at the University of Rochester Laboratory for Laser Energetics (LLE), nanosecond laser pulses are used to drive strong blast waves into two-layer targets. Perturbations on the interface between the two materials are unstable to the Richtmyer-Meshkov instability as a result of shock transit and the Rayleigh-Taylor instability during the deceleration-phase behind the shock front. These experiments are designed to produce a strongly shocked interface whose evolution is a scaled version of the unstable hydrogen-helium interface in core-collapse supernovae such as SN 1987A. The ultimate goal of this research is to develop an understanding of the effect of hydrodynamic instabilities and the resulting transition to turbulence on supernovae observables that remain as yet unexplained. The authors are, at present, particularly interested in the development of the Rayleigh-Taylor instability through the late nonlinear stage, the transition to turbulence, and the subsequent transport of material within the turbulent region. In this paper, the results of numerical simulations of 2D single and multimode experiments are presented. These simulations are run using the 2D Arbitrary Lagrangian Eulerian (ALE) radiation hydrodynamics code CALE [R. T. Barton, Numerical Astrophysics (Jones and Bartlett, Boston, 1985)]. The simulation results are shown to compare well with experimental radiography. A buoyancy-drag model captures the behavior of the single-mode interface, but gives only partial agreement in the multi-mode cases. The Richtmyer-Meshkov and target decompression contributions to the perturbation growth are both estimated and shown to be significant. Significant dependence of the simulation results on the material equation of state (EOS) is demonstrated, and the prospect of continuing the experiments to conclusively demonstrate the transition to turbulence is discussed.

  7. Single-mode, Rayleigh-Taylor growth-rate measurements on the OMEGA laser system

    NASA Astrophysics Data System (ADS)

    Knauer, J. P.; Betti, R.; Bradley, D. K.; Boehly, T. R.; Collins, T. J. B.; Goncharov, V. N.; McKenty, P. W.; Meyerhofer, D. D.; Smalyuk, V. A.; Verdon, C. P.; Glendinning, S. G.; Kalantar, D. H.; Watt, R. G.

    2000-01-01

    The results from a series of single-mode, Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five or six 351 nm laser beams overlapped with total intensities up to 2.5×1014 W/cm2. Experiments were performed with both 3 ns ramp and 3 ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%-7% over a 600 μm diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using throughfoil radiography and was detected with an x-ray framing camera for CH targets. Two-dimensional (2-D) hydrodynamic simulations (ORCHID) [R. L. McCrory and C. P. Verdon, in Inertial Confinement Fusion (Editrice Compositori, Bologna, 1989), pp. 83-124] of the growth of 20, 31, and 60 μm wavelength perturbations were in good agreement with the experimental data when the experimental details, including noise, were included. The amplitude of the simulation optical depth is in good agreement with the experimental optical depth; therefore, great care must be taken when the growth rates are compared to dispersion formulas. Since the foil's initial condition just before it is accelerated is not that of a uniformly compressed foil, the optical density measurement does not accurately reflect the amplitude of the ablation surface but is affected by the initial nonuniform density profile.

  8. Single-mode, Rayleigh-Taylor growth-rate measurements on the OMEGA laser system

    SciTech Connect

    Knauer, J. P.; Betti, R.; Bradley, D. K.; Boehly, T. R.; Collins, T. J. B.; Goncharov, V. N.; McKenty, P. W.; Meyerhofer, D. D.; Smalyuk, V. A.; Verdon, C. P.

    2000-01-01

    The results from a series of single-mode, Rayleigh-Taylor (RT) instability growth experiments performed on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using planar targets are reported. Planar targets with imposed mass perturbations were accelerated using five or six 351 nm laser beams overlapped with total intensities up to 2.5x10{sup 14} W/cm{sup 2}. Experiments were performed with both 3 ns ramp and 3 ns flat-topped temporal pulse shapes. The use of distributed phase plates and smoothing by spectral dispersion resulted in a laser-irradiation nonuniformity of 4%-7% over a 600 {mu}m diam region defined by the 90% intensity contour. The temporal growth of the modulation in optical depth was measured using throughfoil radiography and was detected with an x-ray framing camera for CH targets. Two-dimensional (2-D) hydrodynamic simulations (ORCHID) [R. L. McCrory and C. P. Verdon, in Inertial Confinement Fusion (Editrice Compositori, Bologna, 1989), pp. 83-124] of the growth of 20, 31, and 60 {mu}m wavelength perturbations were in good agreement with the experimental data when the experimental details, including noise, were included. The amplitude of the simulation optical depth is in good agreement with the experimental optical depth; therefore, great care must be taken when the growth rates are compared to dispersion formulas. Since the foil's initial condition just before it is accelerated is not that of a uniformly compressed foil, the optical density measurement does not accurately reflect the amplitude of the ablation surface but is affected by the initial nonuniform density profile. (c) 2000 American Institute of Physics.

  9. Effects of laser-plasma instabilities on hydro evolution in an OMEGA-EP long-scale-length experiment

    NASA Astrophysics Data System (ADS)

    Li, J.; Hu, S. X.; Ren, C.

    2017-02-01

    Laser-plasma instabilities and hydro evolution of the coronal plasma in an OMEGA EP long-scale-length experiment with planar targets were studied with particle-in-cell (PIC) and hydrodynamic simulations. Plasma and laser conditions were first obtained in a two-dimensional DRACO hydro simulation with only inverse-bremsstrahlung absorption. Using these conditions, an OSIRIS PIC simulation was performed to study laser absorption and hot-electron generation caused by laser-plasma instabilities (LPIs) near the quarter-critical region. The obtained PIC information was subsequently coupled to another DRACO simulation to examine how the LPIs affect the overall hydrodynamics. The results showed that the LPI-induced laser absorption increased the electron temperature but did not significantly change the density scale length in the corona.

  10. Effects of laser-plasma instabilities on hydro evolution in an OMEGA-EP long-scale-length experiment

    DOE PAGES

    Li, J.; Hu, S. X.; Ren, C.

    2017-02-28

    Laser-plasma instabilities and hydro evolution of the coronal plasma in an OMEGA EP long-scale-length experiment with planar targets were studied with particle-in-cell (PIC) and hydrodynamic simulations. Plasma and laser conditions were first obtained in a two-dimensional DRACO hydro simulation with only inverse-bremsstrahlung absorption. Using these conditions, an OSIRIS PIC simulation was performed to study laser absorption and hot-electron generation caused by laser-plasma instabilities (LPIs) near the quarter-critical region. The obtained PIC information was subsequently coupled to another DRACO simulation to examine how the LPIs affect the overall hydrodynamics. Lastly, the results showed that the LPI-induced laser absorption increased the electronmore » temperature but did not significantly change the density scale length in the corona.« less

  11. K-Shell absorpsion spectroscopy of direct drive, shock compressed aluminum targets at the Omega laser facility

    NASA Astrophysics Data System (ADS)

    Shepherd, Ronnie; Boehley, Thomas; Bradley, David; Ng, Andrew; Iglesias, Carlos; Moon, Steve; Food, Mark; Collins, Gilbert; Rogers, Forrest; Heeter, Robert; Springer, Paul

    2003-10-01

    We have performed experiments to study plasma effects on bound states. The experiments were performed at the Laboratory for Laser Energetics Omega laser facility. The targets consisted of 25 μ m Be, 15 μ m Si, and 10 μ m of Al with an additional 15 μ m step. The targets were shock compressed using direct drive to form dense, strongly coupled plasmas. The plasma conditions were inferred from equation of state models in conjunction with shock breakout time measurements from VISAR. Time resolved absorption spectroscopy was also performed to study the degree of ionization. Data and simulations will be presented.

  12. Preliminary results of the redesigned Reshock experiment at the OMEGA laser facility

    NASA Astrophysics Data System (ADS)

    Desjardins, Tiffany; di Stefano, Carlos; Merritt, Elizabeth; Doss, Forrest; Flippo, Kirk; Kline, John

    2016-10-01

    The redesigned LANL OMEGA Reshock campaign is exploring the effects of turbulent mixing due to the Richtmyer-Meshkov (RM) instability as part of an ongoing effort to assess the LANL radiation-hydrocode the BHR mix model in the high-energy density regime. Platform improvements have been made to increase the precision of the instability growth measurements. The experiments are conducted in similar geometry to the previous Reshock campaigns. A cylindrical beryllium tube is filled with a low-density CH-foam (ρ 100-150 mg/cc) and a higher density tracer layer that is displaced from an endcap. Two tracer materials have been tested: a low-density plastic (ρ0 = 1.5 g/cc) layer 40µm thick, and an HDC layer (ρ0 = 3.2 g/cc) 15 µm thick. The tracer layers have been ρr matched to the previously used aluminum tracer (ρ0 = 2.43 g/cc). In this platform two shockwaves are generated from opposite ends of the shock tube by a 5 kJ laser pulse, with time delay Δt 3-6ns between them. The primary shockwave generates the initial mixing between the tracer layer and surrounding foam. The second shock leads to a compression of the initial mix layer and to increased turbulence. We will present both initial design simulations for shock timing and tracer choice and preliminary data from the first shot day.

  13. Bremsstrahlung measurements for characterization of intense short-pulse, laser produced fast electrons with OMEGA EP

    NASA Astrophysics Data System (ADS)

    Daykin, Tyler; Sawada, Hiroshi; Sentoku, Yasuhiko; Pandit, Rishi; Chen, Cliff; Beg, Farhat; Chen, Hui; McLean, Harry; Patel, Pravesh; Tommasini, Riccardo

    2016-10-01

    Understanding relativistic fast electron generation and transport inside solids is important for applications such as generation of high energy x-ray sources and fast ignition. An experiment was carried out to study the scaling of the fast electron spectrum and bremsstrahlung generation in multi-pico second laser interactions using 1 ps and 10 ps OMEGA EP short-pulse beam to generate fast electrons at a similar peak intensity of 5x1018 W/cm2. The bremsstrahlung produced by collisions of the fast electrons with background ions was recorded using differential filter stacked spectrometers. A preliminary analysis with a Monte Carlo Code ITS shows that the electrons injection having an electron slope 1.8 MeV matched well with the high energy component of the 1 ps and 10 ps bremsstrahlung measurements. Details of the data analysis and modeling with Monte Carlo and a hybrid particle-in-cell codes will be presented at the conference. Work supported by the UNR Office of the Provost and by DOE/OFES under Contract No. DE-SC0008827. This collaborative work was partially supported under the auspices of the US DOE by LLNL under Contracts No. DE-AC52-07NA27344 and No. DE-FG-02-05ER54834.

  14. Neutron Induced D Breakup in Inertial Confinement Fusion at the Omega Laser Facility

    NASA Astrophysics Data System (ADS)

    Forrest, C. J.; Glebov, V. Yu.; Knauer, J. P.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Stoeckl, C.; Schroder, W. U.; Frenje, J. A.; Gatu Johnson, M.

    2015-11-01

    High-resolution neutron spectroscopy is used to study the deuteron breakup reaction D(n,n ') np in the thermonuclear environment created in inertial confinement fusion experiments at the Omega Laser Facility. Neutrons with an energy of 14.1 MeV generated in the primary D-T fusion reactions scatter elastically and inelastically off the dense (cryogenic) D-T fuel assembly surrounding the central hot spot at peak fuel compression. These neutrons also induce a breakup of the fuel deuterons. The corresponding breakup cross section is measured relative to elastic n -D and n -T scattering, i.e., simultaneously in the same environment. Apart from astrophysical and technological interest, the neutron-induced deuteron breakup reaction is of interest to the physics of nucleon -nucleon forces. For example, theoretical calculations predict a noticeable influence of nucleonic three-body forces on the magnitude of the breakup cross section. Preliminary results from measurements of the neutron contribution in the 2- to 6-MeV range show reasonable agreement with the published ENDL 2008.2 semi-empirical cross-section. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  15. Hydrodynamic simulations of long-scale-length two-plasmon-decay experiments at the Omega Laser Facility

    SciTech Connect

    Hu, S. X.; Michel, D. T.; Edgell, D. H.; Froula, D. H.; Follett, R. K.; Goncharov, V. N.; Myatt, J. F.; Skupsky, S.; Yaakobi, B.

    2013-03-15

    Direct-drive-ignition designs with plastic CH ablators create plasmas of long density scale lengths (L{sub n} {>=} 500 {mu}m) at the quarter-critical density (N{sub qc}) region of the driving laser. The two-plasmon-decay (TPD) instability can exceed its threshold in such long-scale-length plasmas (LSPs). To investigate the scaling of TPD-induced hot electrons to laser intensity and plasma conditions, a series of planar experiments have been conducted at the Omega Laser Facility with 2-ns square pulses at the maximum laser energies available on OMEGA and OMEGA EP. Radiation-hydrodynamic simulations have been performed for these LSP experiments using the two-dimensional hydrocode draco. The simulated hydrodynamic evolution of such long-scale-length plasmas has been validated with the time-resolved full-aperture backscattering and Thomson-scattering measurements. draco simulations for CH ablator indicate that (1) ignition-relevant long-scale-length plasmas of L{sub n} approaching {approx}400 {mu}m have been created; (2) the density scale length at N{sub qc} scales as L{sub n}({mu}m) Asymptotically-Equal-To (R{sub DPP} Multiplication-Sign I{sup 1/4}/2); and (3) the electron temperature T{sub e} at N{sub qc} scales as T{sub e}(keV) Asymptotically-Equal-To 0.95 Multiplication-Sign {radical}(I), with the incident intensity (I) measured in 10{sup 14} W/cm{sup 2} for plasmas created on both OMEGA and OMEGA EP configurations with different-sized (R{sub DPP}) distributed phase plates. These intensity scalings are in good agreement with the self-similar model predictions. The measured conversion fraction of laser energy into hot electrons f{sub hot} is found to have a similar behavior for both configurations: a rapid growth [f{sub hot} Asymptotically-Equal-To f{sub c} Multiplication-Sign (G{sub c}/4){sup 6} for G{sub c} < 4] followed by a saturation of the form, f{sub hot} Asymptotically-Equal-To f{sub c} Multiplication-Sign (G{sub c}/4){sup 1.2} for G{sub c} {>=} 4, with the

  16. Hydrodynamic simulations of long-scale-length two-plasmon-decay experiments at the Omega Laser Facility

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Michel, D. T.; Edgell, D. H.; Froula, D. H.; Follett, R. K.; Goncharov, V. N.; Myatt, J. F.; Skupsky, S.; Yaakobi, B.

    2013-03-01

    Direct-drive-ignition designs with plastic CH ablators create plasmas of long density scale lengths (Ln ≥ 500 μm) at the quarter-critical density (Nqc) region of the driving laser. The two-plasmon-decay (TPD) instability can exceed its threshold in such long-scale-length plasmas (LSPs). To investigate the scaling of TPD-induced hot electrons to laser intensity and plasma conditions, a series of planar experiments have been conducted at the Omega Laser Facility with 2-ns square pulses at the maximum laser energies available on OMEGA and OMEGA EP. Radiation-hydrodynamic simulations have been performed for these LSP experiments using the two-dimensional hydrocode draco. The simulated hydrodynamic evolution of such long-scale-length plasmas has been validated with the time-resolved full-aperture backscattering and Thomson-scattering measurements. draco simulations for CH ablator indicate that (1) ignition-relevant long-scale-length plasmas of Ln approaching ˜400 μm have been created; (2) the density scale length at Nqc scales as Ln(μm)≃(RDPP×I1/4/2); and (3) the electron temperature Te at Nqc scales as Te(keV)≃0.95×√I , with the incident intensity (I) measured in 1014 W/cm2 for plasmas created on both OMEGA and OMEGA EP configurations with different-sized (RDPP) distributed phase plates. These intensity scalings are in good agreement with the self-similar model predictions. The measured conversion fraction of laser energy into hot electrons fhot is found to have a similar behavior for both configurations: a rapid growth [fhot≃fc×(Gc/4)6 for Gc < 4] followed by a saturation of the form, fhot≃fc×(Gc/4)1.2 for Gc ≥ 4, with the common wave gain is defined as Gc=3 × 10-2×IqcLnλ0/Te, where the laser intensity contributing to common-wave gain Iqc, Ln, Te at Nqc, and the laser wavelength λ0 are, respectively, measured in [1014 W/cm2], [μm], [keV], and [μm]. The saturation level fc is observed to be fc ≃ 10-2 at around Gc ≃ 4. The hot

  17. Oral Omega-3 Fatty Acid Supplementation for Laser In Situ Keratomileusis-Associated Dry Eye.

    PubMed

    Goyal, Parul; Jain, Arun K; Malhotra, Chintan

    2017-02-01

    To determine the effect of oral omega-3 fatty acid (ω3FA) supplementation in laser in situ keratomileusis (LASIK)-associated dry eye. In this prospective, open-label study, patients undergoing LASIK were randomized to receive either 1.2 g/d of a triglyceride formulation of oral ω3FA (treatment group) or 400 mg/d vitamin E (control group) for 1 week before and continued for 12 weeks after surgery. Ocular surface disease index, tear breakup time, ocular surface staining, and Schirmer scores were evaluated and compared preoperatively and at 3 months after LASIK. The study included 30 patients in each group. All parameters were comparable at baseline. Ocular surface disease index scores increased comparably in both groups (1.9 ± 0.6 increase in the treatment group; 2.8 ± 0.5 in the control group) (P = 0.267). Compared with baseline levels, tear breakup time decreased significantly (P < 0.01) but comparably in both treatment (-2.3 ± 0.4 seconds decrease) and control (-3.5 ± 0.7 seconds decrease) groups (P = 0.105). More eyes in the control group (43.4%) had conjunctival staining with Lissamine green at 3 months compared with the treatment group (14%) (P = 0.009). The Schirmer score at 3 months was higher (P = 0.003) in the treatment group (30.5 ± 0.90 mm) than in the control group (25.7 ± 1.3 mm) with a increase of 5.9 ± 1.3 mm from baseline in the treatment group and a decrease of 1.5 ± 1.2 mm in the control group. Supplementation with ω3FA in patients undergoing LASIK had a positive influence on tear secretion, whereas tear film stability remained unaffected when compared with the control group.

  18. Investigation of laser pulse length and pre-plasma scale length impact on hot electron generation on OMEGA-EP

    DOE PAGES

    Peebles, J.; Wei, M. S.; Arefiev, A. V.; ...

    2017-02-02

    A series of experiments studying pre-plasma’s effect on electron generation and transport due to a high intensity laser were conducted on the OMEGA-EP laser facility. A controlled pre-plasma was produced in front of an aluminum foil target prior to the arrival of the high intensity short pulse beam. Energetic electron spectra were characterized with magnetic and bremsstrahlung spectrometers. Preplasma and pulse length were shown to have a large impact on the temperature of lower energy, ponderomotive scaling electrons. Furthermore, super-ponderomotive electrons, seen in prior pre-plasma experiments with shorter pulses, were observed without any initial pre-plasma in our experiment. 2D particle-in-cellmore » and radiation-hydrodynamic simulations shed light on and validate these experimental results.« less

  19. Investigation of laser pulse length and pre-plasma scale length impact on hot electron generation on OMEGA-EP

    NASA Astrophysics Data System (ADS)

    Peebles, J.; Wei, M. S.; Arefiev, A. V.; McGuffey, C.; Stephens, R. B.; Theobald, W.; Haberberger, D.; Jarrott, L. C.; Link, A.; Chen, H.; McLean, H. S.; Sorokovikova, A.; Krasheninnikov, S.; Beg, F. N.

    2017-02-01

    A series of experiments studying pre-plasma’s effect on electron generation and transport due to a high intensity laser were conducted on the OMEGA-EP laser facility. A controlled pre-plasma was produced in front of an aluminum foil target prior to the arrival of the high intensity short pulse beam. Energetic electron spectra were characterized with magnetic and bremsstrahlung spectrometers. Pre-plasma and pulse length were shown to have a large impact on the temperature of lower energy, ponderomotive scaling electrons. Super-ponderomotive electrons, seen in prior pre-plasma experiments with shorter pulses, were observed without any initial pre-plasma in our experiment. 2D particle-in-cell and radiation-hydrodynamic simulations shed light on and validate these experimental results.

  20. Comparison of the uniformity of soft and hard x-ray emissions from gold foils irradiated by OMEGA laser beams

    NASA Astrophysics Data System (ADS)

    Seely, John F.; Holland, Glenn E.; Boehly, Thomas R.; Pien, G.; Bradley, David K.

    1997-10-01

    A comparison of the uniformity of the soft and hard x-ray emissions from planar gold foils irradiated by OMEGA laser beams has been performed. A normal-incidence microscope with two multilayer coated mirrors formed 2D images at a wavelength of 48.3 angstroms (257 eV energy). The X5.8 magnified images were recorded by a gated framing camera at various times during the 3 nsec laser pulse. A pinhole camera imaged the x-ray emission in the energy range > 2 keV. On a spatial scale of 10 micrometers , it was found that the soft x-ray images at 257 eV were quite uniform and featureless. In contrast, the hard x-ray images in the energy range > 2 keV were highly nonuniform with numerous features of size 100 - 150 micrometers .

  1. AFM-mapped nanoscale absorber-driven laser damage in UV high-reflector multilayers

    NASA Astrophysics Data System (ADS)

    Papernov, Semyon; Schmid, Ansgar W.; Anzelotti, J.; Smith, Douglas J.; Chrzan, Z. Roman

    1996-05-01

    Submicrometer lateral-size craters that develop independently of the presence of micron-scale growth nodules and whose number density follows the intensity profile of the full laser beam are the dominant laser-damage features in 351-nm high-reflector production coatings on the University of Rochester's 60-beam OMEGA laser. Coupled with the observation that the smallest measured damage craters allow for initiating absorber sizes not larger than 10 nm, the experimental evidence points toward randomly distributed nano-cluster absorbers as the sources for energy transfer from the optical field to the porous film medium.

  2. LLE (Laboratory for Laser Energetics) review

    SciTech Connect

    Kumpan, S.A.

    1990-01-01

    This volume of the LLE Review, covering the period July--September 1990, contains articles in two main sections: the OMEGA Upgrade and Advanced Technology Developments. The first article in Section 1 describes the changes in the overall system design of the 60-beam OMEGA Upgrade since the release of the OMEGA Upgrade Preliminary Design Document in October 1989. It is followed by an article that presents results of an investigation into stimulated rotational Raman scattering as it relates to the propagation of high-fluence ultraviolet laser beams in the OMEGA Upgrade. The third article is a report on the energy-transport measurements made on the multisegmented amplifier (MSA), built as a prototype amplifier for the original OMEGA Upgrade system configuration. The final article in Section 1 describes the design of the 20-cm-clear-aperture, single-segmented amplifier (SSA), which will be the final amplifier in the current OMEGA Upgrade system configuration. Section 2 presents the results to date of an intensive in-house effort at LLE to develop the various optical coatings required for the OMEGA Upgrade.

  3. First Results from Laser-Driven MagLIF Experiments on OMEGA: Time Evolution of Laser Gas Heating Using Soft X-Ray Diagnostics

    NASA Astrophysics Data System (ADS)

    Barnak, D. H.; Betti, R.; Chang, P.-Y.; Davies, J. R.

    2015-11-01

    Magnetized liner inertial fusion (MagLIF) is a promising inertial confinement fusion scheme comprised of three stages: axial magnetization, laser heating of the deuterium -tritium gas fill, and compression of the gas by the liner. To study the physics of MagLIF, a scaled-down version has been designed and implemented on the OMEGA-60 laser. This talk will focus primarily on the heating process of a MagLIF target using a 351-nm laser. A neon-doped deuterium gas capsule was heated using a 2.5-ns square pulse delivering 200 J of laser energy. Spectral analysis of the x-ray emission from the side and the laser entrance hole of the capsule is used to infer the time evolution of the gas temperature. The x-ray spectra for a grid of possible gas temperatures and densities are simulated using Spect3D atomic modeling software. The simulation results are then used to deconvolve the raw signals and obtain density and temperature estimations. A gas temperature lower bound of 100 eV at 1.3 ns after the start of the laser pulse can be inferred from these estimations. The estimations are then compared to 2-D hydrocode modeling. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and by DE-FG02-04ER54786 and DE-FC02-04ER54789 (Fusion Science Center).

  4. Using gamma-ray emission to measure ablator areal density of imploded capsules at the Omega laser

    NASA Astrophysics Data System (ADS)

    Hoffman, N.; Rubery, M.; Herrmann, H.; Kim, Y.; Young, C.; Mack, J.; Wilson, D.; McEvoy, A.; Evans, S.; Sedillo, T.; Stoeffl, W.; Horsfield, C.; Glebov, V.

    2010-11-01

    We have measured the ablator areal density of plastic-shell implosions at the Omega laser, using gamma-ray emission from the capsules detected by the prototype Gamma Reaction History (GRH) diagnostic. The intensity of 4.44-MeV gamma emission from ^12C nuclei in the ablator is proportional to the product of ablator areal density and yield of fusion neutrons, so by detecting the gammas we can infer the ablator areal density, provided we also have a measurement of total neutron yield. Neutron yield is determined from the nTOF experiment at Omega in our approach; alternatively one could use 16.7-MeV gammas from DT fusion. Inferred values of time-averaged carbon areal density are in the range 10-30 mg/cm^2, for a range of implosions. These values are smaller than predicted values based on 1D simulations, which are typically in the range 30-40 mg/cm^2. We discuss possible reasons for the discrepancy, primarily related to mixing.

  5. Extended x-ray absorption fine structure measurements of quasi-isentropically compressed vanadium targets on the OMEGA laser

    SciTech Connect

    Yaakobi, B.; Boehly, T. R.; Sangster, T. C.; Meyerhofer, D. D.; Remington, B. A.; Allen, P. G.; Pollaine, S. M.; Lorenzana, H. E.; Lorenz, K. T.; Hawreliak, J. A.

    2008-06-15

    The use of in situ extended x-ray absorption fine structure (EXAFS) for characterizing nanosecond laser-shocked vanadium, titanium, and iron has recently been demonstrated. These measurements are extended to laser-driven, quasi-isentropic compression experiments (ICE). The radiation source (backlighter) for EXAFS in all of these experiments is obtained by imploding a spherical target on the OMEGA laser [T. R. Boehly et al., Rev. Sci. Instrum. 66, 508 (1995)]. Isentropic compression (where the entropy is kept constant) enables to reach high compressions at relatively low temperatures. The absorption spectra are used to determine the temperature and compression in a vanadium sample quasi-isentropically compressed to pressures of up to {approx}0.75 Mbar. The ability to measure the temperature and compression directly is unique to EXAFS. The drive pressure is calibrated by substituting aluminum for the vanadium and interferometrically measuring the velocity of the back target surface by the velocity interferometer system for any reflector (VISAR). The experimental results obtained by EXAFS and VISAR agree with each other and with the simulations of a hydrodynamic code. The role of a shield to protect the sample from impact heating is studied. It is shown that the shield produces an initial weak shock that is followed by a quasi-isentropic compression at a relatively low temperature. The role of radiation heating from the imploding target as well as from the laser-absorption region is studied. The results show that in laser-driven ICE, as compared with laser-driven shocks, comparable compressions can be achieved at lower temperatures. The EXAFS results show important details not seen in the VISAR results.

  6. Time-resolved Soft X-Ray Imaging (SXRI) diagnostic for use at the NIF and OMEGA lasers (version 2)

    SciTech Connect

    Schneider, M B; Holder, J P; James, D L; Bruns, H C; Celeste, J R; Compton, S; Costa, R L; Ellis, A D; Emig, J A; Hargrove, D; Kalantar, D H; MacGowan, B J; Power, G D; Sorce, C; Rekow, V; Widmann, K; Young, B K; Young, P E; Garcia, O F; McKenney, J; Haugh, M; Goldin, F; MacNeil, L P; Cone, K

    2006-07-21

    The soft x-ray imager (SXRI) built for the first experiments at the National Ignition Facility (NIF) has four soft x-ray channels and one hard x-ray channel. The SXRI is a snout that mounts to a four strip gated imager. This produces four soft x-ray images per strip, which can be separated in time by {approx}60psec. Each soft x-ray channel consists of a mirror plus a filter. The diagnostic was used to study x-ray burnthrough of hot hohlraum targets at the NIF and OMEGA lasers. The SXRI snout design and issues involved in selecting the desired soft x-ray channels are discussed.

  7. Simulation of laser-driven, ablated plasma flows in collisionless shock experiments on OMEGA and the NIF

    NASA Astrophysics Data System (ADS)

    Grosskopf, M. J.; Drake, R. P.; Kuranz, C. C.; Rutter, E. M.; Ross, J. S.; Kugland, N. L.; Plechaty, C.; Remington, B. A.; Spitkovsky, A.; Gargate, L.; Gregori, G.; Bell, A.; Murphy, C. D.; Meinecke, J.; Reville, B.; Sakawa, Y.; Kuramitsu, Y.; Takabe, H.; Froula, D. H.; Fiksel, G.; Miniati, F.; Koenig, M.; Ravasio, A.; Liang, E.; Fu, W.; Woolsey, N.; Park, H.-S.

    2013-03-01

    Experiments investigating the physics of interpenetrating, collisionless, ablated plasma flows have become an important area of research in the high-energy-density field. In order to evaluate the feasibility of designing experiments that will generate a collisionless shock mediated by the Weibel instability on the National Ignition Facility (NIF) laser, computer simulations using the Center for Radiative Shock Hydrodynamics (CRASH) radiation-hydrodynamics model have been carried out. This paper reports assessment of whether the experiment can reach the required scale size while maintaining the low interflow collisionality necessary for the collisionless shock to form. Comparison of simulation results with data from Omega experiments shows the ability of the CRASH code to model these ablated systems. The combined results indicate that experiments on the NIF are capable of reaching the regimes necessary for the formation of a collisionless shock in a laboratory experiment.

  8. Direct optical measurement of the on-shot incoherent focal spot and intensity contrast on the OMEGA EP laser

    DOE PAGES

    Dorrer, C.; Consentino, A.; Irwin, D.

    2016-05-18

    Characterizing the prepulse temporal contrast of optical pulses is required to understand their interaction with matter. Light with relatively low intensity can interact with the target before the main high-intensity pulse. Estimating the intensity contrast, instead of the spatially averaged power contrast, is important to understand intensity-dependent laser–matter interactions. A direct optical approach to determining the on-shot intensity of the incoherent pedestal on an aberrated high-intensity laser system is presented. The spatially resolved focal spot of the incoherent pedestal preceding the main coherent pulse and the intensity contrast are calculated using experimental data. Furthermore, this technique is experimentally validated onmore » one of the chirped pulse amplification beamlines of the OMEGA EP Laser System. The intensity contrast of a 1-kJ, 10-ps laser pulse is shown to be ~10× higher than the power contrast because of the larger spatial extent of the incoherent focal spot relative to the coherent focal spot.« less

  9. Direct optical measurement of the on-shot incoherent focal spot and intensity contrast on the OMEGA EP laser

    SciTech Connect

    Dorrer, C.; Consentino, A.; Irwin, D.

    2016-05-18

    Characterizing the prepulse temporal contrast of optical pulses is required to understand their interaction with matter. Light with relatively low intensity can interact with the target before the main high-intensity pulse. Estimating the intensity contrast, instead of the spatially averaged power contrast, is important to understand intensity-dependent laser–matter interactions. A direct optical approach to determining the on-shot intensity of the incoherent pedestal on an aberrated high-intensity laser system is presented. The spatially resolved focal spot of the incoherent pedestal preceding the main coherent pulse and the intensity contrast are calculated using experimental data. Furthermore, this technique is experimentally validated on one of the chirped pulse amplification beamlines of the OMEGA EP Laser System. The intensity contrast of a 1-kJ, 10-ps laser pulse is shown to be ~10× higher than the power contrast because of the larger spatial extent of the incoherent focal spot relative to the coherent focal spot.

  10. Post shot analysis of plasma conditions of Gold Spheres illuminated by the URLLE Omega laser, as measured via Thomson scattering

    NASA Astrophysics Data System (ADS)

    Rosen, M. D.; Ross, J. S.; Scott, H. A.; Landen, N.; Froula, D.; Dewald, E.; May, M.; Widmann, K.

    2013-10-01

    Recently there was a follow up to the 2006 campaign to illuminate 1 mm diameter gold spheres using the Omega laser at LLE. The 2013 campaign uses Thomson scattering to diagnose the plasma conditions as a function of time, at various radial positions in the coronal, laser heated, blow-off region. Laser irradiances were 1, 5, and 10 × 1014 W/sqcm, usually in a 1 ns pulse duration. Depleted uranium and Ag spheres were also tested. We compare the predictions of plasma conditions using various non-LTE computational models of atomic physics and electron transport (as implemented into the rad-hydro code Lasnex) to this data. The ``high flux model (HFM)'' (DCA atomic physics and non local transport) compares well for some of experiments, while an intermediate model that radiates a bit less total x-ray fluence than the HFM, does better on other experiments. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  11. Hydro-Coupling Effects on Compression Symmetry in Gas-Filled Hohlraum Experiments at the Omega Laser

    SciTech Connect

    Dewalds, E L; Pollaine, S W; Landen, O L; Amendt, P A; Turner, R E; Wallace, R; Campbell, K M; Glenzer, S H

    2003-08-26

    Ignition hohlraum designs use low Z gas fill to slow down the inward progress of high Z ablated plasma from the hohlraum walls preventing large laser spot motion and capsule drive asymmetries. In order to optimize the ignition design, the gas hydro-coupling effect to a fusion capsule asymmetry is presently being assessed in experiments at the Omega laser facility with gas filled hohlraums and foam balls. Our experiments measure the effects of the pressure spike that is generated by direct gas heating by the drive laser beams on the capsule surrogate for various hohlraum gas fill densities (0-2.5 mg/cc). To isolate the effect of the gas-hydro coupling pressure, we have begun by using plastic ''hohlraums'' to reduce the x-ray ablation pressure. The foam ball images measured by x-ray backlighting show increasing pole-hot pressure asymmetry for increasing gas pressure. In addition, the gas hydrodynamics is studied by imaging of a low concentration Xe gas fill dopant. The gas fill self-emission. shows the early pressure spike and its propagation towards the foam ball, as well as the gas stagnation on the holraum axis at later times, both contributing to the capsule asymmetry. These first gas hydro-coupling results are compared to LASNEX simulations.

  12. Direct optical measurement of the on-shot incoherent focal spot and intensity contrast on the OMEGA EP laser

    SciTech Connect

    Dorrer, C.; Consentino, A.; Irwin, D.

    2016-05-18

    Characterizing the prepulse temporal contrast of optical pulses is required to understand their interaction with matter. Light with relatively low intensity can interact with the target before the main high-intensity pulse. Estimating the intensity contrast, instead of the spatially averaged power contrast, is important to understand intensity-dependent laser–matter interactions. A direct optical approach to determining the on-shot intensity of the incoherent pedestal on an aberrated high-intensity laser system is presented. The spatially resolved focal spot of the incoherent pedestal preceding the main coherent pulse and the intensity contrast are calculated using experimental data. Furthermore, this technique is experimentally validated on one of the chirped pulse amplification beamlines of the OMEGA EP Laser System. The intensity contrast of a 1-kJ, 10-ps laser pulse is shown to be ~10× higher than the power contrast because of the larger spatial extent of the incoherent focal spot relative to the coherent focal spot.

  13. Neutron yield study of direct-drive, low-adiabat cryogenic D{sub 2} implosions on OMEGA laser system

    SciTech Connect

    Hu, S. X.; Radha, P. B.; Marozas, J. A.; Betti, R.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Goncharov, V. N.; Igumenshchev, I. V.; Marshall, F. J.; McCrory, R. L.; Meyerhofer, D. D.; Regan, S. P.; Sangster, T. C.; Skupsky, S.; Smalyuk, V. A.; Elbaz, Y.; Shvarts, D.

    2009-11-15

    Neutron yields of direct-drive, low-adiabat ({alpha}{approx_equal}2 to 3) cryogenic D{sub 2} target implosions on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have been systematically investigated using the two-dimensional (2D) radiation hydrodynamics code DRACO[P. B. Radha et al., Phys. Plasmas 12, 056307 (2005)]. Low-mode (l{<=}12) perturbations, including initial target offset, ice-layer roughness, and laser-beam power imbalance, were found to be the primary source of yield reduction for thin-shell (5 {mu}m), low-{alpha}, cryogenic targets. The 2D simulations of thin-shell implosions track experimental measurements for different target conditions and peak laser intensities ranging from 2.5x10{sup 14}-6x10{sup 14} W/cm{sup 2}. Simulations indicate that the fusion yield is sensitive to the relative phases between the target offset and the ice-layer perturbations. The results provide a reasonable good guide to understanding the yield degradation in direct-drive, low-adiabat, cryogenic, thin-shell-target implosions. Thick-shell (10 {mu}m) implosions generally give lower yield over clean than low-l-mode DRACO simulation predictions. Simulations including the effect of laser-beam nonuniformities indicate that high-l-mode perturbations caused by laser imprinting further degrade the neutron yield of thick-shell implosions. To study ICF compression physics, these results suggest a target specification with a {<=}30 {mu}m offset and ice-roughness of {sigma}{sub rms}<3 {mu}m are required.

  14. Neutron Yield Study of Direct-Drive, Low-Adiabat Cryogenic D2 Implosions on OMEGA Laser System

    SciTech Connect

    Hu, S.X.; Radha, P.B.; Marozas, J.A.; Betti, R.; Collins, T.J.B.; Craxton, R.S.; Delettrez, J.A.; Edgell, D.H.; Epstein, R.; Goncharov, V.N.; Igumenshchev, I.V.; Marshall, F.J.; McCrory, R.L.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.; Skupsky, S.; Smalyuk, V.A.; Elbaz, Y.; Shvarts, D.

    2009-11-17

    Neutron yields of direct-drive, low-adiabat (alpha ~~ 2 to 3) cryogenic D2 target implosions on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have been systematically investigated using the two-dimensional (2D) radiation hydrodynamics code DRACO [P. B. Radha et al., Phys. Plasmas 12, 056307 (2005)]. Low-mode (ell <- 12) perturbations, including initial target offset, ice-layer roughness, and laser-beam power imbalance, were found to be the primary source of yield reduction for thin-shell (5 um), low-alpha, cryogenic targets. The 2D simulations of thin-shell implosions track experimental measurements for different target conditions and peak laser intensities ranging from 2.5 x 10^14–6 x 10^14 W/cm^2. Simulations indicate that the fusion yield is sensitive to the relative phases between the target offset and the ice-layer perturbations. The results provide a reasonable good guide to understanding the yield degradation in direct-drive, low-adiabat, cryogenic, thin-shell-target implosions. Thick-shell (10 um) implosions generally give lower yield over clean than low-ell-mode DRACO simulation predictions. Simulations including the effect of laser-beam nonuniformities indicate that high-ell-mode perturbations caused by laser imprinting further degrade the neutron yield of thick-shell implosions. To study ICF compression physics, these results suggest a target specification with a <-30 um offset and ice-roughness of sigma_rms < 3 um are required.

  15. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    SciTech Connect

    Hohenberger, M. Shvydky, A.; Marozas, J. A.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D.; Fiksel, G.; Meyerhofer, D. D.

    2016-09-15

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [Marozas et al., Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ∼50% compared to the nominal OMEGA EP SSD system. The experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

  16. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    NASA Astrophysics Data System (ADS)

    Hohenberger, M.; Shvydky, A.; Marozas, J. A.; Fiksel, G.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Meyerhofer, D. D.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D.

    2016-09-01

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [Marozas et al., Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh-Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ˜50% compared to the nominal OMEGA EP SSD system. The experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

  17. Localized CO2 Laser Treatment for Mitigation of 3(omega) Damage Growth in Fused Silica

    SciTech Connect

    Brusasco, R M; Penetrante, B M; Butler, J A; Hrubesh, L W

    2001-12-07

    A technique for inhibiting the growth of laser-induced surface damage on fused silica, initiated and propagated at the 351 nm laser wavelength, has been investigated. The technique exposes the damage sites to single pulses of a CO{sub 2} laser operating at the 10.6 {micro}m wavelength at or near beam focus. This method results in a very localized treatment of the laser damage site and modifies the site such that laser damage does not propagate further. A laser damage site initiated with a single pulse of 355 nm laser light at {approx} 45 J cm{sup -2} and 7.5 ns pulse duration grows rapidly upon further illumination at 8 J cm{sup -2} with 100% probability. Treatment of these sites with single pulses of 10.6 {micro}m laser light for one second at a power level of between 17 and 37 Watts with a beam diameter of 5 mm alters the damage site such that it does not grow with subsequent 351 nm laser illumination at 8 J cm{sup -2} 10 ns pulse duration for > 1000 shots. The technique has been found to be 100% effective at stopping the growth of the laser damage.

  18. Development of a Buried Layer Platform at the OMEGA laser to Study Coronal (nonLTE) Plasmas

    NASA Astrophysics Data System (ADS)

    Schneider, M. B.; Marley, E. V.; Brown, G. V.; Heeter, R. F.; Barrios, M. A.; Foord, M. E.; Gray, W. J.; Jarrott, L. C.; Liedahl, D. A.; Mauche, C. W.; Widmann, K.

    2016-10-01

    A buried layer platform is being developed at the OMEGA laser to study the radiative properties of coronal (non-LTE) plasmas (ne few 1021 /cm3 , Te 1 - 2 keV) of mid to high Z materials. In the current study, the target was a 200 μm square with equal atomic mixes of gold/iron/vanadium in the center of a 600 μm diameter, 10 μm thick beryllium tamper. The thickness of the buried layer was either 1200 A or 1800 A. Lasers heat the target from both sides for up to 4 ns. The size of the microdot vs time was measured with x-ray imaging (face-on) and x- ray spectroscopy (side-on). The radiant x-ray power was measured with a low-resolution absolutely calibrated x-ray spectrometer (DANTE). The temperature was measured from the Fe and V helium-beta complexes. The use of these measurements to deduce emissivity of the target in the 2-3 keV x-ray range and improvements for future experiments are discussed. This work was performed under the auspices of the U.S. Department of Energy by LLNS, LLC, under Contract No. DE-AC52-07NA27344.

  19. Accessing ultra-high pressures and strain rates in the solid state: An experimental path to extreme materials science on the Omega and NIF lasers

    NASA Astrophysics Data System (ADS)

    Lorenz, K. Thomas

    2005-03-01

    A new approach to materials science at extreme pressures and strain rates has been developed on the Omega laser, using a ramped plasma piston drive. The laser drives a shock through a solid plastic reservoir that unloads at the rear free surface, expands across a vacuum gap, and stagnates on the metal sample under study. This produces a gently increasing ram pressure, compressing the sample nearly isentropically. The peak pressure on the sample, diagnosed with VISAR measurements, can be varied by adjusting the laser energy and pulse length, gap size, and reservoir density, and obeys a simple scaling relation.^1 This has been demonstrated at OMEGA at pressures to 200 GPa in Al foils. In an important application, using in-flight x-ray radiography, the material strength of solid-state samples at high pressure can be inferred by measuring the reductions in the growth rates (stabilization) of Rayleigh-Taylor (RT) unstable interfaces. RT instability measurements of solid Al-6061-T6 and vanadium, at pressures of 20-100 GPa and strain rates of 10^6 to 10^8 s-1, show clear material strength effects. High-pressure experimental designs based on this drive have been developed for the NIF laser, predicting that solid-state samples can be quasi-isentropically driven to pressures an order of magnitude higher than on Omega - accessing new regimes of dense, high-pressure matter. [1] J. Edwards et al., Phys. Rev. Lett., 92, 075002 (2004).

  20. Angular Dependence of 3 omega o/2 Spectra from Laser-Produced Plasmas

    NASA Astrophysics Data System (ADS)

    Young, P. E.; Moody, J. D.; Rozmus, W.

    1999-08-01

    Scattered light at three-halves of the incident laser frequency from solid targets is observed at five different angles. When the incident laser intensity is low enough, rescattering of two plasmon decay (TPD) instability electron plasma waves by ion acoustic waves is not significant. In this regime, Thomson scattering measurements of the electron temperature and the plasma flow velocity allow quantitative comparison of the angular dependence of the spectrum to theory.

  1. Multi-keV X-ray Yields from High-Z Targets Fielded at the OMEGA Laser and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Kane, Jave; Fournier, Kevin; May, Mark; Colvin, Jeffrey; Thomas, Cliff; Marrs, Roscoe; Compton, Steven; Moody, John; Bond, Essex; Davis, John

    2010-11-01

    We report on measurements and modeling of fluxes from X-ray source targets recently shot at the National Ignition Facility (NIF) and at the Omega laser. The targets were thin-walled pipes filled with mixtures of Xe and Ar gas at pressures of 1 to 1.5 atmospheres. The targets were irradiated with 3φ laser light, 20 kJ in 1 ns at Omega and 350 kJ in 5 ns at NIF. The emitted X-ray flux was monitored with multiple channels of X-ray-diode based DANTE instruments, and imaged with gated X-ray detectors. We compare predicted X-ray yields to measure yields. The current modeling appears to under-predict the yield of gas mixtures containing Ar. We also report on design and modeling of Fe foam-filled and stainless steel-lined targets.

  2. Hohlraum-driven mid-Z (SiO2) double-shell implosions on the omega laser facility and their scaling to NIF.

    PubMed

    Robey, H F; Amendt, P A; Milovich, J L; Park, H-S; Hamza, A V; Bono, M J

    2009-10-02

    High-convergence, hohlraum-driven implosions of double-shell capsules using mid-Z (SiO2) inner shells have been performed on the OMEGA laser facility [T. R. Boehly, Opt. Commun. 133, 495 (1997)]. These experiments provide an essential extension of the results of previous low-Z (CH) double-shell implosions [P. A. Amendt, Phys. Rev. Lett. 94, 065004 (2005)] to materials of higher density and atomic number. Analytic modeling, supported by highly resolved 2D numerical simulations, is used to account for the yield degradation due to interfacial atomic mixing. This extended experimental database from OMEGA enables a validation of the mix model, and provides a means for quantitatively assessing the prospects for high-Z double-shell implosions on the National Ignition Facility [Paisner, Laser Focus World 30, 75 (1994)].

  3. Laser-induced damage of KDP crystals by 1omega nanosecond pulses: influence of crystal orientation.

    PubMed

    Reyné, Stéphane; Duchateau, Guillaume; Natoli, Jean-Yves; Lamaignère, Laurent

    2009-11-23

    We investigate the influence of THG-cut KDP crystal orientation on laser damage at 1064 nm under nanosecond pulses. Since laser damage is now assumed to initiate on precursor defects, this study makes a connection between these nanodefects (throughout a mesoscopic description) and the influence of their orientation on laser damage. Some investigations have already been carried out in various crystals and particularly for KDP, indicating propagation direction and polarization dependences. We performed experiments for two orthogonal positions of the crystal and results clearly indicate that KDP crystal laser damage depends on its orientation. We carried out further investigations on the effect of the polarization orientation, by rotating the crystal around the propagation axis. We then obtained the evolution of the damage probability as a function of the rotation angle. To account for these experimental res ts, we propose a laser damage model based on ellipsoid-shaped defects. This modeling is a refined implementation of the DMT model (Drude Mie Thermal) [Dyan et al., J. Opt. Soc. Am. B 25, 1087-1095 (2008)], by introducing absorption efficiency calculations for an ellipsoidal geometry. Modeling simulations are in good agreement with experimental results.

  4. Drive Symmetry Measurements with Ignition Relavent Conditions using Large Scale, Be, Thin Shell Capsules on the Omega Laser

    NASA Astrophysics Data System (ADS)

    Kirkwood, Robert; Dewald, E.; Edwards, J. M.; Milovich, J.; Kalantar, D. H.; Landen, O. L.; Goldman, S. R.; Schmitt, M.

    2008-11-01

    One technique to obtain symmetric ignition implosions on NIF is to measure the symmetry of the hohlraum radiation drive as a function of time by monitoring the shape of thin shell capsules by x-ray backlit imaging. Experiments at the Omega laser facility provided brightly backlit images of 0.7-scale Be capsules doped with 2% Cu under NIC foot conditions by using a 1ns pulse shape for drive and backlighter beams. 16 images of the imploding shell were recorded on each shot with a 4.7 keV (Ti), foil backlighter between 6.6 and 7.4 ns. Separate shots varied the fraction of energy in the cones and the total drive energy. The shell was observed to have a significant P2 distortion when the inner cone power was low, and increasing the inner cone power was shown to produce a symmetric shell with P2 near zero. The results will be compared with simulation of the expected shell distortion to verify the sensitivity of the technique. This Work was performed under the auspices of the U.S. DOE by Lawrence Livermore Lab under contract No. DE-AC52- A27344, LLNL-ABS-405480.

  5. Validation of a Turbulent Kelvin-Helmholtz Shear Layer Model Using a High-Energy-Density OMEGA Laser Experiment

    NASA Astrophysics Data System (ADS)

    Hurricane, O. A.; Smalyuk, V. A.; Raman, K.; Schilling, O.; Hansen, J. F.; Langstaff, G.; Martinez, D.; Park, H.-S.; Remington, B. A.; Robey, H. F.; Greenough, J. A.; Wallace, R.; Di Stefano, C. A.; Drake, R. P.; Marion, D.; Krauland, C. M.; Kuranz, C. C.

    2012-10-01

    Following the successful demonstration of an OMEGA laser-driven platform for generating and studying nearly two-dimensional unstable plasma shear layers [Hurricane et al., Phys. Plasmas 16, 056305 (2009)PHPAEN1070-664X10.1063/1.3096790; Harding et al., Phys. Rev. Lett. 103, 045005 (2009)PRLTAO0031-900710.1103/PhysRevLett.103.045005], this Letter reports on the first quantitative measurement of turbulent mixing in a high-energy-density plasma. As a blast wave moves parallel to an unperturbed interface between a low-density foam and a high-density plastic, baroclinic vorticity is deposited at the interface and a Kelvin-Helmholtz instability-driven turbulent mixing layer is created in the postshock flow due to surface roughness. The spatial scale and density profile of the turbulent layer are diagnosed using x-ray radiography with sufficiently small uncertainty so that the data can be used to constrain turbulent mixing models. The estimated Reynolds number (˜106), Liepmann-Taylor scale (˜0.5μm), and inner viscous scale (˜0.17μm) in the postshock plasma flow are consistent with an “inertial subrange,” within which a Kolmogorov turbulent energy cascade can be active. An illustration of comparing the data set with the predictions of a two-equation turbulence model in the ares radiation hydrodynamics code is also presented.

  6. Validation of a turbulent Kelvin-Helmholtz shear layer model using a high-energy-density OMEGA laser experiment.

    PubMed

    Hurricane, O A; Smalyuk, V A; Raman, K; Schilling, O; Hansen, J F; Langstaff, G; Martinez, D; Park, H-S; Remington, B A; Robey, H F; Greenough, J A; Wallace, R; Di Stefano, C A; Drake, R P; Marion, D; Krauland, C M; Kuranz, C C

    2012-10-12

    Following the successful demonstration of an OMEGA laser-driven platform for generating and studying nearly two-dimensional unstable plasma shear layers [Hurricane et al., Phys. Plasmas 16, 056305 (2009); Harding et al., Phys. Rev. Lett. 103, 045005 (2009)], this Letter reports on the first quantitative measurement of turbulent mixing in a high-energy-density plasma. As a blast wave moves parallel to an unperturbed interface between a low-density foam and a high-density plastic, baroclinic vorticity is deposited at the interface and a Kelvin-Helmholtz instability-driven turbulent mixing layer is created in the postshock flow due to surface roughness. The spatial scale and density profile of the turbulent layer are diagnosed using x-ray radiography with sufficiently small uncertainty so that the data can be used to ~0.17 μm) in the postshock plasma flow are consistent with an "inertial subrange," within which a Kolmogorov turbulent energy cascade can be active. An illustration of comparing the data set with the predictions of a two-equation turbulence model in the ares radiation hydrodynamics code is also presented.

  7. X-ray Spectral Measurements and Collisional Radiative Modeling of Hot, High-Z Plasmas at the Omega Laser

    SciTech Connect

    May, M J; Schneider, M B; Hansen, S B; Chung, H; Hinkel, D E; Baldis, H A; Constantin, C

    2008-02-20

    M-Band and L-Band Gold spectra between 3 to 5 keV and 8 to 13 keV, respectively, have been recorded by a photometrically calibrated crystal spectrometer. The spectra were emitted from the plasma in the laser deposition region of a 'hot hohlraum'. This is a reduced-scale hohlraum heated with {approx} 9 kJ of 351 nm light in a 1 ns square pulse at the Omega laser. The space- and time-integrated spectra included L-Band line emission from Co-like to Ne-like gold. The three L-Band line features were identified to be the 3s {yields} 2p, 3d{sub 5/2} {yields} 2p{sub 3/2} and 3d{sub 3/2} {yields} 2p{sub 1/2} transitions at {approx}9 keV, {approx}10 keV and {approx}13 keV, respectively. M-Band 5f {yields} 3d, 4d {yields} 3p, and 4p {yields} 3s transition features from Fe-like to P-like gold were also recorded between 3 to 5 keV. Modeling from the radiation-hydrodynamics code LASNEX, the collisional-radiative codes FLYCHK and SCRAM, and the atomic structure code FAC were used to model the plasma and generate simulated spectra for comparison with the recorded spectra. Through these comparisons, we have determined the average electron temperature of the emitting plasma to be {approx} 6.5 keV. The electron temperatures predicted by LASNEX appear to be too large by a factor of about 1.5.

  8. X-ray Spectral Measurements and Collisional Radiative Modeling of Hot, Gold Plasmas at the Omega Laser

    SciTech Connect

    May, M J; Schneider, M B; Hansen, S B; Chung, H; Hinkel, D E; Baldis, H A; Constantin, C

    2008-07-02

    M-Band and L-Band Gold spectra between 3 to 5 keV and 8 to 13 keV, respectively, have been recorded by a photometrically calibrated crystal spectrometer. The spectra were emitted from the plasma in the laser deposition region of a 'hot hohlraum'. This is a reduced-scale hohlraum heated with {approx} 9 kJ of 351 nm light in a 1 ns square pulse at the OMEGA laser. The space- and time-integrated spectra included L-Band line emission from Co-like to Ne-like gold. The three L-Band line features were identified to be the 3s {yields} 2p, 3d{sub 5/2} {yields} 2p{sub 3/2} and 3d{sub 3/2} {yields} 2p{sub 1/2} transitions at {approx}9 keV, {approx}10 keV and {approx}13 keV, respectively. M-Band 5f {yields} 3d, 4d {yields} 3p, and 4p {yields} 3s transition features from Fe-like to P-like gold were also recorded between 3 to 5 keV. Modeling from the radiation-hydrodynamics code LASNEX, the collisional-radiative codes FLYCHK and SCRAM, and the atomic structure code FAC were used to model the plasma and generate simulated spectra for comparison with the recorded spectra. Through these comparisons, we have determined the average electron temperature of the emitting plasma to be between 6.0 and 6.5 keV. The electron temperatures predicted by LASNEX appear to be too large by a factor of about 1.5.

  9. Laser plasma interaction on rugby hohlraum on the Omega Laser Facility: Comparisons between cylinder, rugby, and elliptical hohlraums

    NASA Astrophysics Data System (ADS)

    Masson-Laborde, P. E.; Monteil, M. C.; Tassin, V.; Philippe, F.; Gauthier, P.; Casner, A.; Depierreux, S.; Neuville, C.; Villette, B.; Laffite, S.; Seytor, P.; Fremerye, P.; Seka, W.; Teychenné, D.; Debayle, A.; Marion, D.; Loiseau, P.; Casanova, M.

    2016-02-01

    Gas-filled rugby-shaped hohlraums have demonstrated high performances compared to a classical similar diameter cylinder hohlraum with a nearly 40% increase of x-ray drive, 10% higher measured peak drive temperature, and an increase in neutron production. Experimental comparisons have been done between rugby, cylinder, and elliptical hohlraums. The impact of these geometry differences on the laser plasma instabilities is examined. Using comparisons with hydrodynamic simulations carried out with the code FCI2 and postprocessed by Piranah, we have been able to reproduce the stimulated Raman and Brillouin scattering spectrum of the different beams. Using a methodology based on a statistical analysis for the gain calculations, we show that the behavior of the laser plasma instabilities in rugby hohlraums can be reproduced. The efficiency of laser smoothing techniques to mitigate these instabilities are discussed, and we show that while rugby hohlraums exhibit more laser plasma instabilities than cylinder hohlraum, the latter can be mitigated in the case of an elliptical hohlraum.

  10. Solid-state Rayleigh-Taylor experiments in vanadium at Mbar pressures at the Omega laser

    SciTech Connect

    Remington, B A; Park, H S; Lorenz, K T; Cavallo, R M; Pollaine, S M; Prisbrey, S T; Rudd, R E; Becker, R C; Bernier, J V

    2009-06-24

    We present experiments on the Rayleigh-Taylor (RT) instability in the plastic flow regime of solid-state vanadium (V) foils at {approx}1 Mbar pressures and strain rates of 10{sup 6}-10{sup 8} s{sup -1}, using a laser based, ramped-pressure acceleration technique. High pressure material strength causes strong stabilization of the RT instability at short wavelengths. Comparisons with 2D simulations utilizing models of high pressure strength show that the V strength increases by a factor of 3.5 at peak pressure, compared to its ambient strength. An effective lattice viscosity of {approx}400 poise would have a similar effect.

  11. FY14 LLNL OMEGA Experimental Programs

    SciTech Connect

    Heeter, R. F.; Fournier, K. B.; Baker, K.; Barrios, M.; Bernstein, L.; Brown, G.; Celliers, P.; Chen, H.; Coppari, F.; Fratanduono, D.; Johnson, M. G.; Huntington, C.; Jenei, A.; Kraus, R.; Ma, T.; Martinez, D.; McNabb, D.; Millot, M.; Moore, A.; Nagel, S.; Park, H. S.; Patel, P.; Perez, F.; Ping, Y.; Pollock, B.; Ross, J. S.; Rygg, J. R.; Smith, R.; Zylstra, A.; Collins, G.; Landen, O.; Wan, A.; Hsing, W.

    2014-10-13

    In FY14, LLNL’s High-Energy-Density Physics (HED) and Indirect Drive Inertial Confinement Fusion (ICF-ID) programs conducted several campaigns on the OMEGA laser system and on the EP laser system, as well as campaigns that used the OMEGA and EP beams jointly. Overall these LLNL programs led 324 target shots in FY14, with 246 shots using just the OMEGA laser system, 62 shots using just the EP laser system, and 16 Joint shots using Omega and EP together. Approximately 31% of the total number of shots (62 OMEGA shots, 42 EP shots) shots supported the Indirect Drive Inertial Confinement Fusion Campaign (ICF-ID). The remaining 69% (200 OMEGA shots and 36 EP shots, including the 16 Joint shots) were dedicated to experiments for High- Energy-Density Physics (HED). Highlights of the various HED and ICF campaigns are summarized in the following reports.

  12. FY15 LLNL OMEGA Experimental Programs

    SciTech Connect

    Heeter, R. F.; Baker, K. L.; Barrios, M. A.; Beckwith, M. A.; Casey, D. T.; Celliers, P. M.; Chen, H.; Coppari, F.; Fournier, K. B.; Fratanduono, D. E.; Frenje, J.; Huntington, C. M.; Kraus, R. G.; Lazicki, A. E.; Martinez, D. A.; McNaney, J. M.; Millot, M. A.; Pak, A. E.; Park, H. S.; Ping, Y.; Pollock, B. B.; Smith, R. F.; Wehrenberg, C. E.; Widmann, K.; Collins, G. W.; Landen, O. L.; Wan, A.; Hsing, W.

    2015-12-04

    In FY15, LLNL’s High-Energy-Density Physics (HED) and Indirect Drive Inertial Confinement Fusion (ICF-ID) programs conducted several campaigns on the OMEGA laser system and on the EP laser system, as well as campaigns that used the OMEGA and EP beams jointly. Overall these LLNL programs led 468 target shots in FY15, with 315 shots using just the OMEGA laser system, 145 shots using just the EP laser system, and 8 Joint shots using Omega and EP together. Approximately 25% of the total number of shots (56 OMEGA shots and 67 EP shots, including the 8 Joint shots) supported the Indirect Drive Inertial Confinement Fusion Campaign (ICF-ID). The remaining 75% (267 OMEGA shots and 86 EP shots) were dedicated to experiments for High-Energy-Density Physics (HED). Highlights of the various HED and ICF campaigns are summarized in the following reports.

  13. B Meson Decays to mega K*, omega rho, omega omega, omega phi, and omega f0

    SciTech Connect

    Aubert, B.; Barate, R.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G.S.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Karlsruhe U., EKP /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /Pisa U. /INFN, Pisa /Prairie View A-M /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Stony Brook /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U. /Clermont-Ferrand U. /Basilicata U., Potenza

    2006-07-28

    The authors describe searches for B meson decays to the charmless vector-vector final states {omega}K*, {omega}p, {omega}{omega}, and {omega}{phi} with 233 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation at {radical}s = 10.58 GeV. They also search for the vector-scalar B decay to {omega}f{sub 0}.

  14. Laser-Damage-Resistant Photoalignment Layers for High-Peak-Power Liquid Crystal Device Applications

    SciTech Connect

    Marshall, K.L.; Gan, J.; Mitchell, G.; Papernov, S.; Rigatti, A.L.; Schmid, A.W.; Jacobs, S.D.

    2008-10-23

    Large-aperture liquid crystal (LC) devices have been in continuous use since 1995 as polarization control devices in the 40-TW, 351-nm, 60-beam OMEGA Nd:glass laser system at the University of Rochester’s Laboratory for Laser Energetics. The feasibility of using a noncontacting alignment method for high-peak-power LC laser optics by irradiation of a linearly photopolymerizable polymer with polarized UV light was recently investigated. These materials were found to have surprisingly large laser-damage thresholds at 1054 nm, approaching that of bare fused silica (30 to 60 J/cm^2). Their remarkable laser-damage resistance and ease in scalability to large apertures of these photoalignment materials, along with the ability to produce multiple alignment states by photolithographic patterning, opens new doorways for their application in LC devices for optics, photonics, and high-peak-power laser applications.

  15. Demonstration of fuel hot-spot pressure in excess of 50 Gbar for direct-drive, layered deuterium-tritium implosions on OMEGA

    SciTech Connect

    Regan, S. P.; Goncharov, V. N.; Igumenshchev, I. V.; Sangster, T. C.; Betti, R.; Bose, A.; Boehly, T. R.; Bonino, M. J.; Campbell, E. M.; Cao, D.; Collins, T. J. B.; Craxton, R. S.; Davis, A. K.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Frenje, J. A.; Froula, D. H.; Gatu Johnson, M.; Glebov, V. Yu.; Harding, D. R.; Hohenberger, M.; Hu, S. X.; Jacobs-Perkins, D.; Janezic, R.; Karasik, M.; Keck, R. L.; Kelly, J. H.; Kessler, T. J.; Knauer, J. P.; Kosc, T. Z.; Loucks, S. J.; Marozas, J. A.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Obenschain, S. P.; Petrasso, R. D.; Radha, P. B.; Rice, B.; Rosenberg, M. J.; Schmitt, A. J.; Schmitt, M. J.; Seka, W.; Shmayda, W. T.; Shoup, III, M. J.; Shvydky, A.; Skupsky, S.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Ulreich, J.; Wittman, M. D.; Woo, K. M.; Yaakobi, B.; Zuegel, J. D.

    2016-07-07

    A record fuel hot-spot pressure Phs = 56±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium–tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility (NIF), these implosions achieved a Lawson parameter ~60% of the value required for ignition [A. Bose et al., Phys. Rev. E (in press)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is ~40% lower. Furthermore, three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.

  16. Demonstration of fuel hot-spot pressure in excess of 50 Gbar for direct-drive, layered deuterium-tritium implosions on OMEGA

    SciTech Connect

    Regan, S. P.; Goncharov, V. N.; Igumenshchev, I. V.; Sangster, T. C.; Betti, R.; Bose, A.; Boehly, T. R.; Bonino, M. J.; Campbell, E. M.; Cao, D.; Collins, T. J. B.; Craxton, R. S.; Davis, A. K.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Frenje, J. A.; Froula, D. H.; Gatu Johnson, M.; Glebov, V. Yu.; Harding, D. R.; Hohenberger, M.; Hu, S. X.; Jacobs-Perkins, D.; Janezic, R.; Karasik, M.; Keck, R. L.; Kelly, J. H.; Kessler, T. J.; Knauer, J. P.; Kosc, T. Z.; Loucks, S. J.; Marozas, J. A.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Obenschain, S. P.; Petrasso, R. D.; Radha, P. B.; Rice, B.; Rosenberg, M. J.; Schmitt, A. J.; Schmitt, M. J.; Seka, W.; Shmayda, W. T.; Shoup, III, M. J.; Shvydky, A.; Skupsky, S.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Ulreich, J.; Wittman, M. D.; Woo, K. M.; Yaakobi, B.; Zuegel, J. D.

    2016-07-07

    A record fuel hot-spot pressure Phs = 56±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium–tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility (NIF), these implosions achieved a Lawson parameter ~60% of the value required for ignition [A. Bose et al., Phys. Rev. E (in press)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is ~40% lower. Furthermore, three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.

  17. Demonstration of Fuel Hot-Spot Pressure in Excess of 50 Gbar for Direct-Drive, Layered Deuterium-Tritium Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Regan, S. P.; Goncharov, V. N.; Igumenshchev, I. V.; Sangster, T. C.; Betti, R.; Bose, A.; Boehly, T. R.; Bonino, M. J.; Campbell, E. M.; Cao, D.; Collins, T. J. B.; Craxton, R. S.; Davis, A. K.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Frenje, J. A.; Froula, D. H.; Gatu Johnson, M.; Glebov, V. Yu.; Harding, D. R.; Hohenberger, M.; Hu, S. X.; Jacobs-Perkins, D.; Janezic, R.; Karasik, M.; Keck, R. L.; Kelly, J. H.; Kessler, T. J.; Knauer, J. P.; Kosc, T. Z.; Loucks, S. J.; Marozas, J. A.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Obenschain, S. P.; Petrasso, R. D.; Radha, P. B.; Rice, B.; Rosenberg, M. J.; Schmitt, A. J.; Schmitt, M. J.; Seka, W.; Shmayda, W. T.; Shoup, M. J.; Shvydky, A.; Skupsky, S.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Ulreich, J.; Wittman, M. D.; Woo, K. M.; Yaakobi, B.; Zuegel, J. D.

    2016-07-01

    A record fuel hot-spot pressure Phs=56 ±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium-tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility, these implosions achieved a Lawson parameter ˜60 % of the value required for ignition [A. Bose et al., Phys. Rev. E 93, LM15119ER (2016)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is approximately 40% lower. Three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.

  18. Demonstration of fuel hot-spot pressure in excess of 50 Gbar for direct-drive, layered deuterium-tritium implosions on OMEGA

    DOE PAGES

    Regan, S. P.; Goncharov, V. N.; Igumenshchev, I. V.; ...

    2016-07-07

    A record fuel hot-spot pressure Phs = 56±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium–tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility (NIF), these implosions achieved a Lawson parameter ~60% of the value required for ignition [A. Bose et al., Phys. Rev. E (in press)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is ~40%more » lower. Furthermore, three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.« less

  19. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    SciTech Connect

    Hohenberger, M.; Shvydky, A.; Marozas, J. A.; Fiksel, G.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Meyerhofer, D. D.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D.

    2016-09-07

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [J. A. Marozas, J. D. Zuegel, and T. J. B. Collins, Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ~50% compared to the nominal OMEGA EP SSD system. In conclusion, the experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

  20. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    DOE PAGES

    Hohenberger, M.; Shvydky, A.; Marozas, J. A.; ...

    2016-09-07

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [J. A. Marozas, J. D. Zuegel, and T. J. B. Collins, Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSDmore » has been observed to reduce imprint levels by ~50% compared to the nominal OMEGA EP SSD system. In conclusion, the experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.« less

  1. Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

    SciTech Connect

    Hohenberger, M.; Shvydky, A.; Marozas, J. A.; Fiksel, G.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Meyerhofer, D. D.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D.

    2016-09-07

    Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [J. A. Marozas, J. D. Zuegel, and T. J. B. Collins, Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ~50% compared to the nominal OMEGA EP SSD system. In conclusion, the experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

  2. Optics Performance at 1(omega), 2 (omega), and 3 (omega): Final Report on LDRD Project 03-ERD-071

    SciTech Connect

    Honig, J; Adams, J; Carr, C; Demos, S; Feit, M; Mehta, N; Norton, M; Nostrand, M; Rubenchik, A; Spaeth, M

    2006-02-08

    The interaction of intense laser light with dielectric materials is a fundamental applied science problem that is becoming increasingly important with the rapid development of ever more powerful lasers. To better understand the behavior of optical components in large fusion-class laser systems, we are systematically studying the interaction of high-fluence, high-power laser light with high-quality optical components, with particular interest on polishing/finishing and stress-induced defects and surface contamination. We focus on obtaining comparable measurements at three different wavelengths, 1{omega} (1053 nm), 2{omega} (527 nm), and 3{omega} (351 nm).

  3. Increasing efficiency of BEAMnrc-simulated Co-60 beams using directional source biasing

    SciTech Connect

    Walters, B. R. B.

    2015-10-15

    Purpose: This study describes the implementation of a directional source biasing (DSB) scheme for efficiently simulating Cobalt-60 treatment heads using the BEAMnrc Monte Carlo code. Previous simulation of Co-60 beams with BEAMnrc was impractical because of the time required to track photons not directed into the treatment field and to simulate secondary charged particles. Methods: In DSB, efficiency is increased by splitting each photon emitted by the Co-60 source a user-defined number of times. Only those split primary photons directed into a user-defined splitting field (encompassing the treatment field) are sampled, yielding many low-weight photons directed into the field. Efficiency can be further increased by taking advantage of radial symmetry at the top of the treatment head to reduce the number of split primary photons tracked in this portion. There is also an option to generate contaminant electrons in DSB. Results: The DSB scheme in BEAMnrc increases the photon fluence calculation efficiency in a 10 × 10 cm{sup 2} Co-60 beam by a factor of 1800 with a concurrent increase in contaminant electron fluence calculation efficiency by a factor of 1200. Implementation of DSB in beampp, a C++ code for accelerator simulations based on EGSnrc and the C++ class library, egspp, increases photon fluence efficiency by a factor of 2800 and contaminant electron fluence efficiency by a factor of 1600. Optimum splitting numbers are in the range of 20 000–40 000. For dose calculations in a water phantom (0.5 × 0.5 × 0.5 cm{sup 3} voxels) this translates into a factor of ∼400 increase in dose calculation efficiency (all doses > 0.5 × D{sub max}). An example calculation of the ratio of dose to water to dose to chamber (the basis of the beam quality correction factor) to within 0.2% in a realistic chamber using a full simulation of a Co-60 treatment head as a source indicates the practicality of Co-60 simulations with DSB. Conclusions: The efficiency improvement

  4. Demonstration of 55 +/- 7-Gbar Hot-Spot Pressure in Direct-Drive Layered DT Cryogenic Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Regan, S. P.

    2015-11-01

    Direct-drive ignition target designs for the National Ignition Facility (NIF) require hot-spot pressures in excess of 100 Gbar. Only one-third of the required pressure was inferred in earlier experimental campaigns conducted on the 60-beam, 30-kJ, 351-nm OMEGA laser with direct-drive implosions of layered DT cryogenic targets. Laser and target improvements were implemented on OMEGA to increase the stagnation pressure, including a set of phase plates to increase the laser irradiation uniformity on target and a purified fuel with isotope composition reaching a 50:50 DT ratio. Diagnostic improvements were made for a neutron burnwidth measurement with a 40-ps impulse response and a 16-channel Kirkpatrick-Baez microscope to measure gated (30-ps) x-ray images of the core near peak compression with 6- μm resolution. The inferred volume-averaged, peak pressure in the current campaign almost doubled to 55 +/- 7 Gbar with a neutron yield approaching 5 ×1013 . Further target performance improvements to reach hydrodynamic equivalence to ignition on OMEGA require mitigation of cross-beam energy transfer (CBET), which reduces the laser coupling. A proposed technique to reduce CBET by driving the spherical target with overlapping laser beams having individual focal spots smaller than the outside diameter of the target was investigated. The diameter of the target was discretely varied from 800 to 1000 μm, while the laser focal spot size was kept constant at 820 μm. The larger targets driven with up to 30 kJ of laser energy used dynamic bandwidth reduction, where the smoothing by spectral dispersion (SSD) is only applied to the pickets. The smaller targets driven with 26 kJ of laser energy had SSD on the entire pulse. This talk will summarize the results of this CBET mitigation campaign and describe a path forward to achieve ignition hydro-equivalence on OMEGA. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under

  5. FY16 LLNL Omega Experimental Programs

    SciTech Connect

    Heeter, R. F.; Ali, S. J.; Benstead, J.; Celliers, P. M.; Coppari, F.; Eggert, J.; Erskine, D.; Panella, A. F.; Fratanduono, D. E.; Hua, R.; Huntington, C. M.; Jarrott, L. C.; Jiang, S.; Kraus, R. G.; Lazicki, A. E.; LePape, S.; Martinez, D. A.; McNaney, J. M.; Millot, M. A.; Moody, J.; Pak, A. E.; Park, H. S.; Ping, Y.; Pollock, B. B.; Rinderknecht, H.; Ross, J. S.; Rubery, M.; Sio, H.; Smith, R. F.; Swadling, G. F.; Wehrenberg, C. E.; Collins, G. W.; Landen, O. L.; Wan, A.; Hsing, W.

    2016-12-01

    In FY16, LLNL’s High-Energy-Density Physics (HED) and Indirect Drive Inertial Confinement Fusion (ICF-ID) programs conducted several campaigns on the OMEGA laser system and on the EP laser system, as well as campaigns that used the OMEGA and EP beams jointly. Overall, these LLNL programs led 430 target shots in FY16, with 304 shots using just the OMEGA laser system, and 126 shots using just the EP laser system. Approximately 21% of the total number of shots (77 OMEGA shots and 14 EP shots) supported the Indirect Drive Inertial Confinement Fusion Campaign (ICF-ID). The remaining 79% (227 OMEGA shots and 112 EP shots) were dedicated to experiments for High-Energy-Density Physics (HED). Highlights of the various HED and ICF campaigns are summarized in the following reports. In addition to these experiments, LLNL Principal Investigators led a variety of Laboratory Basic Science campaigns using OMEGA and EP, including 81 target shots using just OMEGA and 42 shots using just EP. The highlights of these are also summarized, following the ICF and HED campaigns. Overall, LLNL PIs led a total of 553 shots at LLE in FY 2016. In addition, LLNL PIs also supported 57 NLUF shots on Omega and 31 NLUF shots on EP, in collaboration with the academic community.

  6. Effect of Beam Smoothing and Pulse Shape on the Implosion of DD-Filled CH Shell Targets on OMEGA

    NASA Astrophysics Data System (ADS)

    Delettrez, J. A.; Glebov, V. Yu.; Marshall, F. J.; Stoeckl, C.; Yaakobi, B.; Meyerhofer, D. D.

    1999-11-01

    Over the past two years several implosion experiments were carried out on the 60-beam OMEGA laser in which DD-filled CH shells (some with a CHTi layer imbedded) were irradiated with various laser pulse shapes and smoothing conditions. Target CH shell thicknesses varied from 20 μm to 27 μm with DD-fill variations from 3 to 20 atm, sometimes mixed with ^3He. Two pulse shapes---a 1-ns square pulse and a 2.5-ns pulse with a 10%, 1-ns foot, with and without SSD---provide several levels of laser imprint. Diagnostics include measured neutron yields, fuel ion temperatures, fuel ρR, and shell ρR. Simulations for these experimental conditions were carried out with the 2-D hydrocode ORCHID. The results are compared with the experimental results. The degradation of target performance due to laser nonuniformity is analyzed by comparing the 2-D results with those of 1-D simulations. The effects of pulse shape, target thickness, convergence ratio, and smoothing are presented. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460, the University of Rochester, and the New York State Energy Research and Development Authority.

  7. Using high-intensity laser-generated energetic protons to radiograph directly driven implosions

    NASA Astrophysics Data System (ADS)

    Zylstra, A. B.; Li, C. K.; Rinderknecht, H. G.; Séguin, F. H.; Petrasso, R. D.; Stoeckl, C.; Meyerhofer, D. D.; Nilson, P.; Sangster, T. C.; Le Pape, S.; Mackinnon, A.; Patel, P.

    2012-01-01

    The recent development of petawatt-class lasers with kilojoule-picosecond pulses, such as OMEGA EP [L. Waxer et al., Opt. Photonics News 16, 30 (2005), 10.1364/OPN.16.7.000030], provides a new diagnostic capability to study inertial-confinement-fusion (ICF) and high-energy-density (HED) plasmas. Specifically, petawatt OMEGA EP pulses have been used to backlight OMEGA implosions with energetic proton beams generated through the target normal sheath acceleration (TNSA) mechanism. This allows time-resolved studies of the mass distribution and electromagnetic field structures in ICF and HED plasmas. This principle has been previously demonstrated using Vulcan to backlight six-beam implosions [A. J. Mackinnon et al., Phys. Rev. Lett. 97, 045001 (2006), 10.1103/PhysRevLett.97.045001]. The TNSA proton backlighter offers better spatial and temporal resolution but poorer spatial uniformity and energy resolution than previous D3He fusion-based techniques [C. Li et al., Rev. Sci. Instrum. 77, 10E725 (2006), 10.1063/1.2228252]. A target and the experimental design technique to mitigate potential problems in using TNSA backlighting to study full-energy implosions is discussed. The first proton radiographs of 60-beam spherical OMEGA implosions using the techniques discussed in this paper are presented. Sample radiographs and suggestions for troubleshooting failed radiography shots using TNSA backlighting are given, and future applications of this technique at OMEGA and the NIF are discussed.

  8. Re-examining our inhibitions: A speculative re-analysis of data from gold spheres illuminated by the URLLE Omega laser

    NASA Astrophysics Data System (ADS)

    Rosen, Mordecai; Ross, Steven; Thomas, Cliff

    2015-11-01

    A 2006 campaign, that illuminated 1 mm diameter gold spheres using the Omega laser at LLE, required the simulations to use a ``liberal'' flux limiter of f =0.15 (or equivalently a non-local model) in order to match the high levels of measured x-ray emission. In 2013, Thomson Scattering (TS) diagnosed the plasma conditions in the Au sphere's laser heated corona at various radial positions as a function of time. The simulation model using non-local transport compared well for some of the TS data (for ZTe) but not for all of it. Meanwhile, using this model for hohlraums, led to discrepancies with data (such as drive) when applied to some hohlraums, though less-so for others. As a result, hohlraum models with a more restrictive flux limiter, including a ``two-stream-instability (TSI)'' flux limit model (which, when operative, is effectively f =0.015) are being considered. Here we invoke the possibility that the same ion acoustic turbulence (an outgrowth of the TSI), which acts like an effective scatterer to inhibit electron transport, can, by the same token, also increase absorption. This increase in absorption, applied (speculatively) close by the critical surface, can begin to match the Au sphere x-ray emission, as well as a preponderance of the ZTe data. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  9. Seeding magnetic fields for laser-driven flux compression in high-energy-density plasmas.

    PubMed

    Gotchev, O V; Knauer, J P; Chang, P Y; Jang, N W; Shoup, M J; Meyerhofer, D D; Betti, R

    2009-04-01

    A compact, self-contained magnetic-seed-field generator (5 to 16 T) is the enabling technology for a novel laser-driven flux-compression scheme in laser-driven targets. A magnetized target is directly irradiated by a kilojoule or megajoule laser to compress the preseeded magnetic field to thousands of teslas. A fast (300 ns), 80 kA current pulse delivered by a portable pulsed-power system is discharged into a low-mass coil that surrounds the laser target. A >15 T target field has been demonstrated using a <100 J capacitor bank, a laser-triggered switch, and a low-impedance (<1 Omega) strip line. The device has been integrated into a series of magnetic-flux-compression experiments on the 60 beam, 30 kJ OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The initial application is a novel magneto-inertial fusion approach [O. V. Gotchev et al., J. Fusion Energy 27, 25 (2008)] to inertial confinement fusion (ICF), where the amplified magnetic field can inhibit thermal conduction losses from the hot spot of a compressed target. This can lead to the ignition of massive shells imploded with low velocity-a way of reaching higher gains than is possible with conventional ICF.

  10. Seeding Magnetic Fields for Laser-Driven Flux Compression in High-Energy-Density Plasmas

    SciTech Connect

    Gotchev, O.V.; Knauer, J.P.; Chang, P.Y.; Jang, N.W.; Shoup III, M.J.; Meyerhofer, D.D.; Betti, R.

    2010-03-23

    A compact, self-contained magnetic-seed-field generator (5 to 16 T) is the enabling technology for a novel laser-driven flux-compression scheme in laser-driven targets. A magnetized target is directly irradiated by a kilojoule or megajoule laser to compress the preseeded magnetic field to thousands of teslas. A fast (300 ns), 80 kA current pulse delivered by a portable pulsed-power system is discharged into a low-mass coil that surrounds the laser target. A >15 T target field has been demonstrated using a <100 J capacitor bank, a laser-triggered switch, and a low-impedance (<1 Omega) strip line. The device has been integrated into a series of magnetic-flux-compression experiments on the 60 beam, 30 kJ OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The initial application is a novel magneto-inertial fusion approach [O. V. Gotchev et al., J. Fusion Energy 27, 25 (2008)] to inertial confinement fusion (ICF), where the amplified magnetic field can inhibit thermal conduction losses from the hot spot of a compressed target. This can lead to the ignition of massive shells imploded with low velocity—a way of reaching higher gains than is possible with conventional ICF.

  11. Seeding magnetic fields for laser-driven flux compression in high-energy-density plasmas

    SciTech Connect

    Gotchev, O. V.; Knauer, J. P.; Shoup, M. J. III; Chang, P. Y.; Jang, N. W.; Meyerhofer, D. D.; Betti, R.

    2009-04-15

    A compact, self-contained magnetic-seed-field generator (5 to 16 T) is the enabling technology for a novel laser-driven flux-compression scheme in laser-driven targets. A magnetized target is directly irradiated by a kilojoule or megajoule laser to compress the preseeded magnetic field to thousands of teslas. A fast (300 ns), 80 kA current pulse delivered by a portable pulsed-power system is discharged into a low-mass coil that surrounds the laser target. A >15 T target field has been demonstrated using a <100 J capacitor bank, a laser-triggered switch, and a low-impedance (<1 {Omega}) strip line. The device has been integrated into a series of magnetic-flux-compression experiments on the 60 beam, 30 kJ OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The initial application is a novel magneto-inertial fusion approach [O. V. Gotchev et al., J. Fusion Energy 27, 25 (2008)] to inertial confinement fusion (ICF), where the amplified magnetic field can inhibit thermal conduction losses from the hot spot of a compressed target. This can lead to the ignition of massive shells imploded with low velocity--a way of reaching higher gains than is possible with conventional ICF.

  12. Theory of laser enhancement and suppression of cold reactions: the fermion-boson 6Li+7Li2<-->(variant Planck's over 2pi omega0) 6Li7Li+7Li radiative collision.

    PubMed

    Li, Xuan; Parker, Gregory A; Brumer, Paul; Thanopulos, Ioannis; Shapiro, Moshe

    2008-03-28

    We present a nonperturbative time-dependent quantum mechanical theory of the laser catalysis and control of a bifurcating A+BC<-->(variant Planck's over 2pi omega(0))ABC*(v)<-->(variant Planck's over 2pi omega(0) )AB+C reaction, with ABC*(v) denoting an intermediate, electronically excited, complex of ABC in the vth vibrational state. We apply this theory to the low collision energy fermion-boson light-induced exchange reaction, (6)Li((2)S)+(7)Li(2)((3)Sigma(u)(+))<-->(variant Planck's over 2pi omega(0))((6)Li(7)Li(7)Li)*<-->(variant Planck's over 2pi omega(0))(6)Li(7)Li((3)Sigma(+))+(7)Li((2)S). We show that at very low collision energies and energetically narrow (approximately 0.01 cm(-1)) initial reactant wave packets, it is possible to tune the yield of the exchange reaction from 0 to near-unity (yield >or=99%) values. Controllability is somewhat reduced at collisions involving energetically wider (approximately 1 cm(-1)) initial reactant wave packets. At these energetic bandwidths, the radiative reactive control, although still impressive, is limited to the 0%-76% reactive-probabilities range.

  13. Omega Electroproduction

    SciTech Connect

    Unwuchola, A. D.; Connell, Simon H.; Aurousseau, M.; Dalton, Mark M.

    2013-08-01

    The differential cross section for p(e, e'ω)p has been studied at Q{sup 2} ~ 5.5 (GeV/c)2. Here Q{sup 2} represents the four momentum squared of the virtual photon in the excitation of baryonic resonances by an electron projectile. In order to extract the ω-meson differential cross section from the JLAB data, the data was compared to a full Monte Carlo simulation of the detector based on events generated for omega production in a way that the production cross section was varied to achieve a match to the data. The bin selected for this procedure takes into account the measure of robustness of the stripping of the ω peak from the multi-pion background as well as the statistics in the measured data and the Monte Carlo simulation of the signal and background physics. An error estimation technique for the cross section was based on determining the dependence of the extracted cross section parameters on the experimental set-up (including parameters for the spectrometer, target beam geometeries and performance). We compare our results with a Regge-based model for hadronic content in the t-channel exchange of a photon in Q{sup 2} region of overlap. There is an extension of this data into a completely new region, which is the highest yet measured.

  14. Observation of a Kelvin-helmholtz instability in a high-energy-density plasma on the omega laser.

    PubMed

    Harding, E C; Hansen, J F; Hurricane, O A; Drake, R P; Robey, H F; Kuranz, C C; Remington, B A; Bono, M J; Grosskopf, M J; Gillespie, R S

    2009-07-24

    A laser initiated experiment is described in which an unstable plasma shear layer is produced by driving a blast wave along a plastic surface with sinusoidal perturbations. In response to the vorticity deposited and the shear flow established by the blast wave, the interface rolls up into large vortices characteristic of the Kelvin-Helmholtz instability. The experiment used x-ray radiography to capture the first well-resolved images of Kelvin-Helmholtz vortices in a high-energy-density plasma.

  15. Omega documentation

    SciTech Connect

    Howerton, R.J.; Dye, R.E.; Giles, P.C.; Kimlinger, J.R.; Perkins, S.T.; Plechaty, E.F.

    1983-08-01

    OMEGA is a CRAY I computer program that controls nine codes used by LLNL Physical Data Group for: 1) updating the libraries of evaluated data maintained by the group (UPDATE); 2) calculating average values of energy deposited in secondary particles and residual nuclei (ENDEP); 3) checking the libraries for internal consistency, especially for energy conservation (GAMCHK); 4) producing listings, indexes and plots of the library data (UTILITY); 5) producing calculational constants such as group averaged cross sections and transfer matrices for diffusion and Sn transport codes (CLYDE); 6) producing and updating standard files of the calculational constants used by LLNL Sn and diffusion transport codes (NDFL); 7) producing calculational constants for Monte Carlo transport codes that use group-averaged cross sections and continuous energy for particles (CTART); 8) producing and updating standard files used by the LLNL Monte Carlo transport codes (TRTL); and 9) producing standard files used by the LANL pointwise Monte Carlo transport code MCNP (MCPOINT). The first four of these functions and codes deal with the libraries of evaluated data and the last five with various aspects of producing calculational constants for use by transport codes. In 1970 a series, called PD memos, of internal and informal memoranda was begun. These were intended to be circulated among the group for comment and then to provide documentation for later reference whenever questions arose about the subject matter of the memos. They have served this purpose and now will be drawn upon as source material for this more comprehensive report that deals with most of the matters covered in those memos.

  16. Imaging of Compressed Pure-CH Shells and CH Shells with Titanium-Doped Layers on OMEGA

    NASA Astrophysics Data System (ADS)

    Smalyuk, V. A.; Yaakobi, B.; Goncharov, V. N.; Delettrez, J. A.; Marshall, F. J.; Meyerhofer, D. D.

    1999-11-01

    The compressed shell integrity of spherical targets has been studied using the 60-beam, 30-kJ UV, OMEGA laser system. The emission from the hot core has been imaged through the cold shell at two narrow, x-ray energy bands, absorbing and nonabsorbing by the shell, allowing nonuniformities in the core emission and the cold shell areal density to be measured. Images of the target have been obtained using a pinhole-array with K-edge filters. The x-ray energies used are around 2.8 and 4.5 keV for pure-CH shells, and around 4.5 and 6 keV for titanium-doped layers. Additional images of the shell are obtained with a framed monochromatic x-ray microscope and a time-integrated crystal-spectrometer/pinhole-array combination. We will present measurements of the compressed shell integrity at the stagnation stage of spherical implosions by varying the position of the titanium-doped layer within the shell, by varying the thickness of the CH shell, and by using two different laser pulse shapes. The experimental results will be compared with 2-D (ORCHID) hydrodynamic simulations. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460, the University of Rochester, and the New York State Energy Research and Development Authority.

  17. Photo-aligned liquid crystal devices for high-peak-power laser applications

    NASA Astrophysics Data System (ADS)

    Marshall, K. L.; Dorrer, C.; Vargas, M.; Gnolek, A.; Statt, M.; Chen, S.-H.

    2012-10-01

    Liquid crystal (LC) optical elements have proven themselves as robust and cost-effective components for high-peakpowerlaser systems such as the 60-beam, 40-TW OMEGA Nd:glass laser system at the University of Rochester'sLaboratory for Laser Energetics. Although buffed nylon 6/6 alignment layers are the de facto standard for high-peak-power applications, photoalignment coatings based on coumarin materials have demonstrated exceptionally high near-IR laser-damage resistance. Using conventional photolithographic patterning techniques, high-resolution, photoaligned, nematic LC beam-shaper devices with a contrast ratio of 430:1, a pixel size of 10 μm, an interpixel resolution of 1.7 μm, and laser-damage resistance of 30 J/cm2 (1054-nm, 1-ns pulse) have been demonstrated. Recently, we have extended this photoalignment process to other existing and potential high-peak-power LC optical devices that have previously used buffed alignment coatings. In addition to fabricating photoaligned LC wave-plate prototypes that meet all optical and performance specifications of LC devices currently used on OMEGA, novel LC polarization converters with continuously varying radial or azimuthal polarization states have been fabricated using the same high-damage-threshold materials. These polarization converters have applications not only in high-peak-power lasers but also in microscopy, electron acceleration, and machining.

  18. Omega-6 Fatty Acids

    MedlinePlus

    ... types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean ... from studying specific omega-6 fatty acids or plant oils containing omega-6 fatty acids. See the separate ...

  19. Omega-3 fatty acids

    PubMed Central

    Schwalfenberg, Gerry

    2006-01-01

    OBJECTIVE To examine evidence for the role of omega-3 fatty acids in cardiovascular disease. QUALITY OF EVIDENCE PubMed was searched for articles on the role of omega-3 fatty acids in cardiovascular disease. Level I and II evidence indicates that omega-3 fatty acids are beneficial in improving cardiovascular outcomes. MAIN MESSAGE Dietary intake of omega-3 fatty acids has declined by 80% during the last 100 years, while intake of omega-6 fatty acids has greatly increased. Omega-3 fatty acids are cardioprotective mainly due to beneficial effects on arrhythmias, atherosclerosis, inflammation, and thrombosis. There is also evidence that they improve endothelial function, lower blood pressure, and significantly lower triglycerides. CONCLUSION There is good evidence in the literature that increasing intake of omega-3 fatty acids improves cardiac outcomes. Physicians need to integrate dietary recommendations for consumption of omega-3 fatty acids into their usual cardiovascular care. PMID:16812965

  20. Observation of a Kelvin-Helmholtz Instability in a High-Energy-Density Plasma on the Omega Laser

    SciTech Connect

    Harding, E C; Hansen, J F; Hurricane, O A; Drake, R P; Robey, H F; Kuranz, C C; Remington, B A; Bono, M J; Grosskopf, M J; Gillespie, R S

    2009-02-12

    A laser initiated experiment is described in which an unstable plasma shear layer is produced by driving a blast wave along a plastic surface with sinusoidal perturbations. In response to the vorticity deposited and the shear flow established by the blast wave, the interface rolls up into large vortices characteristic of the Kelvin-Helmholtz (KH) instability. The experiment used x ray radiography to capture the first well-resolved images of KH vortices in a high-energy-density plasma, and possibly the first images of transonic shocks generated by large-scale structures in a shear layer. The physical processes governing the evolution of a stratified fluid flow with a large velocity gradient (i.e., a shear flow) are of fundamental interest to a wide range of research areas including combustion, inertial confinement fusion (ICF), stellar supernovae, and geophysical fluid dynamics. Traditional experiments have used inclined tanks of fluid to initiate a flow, generally at low Reynolds numbers, or wind tunnels that combine two parallel gas flows at the end of a thin wedge, known as a splitter plate. The splitter plate experiments have explored flows with maximum shear velocities on the order of 10{sup 3} m/s and Reynolds numbers up to 10{sup 6}. Here we report the creation of a novel type of shear flow, achieved by confining a laser driven blast wave in a millimeter-sized shock tube, which produced shear velocities on the order of 10{sup 4} m/s and Reynolds numbers of 10{sup 6} in a plasma. This system enabled the first apparent observation of transonic shocklets, which are small, localized shocks believed to develop in response to a local supersonic flow occurring over a growing perturbation. These shocklets have been predicted previously in simulations, but have never to our knowledge been observed. These experiments are also the first to observe the growth of perturbations by the Kelvin-Helmholtz (KH) instability under high-energy-density (HED) conditions. In all

  1. OMEGA FY13 HED requests - LANL

    SciTech Connect

    Workman, Jonathan B; Loomis, Eric N

    2012-06-25

    This is a summary of scientific work to be performed on the OMEGA laser system located at the Laboratory for Laser Energetics in Rochester New York. The work is funded through Science and ICF Campagins and falls under the category of laser-driven High-Energy Density Physics experiments. This summary is presented to the Rochester scheduling committee on an annual basis for scheduling and planning purposes.

  2. Demonstration of Fuel Hot-Spot Pressure in Excess of 50 Gbar for Direct-Drive, Layered Deuterium-Tritium Implosions on OMEGA.

    PubMed

    Regan, S P; Goncharov, V N; Igumenshchev, I V; Sangster, T C; Betti, R; Bose, A; Boehly, T R; Bonino, M J; Campbell, E M; Cao, D; Collins, T J B; Craxton, R S; Davis, A K; Delettrez, J A; Edgell, D H; Epstein, R; Forrest, C J; Frenje, J A; Froula, D H; Gatu Johnson, M; Glebov, V Yu; Harding, D R; Hohenberger, M; Hu, S X; Jacobs-Perkins, D; Janezic, R; Karasik, M; Keck, R L; Kelly, J H; Kessler, T J; Knauer, J P; Kosc, T Z; Loucks, S J; Marozas, J A; Marshall, F J; McCrory, R L; McKenty, P W; Meyerhofer, D D; Michel, D T; Myatt, J F; Obenschain, S P; Petrasso, R D; Radha, P B; Rice, B; Rosenberg, M J; Schmitt, A J; Schmitt, M J; Seka, W; Shmayda, W T; Shoup, M J; Shvydky, A; Skupsky, S; Solodov, A A; Stoeckl, C; Theobald, W; Ulreich, J; Wittman, M D; Woo, K M; Yaakobi, B; Zuegel, J D

    2016-07-08

    A record fuel hot-spot pressure P_{hs}=56±7  Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium-tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility, these implosions achieved a Lawson parameter ∼60% of the value required for ignition [A. Bose et al., Phys. Rev. E 93, 011201(R) (2016)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is approximately 40% lower. Three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.

  3. OMEGA experiments to characterize the Rayleigh-Taylor instability with planar foils

    NASA Astrophysics Data System (ADS)

    Knauer, J. P.

    1996-11-01

    Understanding and control of the Rayleigh-Taylor instability are of critical importance to the eventual sucess of direct-drive inertial-confinement-fusion (ICF). During a capsule implosion the ablation surface is unstable during the acceleration phase, and the fuel-pusher interface is unstable during the deceleration phase. We have continued experiments (begun on the Nova laser facility) to determine both the growth rate and sources of initial perturbations on the 60-beam OMEGA laser facility. These experiments were done with laser irradiation at 351 nm and intensities of (1 ) to ( 3 × 10^14) W/cm^2. The laser system uniformity was improved with smoothing by spectral dispersion (SSD) and distributed phase plates (DPP). We characterized the drive beams with x-ray microscopy and optical equivalent-target-plane (ETP) measurements. Experimental results along with theoretical modeling will be presented for growth rates during the "linear growth phase" (amplitude of perturbation less than 0.1 times the wavelength) at the ablation interface, initial perturbations from smooth and non-SSD irradiation with one to six laser beams, and mitigation of initial imprinting using foam layers.(M. Desselberger, M. W. Jones, J. Edwards, M. Dunne, and O. Willi, Phys. Rev. Lett., 74), 2961, (1995)) The temporal shape of the laser illumination for these experiments is both Gaussian with a 1-ns FWHM and non-Gaussian (a 1-ns rise to a 2-ns constant intensity). Data were collected with both time-dependent and time-integrated x-ray and optical diagnostics in both emission and shadow radiography. footnote In collaboration with R. Betti, T, Boehly, D. Bradley, S. G. Glendinning, D. Kalantar, D.D. Meyerhofer, D. Ofer, V. Smalyuk, C. Verdon, R, Watt, and O. Willi This work was supported by the U. S. Department of Energy Office of Inertial Confinement Fusion under cooperative Agreement No. DE-FC03-92SF19460, the University of Rochester, and the New York State Energy Research and Development

  4. Omega-3 fatty acids (image)

    MedlinePlus

    Omega-3 fatty acids are a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids (EFAs) because they are important for good health. ...

  5. Omega-3 Fatty Acids

    MedlinePlus

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat-like ... people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic ...

  6. Computational study of alkali-metal-noble gas collisions in the presence of nonresonant lasers - Na + Xe + h/2/pi/omega sub 1 + h/2/pi/omega sub 2 system

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; Chang, C.; George, T. F.; Laskowski, B.; Stallcop, J. R.

    1980-01-01

    The collision of Na with Xe in the presence of both the rhodamine-110 dye laser and the Nd-glass laser is investigated within a quantum-mechanical close-coupled formalism, utilizing ab initio potential curves and transition dipole matrix elements. Both one- and two-photon processes are investigated; the Na + Xe system is not asymptotically resonant with the radiation fields, so that these processes can only occur in the molecular collision region. The one-photon processes are found to have measurable cross sections at relatively low intensities; even the two-photon process has a significant section for field intensities as low as 10 MW/sq cm.

  7. Computational study of alkali-metal-noble gas collisions in the presence of nonresonant lasers - Na + Xe + h/2/pi/omega sub 1 + h/2/pi/omega sub 2 system

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; Chang, C.; George, T. F.; Laskowski, B.; Stallcop, J. R.

    1980-01-01

    The collision of Na with Xe in the presence of both the rhodamine-110 dye laser and the Nd-glass laser is investigated within a quantum-mechanical close-coupled formalism, utilizing ab initio potential curves and transition dipole matrix elements. Both one- and two-photon processes are investigated; the Na + Xe system is not asymptotically resonant with the radiation fields, so that these processes can only occur in the molecular collision region. The one-photon processes are found to have measurable cross sections at relatively low intensities; even the two-photon process has a significant section for field intensities as low as 10 MW/sq cm.

  8. Spectroscopic Measurements of Target Preheating on OMEGA

    SciTech Connect

    Elton, R.C.; Griem, H.R.; Iglesias, E.J.

    2000-02-28

    The preheating of laser-heated microballoon targets has been measured by time-resolved x-ray and extreme ultraviolet (euv) spectroscopy on the 30 kJ, 351 nm, 60-beam laser-fusion system at the University of Rochester Laboratory for Laser Energetics. Thin coatings of aluminum overcoated with magnesium served as indicators. both the sequence of the x-ray line emission and the intensity of euv radiation were used to determine a preheating peaking at {approx} 10 ns prior to onset of the main laser pulse, with a power density {approx_equal}1% of the main pulse. The measurements are supported by numerical modeling. Further information is provided by absorption spectra from the aluminum coating, backlighted by continuum from the heated surface. The exact source of the preheating energy remains unknown at present, but most likely arrives from early laser leakage through the system. The present target diagnostic is particularly useful when all beams cannot be monitored directly at all laser wavelengths.

  9. [Omega-3 fatty acids].

    PubMed

    Huyghebaert, C

    2007-01-01

    Omega-3 fatty acids have been drawing the interest of researchers for quite a number of years. The study of the impact of fish consumption on health and particularly on a cardiovascular level is the subject of much research. Some encouraging results have led to the study of omega-3 fatty acids in various other diseases. The interest in 'omega-3' has been widely relayed by the media and a huge market has developed with several allegations in its favour. This article is an attempt to shed light on these health claims, based on currently available scientific data.

  10. Gamma bang time analysis at OMEGA.

    PubMed

    McEvoy, A M; Herrmann, H W; Horsfield, C J; Young, C S; Miller, E K; Mack, J M; Kim, Y; Stoeffl, W; Rubery, M; Evans, S; Sedillo, T; Ali, Z A

    2010-10-01

    Absolute bang time measurements with the gas Cherenkov detector (GCD) and gamma reaction history (GRH) diagnostic have been performed to high precision at the OMEGA laser facility at the University of Rochester with bang time values for the two diagnostics agreeing to within 5 ps on average. X-ray timing measurements of laser-target coupling were used to calibrate a facility-generated laser timing fiducial with rms spreads in the measured coupling times of 9 ps for both GCD and GRH. Increased fusion yields at the National Ignition Facility (NIF) will allow for improved measurement precision with the GRH easily exceeding NIF system design requirements.

  11. {omega} production in pp collisions

    SciTech Connect

    Ramachandran, G.; Vidya, M.S.; Deepak, P.N.; Balasubramanyam, J.; Venkataraya

    2005-09-01

    A model-independent irreducible tensor formalism that was developed earlier to analyze measurements of p-vectorp-vector{yields}pp{pi} deg. is extended to present a theoretical discussion of p-vectorp-vector{yields}pp{omega} and of {omega} polarization in pp{yields}pp{omega}-vector and in pp-vector{yields}pp{omega}-vector. The recent measurement of an unpolarized differential cross section for pp{yields}pp{omega} is analyzed by use of this theoretical formalism.

  12. B meson decays to {omega}K*, {omega}{rho}, {omega}{omega}, {omega}{phi}, and {omega}f{sub 0}

    SciTech Connect

    Aubert, B.; Barate, R.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.

    2006-09-01

    We describe searches for B meson decays to the charmless vector-vector final states {omega}K*, {omega}{rho}, {omega}{omega}, and {omega}{phi} with 233x10{sup 6} BB pairs produced in e{sup +}e{sup -} BB annihilation at {radical}(s)=10.58 GeV. We also search for the vector-scalar B decay to {omega}f{sub 0}. We measure the following branching fractions in units of 10{sup -6}: B(B{sup 0}{yields}{omega}K*{sup 0})=2.4{+-}1.1{+-}0.7 (<4.2), B(B{sup +}{yields}{omega}K*{sup +})=0.6{sub -1.2-0.9}{sup +1.4+1.1} (<3.4), B(B{sup 0}{yields}{omega}{rho}{sup 0})=-0.6{+-}0.7{sub -0.3}{sup +0.8} (<1.5), B(B{sup +}{yields}{omega}{rho}{sup +})=10.6{+-}2.1{sub -1.0}{sup +1.6}, B(B{sup 0}{yields}{omega}{omega})=1.8{sub -0.9}{sup +1.3}{+-}0.4 (<4.0), B(B{sup 0}{yields}{omega}{phi})=0.1{+-}0.5{+-}0.1 (<1.2), and B(B{sup 0}{yields}{omega}f{sub 0})=0.9{+-}0.4{sub -0.1}{sup +0.2} (<1.5). In each case the first error quoted is statistical, the second systematic, and the upper limits are defined at the 90% confidence level. For B{sup +}{yields}{omega}{rho}{sup +} decays we also measure the longitudinal spin component f{sub L}=0.82{+-}0.11{+-}0.02 and the charge asymmetry A{sub CP}=0.04{+-}0.18{+-}0.02.

  13. Progress in Cryogenic Target Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    McCrory, R. L.; Meyerhofer, D. D.; Betti, R.; Boehly, T. R.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Glebov, V. Yu; Goncharov, V. N.; Harding, D. R.; Hu, S. X.; Knauer, J. P.; Marshall, F. J.; McKenty, P. W.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Seka, W.; Short, R. W.; Shvarts, D.; Skupsky, S.; Smalyuk, V. A.; Soures, J. M.; Stoeckl, C.; Theobald, W.; Yaakobi, B.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Séguin, F. H.; Casey, D. T.

    2016-10-01

    Cryogenic deuterium-tritium targets are imploded on the OMEGA Laser System in a direct-drive configuration. Areal densities of approximately 200 mg/cm2 have been measured with implosion velocities of 3 × 107 cm/s. These implosions are used to study the dynamics of cryogenic target compression and to develop areal-density diagnostics that will be used as part of the ignition campaign on the National Ignition Facility.

  14. [Omega-3 and health].

    PubMed

    Herbaut, C

    2006-09-01

    N-3 PUFA (omega-3), and the n-6 PUFA (omega-6) are essential fatty acids. They must be absorbed by alimentation and play a very important role in the coagulation (inhibition of platelets aggregation) and in the inflammatory reaction (anti-inflammatory effects). Their effects have been studied in different sicknesses. In cardiovascular diseases, particularly in coronary diseases, studies demonstrated a decreased mortality in populations who eat an omega-3 rich diet or who take an omega-3 supplement. Among others, sudden death after myocardial infarction is decreased. In inflammatory diseases an effect seem to be found in some studies. In rheumatoid arthritis a decrease of different biological markers of inflammation and in some case a clinical improvement has been noticed. It may be the same in COPD. On the other hand, they seem not to give any protection against cancer in general. At this moment the recommendations for healthy people are to eat twice a week fat fish and to take omega-3 rich oils. For pathological cases, recommendations exist only for coronary disease: 1 g of fish oils : mixture of eicosapentaenoic and docosahexaenoic acids (EPA/DHA) should be given after a myocardial infarction.

  15. [Relevance of Omega-3 and Omega-6 / Omega-3 Ratio in Preventing Cognitive Impairment].

    PubMed

    Nunes, Belina; Pinho, Cristina; Sousa, Cláudia; Melo, Alan Rocha; Bandarra, Narcisa; Silva, Maria Carolina

    2017-03-31

    The epidemiological and social relevance of dementia and mild cognitive impairment increases with life expectancy and prevalence of metabolic disorders. The recognition of an important role for dietary nutrients on cognitive functioning opens new preventive strategies. This work analyses the association between erythrocyte omega-3 index and omega-6 / omega-3 ratio and cognitive performance/ mild cognitive impairment. We selected a random sample of individuals registered at a health centre aged ≥ 55 years. Participants were asked about their alimentary habits, erythrocyte indexes were determined and neuropsychological evaluation included the Montreal Cognitive Assessment and a comprehensive test battery. Mean age of 90 participants was 64 years (sd = 5.6), 71.1% had four years of education and 40% of them had more than one vascular risk factor. Limits for omega-3 index and omega-6 / omega-3 ratio were 2.90 - 9.79 (mean = 6.20; sd = 1.50) and 1.14 - 2.95 (mean = 2.12; sd = 0.39), respectively. Montreal Cognitive Assessment scores ranged from 10 to 29 (mean = 22; sd = 4.5), increasing on average 1 - 2 points for above average omega-3 values and an omega-6 / omega-3 ratio ≤ 2 (Group 1) and decreasing 5 - 6 points for omega-3 below mean values and the same omega-6 / omega-3 ratio (Group 2). Prevalence of mild cognitive impairment was 25.6% (95% CI: 16.4 - 34.7), ranging from 12.5% to 83.3% in the two groups above. This preliminary study is one of the first analyzing the repercussion of omega-3 index and omega-6 / omega-3 ratio on cognitive functioning, considering additionally the participant clinical and dietary profiles. The association found suggests that omega-3 and omega-6 / omega-3 ratio could be important biomarkers in the prevention of cognitive impairment.

  16. From Alpha To Omega

    NASA Astrophysics Data System (ADS)

    Castellano, Doc

    2002-05-01

    Galileo, the Father of Modern Science put forth the first significant Modern Scientific Era/Philosophy. Best represented per: x' = x (+/-) vt. Locating/defining the dynamic x' per a fixed, Cartesian Coordinate, reference frame.----- Einstein, the popularized relativist, utilizing Lorentz's transformation Equations: x' = (x-vt)/squareroot [1 - (v squared/c squared)], c the velocity of light. Arbitrarily decreed that c must be the ultimate universal velocity. Thus, Reporters, the general Public, and Scientists consider/considered, Einstein's OPINION of our Universe, the 'Omega Concept'. ----- Castellano, since 1955, has PROVEN his "Castellano Transformation Equations": X' = (X - vt)/squareroot [ 1 - (v squared/c squared)]. Capital C = or greater than c; IS THE OMEGA CONCEPT. And his "MAPHICS" combining the Philosophy of Mathematics with the Philosophy of Physics is "THE OMEGA PHILOSOPHY". Sufficient PROOFS and details at: http://hometown.aol.com/phdco/myhomepage/index.html Thank you for your interest. My sincere appreciation for your attention and deserved acknowledgments.

  17. From Alpha To Omega

    NASA Astrophysics Data System (ADS)

    Castellano, Doc

    2002-08-01

    Galileo, the Father of Modern Science, put forth the first significant Modern Scientific Era/Philosophy. Best represented per: x' = x (+/-) vt. Locating/defining the dynamic x' in an Euclidean, fixed frame Universe. Einstein, the popularized relativist, utilizing Lorentz's transformation equations: x' = (x - vt)/square root [ 1- (v squared/c squared)], c the velocity of light. Arbitrarily decreed that c must be the ultimate, universal velocity. Thus, Reporters, the general Public and Scientists consider/considered, Einstein's OPINION of our Universe, 'The Omega Concept'. Castellano, since 1954, has PROVEN the "C Transformation Equations": X' = (X - vt)/square root [ 1 - (v squared/C squared)], Capital C = or greater than c; IS THE OMEGA CONCEPT. And "MAPHICS", combining the Philosophy of Mathematics with the Philosophy of Physics is "THE OMEGA PHILOSOPHY". Sufficient PROOFS & details are at: http://hometown.aol.com/phdco/myhomepage/index/html ----- Thank you for your interest. My sincere appreciation for deserved acknowledgements.

  18. High accuracy OMEGA timekeeping

    NASA Technical Reports Server (NTRS)

    Imbier, E. A.

    1982-01-01

    The Smithsonian Astrophysical Observatory (SAO) operates a worldwide satellite tracking network which uses a combination of OMEGA as a frequency reference, dual timing channels, and portable clock comparisons to maintain accurate epoch time. Propagational charts from the U.S. Coast Guard OMEGA monitor program minimize diurnal and seasonal effects. Daily phase value publications of the U.S. Naval Observatory provide corrections to the field collected timing data to produce an averaged time line comprised of straight line segments called a time history file (station clock minus UTC). Depending upon clock location, reduced time data accuracies of between two and eight microseconds are typical.

  19. Improvements for Omega RF preamplifiers

    NASA Technical Reports Server (NTRS)

    Wright, L.

    1976-01-01

    An improved Omega navigation system preamplifier, which provides both ADF and Omega outputs from a single antenna input, is described. This preamp has tuneable bandpass filtering, zero phase shift at both output ports, adjustable gain at the Omega output, and it receives power via the coaxial cable to the receiver front-end.

  20. The Omega Competition.

    ERIC Educational Resources Information Center

    Lanni, Robert P.

    1978-01-01

    Describes a game in which the symbol omega becomes equivalent to the word ohm, and is then modified or incorporated into a picture to represent a common word or phrase. Recommends the game as a way of humanizing the beginning course. (GA)

  1. Simplified OMEGA receivers

    NASA Technical Reports Server (NTRS)

    Burhans, R. W.

    1974-01-01

    The details are presented of methods for providing OMEGA navigational information including the receiver problem at the antenna and informational display and housekeeping systems based on some 4 bit data processing concepts. Topics discussed include the problem of limiters, zero crossing detectors, signal envelopes, internal timing circuits, phase counters, lane position displays, signal integrators, and software mapping problems.

  2. The Omega Competition.

    ERIC Educational Resources Information Center

    Lanni, Robert P.

    1978-01-01

    Describes a game in which the symbol omega becomes equivalent to the word ohm, and is then modified or incorporated into a picture to represent a common word or phrase. Recommends the game as a way of humanizing the beginning course. (GA)

  3. 3(omega) Damage: Growth Mitigation

    SciTech Connect

    Kozlowski, M; Demos, S; Wu, Z-L; Wong, J; Penetrante, B; Hrubesh, L

    2001-02-22

    The design of high power UV laser systems is limited to a large extent by the laser-initiated damage performance of transmissive fused silica optical components. The 3{omega} (i.e., the third harmonic of the primary laser frequency) damage growth mitigation LDRD effort focused on understanding and reducing the rapid growth of laser-initiated surface damage on fused silica optics. Laser-initiated damage can be discussed in terms of two key issues: damage initiated at some type of precursor and rapid damage growth of the damage due to subsequent laser pulses. The objective of the LDRD effort has been the elucidation of laser-induced damage processes in order to quantify and potentially reduce the risk of damage to fused silica surfaces. The emphasis of the first two years of this effort was the characterization and reduction of damage initiation. In spite of significant reductions in the density of damage sites on polished surfaces, statistically some amount of damage initiation should always be expected. The early effort therefore emphasized the development of testing techniques that quantified the statistical nature of damage initiation on optical surfaces. This work led to the development of an optics lifetime modeling strategy that has been adopted by the NIF project to address damage-risk issues. During FY99 interest shifted to the damage growth issue which was the focus of the final year of this project. The impact of the remaining damage sites on laser performance can be minimized if the damage sites did not continue to grow following subsequent illumination. The objectives of the final year of the LDRD effort were to apply a suite of state-of-the-art characterization tools to elucidate the nature of the initiated damage sites, and to identify a method that effectively mitigates further damage growth. Our specific goal is to understand the cause for the rapid growth of damage sites so that we can develop and apply an effective means to mitigate it. The

  4. Occurrence of auroral omega bands

    NASA Astrophysics Data System (ADS)

    Weygand, J. M.; Partamies, N.; Juusola, L.

    2016-12-01

    Omega band aurora has been described as a wave form of the boundary of diffuse aurora which resembles a Greek omega letter. These forms are generally related to auroral activity in the morning sector and during substorm recovery phases. A number of detailed multi-instrument case studies have been reported on omega bands but very few thorough statistical studies are available, suggesting that omega forms are not very common in auroral displays.MIRACLE all-sky camera data from five Lapland stations over 1996-2007 have been searched for omega structures. The diffuse aurora boundary undulations can be identified in the ASC keograms but only a fraction of them qualifies as omegas. We required a clear structure which was traceable for longer than a minute. We also required a structure being taller than wider and we required an eastward propagation for it. We found 458 omega-like structures in total, most of them at the southern part of the auroral oval, in the field-of-view of Sodankylä camera. All omegas occurred after a substorm onset and most of them during a recovery phase. Peak years in the omega occurrence were 2002-2004 in the declining phase of the solar cycle. The substorms with omega bands were found to be more intense than average substorms within the Lapland region. Wave-like undulation was observed not only in the optical data but also in the equivalent current distribution. Omega forms occurred in between the Region 1 and 2 currents, and within a westward electrojet current which appeared stronger than that of average substorms in the same region.We show evidence of auroral omega bands being conjugate features and related to fast Earthward flows in the magnetotail. We discuss a possible scenario of omega formation and the relative occurrence of the omega bands.

  5. Semiclassical study of reactive scattering in a laser field - F + H2 + barred-h times omega times /1.06 microns/ system

    NASA Technical Reports Server (NTRS)

    Yuan, J.-M.; George, T. F.

    1979-01-01

    Semiclassical calculations of collinear F+H2(nu = 0) reactive and inelastic scattering in an Nd-glass laser field of various intensities are described. The decoupling approximation developed for the Miller-George theory is used for nonadiabatic transitions between the electronic-field surfaces, and special attention is paid to the choice of a proper coordinate system for applying the decoupling approximation. An increase in the total reaction probability and population ratio of the nu = 3 over nu = 2 vibrational state of HF occurs suddenly as the field intensity increases beyond 10 TW/sq cm. It is found that in a laser field the H2 molecule can be vibrationally excited while the F atom is electronically excited.

  6. Lightweight HPC beam OMEGA

    NASA Astrophysics Data System (ADS)

    Sýkora, Michal; Jedlinský, Petr; Komanec, Jan

    2017-09-01

    In the design and construction of precast bridge structures, a general goal is to achieve the maximum possible span length. Often, the weight of individual beams makes them difficult to handle, which may be a limiting factor in achieving the desired span. The design of the OMEGA beam aims to solve a part of these problems. It is a thin-walled shell made of prestressed high-performance concrete (HPC) in the shape of inverted Ω character. The concrete shell with prestressed strands is fitted with a non-stressed tendon already in the casting yard and is more easily transported and installed on the site. The shells are subsequently completed with mild steel reinforcement and cores are cast in situ together with the deck. The OMEGA beams can also be used as an alternative to steel - concrete composite bridges. Due to the higher production complexity, OMEGA beam can hardly substitute conventional prestressed beams like T or PETRA completely, but it can be a useful alternative for specific construction needs.

  7. Validation of a Laser-Ray Package in an Eulerian Code

    NASA Astrophysics Data System (ADS)

    Bradley, Paul; Hall, Mike; McKenty, Patrick; Collins, Tim; Keller, David

    2014-10-01

    A laser-ray absorption package was recently installed in the RAGE code by the Laboratory for Laser Energetics (LLE). In this presentation, we describe our use of this package to implode Omega 60 beam symmetric direct drive capsules. The capsules have outer diameters of about 860 microns, CH plastic shell thicknesses between 8 and 32 microns, DD or DT gas fills between 5 and 20 atmospheres, and a 1 ns square pulse of 23 to 27 kJ. These capsule implosions were previously modeled with a calibrated energy source in the outer layer of the capsule, where we matched bang time and burn ion temperature well, but the simulated yields were two to three times higher than the data. We will run simulations with laser ray energy deposition to the experiments and the results to the yield and spectroscopic data. Work performed by Los Alamos National Laboratory under Contract DE-AC52-06NA25396 for the National Nuclear Security Administration of the U.S. Department of Energy.

  8. Quantifying the Growth of Cross-Beam Energy Transfer in Polar-Direct-Drive Implosions at the Omega Laser and National Ignition Facilities

    NASA Astrophysics Data System (ADS)

    Davis, A. K.

    2015-11-01

    Direct-drive inertial confinement fusion requires multiple overlapping laser beams that can drive the cross-beam energy transfer (CBET) instability. This instability is of primary concern because it can reduce the laser energy coupling and can affect the symmetry in a polar-direct-drive (PDD) configuration. An experiment was designed to determine the CBET growth by measuring the angularly resolved mass ablation rate and ablation-front trajectory in a PDD configuration. Adding a thin layer of Si over a CH shell generates two peaks in x-ray self-emission images that are measured with a time-resolved pinhole imager. The inner peak is related to the position of the ablation front and the outer peak corresponds to the position of the interface of the two layers in the plasma. The emergence of the second peak is used to measure the time for the laser to burn through the outer layer, giving the average mass ablation rate of the material. The mass ablation rate was measured by varying the thickness of the outer silicon layer. The shell trajectory and mass ablation rate measured in PDD on the pole, where CBET has little effect, were compared with simulations to validate the electron thermal-transport model. Excellent agreement was obtained when using a 2-D nonlocal transport model, and these observables could not be reproduced with flux-limited models. A similar comparison was performed on the equator where the CBET growth is large. Without the CBET model, the shell velocity and mass ablation rate were significantly overestimated by the simulation. Adding the CBET model reduced the drive on the equator and reproduced the experimental results. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944. In collaboration with, D. Cao, D. T. Michel, M. Hohenberger, R. Epstein, V. N. Goncharov, S. X. Hu, I. V. Igumenshchev, J. A. Marozas, D. D. Meyerhofer, P. B. Radha, S. P. Regan, T. C

  9. Lasers.

    ERIC Educational Resources Information Center

    Schewe, Phillip F.

    1981-01-01

    Examines the nature of laser light. Topics include: (1) production and characteristics of laser light; (2) nine types of lasers; (3) five laser techniques including holography; (4) laser spectroscopy; and (5) laser fusion and other applications. (SK)

  10. Lasers.

    ERIC Educational Resources Information Center

    Schewe, Phillip F.

    1981-01-01

    Examines the nature of laser light. Topics include: (1) production and characteristics of laser light; (2) nine types of lasers; (3) five laser techniques including holography; (4) laser spectroscopy; and (5) laser fusion and other applications. (SK)

  11. Damper Spring For Omega Seal

    NASA Technical Reports Server (NTRS)

    Maclaughlin, Scott T.; Montgomery, Stuart K.

    1993-01-01

    Damper spring reduces deflections of omega-cross-section seal, reducing probability of failure and extending life of seal. Spring is split ring with U-shaped cross section. Placed inside omega seal and inserted with seal into seal cavity. As omega seal compressed into cavity, spring and seal make contact near convolution of seal, and spring becomes compressed also. During operation, when seal dynamically loaded, spring limits deflection of seal, reducing stress on seal.

  12. Prospects for high-gain, high yield National Ignition Facility targets driven by 2(omega) (green) light

    SciTech Connect

    Suter, L J; Glenzer, S; Haan, S; Hammel, B; Manes, K; Meezan, N; Moody, J; Spaeth, M; Divol, L; Oades, K; Stevenson, M

    2003-12-16

    The National Ignition Facility (NIF), operating at green (2{omega}) light, has the potential to drive ignition targets with significantly more energy than the 1.8 MJ it will produce with its baseline, blue (3{omega}) operations. This results in a greatly increased 'target design space', providing a number of exciting opportunities for fusion research. These include the prospect of ignition experiments with capsules absorbing energies in the vicinity of 1 MJ. This significant increase in capsule absorbed energy over the original designs at {approx}150 kJ could allow high-gain, high yield experiments on NIF. This paper reports the progress made exploring 2{omega} for NIF ignition, including potential 2{omega} laser performance, 2{omega} ignition target designs and 2{omega} Laser Plasma Interaction (LPI) studies.

  13. Morphologies of omega band auroras

    NASA Astrophysics Data System (ADS)

    Sato, Natsuo; Yukimatu, Akira Sessai; Tanaka, Yoshimasa; Hori, Tomoaki

    2017-08-01

    We examined the morphological signatures of 315 omega band aurora events observed using the Time History of Events and Macroscale Interactions during Substorm ground-based all-sky imager network over a period of 8 years. We find that omega bands can be classified into the following three subtypes: (1) classical (O-type) omega bands, (2) torch or tongue (T-type) omega bands, and (3) combinations of classical and torch or tongue (O/T-type) omega bands. The statistical results show that T-type bands occur the most frequently (45%), followed by O/T-type bands (35%) and O-type bands (18%). We also examined the morphologies of the omega bands during their formation, from the growth period to the declining period through the maximum period. Interestingly, the omega bands are not stable, but rather exhibit dynamic changes in shape, intensity, and motion. They grow from small-scale bumps (seeds) at the poleward boundary of preexisting east-west-aligned auroras, rather than via the rotation or shear motion of preexisting east-west-aligned auroras, and do not exhibit any shear motion during the periods of auroral activity growth. Furthermore, the auroral luminosity is observed to increase during the declining period, and the total time from the start of the growth period to the end of the declining period is found to be about 20 min. Such dynamical signatures may be important in determining the mechanism responsible for omega band formation.

  14. Initial Neutron Burn Truncation Experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    McKenty, P. W.; Keck, R. L.; Kremens, R. L.; Kearney, K. J.; Verdon, C. P.; Zuegel, J. D.; Cable, M. D.; Ognibene, T. J.; Lerche, R. A.; Griffith, R. L.

    1997-11-01

    The recent deployment of the neutron temporal diagnostic (NTD) on OMEGA has enabled us to perform a series of experiments that will serve as a base line in understanding the effects of various levels of irradiation nonuniformities on neutron burn rates. These experiments were performed using doped and undoped plastic microballoons imploded with 30 kJ of 351-nm (UV) light. Precise control of laser focusing on OMEGA allowed for on-target laser perturbations to be varied from 0.1 to 1.0 μ*m rms. The targets were designed for moderate convergence ( ~*10) and spanned a range of growth factor from ~*50 to 500 ( ~*4 to 6 total e-foldings). Results will be presented depicting the experimental Y*ield O*ver C*lean (YOC) one-dimensionally predicted yield as a function of the calculated distortion fraction and an appraisal of the experimental fuel areal density. Both of these will be evaluated using information gained from the examination of the NTD neutron burn curves. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

  15. Long Duration Backlighter Experiments at Omega

    SciTech Connect

    Reighard, A; Glendinning, S; Young, P; Hsing, W; Foord, M; Schneider, M; Lu, K; Dittrich, T; Wallace, R; Sorce, C

    2008-05-01

    We have successfully demonstrated a 7.5 ns-duration pinhole-apertured backlighter at the Omega laser facility. Pinhole-apertured point-projection backlighting for 8 ns will be useful for imaging evolving features in experiments at the National Ignition Facility. The backlighter consisted of a 20 {micro}m diameter pinhole in a 75 {micro}m thick Ta substrate separated from a Zn emitter (9 keV) by a 400 {micro}m thick high-density carbon piece. The carbon prevented the shock from the laser-driven surface from reaching the substrate before 8 ns and helped minimize x-ray ablation of the pinhole substrate. Grid wires in x-ray framing camera images of a gold grid have a source-limited resolution significantly smaller than the pinhole diameter due to the high aspect ratio of the pinhole, but do not become much smaller at late times.

  16. Neutron Measurements in Small MagLIF Experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Barnak, D. H.; Davies, J. R.; Knauer, J. P.; Betti, R.; Regan, S. P.; Sangster, T. C.; Campbell, E. M.

    2016-10-01

    The Laboratory for Laser Energetics (LLE) is participating in laser-driven magnetized linear inertial fusion (MagLIF) research on the OMEGA Laser System in partnership with Sandia as part of ARPA-E's ALPHA Program. In the current OMEGA setup, a CH cylindrical tube filled with D2 gas is compressed by 40 laser beams, preheated by one of the beams, and an axial magnetic field is applied to limit electron heat loss. Two copper coils provide 10-T magnetic fields. A neutron time-of-flight (nTOF) detector has been designed, fabricated, and calibrated to diagnose primary D-D fusion neutron yield in the range of 1 ×107 to 5 ×109 and ion temperature from 2 to 8 keV. The design details and calibration results of these nTOF detectors will be presented together with neutron measurement results from recent laser-driven MagLIF experiments on OMEGA. The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000568, and the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  17. OMEGA - an operational glacier monitoring system

    NASA Astrophysics Data System (ADS)

    Pellikka, P. K. E.

    2003-04-01

    Glacier changes reflect local climate changes and are one of the most important direct indicators of global climate change. In general, the glaciers are retreating in Europe, but some glaciers are advancing. However, even in small areas glacier responses can be different. The application of glaciers as indicators requires sufficient amount of glaciers, which is possible only with remote sensing methods. Remote sensing data have been used for glacier monitoring from the late 19th century, first as terrestrial photographs, but later as aerial photographs. A new era began in the 1970’s as optical satellite data became available. Since late 1990’s the glacier monitoring could be performed with numerous satellite and airborne sensors ranging from satellite radar data to airborne laser scanner data. All together, the development of new remote sensing technologies and methods provides many possibilities for studies of glacier features and parameters. The glacier parameters of interest in operational monitoring are the changes of glacier area and volume, and the variation of glacier zones, such as snow, firn and ice. These parameters enable the estimation of relative volume change, AAR and equilibrium line, for example. Operational monitoring involves that the remote sensing data to be used is available continuously, the image processing methods are accurate and the processing chain is developed so that the derivation of the aimed parameters works fluently. The OMEGA project aims at the development of an operational glacier monitoring system applying all the potential remote sensing data. The objectives are to develop workflows and semi-automatic image processing methodologies for different data types in order to retrieve glacier parameters, to construct databases of the study glaciers and to develop the prototype of an operational monitoring system. The test glaciers are Hintereisferner in Austria and Engabreen in Norway. The deliverable of the project is the OMEGA

  18. Low cost omega navigation receiver

    NASA Technical Reports Server (NTRS)

    Lilley, R. W.

    1974-01-01

    The development of a low cost Omega navigation receiver is discussed. Emphasis is placed on the completion and testing of a modular, multipurpose Omega receiver which utilizes a digital memory-aided, phase-locked loop to provide phase measurement data to a variety of applications interfaces. The functional units contained in the prototype device are described. The receiver is capable of receiving and storing phase measurements for up to eight Omega signals and computes two switch-selectable lines of position, displaying this navigation data in chart-recorded form.

  19. Omega navigation for general aviation

    NASA Technical Reports Server (NTRS)

    Hollister, W. M.

    1976-01-01

    A 70-hour flight test evaluation of an Omega navigation system was performed using a Piper Cherokee 180, to determine the feasibility of Omega for worldwide general aviation navigation. Measurements were made of position accuracy, noise phenomena, and signal to noise ratio. It was found that Omega accuracy is essentially insensitive to local geography, but that there are isolated local interference phenomena associated with radio transmitters, although the strongest noise source observed was due to the onboard power source for the VHF comm/nav radio. An occurrence of lane jumps was observed when attempting to navigate with one weak station.

  20. Omega-3 Fatty Acids during Pregnancy

    MedlinePlus

    OMEGA-3 FATTY ACIDS DURING PREGNANCY S HARE W ITH W OMEN OMEGA-3 FATTY ACIDS DURING PREGNANCY During pregnancy, your baby gets most ... eat and vitamins you take. Omega-3 fatty acids (omega-3s) are an important family of building ...

  1. Analysis of the vertices {Omega}{sub Q}*{Omega}{sub Q{phi}} and radiative decays {Omega}{sub Q}*{yields}{Omega}{sub Q{gamma}}

    SciTech Connect

    Wang Zhigang

    2010-02-01

    In this article, we study the vertices {Omega}{sub Q}*{Omega}{sub Q{phi}} with the light-cone QCD sum rules, then assume the vector meson dominance of the intermediate {phi}(1020), and calculate the radiative decays {Omega}{sub Q}*{yields}{Omega}{sub Q{gamma}}.

  2. Short Zoom Into Omega Centauri

    NASA Image and Video Library

    This is a zoom into a simulated model of the globular star cluster Omega Centauri. All the stars appear to be moving in random directions, like a swarm of bees. Astronomers used Hubble's exquisite ...

  3. Characterization of omega-3 tablets.

    PubMed

    Vestland, Tina Lien; Jacobsen, Øyvind; Sande, Sverre Arne; Myrset, Astrid Hilde; Klaveness, Jo

    2016-04-15

    Omega-3 nutraceuticals are extensively used as health supplements worldwide. Various administration forms for delivery of omega-3 are available. However, the niche omega-3 tablets have so far remained unexplored. In this work tablets containing 25-40% (w/w) omega-3 oil as triglycerides or ethyl esters were prepared utilizing a direct compaction grade powder with β-cyclodextrin as encapsulating agent. It was found that powders with up to 35% (w/w) triglyceride oil and 30% (w/w) ethyl ester oil, respectively, can be directly compressed into tablets of excellent quality. Physical properties of omega-3 containing powders and tablets are described. The powder X-ray diffractograms of the powders and crushed tablets show evidence of the formation of new crystalline phases not present in β-cyclodextrin. In addition, (1)H NMR data suggest that the ethyl esters form inclusion complexes with β-cyclodextrin. Compaction of other, commercially available, omega-3 powders was performed as a comparison and deemed unsuccessful.

  4. Source geometric considerations for OMEGA Dante measurements.

    PubMed

    May, M J; Patterson, J R; Sorce, C; Widmann, K; Fournier, K B; Perez, F

    2012-10-01

    The Dante is a 15 channel filtered diode array which is installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The system yields the spectrally and temporally resolved radiation flux from 50 eV to 10 keV from various targets (i.e., Hohlraum, gas pipes, etc.). The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and an unfold algorithm applied to the recorded voltages from each channel. The unfold algorithm assumes an emitting source that is spatially uniform and has a constant area as a function of photon energy. The emitting x-ray source is usually considered to be the laser entrance hole (LEH) of a given diameter for Hohlraum type targets or the effective wall area of high conversion efficiency K-shell type targets. This assumption can be problematic for several reasons. High intensity regions or "hot spots" in the x-ray are observed where the drive laser beams strike the target. The "hot spots" create non-uniform emission seen by the Dante. Additionally, thinned walled (50 μm) low-Z targets (C(22)H(10)N(2)O(5)) have an energy dependent source size since the target's walls will be fully opaque for low energies (E < 2-3 keV) yet fully transmissive at higher energies. Determining accurate yields can be challenging for these types of targets. Discussion and some analysis will be presented.

  5. Source geometric considerations for OMEGA Dante measurementsa)

    NASA Astrophysics Data System (ADS)

    May, M. J.; Patterson, J. R.; Sorce, C.; Widmann, K.; Fournier, K. B.; Perez, F.

    2012-10-01

    The Dante is a 15 channel filtered diode array which is installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The system yields the spectrally and temporally resolved radiation flux from 50 eV to 10 keV from various targets (i.e., Hohlraum, gas pipes, etc.). The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and an unfold algorithm applied to the recorded voltages from each channel. The unfold algorithm assumes an emitting source that is spatially uniform and has a constant area as a function of photon energy. The emitting x-ray source is usually considered to be the laser entrance hole (LEH) of a given diameter for Hohlraum type targets or the effective wall area of high conversion efficiency K-shell type targets. This assumption can be problematic for several reasons. High intensity regions or "hot spots" in the x-ray are observed where the drive laser beams strike the target. The "hot spots" create non-uniform emission seen by the Dante. Additionally, thinned walled (50 μm) low-Z targets (C22H10N2O5) have an energy dependent source size since the target's walls will be fully opaque for low energies (E < 2-3 keV) yet fully transmissive at higher energies. Determining accurate yields can be challenging for these types of targets. Discussion and some analysis will be presented.

  6. Omega, the final multiplier

    NASA Astrophysics Data System (ADS)

    Buckley, T. N.

    2008-12-01

    The application of optimisation theory to vegetation processes has rarely extended beyond the context of diurnal to intra-annual gas exchange of individual leaves and crowns. One reason is that the Lagrange multipliers in the leaf-scale solutions, which are marginal products for allocatable photosynthetic resource inputs (water and nitrogen), are mysterious in origin, and their numerical values are difficult to measure -- let alone to predict or interpret in concrete physiological or ecological terms. These difficulties disappear, however, when the optimisation paradigm itself is extended to encompass carbon allocation and growth at the lifespan scale. The trajectories of leaf (and canopy) level marginal products are then implicit in the trajectory of plant and stand structure predicted by optimal carbon allocation. Furthermore, because the input and product are the same resource -- carbon -- in the whole plant optimisation, the product in one time step defines the input constraint, and hence implicitly the marginal product for carbon, in the next time step. This effectively converts the problem from a constrained optimisation of a definite integral, in which the multipliers are undetermined, to an unconstrained maximisation of a state, in which the multipliers are all implicit. This talk will explore how the marginal products for photosynthetic inputs as well as the marginal product for carbon -- i.e., the 'final multiplier,' omega -- are predicted to vary over time and in relation to environmental change during tree growth.

  7. Spatial profile reconstruction of individual componentsof the nonlinear susceptibility tensors {chi}-circumflex {sup (3)}(z, {omega}', {omega}' -{omega}, {omega}) and {chi}-circumflex {sup (3)}(z, 2{omega}{+-}{omega}', {+-}{omega}', {omega}, {omega}) of a one-dimensionally inhomogeneous medium

    SciTech Connect

    Golubkov, A A; Makarov, Vladimir A

    2011-06-30

    We have proved for the first time and proposed an algorithm of unique spatial profile reconstruction of the components {chi}-circumflex {sup (3)}{sub yyyy} of complex tensors {chi}-circumflex {sup (3)}(z, {omega}', {omega}', -{omega}, {omega}) and {chi}-circumflex {sup (3)}(z, 2{omega}{+-}{omega}', {+-}{omega}', {omega}, {omega}), describing four-photon interaction of light waves in a one-dimensionally inhomogeneous plate, whose medium has a symmetry plane m{sub y} that is perpendicular to its surface. For the media with an additional symmetry axis 2{sub z}, 4{sub z}, 6{sub z} or {infinity}{sub z} that is perpendicular to the plate surface, the proposed method can be used to reconstruct about one-fifth of all independent components of the above tensors. (nonlinear optical phenomena)

  8. Implosion spectroscopy in Rugby hohlraums on OMEGA

    NASA Astrophysics Data System (ADS)

    Philippe, Franck; Tassin, Veronique; Bitaud, Laurent; Seytor, Patricia; Reverdin, Charles

    2014-10-01

    The rugby hohlraum concept has been validated in previous experiments on the OMEGA laser facility. This new hohlraum type can now be used as a well-characterized experimental platform to study indirect drive implosion, at higher radiation temperatures than would be feasible at this scale with classical cylindrical hohlraums. Recent experiments have focused on the late stages of implosion and hotspot behavior. The capsules included both a thin buried Titanium tracer layer, 0-3 microns from the inner surface, Argon dopant in the deuterium gas fuel and Germanium doped CH shells, providing a variety of spectral signatures of the plasma conditions in different parts of the target. X-ray spectroscopy and imaging were used to study compression, Rayleigh-Taylor instabilities growth at the inner surface and mix between the shell and gas.

  9. omega-Helices in proteins.

    PubMed

    Enkhbayar, Purevjav; Boldgiv, Bazartseren; Matsushima, Norio

    2010-05-01

    A modification of the alpha-helix, termed the omega-helix, has four residues in one turn of a helix. We searched the omega-helix in proteins by the HELFIT program which determines the helical parameters-pitch, residues per turn, radius, and handedness-and p = rmsd/(N - 1)(1/2) estimating helical regularity, where "rmsd" is the root mean square deviation from the best fit helix and "N" is helix length. A total of 1,496 regular alpha-helices 6-9 residues long with p < or = 0.10 A were identified from 866 protein chains. The statistical analysis provides a strong evidence that the frequency distribution of helices versus n indicates the bimodality of typical alpha-helix and omega-helix. Sixty-two right handed omega-helices identified (7.2% of proteins) show non-planarity of the peptide groups. There is amino acid preference of Asp and Cys. These observations and analyses insist that the omega-helices occur really in proteins.

  10. Propagation of an ultrashort, intense laser pulse in a relativistic plasma

    SciTech Connect

    Ritchie, B.; Decker, C.D.

    1997-12-31

    A Maxwell-relativistic fluid model is developed for the propagation of an ultrashort, intense laser pulse through an underdense plasma. The separability of plasma and optical frequencies ({omega}{sub p} and {omega} respectively) for small {omega}{sub p}/{omega} is not assumed; thus the validity of multiple-scales theory (MST) can be tested. The theory is valid when {omega}{sub p}/{omega} is of order unity or for cases in which {omega}{sub p}/{omega} {much_lt} 1 but strongly relativistic motion causes higher-order plasma harmonics to be generated which overlap the region of the first-order laser harmonic, such that MST would not expected to be valid although its principal validity criterion {omega}{sub p}/{omega} {much_lt} 1 holds.

  11. The NIF x-ray spectrometer calibration campaign at Omega.

    PubMed

    Pérez, F; Kemp, G E; Regan, S P; Barrios, M A; Pino, J; Scott, H; Ayers, S; Chen, H; Emig, J; Colvin, J D; Bedzyk, M; Shoup, M J; Agliata, A; Yaakobi, B; Marshall, F J; Hamilton, R A; Jaquez, J; Farrell, M; Nikroo, A; Fournier, K B

    2014-11-01

    The calibration campaign of the National Ignition Facility X-ray Spectrometer (NXS) was carried out at the Omega laser facility. Spherically symmetric, laser-driven, millimeter-scale x-ray sources of K-shell and L-shell emission from various mid-Z elements were designed for the 2-18 keV energy range of the NXS. The absolute spectral brightness was measured by two calibrated spectrometers. We compare the measured performance of the target design to radiation hydrodynamics simulations.

  12. Omega 3 oils and pregnancy.

    PubMed

    Gallagher, Shawn

    2004-01-01

    Women can safely commence omega 3 intake in early pregnancy to allow the full benefits to be incorporated into the body. Pregnant women should consider the intake of omega 3 oils and evening primrose oil throughout pregnancy in order possibly to prevent preterm delivery, promote an easier birth, assist the baby's brain and eye health and preprogram the baby's cell membranes for optimum lifelong wellness. Benefits to the mother may include prevention of postnatal depression and the comfort of knowing that she is giving her baby a healthy start in life.

  13. Nonlinear features of quantum fluctuations in a slow-inversion laser

    SciTech Connect

    Lariontsev, E. G.

    2011-06-15

    We study the field correlation functions and the natural laser spectrum for a slow-inversion laser with the thresholdless intensity fluctuations. In such a laser, the spontaneous-emission-driven relaxation oscillations are responsible for some unique features: The field correlation function oscillates with the frequency of relaxation oscillations {omega}{sub r} and the laser line changes its profile. We show that appreciably above threshold the laser spectrum consists of three lines. In addition to the main line at the frequency of the lasing mode {omega}{sub c} appear two lines at frequencies {omega}{sub c}+{omega}{sub r} and {omega}{sub c}-{omega}{sub r}. The spontaneous emission noise in such lasers gives rise to nonlinear stochastic effects: Quantum noise affects the oscillation frequency {omega}{sub r} and the decay rates of the field correlation function.

  14. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity.

    PubMed

    Simopoulos, Artemis P

    2016-03-02

    In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity.

  15. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity

    PubMed Central

    Simopoulos, Artemis P.

    2016-01-01

    In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity. PMID:26950145

  16. Digital time slot display for Omega receiver

    NASA Technical Reports Server (NTRS)

    Smith, R. E.

    1976-01-01

    Methods of decoding a digital word to display alpha-numeric characters for driving a standard seven-segment LED display have been devised for Omega station identification. The circuit could replace the system now being used in Ohio University's Omega receivers, which lights one of eight LED's to signify the Omega time slot being received. The letters A through H, representing the Omega stations, can be read directly from the seven-segment display.

  17. Shock-Wave Acceleration of Protons on OMEGA EP

    NASA Astrophysics Data System (ADS)

    Haberberger, D.; Froula, D. H.; Pak, A.; Link, A.; Patel, P.; Fiuza, F.; Tochitsky, S.; Joshi, C.

    2016-10-01

    The creation of an electrostatic shock wave and ensuing ion acceleration is studied on the OMEGA EP Laser System at the Laboratory for Laser Energetics. Previous work using a 10- μm CO2 laser in a H2 gas jet shows promising results for obtaining narrow spectral features in the accelerated proton spectra. Scaling the shock-wave acceleration mechanism to the 1- μm-wavelength drive laser makes it possible to use petawatt-scale laser systems such as OMEGA-EP, but involves tailoring of the plasma profile. To accomplish the necessitated sharp rise to near-critical plasma density and a long exponential fall, an 1- μm-thick CH foil is illuminated on the back side by thermal x rays produced from an irradiated gold foil. The plasma density is measured using the fourth-harmonic probe system, the accelerating fields are probed using an orthogonal proton source, and the accelerated protons and ions are detected with a Thomson parabola. These results will be presented and compared with particle-in-cell simulations. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and LLNL's Laboratory Directed Research and Development program under project 15-LW-095.

  18. Multivariate Analog of Hays Omega-Squared.

    ERIC Educational Resources Information Center

    Sachdeva, Darshan

    The multivariate analog of Hays omega-squared for estimating the strength of the relationship in the multivariate analysis of variance has been proposed in this paper. The multivariate omega-squared is obtained through the use of Wilks' lambda test criterion. Application of multivariate omega-squared to a numerical example has been provided so as…

  19. Source geometric considerations for OMEGA Dante measurements

    SciTech Connect

    May, M. J.; Patterson, J. R.; Sorce, C.; Widmann, K.; Fournier, K. B.; Perez, F.

    2012-10-01

    The Dante is a 15 channel filtered diode array which is installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The system yields the spectrally and temporally resolved radiation flux from 50 eV to 10 keV from various targets (i.e., Hohlraum, gas pipes, etc.). The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and an unfold algorithm applied to the recorded voltages from each channel. The unfold algorithm assumes an emitting source that is spatially uniform and has a constant area as a function of photon energy. The emitting x-ray source is usually considered to be the laser entrance hole (LEH) of a given diameter for Hohlraum type targets or the effective wall area of high conversion efficiency K-shell type targets. This assumption can be problematic for several reasons. High intensity regions or “hot spots” in the x-ray are observed where the drive laser beams strike the target. The “hot spots” create non-uniform emission seen by the Dante. Additionally, thinned walled (50 μm) low-Z targets (C22H10N2O5) have an energy dependent source size since the target's walls will be fully opaque for low energies (E < 2–3 keV) yet fully transmissive at higher energies. Determining accurate yields can be challenging for these types of targets. Discussion and some analysis will be presented.

  20. Source geometric considerations for OMEGA Dante measurements

    SciTech Connect

    May, M. J.; Patterson, J. R.; Widmann, K.; Fournier, K. B.; Perez, F.; Sorce, C.

    2012-10-15

    The Dante is a 15 channel filtered diode array which is installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The system yields the spectrally and temporally resolved radiation flux from 50 eV to 10 keV from various targets (i.e., Hohlraum, gas pipes, etc.). The absolute flux is determined from the radiometric calibration of the x-ray diodes, filters, and mirrors and an unfold algorithm applied to the recorded voltages from each channel. The unfold algorithm assumes an emitting source that is spatially uniform and has a constant area as a function of photon energy. The emitting x-ray source is usually considered to be the laser entrance hole (LEH) of a given diameter for Hohlraum type targets or the effective wall area of high conversion efficiency K-shell type targets. This assumption can be problematic for several reasons. High intensity regions or 'hot spots' in the x-ray are observed where the drive laser beams strike the target. The 'hot spots' create non-uniform emission seen by the Dante. Additionally, thinned walled (50 {mu}m) low-Z targets (C{sub 22}H{sub 10}N{sub 2}O{sub 5}) have an energy dependent source size since the target's walls will be fully opaque for low energies (E < 2-3 keV) yet fully transmissive at higher energies. Determining accurate yields can be challenging for these types of targets. Discussion and some analysis will be presented.

  1. High-Z Coating Experiments on Omega EP

    NASA Astrophysics Data System (ADS)

    Karasik, Max; Oh, J.; Stoeckl, C.; Schmitt, A. J.; Aglitskiy, Y.; Obenschain, S. P.

    2016-10-01

    Previous experiments on Nike KrF laser (λ=248nm) at NRL found that a thin (400-800 Å) high-Z (Au or Pd) overcoat on the target is effective in suppressing broadband imprint. Implementation of this technique on the tripled Nd:glass (351nm) NIF would enable higher uniformity direct-drive experiments there. To this end, we are carrying out experiments using the NIF-like beams of Omega EP. On Nike, a low-intensity, highly smooth prepulse heats and pre-expands the low thermal mass metallic coating to 100 um scale length. This likely improves imprint reduction for longer spatial scales because of increased distance between laser absorption and the ablation surface. The 3 ω beams of Omega EP do not have this feature due to nonlinear harmonic conversion. We introduced a means of pre-expanding the high-Z coating to similar length scale on Omega EP using a soft x-ray prepulse, generated by irradiating an auxiliary Au foil 1cm in front of the main target tens of ns prior to the main target drive. Coating dynamics are measured using side-on radiography. The effectiveness of pre-expansion on imprint reduction will be assessed by measurements of the RT-amplified imprint using monochromatic curved crystal radiography. Work supported by the Department of Energy/NNSA.

  2. Measurement of the Omega0(c) lifetime

    SciTech Connect

    Iori, M.; Ayan, A.S.; Akgun, U.; Alkhazov, G.; Amaro-Reyes, J.; Atamantchouk, A.G.; Balatz, M.Y.; Blanco-Covarrubias, A.; Bondar, N.F.; Cooper, P.S.; Dauwe, L.J.; /Ball State U. /Bogazici U. /Carnegie Mellon U. /Rio de Janeiro, CBPF /Fermilab /Serpukhov, IHEP /Beijing, Inst. High Energy Phys. /Moscow, ITEP /Heidelberg, Max Planck Inst. /Moscow State U. /St. Petersburg, INP

    2007-01-01

    The authors report a precise measurement of the {Omega}{sub c}{sup 0} lifetime. The data were taken by the SELEX (E781) experiment using 600 GeV/c {Sigma}{sup -}, {pi}{sup -} and p beams. The measurement has been made using 83 {+-} 19 reconstructed {Omega}{sub c}{sup 0} in the {Omega}{sup -} {pi}{sup -}{pi}{sup +}{pi}{sup +} and {Omega}{sup -} {pi}{sup +} decay modes. The lifetime of the {Omega}{sub c}{sup 0} is measured to be 65 {+-} 13(stat) {+-} 9(sys) fs.

  3. Direct-drive implosion physics: Results from OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Radha, P. B.; Goncharov, V. N.; Hohenberger, M.; Sangster, T. C.; Betti, R.; Craxton, R. S.; Edgell, D. H.; Epstein, R.; Froula, D. H.; Marozas, J. A.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Hu, S. X.; Seka, W.; Shvydky, A.; Skupsky, S.; Frenje, J. A.; Gatu-Johnson, M.; Petrasso, R. D.; Ma, T.; Pape, S. Le; MacKinnon, A. J.

    2016-10-01

    Direct-drive-implosion experiments from both OMEGA and the National Ignition Facility (NIF) are critical to gain confidence in ignition predictions on the NIF. Adequate performance of hydrodynamically scaled 1.8-MJ ignition designs must be obtained on OMEGA at 26 kJ. Implosions on the NIF must be used to identify and mitigate the effect of laser-plasma interactions (LPI's) on hydrodynamic parameters at the NIF scale. Results from spherically driven OMEGA cryogenic implosion experiments are described. Mitigation of nonuniformity sources and cross-beam energy transfer (CBET) is important for improving target performance on OMEGA. Initial polar-driven implosion experiments on the NIF have provided valuable measurements of trajectory and symmetry. Simulations that include the effect of CBET more closely reproduce the observed velocity.

  4. Direct-drive implosion physics: Results from OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Radha, P. B.; Goncharov, V. N.; Hohenberger, M.; Sangster, T. C.; Betti, R.; Craxton, R. S.; Edgell, D. H.; Epstein, R.; Froula, D. H.; Marozas, J. A.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Hu, S. X.; Seka, W.; Shvydky, A.; Skupsky, S.; Frenje, J. A.; Gatu-Johnson, M.; Petrasso, R. D.; Ma, T.; Le Pape, S.; Mackinnon, A. J.

    2016-03-01

    Direct-drive-implosion experiments from both OMEGA and the National Ignition Facility (NIF) are critical to gain confidence in ignition predictions on the NIF. Adequate performance of hydrodynamically scaled 1.8-MJ ignition designs must be obtained on OMEGA at 26 kJ. Implosions on the NIF must be used to identify and mitigate the effect of laser-plasma interactions (LPI's) on hydrodynamic parameters at the NIF scale. Results from spherically driven OMEGA cryogenic implosion experiments are described. Mitigation of nonuniformity sources and cross-beam energy transfer (CBET) is important for improving target performance on OMEGA. Initial polar-driven implosion experiments on the NIF have provided valuable measurements of trajectory and symmetry. Simulations that include the effect of CBET more closely reproduce the observed velocity.

  5. KULL Simulations of OMEGA Radiation Flow Experiments

    NASA Astrophysics Data System (ADS)

    Kallman, J.; MacLaren, S.; Baker, K.; Brunner, T.; Lewis, K.; Zika, M.

    2013-10-01

    The problem of radiation flow in a right circular cylinder is of interest for the verification and validation of radiation codes since the flow is analytically analogous to diffusive free molecular flow in a similar geometry. Experiments were conducted on the OMEGA laser utilizing a low-density heated-cylindrical-wall target. The targets consisted of a 1.6 mm diameter gold hohlraum containing an on-axis 700 μm diameter SiO2 cylinder inside an 80 μm thick Ta2O5 aerogel tube. The FY13 targets also feature ``light-pipe'' diagnostics to measure the progression of the radiation front inside the foam. Simulations were run with the KULL multi-physics code, employing a new laser ray-tracing package. Comparisons of synthetic diagnostics derived from code results to x-ray measurements of drive temperature and heat front propagation provide a methodology to constrain simulation models. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. KULL Simulations of OMEGA Radiation Flow Experiments

    NASA Astrophysics Data System (ADS)

    Kallman, J.; MacLaren, S.; Baker, K.; Amala, P.; Lewis, K.; Zika, M.

    2012-10-01

    The problem of radiation flow in a right circular cylinder is of interest for the verification and validation of radiation codes, which utilize several mechanisms for determining radiation transport (diffusion, discrete ordinates, and Monte Carlo). This flow is analogous to free molecular flow in a similar geometry.footnotetextE. Garelis and T.E. Wainwright. Phys. Fluids. 16, 4 (1973) A series of experiments were conducted on the OMEGA laser in cases with a low-density heated cylindrical wall. The experiments consisted of a 1.6 mm diameter gold hohlraum containing an on-axis 700 μm diameter SiO2 cylinder contained in an 80 μm thick carbon foam tube. Five shots panning three test cases were used: the nominal geometry described above (heated wall), the carbon tube replaced with solid gold, and a gold cap placed on the laser end of the cylinder assembly to block axial radiation flow. Simulations of each experimental target type were run with the KULL radiation code, and were used to compare the different radiation transport packages in KULL by employing synthetic diagnostics to match the experimental DANTE cavity radiation temperature time history and soft x-ray images taken by a streak camera imaging the far end of the hohlraum.

  7. Uncertainty analysis technique for OMEGA Dante measurements.

    PubMed

    May, M J; Widmann, K; Sorce, C; Park, H-S; Schneider, M

    2010-10-01

    The Dante is an 18 channel x-ray filtered diode array which records the spectrally and temporally resolved radiation flux from various targets (e.g., hohlraums, etc.) at x-ray energies between 50 eV and 10 keV. It is a main diagnostic installed on the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The absolute flux is determined from the photometric calibration of the x-ray diodes, filters and mirrors, and an unfold algorithm. Understanding the errors on this absolute measurement is critical for understanding hohlraum energetic physics. We present a new method for quantifying the uncertainties on the determined flux using a Monte Carlo parameter variation technique. This technique combines the uncertainties in both the unfold algorithm and the error from the absolute calibration of each channel into a one sigma Gaussian error function. One thousand test voltage sets are created using these error functions and processed by the unfold algorithm to produce individual spectra and fluxes. Statistical methods are applied to the resultant set of fluxes to estimate error bars on the measurements.

  8. Multidimensional Study of High-Adiabat OMEGA Cryogenic Experiments

    NASA Astrophysics Data System (ADS)

    Collins, T. J. B.; Betti, R.; Bose, A.; Christopherson, A. R.; Knauer, J. P.; Marozas, J. A.; Maximov, A. V.; Mora, A.; Radha, P. B.; Shang, W.; Shvydky, A.; Stoeckl, C.; Woo, K. M.; Varchas, G.

    2016-10-01

    Despite recent advances in modeling laser direct-drive inertial confinement fusion (ICF) experiments, there remains a predictability gap. This is particularly shown by the shortfall in hot-spot pressures inferred from OMEGA cryogenic implosions. To address this, a series of high-adiabat, cryogenic implosions were performed on OMEGA. These shots were performed with and without single-beam smoothing by spectral dispersion, at low and high drive intensities. These shots represent a regime where good agreement with simulation is expected because of the high adiabat. Multidimensional simulations of these shots will be presented with an emphasis on comparison with experimental indicators of departure from spherical symmetry (``1-D-ness''). The roles of short- and long-wavelength perturbations are considered. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  9. Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facility

    SciTech Connect

    Nora, R.; Betti, R.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Meyerhofer, D. D.; McCrory, R. L.

    2014-05-15

    The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8 MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6 × 10{sup 13} and ∼0.3 g/cm{sup 2}, respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA.

  10. Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Nora, R.; Betti, R.; Anderson, K. S.; Shvydky, A.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Marozas, J. A.; Collins, T. J. B.; Radha, P. B.; Hu, S. X.; Epstein, R.; Marshall, F. J.; McCrory, R. L.; Sangster, T. C.; Meyerhofer, D. D.

    2014-05-01

    The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8 MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6 × 1013 and ˜0.3 g/cm2, respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA.

  11. Murray and the Omega Minus

    NASA Astrophysics Data System (ADS)

    Samios, Nicholas P.

    The exciting findings and activities in particle physics in the 50's and 60's will be discussed from an experimentalist's viewpoint. Particular emphasis will be placed on the description of several crucial discoveries (including the omega minus) and on the remarkable insight, guidance, and major contributions of Murray Gell-Mann to the understanding of the symmetry of hadrons which led to the development of the standard model of the strong interactions.

  12. Murray and the Omega Minus

    SciTech Connect

    Samios, N.P.

    2010-08-20

    The exciting findings and activities in particle physics in the 50's and 60's will be discussed from an experimentalist's viewpoint. Particular emphasis will be placed on the description of several crucial discoveries (including the omega minus) and on the remarkable insight, guidance, and major contributions of Murray Gell-Mann to the understanding of the symmetry of hadrons which led to the development of the standard model of the strong interactions.

  13. Murray and the Omega Minus

    NASA Astrophysics Data System (ADS)

    Samios, Nicholas P.

    2011-11-01

    The exciting findings and activities in particle physics in the 50's and 60's will be discussed from an experimentalist's viewpoint. Particular emphasis will be placed on the description of several crucial discoveries (including the omega minus) and on the remarkable insight, guidance, and major contributions of Murray Gell-Mann to the understanding of the symmetry of hadrons which led to the development of the standard model of the strong interactions.

  14. Omega-3 deficiency impairs honey bee learning.

    PubMed

    Arien, Yael; Dag, Arnon; Zarchin, Shlomi; Masci, Tania; Shafir, Sharoni

    2015-12-22

    Deficiency in essential omega-3 polyunsaturated fatty acids (PUFAs), particularly the long-chain form of docosahexaenoic acid (DHA), has been linked to health problems in mammals, including many mental disorders and reduced cognitive performance. Insects have very low long-chain PUFA concentrations, and the effect of omega-3 deficiency on cognition in insects has not been studied. We show a low omega-6:3 ratio of pollen collected by honey bee colonies in heterogenous landscapes and in many hand-collected pollens that we analyzed. We identified Eucalyptus as an important bee-forage plant particularly poor in omega-3 and high in the omega-6:3 ratio. We tested the effect of dietary omega-3 deficiency on olfactory and tactile associative learning of the economically highly valued honey bee. Bees fed either of two omega-3-poor diets, or Eucalyptus pollen, showed greatly reduced learning abilities in conditioned proboscis-extension assays compared with those fed omega-3-rich diets, or omega-3-rich pollen mixture. The effect on performance was not due to reduced sucrose sensitivity. Omega-3 deficiency also led to smaller hypopharyngeal glands. Bee brains contained high omega-3 concentrations, which were only slightly affected by diet, suggesting additional peripheral effects on learning. The shift from a low to high omega-6:3 ratio in the Western human diet is deemed a primary cause of many diseases and reduced mental health. A similar shift seems to be occurring in bee forage, possibly an important factor in colony declines. Our study shows the detrimental effect on cognitive performance of omega-3 deficiency in a nonmammal.

  15. Omega-3 deficiency impairs honey bee learning

    PubMed Central

    Arien, Yael; Dag, Arnon; Zarchin, Shlomi; Masci, Tania

    2015-01-01

    Deficiency in essential omega-3 polyunsaturated fatty acids (PUFAs), particularly the long-chain form of docosahexaenoic acid (DHA), has been linked to health problems in mammals, including many mental disorders and reduced cognitive performance. Insects have very low long-chain PUFA concentrations, and the effect of omega-3 deficiency on cognition in insects has not been studied. We show a low omega-6:3 ratio of pollen collected by honey bee colonies in heterogenous landscapes and in many hand-collected pollens that we analyzed. We identified Eucalyptus as an important bee-forage plant particularly poor in omega-3 and high in the omega-6:3 ratio. We tested the effect of dietary omega-3 deficiency on olfactory and tactile associative learning of the economically highly valued honey bee. Bees fed either of two omega-3–poor diets, or Eucalyptus pollen, showed greatly reduced learning abilities in conditioned proboscis-extension assays compared with those fed omega-3–rich diets, or omega-3–rich pollen mixture. The effect on performance was not due to reduced sucrose sensitivity. Omega-3 deficiency also led to smaller hypopharyngeal glands. Bee brains contained high omega-3 concentrations, which were only slightly affected by diet, suggesting additional peripheral effects on learning. The shift from a low to high omega-6:3 ratio in the Western human diet is deemed a primary cause of many diseases and reduced mental health. A similar shift seems to be occurring in bee forage, possibly an important factor in colony declines. Our study shows the detrimental effect on cognitive performance of omega-3 deficiency in a nonmammal. PMID:26644556

  16. Omega-X micromachining system

    DOEpatents

    Miller, Donald M.

    1978-01-01

    A micromachining tool system with X- and omega-axes is used to machine spherical, aspherical, and irregular surfaces with a maximum contour error of 100 nonometers (nm) and surface waviness of no more than 0.8 nm RMS. The omega axis, named for the angular measurement of the rotation of an eccentric mechanism supporting one end of a tool bar, enables the pulse increments of the tool toward the workpiece to be as little as 0 to 4.4 nm. A dedicated computer coordinates motion in the two axes to produce the workpiece contour. Inertia is reduced by reducing the mass pulsed toward the workpiece to about one-fifth of its former value. The tool system includes calibration instruments to calibrate the micromachining tool system. Backlash is reduced and flexing decreased by using a rotary table and servomotor to pulse the tool in the omega-axis instead of a ball screw mechanism. A thermally-stabilized spindle rotates the workpiece and is driven by a motor not mounted on the micromachining tool base through a torque-smoothing pulley and vibrationless rotary coupling. Abbe offset errors are almost eliminated by tool setting and calibration at spindle center height. Tool contour and workpiece contour are gaged on the machine; this enables the source of machining errors to be determined more readily, because the workpiece is gaged before its shape can be changed by removal from the machine.

  17. The Effect of Low Omega-3/Omega-6 Ratio on Auditory Nerve Conduction in Rat Pups.

    PubMed

    Farahani, Saeid; Motasaddi Zarandy, Masoud; Hassanzadeh, Gholamreza; Shidfar, Farzad; Jalaie, Shohreh; Rahimi, Vida

    2015-01-01

    The biological effects of omega-3 and omega-6 fatty acids are determined by their mutual interactions. This interaction extremely affects various functions. Lower consumption of omega-3 during gestation leads to various disorders, even in hearing. We aimed to assess the effect of low omega-3/omega-6 ratios on auditory nerve conduction. In this experimental study, the auditory brainstem response test was performed on 24-day-old rat (n=14). The rats were divided into case (low omega-3/omega-6 ratio during gestation and lactation) and control groups. Variables such as P1, P3, and P4 absolute latency period, interpeaks (P3-P4, P1-P3, and P1-P4), and P4/P1 amplitude ratio were measured. We found an increased P4 omega-3/omega-6 ratio in the group with a low omega-3/omega-6 ratio (P<0.01). No significant difference was observed in the P1 and P3 absolute latency period between the studied groups  (P>0.05).  Also, no significant difference was observed between the groups with respect to the P1-P3 interpeak latency (IPL) periods (P>0.05); while the P1-P4 and P3-P4 IPLs were significantly increased in the group with a low omega-3/omega-6 ratio (P<0.05). The P4/P1 amplitude ratio significantly decreased in the group with a low omega-3/omega-6 ratio (P<0.05). Results confirmed the negative effects of low omega-3/omega-6 ratio on the auditory system and hearing.

  18. National direct-drive program on OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Goncharov, V. N.; Regan, S. P.; Campbell, E. M.; Sangster, T. C.; Radha, P. B.; Myatt, J. F.; Froula, D. H.; Betti, R.; Boehly, T. R.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Glebov, V. Yu; Harding, D. R.; Hu, S. X.; Igumenshchev, I. V.; Marshall, F. J.; McCrory, R. L.; Michel, D. T.; Seka, W.; Shvydky, A.; Stoeckl, C.; Theobald, W.; Gatu-Johnson, M.

    2017-01-01

    A major advantage of the laser direct-drive (DD) approach to ignition is the increased fraction of laser drive energy coupled to the hot spot and relaxed hot-spot requirements for the peak pressure and convergence ratios relative to the indirect-drive approach at equivalent laser energy. With the goal of a successful ignition demonstration using DD, the recently established national strategy has several elements and involves multiple national and international institutions. These elements include the experimental demonstration on OMEGA cryogenic implosions of hot-spot conditions relevant for ignition at MJ-scale energies available at the National Ignition Facility (NIF) and developing an understanding of laser-plasma interactions and laser coupling using DD experiments on the NIF. DD designs require reaching central stagnation pressures in excess of 100 Gbar. The current experiments on OMEGA have achieved inferred peak pressures of 56 Gbar (Regan et al 2016 Phys. Rev. Lett. 117 025001). Extensive analysis of the cryogenic target experiments and two- and three-dimensional simulations suggest that power balance, target offset, and target quality are the main limiting factors in target performance. In addition, cross-beam energy transfer (CBET) has been identified as the main mechanism reducing laser coupling. Reaching the goal of demonstrating hydrodynamic equivalence on OMEGA includes improving laser power balance, target position, and target quality at shot time. CBET must also be significantly reduced and several strategies have been identified to address this issue.

  19. Two-Dimensional Simulations of Plastic-Shell, Direct-Drive Implosions on OMEGA

    SciTech Connect

    Radha, P.B.; Goncharov, V.N.; Collins, T.J.B.; Delettrez, J.A.; Elbaz, Y.; Glebov, V.Yu.; Keck, R.L.; Keller, D.E.; Knauer, J.P.; Marozas, J.A.; Marshall, F.J.; McKenty, P.W.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.; Shvarts, D.; Skupsky, S.; Srebro, Y.; Town, R.P.J.; Stoeckl, C.

    2005-02-18

    Multidimensional hydrodynamic properties of high-adiabat direct-drive plastic-shell implosions on the OMEGA laser system are investigated using the multidimensional hydrodynamic code, DRACO. Multimode simulations including the effects of nonuniform illumination and target roughness indicate that shell stability during the acceleration phase plays a critical role in determining target performance.

  20. Using Caenorhabditis elegans to Uncover Conserved Functions of Omega-3 and Omega-6 Fatty Acids.

    PubMed

    Watts, Jennifer L

    2016-02-02

    The nematode Caenorhabditis elegans is a powerful model organism to study functions of polyunsaturated fatty acids. The ability to alter fatty acid composition with genetic manipulation and dietary supplementation permits the dissection of the roles of omega-3 and omega-6 fatty acids in many biological process including reproduction, aging and neurobiology. Studies in C. elegans to date have mostly identified overlapping functions of 20-carbon omega-6 and omega-3 fatty acids in reproduction and in neurons, however, specific roles for either omega-3 or omega-6 fatty acids are beginning to emerge. Recent findings with importance to human health include the identification of a conserved Cox-independent prostaglandin synthesis pathway, critical functions for cytochrome P450 derivatives of polyunsaturated fatty acids, the requirements for omega-6 and omega-3 fatty acids in sensory neurons, and the importance of fatty acid desaturation for long lifespan. Furthermore, the ability of C. elegans to interconvert omega-6 to omega-3 fatty acids using the FAT-1 omega-3 desaturase has been exploited in mammalian studies and biotechnology approaches to generate mammals capable of exogenous generation of omega-3 fatty acids.

  1. Using Caenorhabditis elegans to Uncover Conserved Functions of Omega-3 and Omega-6 Fatty Acids

    PubMed Central

    Watts, Jennifer L.

    2016-01-01

    The nematode Caenorhabditis elegans is a powerful model organism to study functions of polyunsaturated fatty acids. The ability to alter fatty acid composition with genetic manipulation and dietary supplementation permits the dissection of the roles of omega-3 and omega-6 fatty acids in many biological process including reproduction, aging and neurobiology. Studies in C. elegans to date have mostly identified overlapping functions of 20-carbon omega-6 and omega-3 fatty acids in reproduction and in neurons, however, specific roles for either omega-3 or omega-6 fatty acids are beginning to emerge. Recent findings with importance to human health include the identification of a conserved Cox-independent prostaglandin synthesis pathway, critical functions for cytochrome P450 derivatives of polyunsaturated fatty acids, the requirements for omega-6 and omega-3 fatty acids in sensory neurons, and the importance of fatty acid desaturation for long lifespan. Furthermore, the ability of C. elegans to interconvert omega-6 to omega-3 fatty acids using the FAT-1 omega-3 desaturase has been exploited in mammalian studies and biotechnology approaches to generate mammals capable of exogenous generation of omega-3 fatty acids. PMID:26848697

  2. Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids

    PubMed Central

    Berquin, Isabelle M.; Min, Younong; Wu, Ruping; Wu, Jiansheng; Perry, Donna; Cline, J. Mark; Thomas, Mike J.; Thornburg, Todd; Kulik, George; Smith, Adrienne; Edwards, Iris J.; D’Agostino, Ralph; Zhang, Hao; Wu, Hong; Kang, Jing X.; Chen, Yong Q.

    2007-01-01

    Although a causal role of genetic alterations in human cancer is well established, it is still unclear whether dietary fat can modulate cancer risk in a predisposed population. Epidemiological studies suggest that diets rich in omega-3 polyunsaturated fatty acids reduce cancer incidence. To determine the influence of fatty acids on prostate cancer risk in animals with a defined genetic lesion, we used prostate-specific Pten-knockout mice, an immune-competent, orthotopic prostate cancer model, and diets with defined polyunsaturated fatty acid levels. We found that omega-3 fatty acids reduced prostate tumor growth, slowed histopathological progression, and increased survival, whereas omega-6 fatty acids had opposite effects. Introducing an omega-3 desaturase, which converts omega-6 to omega-3 fatty acids, into the Pten-knockout mice reduced tumor growth similarly to the omega-3 diet. Tumors from mice on the omega-3 diet had lower proportions of phosphorylated Bad and higher apoptotic indexes compared with those from mice on omega-6 diet. Knockdown of Bad eliminated omega-3–induced cell death, and introduction of exogenous Bad restored the sensitivity to omega-3 fatty acids. Our data suggest that modulation of prostate cancer development by polyunsaturated fatty acids is mediated in part through Bad-dependent apoptosis. This study highlights the importance of gene-diet interactions in prostate cancer. PMID:17607361

  3. Omega-3 fats: Good for your heart

    MedlinePlus

    ... checkbook. Oily fish rich in omega-3s include: Salmon Mackerel Albacore tuna Trout Sardines ... Oily fish, such as salmon and tuna, contain 2 kinds of omega-3s. These are EPA and DHA. Both have direct benefits for your heart. ...

  4. LLNL Experiments at OMEGA in FY05

    SciTech Connect

    Turner, R E

    2005-10-06

    During FY05, LLNL was scheduled for 372 shots on Omega. These were distributed into 191 planned shots for the Inertial Confinement Fusion (ICF) program, and 181 planned shots for the High Energy Density Sciences (HEDS) program. The actual Omega performance averaged 6% more shots than scheduled. A brief summary of the various campaigns follows, starting with HEDS experiments.

  5. Statistical study of auroral omega bands

    NASA Astrophysics Data System (ADS)

    Partamies, Noora; Weygand, James M.; Juusola, Liisa

    2017-09-01

    The presence of very few statistical studies on auroral omega bands motivated us to test-use a semi-automatic method for identifying large-scale undulations of the diffuse aurora boundary and to investigate their occurrence. Five identical all-sky cameras with overlapping fields of view provided data for 438 auroral omega-like structures over Fennoscandian Lapland from 1996 to 2007. The results from this set of omega band events agree remarkably well with previous observations of omega band occurrence in magnetic local time (MLT), lifetime, location between the region 1 and 2 field-aligned currents, as well as current density estimates. The average peak emission height of omega forms corresponds to the estimated precipitation energies of a few keV, which experienced no significant change during the events. Analysis of both local and global magnetic indices demonstrates that omega bands are observed during substorm expansion and recovery phases that are more intense than average substorm expansion and recovery phases in the same region. The omega occurrence with respect to the substorm expansion and recovery phases is in a very good agreement with an earlier observed distribution of fast earthward flows in the plasma sheet during expansion and recovery phases. These findings support the theory that omegas are produced by fast earthward flows and auroral streamers, despite the rarity of good conjugate observations.

  6. Antiperoxidative properties of oil mixes of high ratio Omega-9:Omega-6 and low ratio Omega-6:Omega-3 after molar extraction in rats.

    PubMed

    Melo, Radamés Bezerra; Guimarães, Sérgio Botelho; Silva, Paulo Goberlânio de Barros; Oriá, Reinaldo Barreto; Melo, José Ulisses de Souza; Vasconcelos, Paulo Roberto Leitão

    2014-06-01

    To evaluate the antioxidant and antiperoxidative effects of oil mixes of high ratio Omega-9:Omega-6 and low ratio Omega-6:Omega-3 in the third day after tooth extraction in rats. Thirty-two male Wistar rats (270-310 g) were randomly distributed in two groups: Control (n=24) and Test (n=8). Control group was divided into three subgroups (n=8): G1: Sham-Saline; G2: Saline; G3: Isolipid. G1 and G2 animals received NaCl 0.9% while G3 rats were treated with an isolipid mixture (alpha-linolenic acid - ALA) containing -6/-3 oils (8:1 ratio) and-9/-6 (0.4:1 ratio). Test group animals (G4) received oily mixtures (alpha-linolenic acid - ALA, docosahexaenoic acid - DHA, eicosapentaenoic acid - EPA) of -6/-3 (1.4:1 ratio) and -9/-6 (3.4:1 ratio). Saline and oils were administered by gavage during four days before and three days after first mandibular molar extraction. Following, samples (arterial blood and alveolar mucosa) were collected for glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) assays. Oil mixes induced a significant decrease in GSH and TBARS tissue and plasma concentrations in the third day post-surgery. Gavage administration of oil mixes of high ratio Omega-9:Omega-6 and low ratio Omega-6:Omega-3 after molar extraction in rats induces a significant decrease in lipid peroxidation.

  7. M54 + SAGITTARIUS = {omega} CENTAURI

    SciTech Connect

    Carretta, E.; Bragaglia, A.; Bellazzini, M.; Gratton, R. G.; Lucatello, S.; Momany, Y.; D'Orazi, V.; Catanzaro, G.; Leone, F.; Piotto, G. E-mail: angela.bragaglia@oabo.inaf.it E-mail: raffaele.gratton@oapd.inaf.it E-mail: valentina.dorazi@oapd.inaf.it

    2010-05-01

    We derive homogeneous abundances of Fe, O, Na, and {alpha}-elements from high-resolution FLAMES spectra for 76 red giant stars in NGC 6715 (M54) and for 25 red giants in the surrounding nucleus of the Sagittarius (Sgr) dwarf galaxy. Our main findings are the following. (1) We confirm that M54 shows intrinsic metallicity dispersion, {approx}0.19 dex rms. (2) When the stars of the Sgr nucleus are included, the metallicity distribution strongly resembles that in {omega} Cen; the relative contribution of the most metal-rich stars is, however, different in these two objects. (3) In both globular clusters (GCs) there is a very extended Na-O anticorrelation, which is a signature of different stellar generations born within the cluster. (4) The metal-poor and metal-rich components in M54 (and {omega} Cen) show clearly distinct extension of the Na-O anticorrelation, the most heavily polluted stars being those of the metal-rich component. We propose a tentative scenario for cluster formation that could explain these features. Finally, similarities and differences found in the two most massive GCs in our Galaxy can be easily explained if they are similar objects (nuclear clusters in dwarf galaxies) observed at different stages of their dynamical evolution.

  8. Clock synchronization experiments using OMEGA transmissions

    NASA Technical Reports Server (NTRS)

    Chi, A. R.; Wardrip, S. C.

    1973-01-01

    The OMEGA transmissions from North Dakota on 13.10 and 12.85 kHz were monitored at several sites using a recently developed OMEGA timing receiver specifically designed for this purpose. The experiments were conducted at Goddard Space Flight Center, Greenbelt, Maryland; U.S. Naval Observatory, Washington, D.C.; and at the NASA tracking station, Rosman, North Carolina. Results show that cycle identification of the two carrier frequencies was made at each test site, thus, coarse time (76 microseconds) from the OMEGA transmitted signals to within the ambiguity period of each OMEGA frequency was extracted. The fine time determination, which was extracted from the phase difference between the received OMEGA signals and locally generated signals, was about + or - 2 microseconds for daytime reception and about + or - 5 microseconds for nighttime reception.

  9. Omega-3 fatty acids and anorexia.

    PubMed

    Goncalves, Carolina G; Ramos, Eduardo J B; Suzuki, Susumu; Meguid, Michael M

    2005-07-01

    To review the mechanisms of action of omega-3 fatty acids and their role in the brain, as well as their therapeutic implications in anorexia. Recent studies have demonstrated that omega-3 fatty acids modulate changes in the concentrations and actions of several orexigenic and anorexigenic neuropeptides in the brain, including neuropeptide Y, alpha-melanocyte stimulating hormone and the neurotransmitters serotonin and dopamine. In patients with acute and chronic inflammatory conditions, low tissue concentrations of omega-3 fatty acids and high concentrations of proinflammatory cytokines are found, in association with anorexia and decreased food intake. The data suggest that omega-3 fatty acid supplementation suppresses proinflammatory cytokine production and improves food intake by normalizing hypothalamic orexigenic peptides and neurotransmitters. Based on current data, omega-3 fatty acid supplementation has a role in the treatment of anorexia by stimulating the production and release of orexigenic neurotransmitters in food intake regulatory nuclei in the hypothalamus.

  10. OMEGA: A NEW COLD X-RAY SIMULATION FACILITY FOR THE EVALUATION OF OPTICAL COATINGS

    SciTech Connect

    Fisher, J H; Newlander, C D; Fournier, K B; Beutler, D E; Coverdale, C A; May, M J; Tobin, M; Davis, J F; Shiekh, D

    2007-04-27

    We report on recent progress for the development of a new cold X-ray optical test capability using the Omega Facility located at the Laboratory for Laser Energetics (LLE) at the University of Rochester. These tests were done on the 30 kJ OMEGA laser at the Laboratory for Laser Energetics (LLE) at the University of Rochester, Rochester, NY. We conducted a six-shot series called OMEGA II on 14 July 2006 in one eight-hour day (supported by the Defense Threat Reduction Agency). The initial testing was performed using simple protected gold optical coatings on fused silica substrates. PUFFTFT analyses were completed and the specimen's thermal lateral stress and transverse stress conditions were calculated and interpreted. No major anomalies were detected. Comparison of the pre- and posttest reflective measurements coupled with the TFCALC analyses proved invaluable in guiding the analyses and interpreting the observed damage. The Omega facility is a high quality facility for performing evaluation of optical coatings and coupons and provides experience for the development of future National Ignition Facility (NIF) testing.

  11. Final Report: Posttest Analysis of Omega II Optical Specimens

    SciTech Connect

    Newlander, C D; Fisher, J H

    2007-01-30

    Preliminary posttest analyses have been completed on optical specimens exposed during the Omega II test series conducted on 14 July 2006. The Omega Facility, located at the Laboratory for Laser Energetics (LLE) at the University of Rochester was used to produce X-ray environments through the interaction of intense pulsed laser radiation upon germanium-loaded silica aerogels. The optical specimen testing was supported by GH Systems through experiment design, pre- and post-test analyses, specimen acquisition, and overall technical experience. The test specimens were fabricated and characterized by Surface Optics Corporation (SOC), San Diego, CA and were simple protected gold coatings on silica substrates. Six test specimens were exposed, five filtered with thin beryllium foil filters, and one unfiltered which was exposed directly to the raw environment. The experimental objectives were: (1) demonstrate that tests of optical specimens could be performed at the Omega facility; (2) evaluate the use and survivability of beryllium foil filters as a function of thickness; (3) obtain damage data on optical specimens which ranged from no damage to damage; (4) correlate existing thermal response models with the damage data; (5) evaluate the use of the direct raw environment upon the specimen response and the ability/desirability to conduct sensitive optical specimen tests using the raw environment; and (6) initiate the development of a protocol for performing optical coatings/mirror tests. This report documents the activities performed by GH Systems in evaluating and using the environments provided by LLNL, the PUFFTFT analyses performed using those environments, and the calculated results compared to the observed and measured posttest data.

  12. Rayleigh scattering of a Gaussian laser beam from expanding clusters

    SciTech Connect

    Kumar, Manoj; Tripathi, V. K.

    2009-12-15

    Rayleigh scattering of an intense laser with Gaussian temporal and radial profiles from clustered gases is examined. The laser quickly converts the clusters into plasma balls with electron cloud of each ball executing large excursions about the ion sphere. The laser also heats the electrons. As the clusters expand under hydrodynamic pressure, plasma frequency of the cluster electrons omega{sub pe} decreases. The temporal rate of decrease in omega{sub pe} is maximum on laser axis and falls off with r. As the electron density of a cluster approaches plasma resonance, omega{sub pe}=omegasq root(3) (where omega is the frequency of the laser) the oscillatory electron cloud of the cluster produces resonantly enhanced Rayleigh scattering. This resonant enhancement first occurs in clusters on laser axis and afterward in farther clusters. The diffraction divergence of the laser limits the length of the cluster plasma, hence the Rayleigh scattering.

  13. [Lasers].

    PubMed

    Passeron, T

    2012-11-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients.

  14. Lasers.

    PubMed

    Passeron, T

    2012-12-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients.

  15. Three-dimensional hydrodynamic simulations of OMEGA implosions

    DOE PAGES

    Igumenshchev, I. V.; Michel, D. T.; Shah, R. C.; ...

    2017-03-30

    Here, the effects of large-scale (with Legendre modes ≲10) asymmetries in OMEGA direct-drive implosions caused by laser illumination nonuniformities (beam-power imbalance and beam mispointing and mistiming), target offset, and variation in target-layer thickness were investigated using the low-noise, three-dimensional Eulerian hydrodynamic code ASTER. Simulations indicate that these asymmetries can significantly degrade the implosion performance. The most important sources of the asymmetries are the target offsets (~10 to 20 μm), beam-power imbalance (σrms ~ 10%), and variations (~5%) in target-layer thickness. Large-scale asymmetries distort implosion cores, resulting in a reduced hot-spot confinement and an increased residual kinetic energy of implosion targets.more » The ion temperature inferred from the width of simulated neutron spectra is influenced by bulk fuel motion in the distorted hot spot and can result in up to an ~1 -keV increase in apparent temperature. Similar temperature variations along different lines of sight are observed. Demonstrating hydrodynamic equivalence to ignition designs on OMEGA requires a reduction in large-scale target and laser-imposed nonuniformities, minimizing target offset, and employing highly efficient mid-adiabat (α = 4) implosion designs, which mitigate cross-beam energy transfer and suppress short-wavelength Rayleigh–Taylor growth.« less

  16. Laboratory astrophysical collisionless shock experiments on Omega and NIF

    NASA Astrophysics Data System (ADS)

    Park, Hye-Sook; Ross, J. S.; Huntington, C. M.; Fiuza, F.; Ryutov, D.; Casey, D.; Drake, R. P.; Fiksel, G.; Froula, D.; Gregori, G.; Kugland, N. L.; Kuranz, C.; Levy, M. C.; Li, C. K.; Meinecke, J.; Morita, T.; Petrasso, R.; Plechaty, C.; Remington, B.; Sakawa, Y.; Spitkovsky, A.; Takabe, H.; Zylstra, A. B.

    2016-03-01

    We are performing scaled astrophysics experiments on Omega and on NIF. Laser driven counter-streaming interpenetrating supersonic plasma flows can be studied to understand astrophysical electromagnetic plasma phenomena in a controlled laboratory setting. In our Omega experiments, the counter-streaming flow plasma state is measured using Thomson scattering diagnostics, demonstrating the plasma flows are indeed super-sonic and in the collisionless regime. We observe a surprising additional electron and ion heating from ion drag force in the double flow experiments that are attributed to the ion drag force and electrostatic instabilities. [1] A proton probe is used to image the electric and magnetic fields. We observe unexpected large, stable and reproducible electromagnetic field structures that arise in the counter-streaming flows [2]. The Biermann battery magnetic field generated near the target plane, advected along the flows, and recompressed near the midplane explains the cause of such self-organizing field structures [3]. A D3He implosion proton probe image showed very clear filamentary structures; three-dimensional Particle-In-Cell simulations and simulated proton radiography images indicate that these filamentary structures are generated by Weibel instabilities and that the magnetization level (ratio of magnetic energy over kinetic energy in the system) is ∼0.01 [4]. These findings have very high astrophysical relevance and significant implications. We expect to observe true collisionless shock formation when we use >100 kJ laser energy on NIF.

  17. Two crystal x-ray spectrometers for OMEGA experiments

    NASA Astrophysics Data System (ADS)

    Reverdin, C.; Casner, A.; Girard, F.; Lecherbourg, L.; Loupias, B.; Tassin, V.; Philippe, F.

    2016-11-01

    Two x-ray spectrometers have been built for x-ray spectroscopy of laser-produced plasmas on OMEGA at the Laboratory for Laser Energetics (LLE) by Commissariat a ̀ l'Energie Atomique et aux énergies alternatives (CEA). The accessible photon energy range is from 1.5 to 20 keV. The first spectrometer, called X-ray CEA Crystal Spectrometer with a Charge-Injection Device (XCCS-CID), records three spectra with three crystals coupled to a time integrated CID camera. The second one, called X-ray CEA Crystal Spectrometer (XCCS) with a framing camera, is time resolved and records four spectra with two crystals on the four frames of a framing camera. Cylindrical crystals are used in Johan geometry. Each spectrometer is positioned with a ten-inch manipulator inside the OMEGA target chamber. In each experiment, after choosing a spectral window, a specific configuration is designed and concave crystals are precisely positioned on a board with angled wedges and spacers. Slits on snouts enable 1D spatial resolution to distinguish spectra emitted from different parts of the target.

  18. Symmetry Experiments on Omega with LMJ like Multiple Beam Cones Irradation

    SciTech Connect

    Richard, A L; Jadaud, J P; Dague, N; Monteil, M C; Turner, R E; Bradley, D; Wallace, R J; Landen, O L; Soures, J M; Morse, S; Pien, G

    2000-07-17

    We carried out a set of experiments on the Omega laser facility at Rochester with Laser MegaJoule (LMJ) like indirect drive irradiation. We studied the irradiation non-uniformity with the foam ball radiography technique and the implosion symmetry with (D{sub 2} + Argon) filled capsules core emission. Cylindrical ''Nova scale 1'' thin wall hohlraums were used. Forty of the Omega beams, arranged in three cones on each side of the hohlraum (5, 5, and lo), were used to create the X-ray drive. Eight additional beams were used on a Ti source to radiograph the foam balls. The shaped laser pulse was about 3 ns duration. The radiation drive was measured on each shot. The images were recorded with a 5 prn resolution Gated X-ray Imager coupled to a CCD camera.

  19. Laser-Matter Interactions with a 527 nm Drive

    SciTech Connect

    Glenzer, S; Niemann, C; Witman, P; Wegner, P; Mason, D; Haynam, C; Parham, T; Datte, P

    2007-02-16

    The primary goal of this Exploratory Research is to develop an understanding of laser-matter interactions with 527-nm light (2{omega}) for studies of interest to numerous Laboratory programs including inertial confinement fusion (ICF), material strength, radiation transport, and hydrodynamics. In addition, during the course of this work we will develop the enabling technology and prototype instrumentation to diagnose a high fluence laser beam for energy, power, and near field intensity profile at 2{omega}. Through this Exploratory Research we have established an extensive experimental and modeling data base on laser-matter interaction with 527 nm laser light (2{omega}) in plasma conditions of interest to numerous Laboratory programs. The experiments and the laser-plasma interaction modeling using the code pF3D have shown intensity limits and laser beam conditioning requirements for future 2{omega} laser operations and target physics experiments on the National Ignition Facility (NIF). These findings have set requirements for which present radiation-hydrodynamic simulations indicate the successful generation of relevant pressure regimes in future 2{omega} experiments. To allow these experiments on the NIF, optics and optical mounts were prepared for the 18mm Second Harmonic Generation Crystal (SHG crystal) that would provide the desired high conversion efficiency from 1{omega} to 2{omega}. Supporting experimental activities on NIF included high-energy 1{omega} shots at up to 22kJ/beamline (4MJ full NIF 1{omega} equivalent energy) that demonstrated, in excess, the 1{omega} drive capability of the main laser that is required for 2{omega} operations. Also, a very extensive 3{omega} campaign was completed (see ''The National Ignition Facility Laser Performance Status'' UCRL-JRNL-226553) that demonstrated that not only doubling the laser, but also tripling the laser (a much more difficult and sensitive combination) met our model predictions over a wide range of laser

  20. Three-Dimensional Hydrodynamic Simulations of OMEGA Implosions

    NASA Astrophysics Data System (ADS)

    Igumenshchev, I. V.

    2016-10-01

    The effects of large-scale (with Legendre modes less than 30) asymmetries in OMEGA direct-drive implosions caused by laser illumination nonuniformities (beam-power imbalance and beam mispointing and mistiming) and target offset, mount, and layers nonuniformities were investigated using three-dimensional (3-D) hydrodynamic simulations. Simulations indicate that the performance degradation in cryogenic implosions is caused mainly by the target offsets ( 10 to 20 μm), beampower imbalance (σrms 10 %), and initial target asymmetry ( 5% ρRvariation), which distort implosion cores, resulting in a reduced hot-spot confinement and an increased residual kinetic energy of the stagnated target. The ion temperature inferred from the width of simulated neutron spectra are influenced by bulk fuel motion in the distorted hot spot and can result in up to 2-keV apparent temperature increase. Similar temperature variations along different lines of sight are observed. Simulated x-ray images of implosion cores in the 4- to 8-keV energy range show good agreement with experiments. Demonstrating hydrodynamic equivalence to ignition designs on OMEGA requires reducing large-scale target and laser-imposed nonuniformities, minimizing target offset, and employing high-efficient mid-adiabat (α = 4) implosion designs that mitigate cross-beam energy transfer (CBET) and suppress short-wavelength Rayleigh-Taylor growth. These simulations use a new low-noise 3-D Eulerian hydrodynamic code ASTER. Existing 3-D hydrodynamic codes for direct-drive implosions currently miss CBET and noise-free ray-trace laser deposition algorithms. ASTER overcomes these limitations using a simplified 3-D laser-deposition model, which includes CBET and is capable of simulating the effects of beam-power imbalance, beam mispointing, mistiming, and target offset. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  1. Observation of an Excited Charm Baryon Omega^*_C Decaying to Omega^0_C Gamma

    SciTech Connect

    Aubert, B

    2006-11-15

    The authors report the first observation of an excited singly-charmed baryon {Omega}*{sub c} (css) in the radiative decay {Omega}{sub c}{sup 0}{gamma}, where the {Omega}{sub c}{sup 0} baryon is reconstructed in the decays to the final states {Omega}{sup -}{pi}{sup +}, {Omega}{sup -} {pi}{sup +}{pi}{sup 0}, {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}, and {Xi}{sup -} K{sup -} {pi}{sup +}{pi}{sup +}. This analysis is performed using a dataset of 230.7 fb{sup -1} collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The mass difference between the {Omega}*{sub c} and the {Omega}{sub c}{sup 0} baryons is measured to be 70.8 {+-} 1.0(stat) {+-} 1.1(syst) MeV/c{sup 2}. They also measure the ratio of inclusive production cross sections of {Omega}*{sub c} and {Omega}{sub c}{sup 0} in e{sup +}e{sup -} annihilation.

  2. Periodontal condition in relation to intake of omega-3 and omega-6 polyunsaturated fatty acids.

    PubMed

    Jauhiainen, Leena; Ylöstalo, Pekka; Männistö, Satu; Kanerva, Noora; Knuuttila, Matti; Suominen, Anna L

    2016-11-01

    To examine whether the intake of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) is associated with periodontal condition. The study population consisted of non-smoking, non-diabetic and non-rheumatoid individuals in the Health 2000 Survey in Finland. Analyses were made in two age groups: 30-49 years (n = 1212) and 50-79 years (n = 980). Clinically determined sextants with gingival bleeding and teeth with periodontal pockets were used as outcome variables. Dietary data were collected by a validated food frequency questionnaire. Energy-adjusted intakes of arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), omega-3 and omega-6 PUFAs, as well as ratios of EPA/AA and of DHA/AA, and omega-3/omega-6 PUFAs were used as exposures. Prevalence rate ratios were estimated using Poisson regression models. In this population, there were no statistically significant associations between the examined omega-3 or omega-6 fatty acids or their ratios and the periodontal outcome variables. This cross-sectional study provided evidence that individual omega-3 or omega-6 fatty acids, their subclasses or ratios are not associated with periodontal health among a non-diabetic, non-rheumatoid and non-smoking population. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    NASA Astrophysics Data System (ADS)

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Séguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J.; Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A.; McKernan, M. A.; Moran, M.; Rygg, J. R.; Yeoman, M. F.; Zacharias, R.; Leeper, R. J.; Fletcher, K.; Farrell, M.; Jasion, D.; Kilkenny, J.; Paguio, R.

    2013-04-01

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  4. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF.

    PubMed

    Casey, D T; Frenje, J A; Johnson, M Gatu; Séguin, F H; Li, C K; Petrasso, R D; Glebov, V Yu; Katz, J; Magoon, J; Meyerhofer, D D; Sangster, T C; Shoup, M; Ulreich, J; Ashabranner, R C; Bionta, R M; Carpenter, A C; Felker, B; Khater, H Y; LePape, S; MacKinnon, A; McKernan, M A; Moran, M; Rygg, J R; Yeoman, M F; Zacharias, R; Leeper, R J; Fletcher, K; Farrell, M; Jasion, D; Kilkenny, J; Paguio, R

    2013-04-01

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  5. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    SciTech Connect

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J.; Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A.; and others

    2013-04-15

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  6. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    DOE PAGES

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; ...

    2013-04-18

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, iontemperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describesmore » ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.« less

  7. Demonstrating ignition hydrodynamic equivalence in direct-drive cryogenic implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Goncharov, V. N.; Regan, S. P.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Campbell, E. M.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu; Harding, D. R.; Hu, S. X.; Igumenshchev, I. V.; Marshall, F. J.; McCrory, R. L.; Michel, D. T.; Myatt, J. F.; Radha, P. B.; Seka, W.; Shvydky, A.; Stoeckl, C.; Theobald, W.; Yaakobi, B.; Gatu-Johnson, M.

    2016-05-01

    Achieving ignition in a direct-drive cryogenic implosion at the National Ignition Facility (NIF) requires reaching central stagnation pressures in excess of 100 Gbar, which is a factor of 3 to 4 less than what is required for indirect-drive designs. The OMEGA Laser System is used to study the physics of cryogenic implosions that are hydrodynamically equivalent to the spherical ignition designs of the NIF. Current cryogenic implosions on OMEGA have reached 56 Gbar, and implosions with shell convergence CR< 17 and fuel adiabat α > 3.5 proceed close to 1-D predictions. Demonstrating hydrodynamic equivalence on OMEGA will require reducing coupling losses caused by cross-beam energy transfer (CBET), minimizing long- wavelength nonuniformity seeded by power imbalance and target offset, and removing target debris occumulated during cryogenic target production.

  8. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    SciTech Connect

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J.; Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A.; McKernan, M. A.; Moran, M.; Rygg, J. R.; Yeoman, M. F.; Zacharias, R.; Leeper, R. J.; Fletcher, K.; Farrell, M.; Jasion, D.; Kilkenny, J.; Paguio, R.

    2013-04-18

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, iontemperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  9. Omega-3 polyunsaturated fatty acids.

    PubMed

    Hull, Mark A

    2011-08-01

    Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are naturally occurring omega (ω)-3 long-chain polyunsaturated fatty acids (PUFAs), which are found in highest quantities in oily fish such as sardines and mackerel. Epidemiological studies of the association between fish intake, ω-3 PUFA intake or blood ω-3 PUFA levels and colorectal cancer (CRC) risk have not consistently suggested beneficial effects of ω-3 PUFAs on CRC (and other gastrointestinal cancer) risk. However, dietary administration of one or both of the main ω-3 PUFAs in rodent models of colorectal carcinogenesis has been demonstrated to reduce colorectal tumour size and multiplicity, compatible with CRC chemopreventative activity. EPA has now been demonstrated to reduce rectal polyp number and size in patients with familial adenomatous polyposis. A randomized polyp prevention trial of EPA is underway in order to test chemopreventative efficacy against 'sporadic' colorectal neoplasia. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Omega-3 fatty acids and neuropsychiatric disorders.

    PubMed

    Young, Genevieve; Conquer, Julie

    2005-01-01

    Epidemiological evidence suggests that dietary consumption of the long chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), commonly found in fish or fish oil, may modify the risk for certain neuropsychiatric disorders. As evidence, decreased blood levels of omega-3 fatty acids have been associated with several neuropsychiatric conditions, including Attention Deficit (Hyperactivity) Disorder, Alzheimer's Disease, Schizophrenia and Depression. Supplementation studies, using individual or combination omega-3 fatty acids, suggest the possibility for decreased symptoms associated with some of these conditions. Thus far, however, the benefits of supplementation, in terms of decreasing disease risk and/or aiding in symptom management, are not clear and more research is needed. The reasons for blood fatty acid alterations in these disorders are not known, nor are the potential mechanisms by which omega-3 fatty acids may function in normal neuronal activity and neuropsychiatric disease prevention and/or treatment. It is clear, however, that DHA is the predominant n-3 fatty acid found in the brain and that EPA plays an important role as an anti-inflammatory precursor. Both DHA and EPA can be linked with many aspects of neural function, including neurotransmission, membrane fluidity, ion channel and enzyme regulation and gene expression. This review summarizes the knowledge in terms of dietary omega-3 fatty acid intake and metabolism, as well as evidence pointing to potential mechanisms of omega-3 fatty acids in normal brain functioning, development of neuropsychiatric disorders and efficacy of omega-3 fatty acid supplementation in terms of symptom management.

  11. Understanding the branching ratios of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, {omega}{phi} observed at BES-III

    SciTech Connect

    Chen Dianyong; He Jun; Li Xueqian; Liu Xiang

    2010-04-01

    In this work, we discuss the contribution of the mesonic loops to the decay rates of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, which are suppressed by the helicity selection rules and {chi}{sub c1{yields}{phi}{omega}}, which is a double-Okubo-Zweig-Iizuka forbidden process. We find that the mesonic loop effects naturally explain the clear signals of {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega} decay modes observed by the BES Collaboration. Moreover, we investigate the effects of the {omega}-{phi} mixing, which may result in the order of magnitude of the branching ratio BR({chi}{sub c1{yields}{omega}{phi}}) being 10{sup -7}. Thus, we are waiting for the accurate measurements of the BR({chi}{sub c1{yields}{omega}{omega}}), BR({chi}{sub c1{yields}{phi}{phi}}), and BR({chi}{sub c1{yields}{omega}{phi}}), which may be very helpful for testing the long-distant contribution and the {omega}-{phi} mixing in {chi}{sub c1{yields}{phi}{phi}}, {omega}{omega}, {omega}{phi} decays.

  12. Mars Express OMEGA Observations over Terra Meridiani

    NASA Technical Reports Server (NTRS)

    Arvidson, R. E.; Poulet, F.; Bibring, J.-P.; Wolff, M.; Gendrin, A.; Morris, R. V.; Freeman, J. J.; Bellucci, G.

    2005-01-01

    The OMEGA hyperspectral imager (0.35 to 5.08 micrometers) covered the hematite-bearing plains and underlying etched terrains of Terra Meridiani during several orbits with spatial resolutions ranging from several hundred meters to approximately 2 km. We extracted and analyzed surface reflectance spectra from OMEGA data for the approximately 864,000 square kilometers surrounding the Opportunity site. In this paper we focus on analysis of OMEGA orbit 485 data for the plains and etched terrains located to the northeast of the Opportunity landing site.

  13. Omega-3 fatty acids for cystic fibrosis.

    PubMed

    Oliver, Colleen; Jahnke, Nikki

    2011-08-10

    Studies suggest that a diet rich in omega-3 essential fatty acids may have beneficial anti-inflammatory effects for chronic conditions such as cystic fibrosis. To determine whether there is evidence that omega-3 polyunsaturated fatty acid supplementation reduces morbidity and mortality and to identify any adverse events associated with supplementation. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Authors and persons interested in the subject of the review were contacted.Date of last search: 10 March 2011. Randomised controlled trials in people with cystic fibrosis comparing omega-3 fatty acid supplements with placebo. Two authors independently selected studies for inclusion, extracted data and assessed the risk of bias of the studies. The searches identified 13 studies; four studies with 91 participants were included. Two studies compared omega-3 fatty acids to olive oil for six weeks. One study compared a liquid dietary supplement containing omega-3 fatty acids to one without for six months. One study compared omega-3 fatty acids and omega-6 fatty acids to a control (capsules with customised fatty acid blends) for three months. Only one short-term study (19 participants) comparing omega-3 to placebo reported a significant improvement in lung function and Shwachman score and a reduction in sputum volume in the omega-3 group. Another study (43 participants) demonstrated a significant increase in serum phospholipid essential fatty acid content and a significant drop in the n-6/n-3 fatty acid ratio following omega-3 fatty acid supplementation compared to control. The longer-term study (17 participants) demonstrated a significant increase in essential fatty acid content in neutrophil membranes and a significant decrease in the leukotriene B4 to leukotriene B5 ratio

  14. Diurnal measurements with prototype CMOS Omega receivers

    NASA Technical Reports Server (NTRS)

    Burhans, R. W.

    1976-01-01

    Diurnal signals from eight omega channels have been monitored at 10.2 KHz for selected station pairs. All eight Omega stations have been received at least 50 percent of the time over a 24 hour period during the month of October 1976. The data presented confirm the expected performance of the CMOS omega sensor processor in being able to digsignals out of a noisy environment. Of particular interest are possibilities for use of antipodal reception phenomena and a need for some ways of correcting for multi-modal propagation effects.

  15. Polarimetry diagnostic on OMEGA EP using a 10-ps, 263-nm probe beam.

    PubMed

    Davies, A; Haberberger, D; Boni, R; Ivancic, S; Brown, R; Froula, D H

    2014-11-01

    A polarimetry diagnostic was built and characterized for magnetic-field measurements in laser-plasma experiments on the OMEGA EP laser. This diagnostic was built into the existing 4ω (263-nm) probe system that employs a 10-ps laser pulse collected with an f/4 imaging system. The diagnostic measures the rotation of the probe beam's polarization. The polarimeter uses a Wollaston prism to split the probe beam into orthogonal polarization components. Spatially localized intensity variations between images indicate polarization rotation. Magnetic fields can be calculated by combining the polarimetry data with the measured plasma density profile obtained from angular filter refractometry.

  16. Polarimetry diagnostic on OMEGA EP using a 10-ps, 263-nm probe beam

    SciTech Connect

    Davies, A. Haberberger, D.; Boni, R.; Ivancic, S.; Brown, R.; Froula, D. H.

    2014-11-15

    A polarimetry diagnostic was built and characterized for magnetic-field measurements in laser-plasma experiments on the OMEGA EP laser. This diagnostic was built into the existing 4ω (263-nm) probe system that employs a 10-ps laser pulse collected with an f/4 imaging system. The diagnostic measures the rotation of the probe beam's polarization. The polarimeter uses a Wollaston prism to split the probe beam into orthogonal polarization components. Spatially localized intensity variations between images indicate polarization rotation. Magnetic fields can be calculated by combining the polarimetry data with the measured plasma density profile obtained from angular filter refractometry.

  17. Reactive Carbonyl Species Derived from Omega-3 and Omega-6 Fatty Acids.

    PubMed

    Wang, Yu; Cui, Ping

    2015-07-22

    Inflammation-related reactive oxygen species (ROS) and reactive nitrogen species (RNS) are associated with the development of cancer. ROS and RNS can directly damage biomacromolecules such as proteins, DNA, and lipids. Lipid peroxidation, however, can result in reactive carbonyl species (RCS) that can also modify proteins and DNA. In contrast to an extensive literature on the modification of proteins and DNA from omega-6 fatty acids, there are few studies on RCS generation from other fatty acids, particularly omega-3 fatty acids, which are frequently consumed from the diet and diet supplements. Therefore, a comparison between omega-3 and omega-6 fatty acids has been conducted. LC-MS/MS analysis of carbonyl-dinitrophenylhydrazine (DNPH) standards yielded characteristic fragment ions. Autoxidation products of α-linolenic acid and linoleic acid were then derivatized with DNPH and analyzed by LC-MS/MS. The results showed that α-linolenic acid, an omega-3 fatty acid, generated more acrolein and crotonaldehyde than did linoleic acid, an omega-6 fatty acid. Omega-3 fatty acids might be easily degraded to smaller monoaldehydes or dicarbonyls. Omega-3 fatty acids have been considered as health improvement components for a long time. However, on the basis of the results presented here, use of omega-3 fatty acids should be re-evaluated in vivo for safety purposes.

  18. First Scaled-Down Integrated MagLIF Experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Davies, J. R.; Barnak, D. H.; Betti, R.; Glebov, V. Yu.; Knauer, J. P.; Regan, S. P.

    2016-10-01

    Magnetized liner inertial fusion (MagLIF) is an inertial confinement fusion (ICF) scheme that relies on compression of a cylindrical, magnetized, preheated plasma to achieve fusion conditions with a lower implosion velocity and a lower convergence ratio than conventional ICF. MagLIF research to date has been centered on the Z pulsed-power machine at Sandia National Laboratories-the only facility capable of carrying out such experiments. A laser-driven version of MagLIF has now been implemented on the OMEGA laser at the Laboratory for Laser Energetics, using targets roughly ten times smaller in linear dimensions than Z targets. Laser-driven MagLIF on OMEGA will test the scaling of MagLIF and provide a higher shot rate with better diagnostic access than Z. Preliminary results from integrated MagLIF experiments on OMEGA will be presented for the first time. The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000568, and the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  19. Elementary Education: What Is Project Omega?

    ERIC Educational Resources Information Center

    Kirman, Joseph M.

    1980-01-01

    Describes Project Omega for Research in Remote Sensing Education, a program in space education designed for inservice training of elementary social studies teachers. Explains a few research areas dealing with the classroom applications of Landsat imagery. (CS)

  20. Zooming in on Omega Centauri Stellar Motion

    NASA Image and Video Library

    This movie sequence begins with a ground-based image of the giant globular star cluster Omega Centauri and zooms very tightly in to a Hubble Space Telescope image of the central region of the clust...

  1. Omega-3 Fatty Acid supplementation during pregnancy.

    PubMed

    Greenberg, James A; Bell, Stacey J; Ausdal, Wendy Van

    2008-01-01

    Omega-3 fatty acids are essential and can only be obtained from the diet. The requirements during pregnancy have not been established, but likely exceed that of a nonpregnant state. Omega-3 fatty acids are critical for fetal neurodevelopment and may be important for the timing of gestation and birth weight as well. Most pregnant women likely do not get enough omega-3 fatty acids because the major dietary source, seafood, is restricted to 2 servings a week. For pregnant women to obtain adequate omega-3 fatty acids, a variety of sources should be consumed: vegetable oils, 2 low-mercury fish servings a week, and supplements (fish oil or algae-based docosahexaenoic acid).

  2. Elementary Education: What Is Project Omega?

    ERIC Educational Resources Information Center

    Kirman, Joseph M.

    1980-01-01

    Describes Project Omega for Research in Remote Sensing Education, a program in space education designed for inservice training of elementary social studies teachers. Explains a few research areas dealing with the classroom applications of Landsat imagery. (CS)

  3. OMEGA for the Future of Biofuels

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan

    2010-01-01

    OMEGA: Offshore Membrane Enclosure for Growing Algae. To develop a photobioreactor (PBR) for growing algae (Oil, food, fertilizer) that does not compete with agriculture for land (deployed offshore), water or fertilizer (uses/treats wastewater).

  4. Omega Psi Phi Fraternity Recognizes Bolden

    NASA Image and Video Library

    2010-01-19

    NASA Administrator Charles Bolden, 4th from left, is presented a plaque in honor of him becoming the 12th NASA Administrator by NASA Headquarters members of his fraternity, Omega Psi Phi: from left, Andrew Hubbard, Clinton Green, Carl Person, Dwayne Brown, and Elbert Cox, right. Omega Psi Phi Fraternity, Inc. was founded at Howard University on Nov. 17, 1911. The phrase “friendship is essential to the soul," is the fraternity’s motto. Photo Credit: (NASA/Bill Ingalls)

  5. North Pacific Omega Navigation System Validation.

    DTIC Science & Technology

    1981-12-31

    based upon comparisons with "Loran-C, radar and visual" whose absolute accuracy as references could not be assessed. Similarly, the M/S Nopal Lane...Mellon ..................................... A-82 A5.1.5 M/S Nopal Lane ................... ......... .... .. A-83 A5.1.6 Submarine Omega Performance...From Omega Log of M/S NOPAL LANE .................... A-84 A5-2 Western Airlines Flights - 1978 .......................... A-85 AA-1 Difference Between

  6. Optical Omega network: a compact implementation technique

    NASA Astrophysics Data System (ADS)

    Wong, K. W.; Cheng, L. M.

    1995-10-01

    We propose a technique for the compact implementation of an optical Omega network. This technique utilizes the concept that both the perfect-shuffle interconnection and the switching stages can be realized by the same procedures, i.e., duplicate, shift, superimpose, and mask. As a result, a single set of optics is sufficient to realize the whole Omega network in a time-multiplexed recursive manner. Optical setups were designed and a proof-of-principle experiment was performed.

  7. Neurological benefits of omega-3 fatty acids.

    PubMed

    Dyall, S C; Michael-Titus, A T

    2008-01-01

    The central nervous system is highly enriched in long-chain polyunsaturated fatty acid (PUFA) of the omega-6 and omega-3 series. The presence of these fatty acids as structural components of neuronal membranes influences cellular function both directly, through effects on membrane properties, and also by acting as a precursor pool for lipid-derived messengers. An adequate intake of omega-3 PUFA is essential for optimal visual function and neural development. Furthermore, there is increasing evidence that increased intake of the long-chain omega-3 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may confer benefits in a variety of psychiatric and neurological disorders, and in particular neurodegenerative conditions. However, the mechanisms underlying these beneficial effects are still poorly understood. Recent evidence also indicates that in addition to the positive effects seen in chronic neurodegenerative conditions, omega-3 PUFA may also have significant neuroprotective potential in acute neurological injury. Thus, these compounds offer an intriguing prospect as potentially new therapeutic approaches in both chronic and acute conditions. The purpose of this article is to review the current evidence of the neurological benefits of omega-3 PUFA, looking specifically at neurodegenerative conditions and acute neurological injury.

  8. Omega-3 fatty acids and cardiovascular disease.

    PubMed

    Jain, A P; Aggarwal, K K; Zhang, P-Y

    2015-01-01

    Cardioceuticals are nutritional supplements that contain all the essential nutrients including vitamins, minerals, omega-3-fatty acids and other antioxidants like a-lipoic acid and coenzyme Q10 in the right proportion that provide all round protection to the heart by reducing the most common risks associated with the cardiovascular disease including high low-density lipoprotein cholesterol and triglyceride levels and factors that contribute to coagulation of blood. Omega-3 fatty acids have been shown to significantly reduce the risk for sudden death caused by cardiac arrhythmias and all-cause mortality in patients with known coronary heart disease. Omega-3 fatty acids are also used to treat hyperlipidemia and hypertension. There are no significant drug interactions with omega-3 fatty acids. The American Heart Association recommends consumption of two servings of fish per week for persons with no history of coronary heart disease and at least one serving of fish daily for those with known coronary heart disease. Approximately 1 g/day of eicosapentaenoic acid plus docosahexaenoic acid is recommended for cardio protection. Higher dosages of omega-3 fatty acids are required to reduce elevated triglyceride levels (2-4 g/day). Modest decreases in blood pressure occur with significantly higher dosages of omega-3 fatty acids.

  9. Barium Abundances in Omega Centauri Candidate Stars

    NASA Astrophysics Data System (ADS)

    Skipper, Joy Nicole; Sobeck, Jennifer; Majewski, Steven R.; Rochford Hayes, Christian; Cunha, Katia M. L.; Smith, Verne V.; Damke, Guillermo; García Pérez, Ana; Nidever, David L.

    2017-01-01

    The "globular cluster" omega Centauri has several peculiar features that set it apart from other Milky Way globular clusters, such as its large mass, extended size, oblate shape, internal rotation, large age and metallicity spreads, and retrograde orbit. Because of these properties it is thought that Omega Cen may be a heavily stripped remnant of a Milky Way-captured dwarf spheroidal galaxy, now currently orbiting (backwards) near the Galactic plane (e.g., Lee et al. 1999, Majewski et al. 2000). A previous search within a large, all-sky low resolution spectroscopic and photometric catalog of giant stars by Majewski et al. (2012) identified candidate retrograde stars near that plane also having kinematics consistent with being stripped debris from omega Cen, based on tidal destruction models of the system. To confirm their status as omega Centauri members, high resolution spectroscopy was undertaken of a subsample of a dozen of these candidates, and most were found by Majewski et al. to exhibit very high relative Ba abundances (as measured by the 5854 transition) — a peculiar characteristic of the omega Centauri system as originally shown by Smith et al. (2000) and Norris & Da Costa (1998). Thus, these results showed the likelihood of a connection between these widely distributed field stars and omega Centauri.We have continued this spectroscopic investigation with an expanded sample of candidate tidally-stripped omega Cen giant stars. High-resolution spectra were obtained in the wavelength region (4140~6210A) with the Ultraviolet Visual Echelle Spectrograph (UVES) on the 8.0-m Very Large Telescope (VLT) for additional candidates. For these data, we have employed multiple transitions to derive reliable [Ba/Fe] ratios. We will compare these and other derived abundances to those of the omega Cen core, other globular cluster and field stars. Any additionally-confirmed omega Cen debris stars to combine with those from the previous studies will allow for a more

  10. Simulation and Analysis of Time-Resolved Narrowband Radiographs of Cryogenic Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Epstein, R.; Stoeckl, C.; Goncharov, V. N.; McKenty, P. W.; Regan, S. P.

    2016-10-01

    Spherical polymer shells containing cryogenic DT ice layers have been imploded on the OMEGA Laser System and radiographed with Al backlighter targets (hν = 1.865keV) driven with 20-ps IR pulses from the OMEGA EP Laser System. X-ray radiographs have been simulated using DRACO and Spect3D. The shadows of the converging DT ice and polymer shell edges at times before and after stagnation are visible while the self-emission is minimized using a time-resolved (40-ps) narrowband crystal imaging system. The self-emission from the diverging shock wave following stagnation is also visible. The simulated radiographs will be compared to the measured ones to investigate the feasibility of diagnosing the low-mode asymmetry in the compressed DT shell around stagnation. This material is based upon work supported by the U.S. Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  11. The MicrOmega Investigation Onboard ExoMars

    NASA Astrophysics Data System (ADS)

    Bibring, Jean-Pierre; Hamm, Vincent; Pilorget, Cédric; Vago, Jorge L.; MicrOmega Team

    2017-07-01

    MicrOmega is a visible near-infrared hyperspectral microscope that is designed to characterize the texture and composition of martian samples presented to the instrument within the ExoMars rover's analytical laboratory drawer. The spectral range (0.5-3.65 μm) and the spectral sampling (20 cm-1 from 0.95 to 3.65 μm) of MicrOmega have been chosen to allow the identification of most constituent minerals, ices/frosts, and organics with astrobiological relevance within each 20 × 20 μm2 pixel over a 5 × 5 mm2 field of view. Such an unprecedented characterization will enable (1) identification of most major and minor phases, including the potential organics; (2) ascription of their mineralogical context, as a critical set of clues with which to decipher their formation process; and (3) location of specific grains or regions of interest in the samples, which will be further analyzed by Raman Laser Spectrometer and/or Mars Organic Molecule Analyzer.

  12. Initial results from the DSPlanar experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Dodd, E. S.; Merritt, E. C.; Montgomery, D. S.; Daughton, W.; Schmidt, D. W.; Cardenas, T.; Wilson, D. C.; Batha, S. H.

    2016-10-01

    Recently, LANL has begun a project aimed ultimately at fielding a neutron-producing double-shell capsule at the National Ignition Facility (NIF). Initial experiments have begun at both the NIF and OMEGA laser facilities over the last year. At OMEGA, halfraum-driven planar targets will be used to study physics issues important to double shell implosions, but outside of a convergent geometry. In particular, side-on radiography through a tube has advantages over imaging through the hohlraum and double-shell capsule at NIF. We plan to study a number physics issues with this platform, including both 1-d and higher dimensional effects. In 1-d, momentum transfer from the ablator to the inner shell, and the effect of pre-heat on the inner shell can be studied. Higher dimensional effects, in the form of hydrodynamic instabilities, can also be studied. Pre-heat expansion of the inner shell can lead to an unstable interface, which can be mitigated by a tamper layer. Manufacturing tolerances can be used to mitigate against feature-driven instability growth, such as from a glue joint or fill tube. Initial results on the amount pre-heat from various ablator materials will be given, along with a discussion of future plans. Supported under the US DOE by the LANS, LLC under contract DE-AC52-06NA25396. LA-UR-16-25044.

  13. Balancing omega-6 and omega-3 fatty acids in ready-to-use therapeutic foods (RUTF).

    PubMed

    Brenna, J Thomas; Akomo, Peter; Bahwere, Paluku; Berkley, James A; Calder, Philip C; Jones, Kelsey D; Liu, Lei; Manary, Mark; Trehan, Indi; Briend, André

    2015-05-15

    Ready-to-use therapeutic foods (RUTFs) are a key component of a life-saving treatment for young children who present with uncomplicated severe acute malnutrition in resource limited settings. Increasing recognition of the role of balanced dietary omega-6 and omega-3 polyunsaturated fatty acids (PUFA) in neurocognitive and immune development led two independent groups to evaluate RUTFs. Jones et al. (BMC Med 13:93, 2015), in a study in BMC Medicine, and Hsieh et al. (J Pediatr Gastroenterol Nutr 2015), in a study in the Journal of Pediatric Gastroenterology and Nutrition, reformulated RUTFs with altered PUFA content and looked at the effects on circulating omega-3 docosahexaenoic acid (DHA) status as a measure of overall omega-3 status. Supplemental oral administration of omega-3 DHA or reduction of RUTF omega-6 linoleic acid using high oleic peanuts improved DHA status, whereas increasing omega-3 alpha-linolenic acid in RUTF did not. The results of these two small studies are consistent with well-established effects in animal studies and highlight the need for basic and operational research to improve fat composition in support of omega-3-specific development in young children as RUTF use expands.

  14. Meat quality of Argentinean "Camperos" chicken enhanced in omega-3 and omega-9 fatty acids.

    PubMed

    Azcona, J O; Garcia, P T; Cossu, M E; Iglesias, B F; Picallo, A; Perez, C; Gallinger, C I; Schang, M J; Canet, Z E

    2008-07-01

    Five diets were assessed with the aim of increasing oleic fatty acid and omega-3 polyunsaturated fatty acid content in 'campero' poultry meat and evaluating their influence on sensory attributes. Animals from treatment 1 (T1) were confined and fed with corn/soybean diet; in T2, animals were fed with a corn/soybean mix with free access to pasture; T3 diet had high oleic sunflower seeds (HOSS) and linseeds with access to pasture; T4 diet was similar to T2 with free access to chicory instead of pasture and T5 diet was similar to T3 with free access to chicory instead of pasture. Linseeds and HOSS supplementation significantly increased the fatty acids profile, regardless of forage supply. T3 MUFA content was significantly higher than in the other treatments. Due to the high presence of omega-3 PUFA in linseeds and HOSS treatments (T3 and T5), meat omega-6/omega-3 ratio decreased from 9 to 4. The presence of off-flavours was not influenced by diets but there was an interaction between portion and storage conditions. 'Poultry meat' aroma was only influenced by the storage conditions, being slight after 4 months of freezing, while presence of off-aromas was affected by diets. We conclude that it is possible to produce 'campero' poultry meat with enhanced omega-3 and omega-9 content and a low omega-6/omega-3 ratio using diets based on linseed and HOSS, without any important change in sensory properties.

  15. Measurements of B meson decays to (omega)K* and (omega)(rho)

    SciTech Connect

    Aubert, B; Cheng, C H; Lange, D J; Simani, M C; . Wright, D M; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R H; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Y G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Abe, T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, G; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Keith, D W . S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, H; Strube, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Collaboration, B

    2006-03-14

    The authors describe searches for B meson decays to the charmless vector-vector final states {omega}K* and {omega}{rho} in 89 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation at {radical}s = 10.58 GeV.

  16. Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

    NASA Astrophysics Data System (ADS)

    Philippe, F.; Tassin, V.; Depierreux, S.; Gauthier, P.; Masson-Laborde, P. E.; Monteil, M. C.; Seytor, P.; Villette, B.; Lasinski, B.; Park, H. S.; Ross, J. S.; Amendt, P.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Williams, E.; Michel, P.; Frenje, J.; Gatu-Johnson, M.; Li, C. K.; Petrasso, R.; Glebov, V.; Sorce, C.; Stoeckl, C.; Nikroo, A.; Giraldez, E.

    2014-07-01

    A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results.

  17. Mitigation of cross-beam energy transfer: Implication of two-state focal zooming on OMEGA

    SciTech Connect

    Froula, D. H.; Kessler, T. J.; Igumenshchev, I. V.; Betti, R.; Goncharov, V. N.; Huang, H.; Hu, S. X.; Hill, E.; Kelly, J. H.; Meyerhofer, D. D.; Shvydky, A.; Zuegel, J. D.

    2013-08-15

    Cross-beam energy transfer (CBET) during OMEGA low-adiabat cryogenic experiments reduces the hydrodynamic efficiency by ∼35%, which lowers the calculated one-dimensional (1-D) yield by a factor of 7. CBET can be mitigated by reducing the diameter of the laser beams relative to the target diameter. Reducing the diameter of the laser beams by 30%, after a sufficient conduction zone has been generated (two-state zooming), is predicted to maintain low-mode uniformity while recovering 90% of the kinetic energy lost to CBET. A radially varying phase plate is proposed to implement two-state zooming on OMEGA. A beam propagating through the central half-diameter of the phase plate will produce a large spot, while a beam propagating through the outer annular region of the phase plate will produce a narrower spot. To generate the required two-state near-field laser-beam profile, a picket driver with smoothing by spectral dispersion (SSD) would pass through an apodizer, forming a beam of half the standard diameter. A second main-pulse driver would co-propagate without SSD through its own apodizer, forming a full-diameter annular beam. Hydrodynamic simulations, using the designed laser spots produced by the proposed zooming scheme on OMEGA, show that implementing zooming will increase the implosion velocity by 25% resulting in a 4.5× increase in the 1-D neutron yield. Demonstrating zooming on OMEGA would validate a viable direct-drive CBET mitigation scheme and help establish a pathway to hydrodynamically equivalent direct-drive–ignition implosions by increasing the ablation pressure (1.6×), which will allow for more stable implosions at ignition-relevant velocities.

  18. Next-generation laser for inertial confinement fusion

    SciTech Connect

    Marshall, C; Bibeau, C; Bayramian, A; Beach, R; Ebbers, C A; Emanuel, M; Freitas, B; Fulkerson, S; Honea, E; Krupke, B; Lawson, J; Orth, C; Payne, S; Petty, C; Powell, H; Schaffers, K; Skidmore, J; Smith, L; Sutton, S; Telford, S

    1998-03-13

    We are developing and building the ''Mercury'' laser system as the first in a series of a new generation of diode-pumped solid-state lasers (DPSSL) for advanced high energy density (HED) physics experiments at LLNL. Mercury will be the first integrated demonstration of a scalable laser architecture compatible with advanced Inertial Confinement Fusion (ICF) goals. Primary performance goals include 10% efficiencies at 10 Hz and a <10 ns pulse with l {omega} energies of 100 J and with 2 {omega}/3 {omega} frequency conversion. Achieving this performance will provide a near term capability for HED experiments and prove the potential of DPSSLs for inertial fusion energy (IFE).

  19. Multi-keV x-ray sources from HYBRID targets on GEKKO and OMEGA facilities

    NASA Astrophysics Data System (ADS)

    Primout, M.; Girard, F.; Villette, B.; Stemmler, Ph.; Brebion, D.; Nishimura, H.; Matsuoka, Y.; Yamamoto, N.; Marrs, R.; Kay, J.; Fournier, K. B.

    2013-11-01

    The feasibility of efficient X-ray sources for radiography on the LMJ (Laser MégaJoule) in the multi-kJ/ns range was demonstrated on the OMEGA laser facility (Univ. Rochester) from 2002 to 2004 [1,2]. We significantly enhanced the conversion efficiency of titanium (4-6 keV), copper (8-10 keV) and germanium (9-13 keV) foils by using an optimized pre-pulse/pulse combination. Since higher X-ray energy and therefore electronic temperature need hydroconfinement, plastic cylindrical hohlraums internally coated with titanium, copper and germanium with various OMEGA beam configurations were successfully tested from 2005 to 2009 [3-5]. In addition, many shots with metal-doped aerogel (Ti, Fe, Ge) were tested on OMEGA [6]. Recently we tested a new concept of "HYBRID sources" based on the combination of a thin titanium foil at the exit hole of a plastic cylinder filled with very low density SiO2 aerogel (2 and 5 mg/cc). The benefit of the underdense medium is, first, to transport the laser energy to the titanium foil after its conversion into a supersonic ionization front and, second, to prevent foil expansion and excessive kinetic energy losses by longitudinal hydroconfinement.

  20. Thermodynamical properties of dark energy with the equation of state {omega}={omega}{sub 0}+{omega}{sub 1}z

    SciTech Connect

    Zhang Yongping; Yi Zelong; Zhang Tongjie; Liu Wenbiao

    2008-01-15

    The thermodynamical properties of dark energy are usually investigated with the equation of state {omega}={omega}{sub 0}+{omega}{sub 1}z. Recent observations show that our Universe is accelerating, and the apparent horizon and the event horizon vary with redshift z. Because definitions of the temperature and entropy of a black hole are used to describe the two horizons of the Universe, we examine the thermodynamical properties of the Universe, which is enveloped by the apparent horizon and the event horizon, respectively. We show that the first and the second laws of thermodynamics inside the apparent horizon in any redshift are satisfied, while they are broken down inside the event horizon in some redshifts. Therefore, the apparent horizon for the Universe may be the boundary of thermodynamical equilibrium for the Universe like the event horizon for a black hole.

  1. Secondary-Proton Spectra from D_2-Filled OMEGA Targets

    NASA Astrophysics Data System (ADS)

    Séguin, F. H.; Frenje, J. A.; Li, C. K.; Hicks, D. G.; Green, K. M.; Petrasso, R. D.; Glebov, V. Yu.; Stoeckl, C.; Radha, P. B.; Soures, J. M.; Meyerhofer, D. D.; Roberts, S.; Sorce, C.; Sangster, T. C.; Padalino, S.; Fletcher, K.

    2000-10-01

    Spectroscopic measurements of secondary fusion protons of imploded D_2-filled capsules in ICF experiments are now carried out with magnet-based charged-particle spectrometers and with a new type of ``range filter''-based detector utilizing special filters and CR39 nuclear track detectors. The mean proton energy determines the capsule's total areal density (ρR). Measurement of proton yield, in combination with the primary and secondary neutron yield, provides an estimate of fuel parameters. Recent data from OMEGA implosions will be presented. This work was performed in part at the LLE National Laser Users' Facility (NLUF), and was supported in part by the U.S. DOE Contract DE-FG03-99SF21782, LLE subcontract PO410025G, LLNL subcontract B313975, and by the U.S. DOE Office of ICF under Coop. Agreem. No. DE-FC03-92SF19460.

  2. Simulations of the propagation of multiple-FM smoothing by spectral dispersion on OMEGA EP

    DOE PAGES

    Kelly, J. H.; Shvydky, A.; Marozas, J. A.; ...

    2013-02-18

    A one-dimensional (1-D) smoothing by spectral dispersion (SSD) system for smoothing focal-spot nonuniformities using multiple modulation frequencies has been commissioned on one long-pulse beamline of OMEGA EP, the first use of such a system in a high-energy laser. Frequency modulation (FM) to amplitude modulation (AM) conversion in the infrared (IR) output, frequency conversion, and final optics affected the accumulation of B-integral in that beamline. Modeling of this FM-to-AM conversion using the code Miró. was used as input to set the beamline performance limits for picket (short) pulses with multi-FM SSD applied. This article first describes that modeling. The 1-D SSDmore » analytical model of Chuang is first extended to the case of multiple modulators and then used to benchmark Miró simulations. Comparison is also made to an alternative analytic model developed by Hocquet et al. With the confidence engendered by this benchmarking, Miró results for multi-FM SSD applied on OMEGA EP are then presented. The relevant output section(s) of the OMEGA EP Laser System are described. The additional B-integral in OMEGA EP IR components upstream of the frequency converters due to AM is modeled. The importance of locating the image of the SSD dispersion grating at the frequency converters is demonstrated. In conclusion, since frequency conversion is not performed in OMEGA EP’s target chamber, the additional AM due to propagation to the target chamber’s vacuum window is modeled.« less

  3. Simulations of the propagation of multiple-FM smoothing by spectral dispersion on OMEGA EP

    SciTech Connect

    Kelly, J. H.; Shvydky, A.; Marozas, J. A.; Guardalben, M. J.; Kruschwitz, B. E.; Waxer, L. J.; Dorrer, C.; Hill, E.; Okishev, A. V.; Di Nicola, J.-M.

    2013-02-18

    A one-dimensional (1-D) smoothing by spectral dispersion (SSD) system for smoothing focal-spot nonuniformities using multiple modulation frequencies has been commissioned on one long-pulse beamline of OMEGA EP, the first use of such a system in a high-energy laser. Frequency modulation (FM) to amplitude modulation (AM) conversion in the infrared (IR) output, frequency conversion, and final optics affected the accumulation of B-integral in that beamline. Modeling of this FM-to-AM conversion using the code Miró. was used as input to set the beamline performance limits for picket (short) pulses with multi-FM SSD applied. This article first describes that modeling. The 1-D SSD analytical model of Chuang is first extended to the case of multiple modulators and then used to benchmark Miró simulations. Comparison is also made to an alternative analytic model developed by Hocquet et al. With the confidence engendered by this benchmarking, Miró results for multi-FM SSD applied on OMEGA EP are then presented. The relevant output section(s) of the OMEGA EP Laser System are described. The additional B-integral in OMEGA EP IR components upstream of the frequency converters due to AM is modeled. The importance of locating the image of the SSD dispersion grating at the frequency converters is demonstrated. In conclusion, since frequency conversion is not performed in OMEGA EP’s target chamber, the additional AM due to propagation to the target chamber’s vacuum window is modeled.

  4. Omega 3 fatty acids in the elderly.

    PubMed

    Ubeda, Natalia; Achón, María; Varela-Moreiras, Gregorio

    2012-06-01

    Population ageing affects the entire world population. Also at world level one can observe a sharp increase in the proportion of older people. The challenge posed by population ageing translates into ensuring that the extra years of life will be as good as possible, free from high-cost dependency. Omega-3 fatty acids are now generally recognized as potential key nutrients to prevent the pathological conditions associated to the aging process. Ageing physiological process, its association with quality of life and the impact of omega-3 fatty acids intake and/or status is the focus of the present review. This report deals with the effects of omega-3 fatty acids on normal aging of older adults ( ≥ 65 years) mainly on the effects such as nutritional status itself, cognition, bone health, muscle tonus, and general health status. The preliminary broad search of the literature on the effects of omega-3 fatty acids on normal aging yielded 685 citations. Forty two full text papers were checked for inclusion and thirty six studies were finally included in this review. It may be concluded that paradoxically even though the elderly population is the largest one, the number of studies and the methodology employed clearly lacks of sufficient evidence to establish definite conclusions on the effects of omega-3 fatty acids on aging metabolism without pathological conditions and on quality of life.

  5. Rare B Meson Decays With Omega Mesons

    SciTech Connect

    Zhang, Lei; /Colorado U.

    2006-04-24

    Rare charmless hadronic B decays are particularly interesting because of their importance in understanding the CP violation, which is essential to explain the matter-antimatter asymmetry in our universe, and of their roles in testing the ''effective'' theory of B physics. The study has been done with the BABAR experiment, which is mainly designed for the study of CP violation in the decays of neutral B mesons, and secondarily for rare processes that become accessible with the high luminosity of the PEP-II B Factory. In a sample of 89 million produced B{bar B} pairs on the BABAR experiment, we observed the decays B{sup 0} {yields} {omega}K{sup 0} and B{sup +} {yields} {omega}{rho}{sup +} for the first time, made more precise measurements for B{sup +} {yields} {omega}h{sup +} and reported tighter upper limits for B {yields} {omega}K* and B{sup 0} {yields} {omega}{rho}{sup 0}.

  6. Computer-aided design and modeling of nickel dithiolene near-infrared dyes. 1998 summer research program for high school juniors at the University of Rochester`s Laboratory for Laser Energetics: Student research reports

    SciTech Connect

    Corsello, S.

    1999-03-01

    Recent advances in computational chemistry have made it feasible to design many types of molecules and predict their properties theoretically. The author applied these techniques to the design of organometallic transition-metal dyes absorbing in the near-infrared region of the spectrum which possess the combination of a large molar extinction coefficient, good chemical and thermal stability, and a high solubility in liquid crystal (LC) hosts. These properties are required for the dye to function as a near-infrared (IR) attenuator in a liquid crystal point diffraction interferometer (LCPDI) device that will be used as a beam diagnostic on the 60-beam OMEGA solid-state Nd:glass laser system at the University of Rochester`s Laboratory for Laser Energetics. Using commercially available software, both the absorption spectra and solubility characteristics of bis[1,2-di-(p-n alkoxyphenyl)ethane-1,2-dithione] nickel dye complexes were modeled in an isotropic host (cyclohexane) and, in most cases, excellent agreement was found with experimental data. Two additional compounds utilizing the same nickel dithiolene core but with alkylthio and phenylalkylthio terminal groups have been designed and show excellent potential to produce dramatic improvements in both solubility and optical density (absorbance) in liquid crystalline hosts. Based upon my work, a new dye not previously reported, 2(C{sub 4}S)2(C{sub 4}SPh)DTNi, has been proposed to satisfy the LCPDI device requirements. The nickel dithiolene dyes may also find important applications in other technology areas such as near-IR photography and laser-based near-IR communications.

  7. A Protective Lipidomic Biosignature Associated with a Balanced Omega-6/Omega-3 Ratio in fat-1 Transgenic Mice

    PubMed Central

    Wang, Bin; Strassburg, Katrin; Doneanu, Angela; Johnson, Jay; Baker, Andrew; Hankemeier, Thomas; Murphy, James; Vreeken, Rob J.; Langridge, James; Kang, Jing X.

    2014-01-01

    A balanced omega-6/omega-3 polyunsaturated fatty acid (PUFA) ratio has been linked to health benefits and the prevention of many chronic diseases. Current dietary intervention studies with different sources of omega-3 fatty acids (omega-3) lack appropriate control diets and carry many other confounding factors derived from genetic and environmental variability. In our study, we used the fat-1 transgenic mouse model as a proxy for long-term omega-3 supplementation to determine, in a well-controlled manner, the molecular phenotype associated with a balanced omega-6/omega-3 ratio. The fat-1 mouse can convert omega-6 to omega-3 PUFAs, which protect against a wide variety of diseases including chronic inflammatory diseases and cancer. Both wild-type (WT) and fat-1 mice were subjected to an identical diet containing 10% corn oil, which has a high omega-6 content similar to that of the Western diet, for a six-month duration. We used a multi-platform lipidomic approach to compare the plasma lipidome between fat-1 and WT mice. In fat-1 mice, an unbiased profiling showed a significant increase in the levels of unesterified eicosapentaenoic acid (EPA), EPA-containing cholesteryl ester, and omega-3 lysophosphospholipids. The increase in omega-3 lipids is accompanied by a significant reduction in omega-6 unesterified docosapentaenoic acid (omega-6 DPA) and DPA-containing cholesteryl ester as well as omega-6 phospholipids and triacylglycerides. Targeted lipidomics profiling highlighted a remarkable increase in EPA-derived diols and epoxides formed via the cytochrome P450 (CYP450) pathway in the plasma of fat-1 mice compared with WT mice. Integration of the results of untargeted and targeted analyses has identified a lipidomic biosignature that may underlie the healthful phenotype associated with a balanced omega-6/omega-3 ratio, and can potentially be used as a circulating biomarker for monitoring the health status and the efficacy of omega-3 intervention in humans. PMID

  8. A protective lipidomic biosignature associated with a balanced omega-6/omega-3 ratio in fat-1 transgenic mice.

    PubMed

    Astarita, Giuseppe; McKenzie, Jennifer H; Wang, Bin; Strassburg, Katrin; Doneanu, Angela; Johnson, Jay; Baker, Andrew; Hankemeier, Thomas; Murphy, James; Vreeken, Rob J; Langridge, James; Kang, Jing X

    2014-01-01

    A balanced omega-6/omega-3 polyunsaturated fatty acid (PUFA) ratio has been linked to health benefits and the prevention of many chronic diseases. Current dietary intervention studies with different sources of omega-3 fatty acids (omega-3) lack appropriate control diets and carry many other confounding factors derived from genetic and environmental variability. In our study, we used the fat-1 transgenic mouse model as a proxy for long-term omega-3 supplementation to determine, in a well-controlled manner, the molecular phenotype associated with a balanced omega-6/omega-3 ratio. The fat-1 mouse can convert omega-6 to omega-3 PUFAs, which protect against a wide variety of diseases including chronic inflammatory diseases and cancer. Both wild-type (WT) and fat-1 mice were subjected to an identical diet containing 10% corn oil, which has a high omega-6 content similar to that of the Western diet, for a six-month duration. We used a multi-platform lipidomic approach to compare the plasma lipidome between fat-1 and WT mice. In fat-1 mice, an unbiased profiling showed a significant increase in the levels of unesterified eicosapentaenoic acid (EPA), EPA-containing cholesteryl ester, and omega-3 lysophosphospholipids. The increase in omega-3 lipids is accompanied by a significant reduction in omega-6 unesterified docosapentaenoic acid (omega-6 DPA) and DPA-containing cholesteryl ester as well as omega-6 phospholipids and triacylglycerides. Targeted lipidomics profiling highlighted a remarkable increase in EPA-derived diols and epoxides formed via the cytochrome P450 (CYP450) pathway in the plasma of fat-1 mice compared with WT mice. Integration of the results of untargeted and targeted analyses has identified a lipidomic biosignature that may underlie the healthful phenotype associated with a balanced omega-6/omega-3 ratio, and can potentially be used as a circulating biomarker for monitoring the health status and the efficacy of omega-3 intervention in humans.

  9. OMEGA Observations of Mars Analogue Rocks

    NASA Technical Reports Server (NTRS)

    Bonello, G.; Bibring, J. P.; Morris, R. V.; Mustard, J. F.

    2003-01-01

    In the last 20 years, imaging spectrometry in the visible and near infrared onboard spacecraft has become an essential technique to study surfaces and atmospheres of planetary objects, prior and in addition to in-situ analyses. Remote sensing experiments analyzing the sunlight reflected by planetary surfaces can be used to derive the mineralogical composition and physical properties of the natural surfaces and atmospheres observed. This technique was successfully used on Mars with ISM instrument. As an improvement of ISM, OMEGA onboard MARS-EXPRESS will play a key role in the mineralogical mapping of the Martian surface. We present the reflectance measurements made with OMEGA during on ground calibration sessions on natural slabs of rocks and minerals part of a database which will be used on similar future American instruments (as CRISM onboard MRO). We discuss the implication on the scientific capabilities of OMEGA instrument.

  10. Motion perception: from phi to omega.

    PubMed Central

    Rose, D; Blake, R

    1998-01-01

    When human observers view dynamic random noise, such as television 'snow', through a curved or annular aperture, they experience a compelling illusion that the noise is moving smoothly and coherently around the curve (the 'omega effect'). In several series of experiments, we have investigated the conditions under which this effect occurs and the possible mechanisms that might cause it. We contrast the omega effect with 'phi motion', seen when an object suddenly changes position. Our conclusions are that the visual scene is first segmented into objects before a coherent velocity is assigned to the texture on each object's surface. The omega effect arises because there are motion mechanisms that deal specifically with object rotation and these interact with pattern mechanisms sensitive to curvature. PMID:9684292

  11. [Omega-3 fatty acids and cognition].

    PubMed

    Hashimoto, Michio

    2014-04-01

    Docosahexaenoic acid, the most abundant omega3 fatty acid in the brain, plays a role in cognitive development, learning ability, neuronal membrane plasticity, synaptogenesis, and neurogenesis, all of which are involved in synaptic transmission and the well-being of normal brain functions, and search on the functionality is still in progress. Establishment of prevention and treatment of neuropsychiatric illnesses, such as dementia is not easy, but from numerous basic and epidemiological studies, increase of omega3 fatty acid dietary intake is reported likely to prevent the onset of dementia. This paper is outlined the relevance of cognitive function and omega3 fatty acids, especially docosahexaenoic acid, and the possibility of preventive effect of the fatty acid on dementia.

  12. Omega-3 fatty acids for cystic fibrosis.

    PubMed

    Oliver, Colleen; Watson, Helen

    2016-01-05

    Studies suggest that a diet rich in omega-3 essential fatty acids may have beneficial anti-inflammatory effects for chronic conditions such as cystic fibrosis. This is an updated version of a previously published review. To determine whether there is evidence that omega-3 polyunsaturated fatty acid supplementation reduces morbidity and mortality and to identify any adverse events associated with supplementation. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Authors and persons interested in the subject of the review were contacted.Date of last search: 13 August 2013. Randomised controlled trials in people with cystic fibrosis comparing omega-3 fatty acid supplements with placebo. Two authors independently selected studies for inclusion, extracted data and assessed the risk of bias of the studies. The searches identified 15 studies; four studies with 91 participants (children and adults) were included; duration of studies ranged from six weeks to six months. Two studies were judged to be at low risk of bias based on adequate randomisation but this was unclear in the other two studies. Three of the studies adequately blinded patients, however, the risk of bias was unclear in all studies with regards to allocation concealment and selective reporting.Two studies compared omega-3 fatty acids to olive oil for six weeks. One study compared a liquid dietary supplement containing omega-3 fatty acids to one without for six months. One study compared omega-3 fatty acids and omega-6 fatty acids to a control (capsules with customised fatty acid blends) for three months. Only one short-term study (19 participants) comparing omega-3 to placebo reported a significant improvement in lung function and Shwachman score and a reduction in sputum volume in the omega-3 group. Another

  13. Dietary omega-3 and omega-6 fatty acids compete in producing tissue compositions and tissue responses.

    PubMed

    Lands, Bill

    2014-11-01

    Serious food-related health disorders may be prevented by recognizing the molecular processes that connect the dietary intake of vitamin-like fatty acids to tissue accumulation of precursors of potent hormone-like compounds that cause harmful tissue responses. Conversion of dietary 18-carbon omega-3 and omega-6 polyunsaturated fatty acids to tissue 20- and 22-carbon highly unsaturated fatty acids (HUFAs) is catalyzed by promiscuous enzymes that allow different types of fatty acid to compete among each other for accumulation in tissue HUFA. As a result, food choices strongly influence the types of accumulated tissue HUFA. However, the conversion of tissue HUFA to active hormones and their receptor-mediated actions occurs with discriminating enzymes and receptors that give more intense responses for the omega-6 and omega-3 hormones. Undesired chronic health disorders, which are made worse by excessive omega-6 hormone actions, can be prevented by eating more omega-3 fats, less omega-6 fats, and fewer calories per meal.

  14. Effects of Diets Enriched in Omega-9 or Omega-6 Fatty Acids on Reproductive Process.

    PubMed

    Mousavi, Seyedeh Neda; Koohdani, Fariba; Shidfar, Farzad; Shafiei-Neek, Leila

    2016-06-01

    Maternal type and amounts of dietary fatty acids affect on reproductive process in the mice. The present study investigated the effects of maternal supplementation with different amounts of omega-6 or omega-9 during pregnancy on the number of offspring, sex-ratio and duration of gestation. Eight-week-old female C57BL/6 mice were randomly assigned into four dietary groups including low omega-6 (16%; LO6), low omega-9 (16%; LO9), high omega-6 (45%; HO6) and high omega-9 (45%; HO9) during gestation. Number of offspring, sex-ratio and duration of pregnancy were compared among four dietary groups. There was significant difference between LO6 and HO6 (p < 0.0001), LO9 and HO9 (p < 0.0001) groups in total number of pups. The number of female and male offspring were significantly different between LO6 and LO9 (p = 0.009 and p = 0.001, respectively), LO9 and HO9 (p = 0.01 and p = 0.025) groups. Duration of pregnancy was significantly higher in low fat diet than high fat diet groups (< 0.001). High fat diet reduced number of pups, gestation duration and lead to early labor. Omega-9 fatty acids shifted sex of offspring to females.

  15. Effects of Diets Enriched in Omega-9 or Omega-6 Fatty Acids on Reproductive Process

    PubMed Central

    Mousavi, Seyedeh Neda; Koohdani, Fariba; Shidfar, Farzad; Shafiei-Neek, Leila

    2016-01-01

    Objective: Maternal type and amounts of dietary fatty acids affect on reproductive process in the mice. The present study investigated the effects of maternal supplementation with different amounts of omega-6 or omega-9 during pregnancy on the number of offspring, sex-ratio and duration of gestation. Materials and methods: Eight-week-old female C57BL/6 mice were randomly assigned into four dietary groups including low omega-6 (16%; LO6), low omega-9 (16%; LO9), high omega-6 (45%; HO6) and high omega-9 (45%; HO9) during gestation. Number of offspring, sex-ratio and duration of pregnancy were compared among four dietary groups. Results: There was significant difference between LO6 and HO6 (p < 0.0001), LO9 and HO9 (p < 0.0001) groups in total number of pups. The number of female and male offspring were significantly different between LO6 and LO9 (p = 0.009 and p = 0.001, respectively), LO9 and HO9 (p = 0.01 and p = 0.025) groups. Duration of pregnancy was significantly higher in low fat diet than high fat diet groups (< 0.001). Conclusion: High fat diet reduced number of pups, gestation duration and lead to early labor. Omega-9 fatty acids shifted sex of offspring to females. PMID:27648098

  16. Inertial Confinement Fusion Implosions with Seeded Magnetic Fields on OMEGA

    NASA Astrophysics Data System (ADS)

    Hohenberger, M.

    2011-10-01

    Experiments applying laser-driven magnetic-flux compression to inertial confinement fusion (ICF) experiments to enhance the fuel-assembly performance are described. Spherical CH targets filled with 10 atm of deuterium gas were imploded by the OMEGA laser in polar-drive geometry. The targets were embedded with an 80-kG magnetic seed field. Upon laser irradiation, the high-implosion velocities and ionization of the target fill lead to trapping of the magnetic field inside the capsule and its amplification through flux compression to up to tens of megagauss. At such strong magnetic fields, the hot spot inside a spherical target becomes strongly magnetized, reducing the heat losses through electron confinement. The experimentally observed ion temperature was enhanced by 15% and the neutron yield was increased by 30%, compared to nonmagnetized implosions. This represents the first experimental verification of performance enhancement resulting from embedding a strong magnetic field into an ICF capsule. The compressed field was probed via proton deflectometry using the 14.7-MeV protons generated in the D+3He fusion reactions from a laser-imploded glass microballoon. Experimental data for the fuel-assembly performance and magnetic field are compared to numerical results from combining the 1-D hydrodynamics code LILAC with a 2-D, azimuthal symmetry MHD postprocessor. This work was supported by the U.S. Department of Energy under Cooperative Agreement No. DE-FC02-04ER54789 and DE-FC52-08NA28302. In collaboration with P.-Y. Chang, G. Fiksel, J. P. Knauer, R. Betti, F. J. Marshall, and D. D. Meyerhofer (Laboratory for Laser Energetics, Univ. of Rochester), and F. H. Séguin and R. D. Petrasso (PSFC, MIT).

  17. Polar-direct-drive experiments with contoured-shell targets on OMEGA

    DOE PAGES

    Marshall, F. J.; Radha, P. B.; Bonino, M. J.; ...

    2016-01-28

    Polar-driven direct-drive experiments recently performed on the OMEGA Laser System have demonstrated the efficacy of using a target with a contoured shell with varying thickness to improve the symmetry and fusion performance of the implosion. The polar-driven contoured-shell implosions have substantially reduced low mode perturbations compared to polar-driven spherical-shell implosions as diagnosed by x-ray radiographs up to shell stagnation. As a result, fusion yields were increased by more than a factor of ~2 without increasing the energy of the laser by the use of contoured shells.

  18. Polar-direct-drive experiments with contoured-shell targets on OMEGA

    SciTech Connect

    Marshall, F. J.; Radha, P. B.; Bonino, M. J.; Delettrez, J. A.; Epstein, R.; Glebov, V. Yu.; Harding, D. R.; Stoeckl, C.; Frenje, J. A.; Gatu Johnson, M.; Séguin, F. H.; Sio, H.; Zylstra, A.; Giraldez, E.

    2016-01-15

    Polar-driven direct-drive experiments recently performed on the OMEGA Laser System have demonstrated the efficacy of using a target with a contoured shell with varying thickness to improve the symmetry and fusion performance of the implosion. The polar-driven contoured-shell implosions have substantially reduced low mode perturbations compared to polar-driven spherical-shell implosions as diagnosed by x-ray radiographs up to shell stagnation. Fusion yields were increased by more than a factor of ∼2 without increasing the energy of the laser by the use of contoured shells.

  19. Dietary omega-3 fatty acids for women.

    PubMed

    Bourre, Jean-Marie

    2007-01-01

    This review details the specific needs of women for omega-3 fatty acids, including alpha linoleic acid (ALA) and the very long chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega-3 fatty acid (dietary or in capsules) ensures that a woman's adipose tissue contains a reserve of these fatty acids for the developing fetus and the breast-fed newborn infant. This ensures the optimal cerebral and cognitive development of the infant. The presence of large quantities of EPA and DHA in the diet slightly lengthens pregnancy, and improves its quality. Human milk contains both ALA and DHA, unlike that of other mammals. Conditions such as diabetes can alter the fatty acid profile of mother's milk, while certain diets, like those of vegetarians, vegans, or even macrobiotic diets, can have the same effect, if they do not include seafood. ALA, DHA and EPA, are important for preventing ischemic cardiovascular disease in women of all ages. Omega-3 fatty acids can help to prevent the development of certain cancers, particularly those of the breast and colon, and possibly of the uterus and the skin, and are likely to reduce the risk of postpartum depression, manic-depressive psychosis, dementias (Alzheimer's disease and others), hypertension, toxemia, diabetes and, to a certain extend, age-related macular degeneration. Omega-3 fatty acids could play a positive role in the prevention of menstrual syndrome and postmenopausal hot flushes. The normal western diet contains little ALA (less than 50% of the RDA). The only adequate sources are rapeseed oil (canola), walnuts and so-called "omega-3" eggs (similar to wild-type or Cretan eggs). The amounts of EPA and DHA in the diet vary greatly from person to person. The only good sources are fish and seafood, together with "omega-3" eggs.

  20. Measurement of the spin of the omega(-) hyperon.

    PubMed

    Aubert, B; Barate, R; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Del Amo Sanchez, P; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, Ch; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Staengle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Galeazzi, F; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; John, M J J; Malclès, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Martinez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihalyi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2006-09-15

    A measurement of the spin of the Omega(-) hyperon produced through the exclusive process Xi(c)(0)-->Omega(-)K(+) is presented using a total integrated luminosity of 116 fb(-1) recorded with the BABAR detector at the e(+)e(-) asymmetric-energy B factory at SLAC. Under the assumption that the Xi(c)(0) has spin 1/2, the angular distribution of the Lambda from Omega(-)-->LambdaK(-) decay is inconsistent with all half-integer Omega(-) spin values other than 3/2. Lower statistics data for the process Omega(c)(0)-->Omega(-)pi(+) from a 230 fb(-1) sample are also found to be consistent with Omega(-) spin 3/2. If the Xi(c)(0) spin were 3/2, an Omega(-) spin of 5/2 could not be excluded.

  1. Dual-shank attachment design for omega seals

    DOEpatents

    Sattinger, Stanley S.

    1978-01-01

    An improved apparatus and process for attaching welded omega seal segments to reactor heads, standpipes, mechanisms, and plugs comprises a first shank in combination with a second shank to attach an omega seal at a metal-to-metal interface.

  2. Hierarchical Analysis of the Omega Ontology

    SciTech Connect

    Joslyn, Cliff A.; Paulson, Patrick R.

    2009-12-01

    Initial delivery for mathematical analysis of the Omega Ontology. We provide an analysis of the hierarchical structure of a version of the Omega Ontology currently in use within the US Government. After providing an initial statistical analysis of the distribution of all link types in the ontology, we then provide a detailed order theoretical analysis of each of the four main hierarchical links present. This order theoretical analysis includes the distribution of components and their properties, their parent/child and multiple inheritance structure, and the distribution of their vertical ranks.

  3. Binary phase locked loops for Omega receivers

    NASA Technical Reports Server (NTRS)

    Chamberlin, K.

    1974-01-01

    An all-digital phase lock loop (PLL) is considered because of a number of problems inherent in an employment of analog PLL. The digital PLL design presented solves these problems. A single loop measures all eight Omega time slots. Memory-aiding leads to the name of this design, the memory-aided phase lock loop (MAPLL). Basic operating principles are discussed and the superiority of MAPLL over the conventional digital phase lock loop with regard to the operational efficiency for Omega applications is demonstrated.

  4. Flight evaluation: Ohio University omega receiver base

    NASA Technical Reports Server (NTRS)

    Chamberlin, K. A.; Lilley, R. W.; Salter, R. J.

    1974-01-01

    A flight evaluation is presented of the Ohio University Omega Receiver Base, developed under the NASA Tri-University Program in Air Transportation, to provide a vehicle for the transfer of flight-test data to NASA and to other participants in the Tri-University program. Chart recordings of flight data are given, along with chronological listings of significant events which occurred during the flight. Digital data was prepared in data-processing card form for distribution. Data include phase measurements from all eight Omega time-slots for the duration of the flight, plus event marks which serve to correlate the phase data with flight-path documentation.

  5. OmegaCAM: ESO's Newest Imager

    NASA Astrophysics Data System (ADS)

    Kuijken, K.

    2011-12-01

    OmegaCAM, the 300-megapixel wide-field optical camera on the new VLT Survey Telescope (VST), was commissioned between March and August of this year. This new capability in ESO's arsenal takes images of 1 degree by 1° patches of the sky, at 0.2 arcseconds per pixel resolution and of image quality well-matched to the natural seeing on Paranal. The commissioning and OmegaCAM's scientific niche as a high image quality, ultra-violet- sensitive wide-field survey instrument are briefly discussed.

  6. Omega 3 fatty acids and the eye.

    PubMed

    Cakiner-Egilmez, Tulay

    2008-01-01

    The health benefits of fish oil have been known for decades. Most of the health benefits of fish oil can be attributed to the presence of omega-3 essential fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Clinical studies have suggested that DHA and EPA lower triglycerides; slow the buildup of atherosclerotic plaques; lower blood pressure slightly; as well as reduce the risk of death, heart attack, and arrhythmias. Studies have also shown that omega-3 fatty acids may slow the progression of vision loss from AMD and reverse the signs of dry eye syndrome.

  7. [Antioxidant activity of vegetable oils with various omega-6/omega-3 fatty acids ratio].

    PubMed

    Guseva, D A; Prozorovskaia, N N; Shironin, A V; Sanzhakov, M A; Evteeva, N M; Rusina, I F; Kasaikina, O T

    2010-01-01

    Antioxidant activity and the oxidative stability were investigated in flax, sesame, silybum oils and oils with different omega-6/omega-3 fatty acid ratio. The content of antioxidants (AO) in crude oils and their reactivity towards peroxyl radicals were studied using kinetic method for addition of oil in a model reaction of cumol oxidation. There were correlations between PUFA/omega-9 and thermal stability (50 degrees C); between gamma-tocopherol content and resistantance to oxidative changes after storage at (10 +/- 2) degrees C for 6 months.

  8. Simulations of the propagation of multiple-FM smoothing by spectral dispersion on OMEGA EP

    NASA Astrophysics Data System (ADS)

    Kelly, J. H.; Shvydky, A.; Marozas, J. A.; Guardalben, M. J.; Kruschwitz, B. E.; Waxer, L. J.; Dorrer, C.; Hill, E.; Okishev, A. V.; Di Nicola, J.-M.

    2013-02-01

    A one-dimensional (1-D) smoothing by spectral dispersion (SSD) system for smoothing focal-spot nonuniformities using multiple modulation frequencies has been commissioned on one long-pulse beamline of OMEGA EP, the first use of such a system in a high-energy laser. Frequency modulation (FM) to amplitude modulation (AM) conversion in the infrared (IR) output, frequency conversion, and final optics affected the accumulation of B-integral in that beamline. Modeling of this FM-to-AM conversion using the code Miró [Morice, O., "Miró: Complete modeling and software for pulse amplification and propagation in high-power laser systems," Opt. Eng. 42(6), 1530-1541 (2003).] was used as input to set the beamline performance limits for picket (short) pulses with multi-FM SSD applied. This article first describes that modeling. The 1-D SSD analytical model of Chuang [Chuang, Y.-H., "Amplification of broad-bandwidth phase-modulated laser counterpropagating light waves in homogeneous plasma," Ph.D. thesis, University of Rochester (September 1991).] is first extended to the case of multiple modulators and then used to benchmark Miró simulations. Comparison is also made to an alternative analytic model developed by Hocquet et al. [Hocquet, S., Penninckx, D., Bordenave, E., Gouédard, C. and Jaouën, Y., "FM-to-AM conversion in high-power lasers," Appl. Opt. 47(18), 3338-3349 (2008).] With the confidence engendered by this benchmarking, Miró results for multi-FM SSD applied on OMEGA EP are then presented. The relevant output section(s) of the OMEGA EP Laser System are described. The additional B-integral in OMEGA EP IR components upstream of the frequency converters due to AM is modeled. The importance of locating the image of the SSD dispersion grating at the frequency converters is demonstrated. Finally, since frequency conversion is not performed in OMEGA EP's target chamber, the additional AM due to propagation to the target chamber's vacuum window is modeled.

  9. Spin-forbidden c {sup 3}{Sigma}{sup +}({Omega}=1)<- X {sup 1}{Sigma}{sup +} transition in NaCs: Investigation of the {Omega}=1 state in hot and cold environments

    SciTech Connect

    Grochola, A.; Kowalczyk, P.; Szczepkowski, J.; Jastrzebski, W.; Wakim, A.; Zabawa, P.; Bigelow, N. P.

    2011-07-15

    Comprehensive spectroscopic studies of hot and ultracold samples of NaCs molecules were combined to complete the investigation of the (3){Omega}=1 <- X {sup 1}{Sigma}{sup +} transition for the NaCs molecule. Polarization labeling, photoassociation, and pulsed laser depletion spectroscopy were used to collect data on rovibrational levels of the (3){Omega}=1 state [here described as the c {sup 3}{Sigma}{sup +} state in Hund's case (a) notation]. The highest observed level was v=72 located {approx}5 GHz below the atomic asymptote Na(3 {sup 2}S{sub 1/2}) + Cs(6 {sup 2}P{sub 3/2}). Approximately 1400 levels were used to construct the potential energy curve of the (3){Omega}=1 state for the full range of interatomic distances.

  10. Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions

    ERIC Educational Resources Information Center

    Padilla, Miguel A.; Divers, Jasmin

    2013-01-01

    The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…

  11. Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions

    ERIC Educational Resources Information Center

    Padilla, Miguel A.; Divers, Jasmin

    2013-01-01

    The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…

  12. Baryon spectroscopy and the omega minus

    SciTech Connect

    Samios, N.P.

    1994-12-31

    In this report, I will mainly discuss baryon resonances with emphasis on the discovery of the {Omega}{sup {minus}}. However, for completeness, I will also present some data on the meson resonances which together with the baryons led to the uncovering of the SU(3) symmetry of particles and ultimately to the concept of quarks.

  13. Omega Navigation System Course Book. Volume 1.

    DTIC Science & Technology

    1994-07-01

    Chabrier, La Reunion, Fr. Socotra Island (U.K.) Delagoa Bay (South Africa) Seychelles Islands (U.K.) Tierra del Fuego, Chile Golfo Nuevo, Chubut...inherent operational limitations of individual systems. As a stand-alone navigation system, Omega provides an advertised worldwide navigation capa - bility

  14. Omega time transmissions and receiving requirements

    NASA Technical Reports Server (NTRS)

    Chi, A. R.; Fletcher, L. A.; Casselman, C. J.

    1971-01-01

    A short history is given of the development of dual VLF time transmission techniques. The theory of time recovery from the relative phase of the dual frequency transmission is presented. The transmission and receiving requirements for cycle identification and cycle ambiguity resolution are described. Finally, an experiment to test the capability of time transmission of the OMEGA system is proposed

  15. Omega-3 Index and Cardiovascular Health

    PubMed Central

    von Schacky, Clemens

    2014-01-01

    Recent large trials with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the cardiovascular field did not demonstrate a beneficial effect in terms of reductions of clinical endpoints like total mortality, sudden cardiac arrest or other major adverse cardiac events. Pertinent guidelines do not uniformly recommend EPA + DHA for cardiac patients. In contrast, in epidemiologic findings, higher blood levels of EPA + DHA were consistently associated with a lower risk for the endpoints mentioned. Because of low biological and analytical variability, a standardized analytical procedure, a large database and for other reasons, blood levels of EPA + DHA are frequently assessed in erythrocytes, using the HS-Omega-3 Index® methodology. A low Omega-3 Index fulfills the current criteria for a novel cardiovascular risk factor. Neutral results of intervention trials can be explained by issues of bioavailability and trial design that surfaced after the trials were initiated. In the future, incorporating the Omega-3 Index into trial designs by recruiting participants with a low Omega-3 Index and treating them within a pre-specified target range (e.g., 8%–11%), will make more efficient trials possible and provide clearer answers to the questions asked than previously possible. PMID:24566438

  16. Cryogneic-Target Performance and Implosion Physics Studies on OMEGA

    SciTech Connect

    Smalyuk, V.A.; Betti, R.; Boehly, T.R.; Craxton, R.S.; Delettrez, J.A.; Edgell, D.H.; Glebov, V.Yu.; Goncharov, V.N.; Harding, D.R.; Hu, S.X.; Knauer, J.P.; Marshall, F.J.; McCrory, R.L.; McKenty, P.W.; Meyerhofer, D.D.; Radha, R.B.; Regan, S.P.; Sangster, T.C.; Seka, W.; Short, R.W.; Shvarts, D.; Skupsky, S.; Soures, J.M.; Stoeckl, C.; Yaakobi, B.; Frenje, J.A.; Li, C.K.; Petrasso, R.D.; Seguin, F.H.

    2009-03-06

    Recent progress in direct-drive cryogenic implosions on the OMEGA Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is reviewed. Ignition-relevant areal densities of ~200 mg/cm^2 in cryogenic D2 implosions with peak laser-drive intensities of ~5 x 10^14 W/cm^2 were previously reported [T. C. Sangster et al., Phys. Rev. Lett. 100, 185006 (2008)]. The laser intensity is increased to ~10^15 W/cm^2 to demonstrate ignition-relevant implosion velocities of 3–4 x 10^7 cm/ s, providing an understanding of the relevant target physics. Planar-target acceleration experiments show the importance of the nonlocal electron-thermal-transport effects for modeling the laser drive. Nonlocal and hot-electron preheat is observed to stabilize the Rayleigh–Taylor growth at a peak drive intensity of ~10^15 W/cm^2. The shell preheat caused by hot electrons generated by two-plasmon-decay instability was reduced by using Si-doped ablators. The measured compressibility of planar plastic targets driven with high-compression shaped pulses agrees well with one-dimensional simulations at these intensities. Shock mistiming has contributed to compression degradation of recent cryogenic implosions driven with continuous pulses. Multiple-picket (shock-wave) target designs make it possible for a more robust tuning of the shock-wave arrival times. Cryogenic implosions driven with double-picket pulses demonstrate somewhat improved compression performance at a peak drive intensity of ~10^15 W/cm^2.

  17. Neutron temporal diagnostic for high-yield deuterium–tritium cryogenic implosions on OMEGA

    SciTech Connect

    Stoeckl, C.; Boni, R.; Ehrne, F.; Forrest, C. J.; Glebov, V. Yu.; Katz, J.; Lonobile, D. J.; Magoon, J.; Regan, S. P.; Shoup, M. J.; Sorce, A.; Sorce, C.; Sangster, T. C.; Weiner, D.

    2016-05-15

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic deuterium–tritium (DT) implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments—a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ∼16 m to a streak camera in a well-shielded location. An ∼200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ∼40 ± 10 ps was measured in a dedicated experiment using hard x-rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. The measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

  18. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

    DOE PAGES

    Stoeckl, C.; Boni, R.; Ehrne, F.; ...

    2016-05-10

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic DT implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments—a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ~16 m to a streak camera in amore » well-shielded location. An ~200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ~40±10 ps was measured in a dedicated experiment using hard x rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. Furthermore, the measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.« less

  19. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

    SciTech Connect

    Stoeckl, C.; Boni, R.; Ehrne, F.; Forrest, C. J.; Glebov, V. Yu.; Katz, J.; Lonobile, D. J.; Magoon, J.; Regan, S. P.; Shoup, III, M. J.; Sorce, A.; Sorce, C.; Sangster, T. C.; Weiner, D.

    2016-05-10

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic DT implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments—a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ~16 m to a streak camera in a well-shielded location. An ~200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ~40±10 ps was measured in a dedicated experiment using hard x rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. Furthermore, the measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

  20. Simulations of X-ray Emission from Omega Fill Tube Experiments

    SciTech Connect

    Langer, S; Izumi, N; Dittrich, T; Haan, S

    2006-11-13

    The capsules used in ignition experiments on the National Ignition Facility (NIF) laser will have a layer of frozen DT inside a low-Z shell. Liquid DT will be injected through a narrow fill tube that penetrates the shell and frozen in place. The fill tube is a perturbation on the surface of the capsule and hydrodynamic instabilities will cause this perturbation to grow during an implosion. Experiments to investigate the growth of perturbations due to fill tubes have been carried out on the Omega laser. The goal of these experiments was to validate simulations at Omega energy scales and thus increase confidence in the use of simulations in planning for NIF experiments. Simulations show that the fill tube leads to a jet of shell material that penetrates into the DT fuel. Simulations will be used to pick experimental conditions in which the jet is small enough that it does not significantly reduce the yield of a NIF implosion. This paper compares experiments in which bumps and stalks were used as fill tube surrogates to 2D simulations of x-ray emission from Omega capsule implosions. Experiments and simulations are in reasonable agreement on the size of a bump or stalk required to produce a jet that is visible above the emission from a (nominally) smooth capsule.

  1. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

    SciTech Connect

    Stoeckl, C.; Boni, R.; Ehrne, F.; Forrest, C. J.; Glebov, V. Yu.; Katz, J.; Lonobile, D. J.; Magoon, J.; Regan, S. P.; Shoup, III, M. J.; Sorce, A.; Sorce, C.; Sangster, T. C.; Weiner, D.

    2016-05-10

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic DT implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments—a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ~16 m to a streak camera in a well-shielded location. An ~200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ~40±10 ps was measured in a dedicated experiment using hard x rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. Furthermore, the measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

  2. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Stoeckl, C.; Boni, R.; Ehrne, F.; Forrest, C. J.; Glebov, V. Yu.; Katz, J.; Lonobile, D. J.; Magoon, J.; Regan, S. P.; Shoup, M. J.; Sorce, A.; Sorce, C.; Sangster, T. C.; Weiner, D.

    2016-05-01

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic deuterium-tritium (DT) implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments—a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ˜16 m to a streak camera in a well-shielded location. An ˜200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ˜40 ± 10 ps was measured in a dedicated experiment using hard x-rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. The measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

  3. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA.

    PubMed

    Stoeckl, C; Boni, R; Ehrne, F; Forrest, C J; Glebov, V Yu; Katz, J; Lonobile, D J; Magoon, J; Regan, S P; Shoup, M J; Sorce, A; Sorce, C; Sangster, T C; Weiner, D

    2016-05-01

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic deuterium-tritium (DT) implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments-a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ∼16 m to a streak camera in a well-shielded location. An ∼200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ∼40 ± 10 ps was measured in a dedicated experiment using hard x-rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. The measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

  4. Omega-3 Fatty Acids in the Management of Epilepsy.

    PubMed

    Tejada, Silvia; Martorell, Miquel; Capó, Xavier; Tur, Josep A; Pons, Antoni; Sureda, Antoni

    2016-01-01

    Omega-3 and omega-6 fatty acids are polyunsaturated fatty acids (PUFAs) with multiple double bonds. Linolenic and alpha-linolenic acids are omega-6 and omega-3 PUFAs, precursors for the synthesis of long-chain PUFAs (LC-PUFAs), such as arachidonic acid (omega-6 PUFA), and eicosapentaenoic and docosahexaenoic acids (omega-3 PUFAs). The three most important omega-3 fatty acids are alpha-linolenic, eicosapentaenoic and docosahexaenoic acids, which cannot be synthesized in enough amounts by the body, and therefore they must be supplied by the diet. Omega-3 fatty acids are essential for the correct functioning of the organism and participate in many physiological processes in the brain. Epilepsy is a common and heterogeneous chronic brain disorder characterized by recurrent epileptic seizures leading to neuropsychiatric disabilities. The prevalence of epilepsy is high achieving about 1% of the general population. There is evidence suggesting that omega-3 fatty acids may have neuroprotective and anticonvulsant effects and, accordingly, may have a potential use in the treatment of epilepsy. In the present review, the potential use of omega-3 fatty acids in the treatment of epilepsy, and the possible proposed mechanisms of action are discussed. The present article summarizes the recent knowledge of the potential protective role of dietary omega-3 fatty acids in epilepsy.

  5. Relativistic second-harmonic generation of a laser from underdense plasmas

    SciTech Connect

    Singh, K.P.; Gupta, D.N.; Yadav, Sushila; Tripathi, V.K.

    2005-01-01

    A high intensity laser obliquely incident on a vacuum-plasma interface produces second-harmonic radiation in the reflected component. The efficiency of second-harmonic generation increases with the angle of incidence, up to critical angle of incidence (our model is not valid beyond critical angle of incidence). The efficiency also depends on electron density, showing a maximum at {omega}{sub p}{sup 2}/{omega}{sup 2} congruent with 0.7, where {omega}{sub p} and {omega} are relativistic plasma frequency and laser frequency, respectively. The efficiency of second-harmonic generation increases sharply with laser intensity in the nonrelativistic regime and saturates at higher intensities. The intensity of the second harmonic is proportional to square of the laser intensity at low pump laser intensities and tends to proportional to laser intensity in the strong relativistic regime.

  6. Improving cryogenic deuterium–tritium implosion performance on OMEGA

    SciTech Connect

    Sangster, T. C.; Goncharov, V. N.; Betti, R.; Radha, P. B.; Boehly, T. R.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Froula, D. H.; Glebov, Y. Yu.; Harding, D. R.; Hohenberger, M.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H.; Kessler, T. J.; and others

    2013-05-15

    A flexible direct-drive target platform is used to implode cryogenic deuterium–tritium (DT) capsules on the OMEGA laser [Boehly et al., Opt. Commun. 133, 495 (1997)]. The goal of these experiments is to demonstrate ignition hydrodynamically equivalent performance where the laser drive intensity, the implosion velocity, the fuel adiabat, and the in-flight aspect ratio (IFAR) are the same as those for a 1.5-MJ target [Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)] designed to ignite on the National Ignition Facility [Hogan et al., Nucl. Fusion 41, 567 (2001)]. The results from a series of 29 cryogenic DT implosions are presented. The implosions were designed to span a broad region of design space to study target performance as a function of shell stability (adiabat) and implosion velocity. Ablation-front perturbation growth appears to limit target performance at high implosion velocities. Target outer-surface defects associated with contaminant gases in the DT fuel are identified as the dominant perturbation source at the ablation surface; performance degradation is confirmed by 2D hydrodynamic simulations that include these defects. A trend in the value of the Lawson criterion [Betti et al., Phys. Plasmas 17, 058102 (2010)] for each of the implosions in adiabat–IFAR space suggests the existence of a stability boundary that leads to ablator mixing into the hot spot for the most ignition-equivalent designs.

  7. Charged-Particle Acceleration and Energy Loss Measurements on OMEGA

    NASA Astrophysics Data System (ADS)

    Hicks, D. G.; Li, C. K.; Séguin, F. H.; Ram, A. K.; Frenje, J. A.; Petrasso, R. D.; Soures, J. M.; Glebov, V. Yu.; Meyerhofer, D. D.; Roberts, S.; Sorce, C.; Stoeckl, C.; Sangster, T. C.; Phillips, T. W.

    2000-10-01

    Measurements have been made of charged fusion products produced in D ^3He-filled targets irradiated on OMEGA. Comparing the energy shifts of four particle types has probed two distinct physical processes: electrostatic acceleration in the low-density corona and energy loss in the high-density target. When the burn occurred during the laser pulse, particle energy shifts were dominated by acceleration effects. Using a simple mode, the time history of the target's electrostatic potential was found and shown to decay to zero soon after laser irradiation was complete. When the burn occurred after the pulse, particle energy shifts were dominated by energy losses in the target, allowing charged-particle stopping-power predictions to be tested. The results provide the first verification of the general form of stopping power theories over a wide velocity range. This work was supported by the U.S. DOE Office of ICF under Coop. Agreem. No. DE-FC03-92SF19460.

  8. A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA

    SciTech Connect

    Glebov, V. Yu. Forrest, C. J.; Marshall, K. L.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J.; Stoeckl, C.

    2014-11-15

    A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D{sub 2} neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

  9. Time history prediction of direct-drive implosions on the Omega facility

    SciTech Connect

    Laffite, S.; Bourgade, J. L.; Caillaud, T.; Delettrez, J A; Frenje, J. A.; Girard, F.; Glebov, V. Yu.; Joshi, Tirtha Raj; Landoas, O.; Legay, G.; Lemaire, S.; Mancini, R. C.; Marshall, F. J.; Masse, L.; Masson-Laborde, P. E.; Michel, D. T.; Philippe, F.; Reverdin, C.; Seka, W.; Tassin, V.

    2016-01-14

    We present in this article direct-drive experiments that were carried out on the Omega facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. Two different pulse shapes were tested in order to vary the implosion stability of the same target whose parameters, dimensions and composition, remained the same. The direct-drive configuration on the Omega facility allows the accurate time-resolvedmeasurement of the scattered light. We show that, provided the laser coupling is well controlled, the implosion time history, assessed by the “bang-time” and the shell trajectory measurements, can be predicted. This conclusion is independent on the pulse shape. In contrast, we show that the pulse shape affects the implosion stability, assessed by comparing the target performances between prediction and measurement. For the 1-ns square pulse, the measuredneutron number is about 80% of the prediction. Lastly, for the 2-step 2-ns pulse, we test here that this ratio falls to about 20%.

  10. Design of Platforms for Backlighting Spherical Implosions on OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Craxton, R. S.; Hohenberger, M.; Kehoe, W. E.; Marshall, F. J.; Michel, D. T.; Radha, P. B.; Rosenberg, M. J.

    2016-10-01

    A common problem when backlighting implosions on OMEGA and at the National Ignition Facility (NIF) is that the implosion uniformity can be compromised by the loss of those beams used to drive the backlighter. The 2-D hydrodynamics code SAGE, which includes 3-D laser ray tracing, has been used to design irradiation configurations in which beam pointings and energies are adjusted to restore optimal implosion uniformity. Experimental x-ray self-emission images have demonstrated the effectiveness of these configurations for an OMEGA platform in which six beams are removed to drive the backlighter and a polar-drive NIF platform in which two quads are removed. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  11. A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA.

    PubMed

    Glebov, V Yu; Forrest, C J; Marshall, K L; Romanofsky, M; Sangster, T C; Shoup, M J; Stoeckl, C

    2014-11-01

    A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D2 neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

  12. High-Performance Cryogenic Designs for OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Goncharov, V. N.; Collins, T. J. B.; Marozas, J. A.; Regan, S. P.; Betti, R.; Boehly, T. R.; Campbell, E. M.; Froula, D. H.; Igumenshchev, I. V.; McCrory, R. L.; Myatt, J. F.; Radha, P. B.; Sangster, T. C.; Shvydky, A.

    2016-10-01

    The main advantage of laser symmetric direct drive (SDD) is a significantly higher coupled drive laser energy to the hot-spot internal energy at stagnation compared to that of laser indirect drive. Because of coupling losses resulting from cross-beam energy transfer (CBET), however, reaching ignition conditions on the NIF with SDD requires designs with excessively large in-flight aspect ratios ( 30). Results of cryogenic implosions performed on OMEGA show that such designs are unstable to short-scale nonuniformity growth during shell implosion. Several CBET reduction strategies have been proposed in the past. This talk will discuss high-performing designs using several CBET-mitigation techniques, including using drive laser beams smaller than the target size and wavelength detuning. Designs that are predicted to reach alpha burning regimes as well as a gain of 10 to 40 at the NIF-scale will be presented. Hydrodynamically scaled OMEGA designs with similar CBET-reduction techniques will also be discussed. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  13. New insights into the health effects of dietary saturated and omega-6 and omega-3 polyunsaturated fatty acids

    PubMed Central

    2012-01-01

    Cardiovascular diseases and cancers are leading causes of morbidity and mortality. Reducing dietary saturated fat and replacing it with polyunsaturated fat is still the main dietary strategy to prevent cardiovascular diseases, although major flaws have been reported in the analyses supporting this approach. Recent studies introducing the concept of myocardial preconditioning have opened new avenues to understand the complex interplay between the various lipids and the risk of cardiovascular diseases. The optimal dietary fat profile includes a low intake of both saturated and omega-6 fatty acids and a moderate intake of omega-3 fatty acids. This profile is quite similar to the Mediterranean diet. On the other hand, recent studies have found a positive association between omega-6 and breast cancer risk. In contrast, omega-3 fatty acids do have anticancer properties. It has been shown that certain (Mediterranean) polyphenols significantly increase the endogenous synthesis of omega-3 whereas high intake of omega-6 decreases it. Finally, epidemiological studies suggest that a high omega-3 to omega-6 ratio may be the optimal strategy to decrease breast cancer risk. Thus, the present high intake of omega-6 in many countries is definitely not the optimal strategy to prevent cardiovascular disease and cancers. A moderate intake of plant and marine omega-3 in the context of the traditional Mediterranean diet (low in saturated and omega-6 fatty acids but high in plant monounsaturated fat) appears to be the best approach to reduce the risk of both cardiovascular diseases and cancers, in particular breast cancer. PMID:22613931

  14. A host-microbiome interaction mediates the opposing effects of omega-6 and omega-3 fatty acids on metabolic endotoxemia.

    PubMed

    Kaliannan, Kanakaraju; Wang, Bin; Li, Xiang-Yong; Kim, Kui-Jin; Kang, Jing X

    2015-06-11

    Metabolic endotoxemia, commonly derived from gut dysbiosis, is a primary cause of chronic low grade inflammation that underlies many chronic diseases. Here we show that mice fed a diet high in omega-6 fatty acids exhibit higher levels of metabolic endotoxemia and systemic low-grade inflammation, while transgenic conversion of tissue omega-6 to omega-3 fatty acids dramatically reduces endotoxemic and inflammatory status. These opposing effects of tissue omega-6 and omega-3 fatty acids can be eliminated by antibiotic treatment and animal co-housing, suggesting the involvement of the gut microbiota. Analysis of gut microbiota and fecal transfer revealed that elevated tissue omega-3 fatty acids enhance intestinal production and secretion of intestinal alkaline phosphatase (IAP), which induces changes in the gut bacteria composition resulting in decreased lipopolysaccharide production and gut permeability, and ultimately, reduced metabolic endotoxemia and inflammation. Our findings uncover an interaction between host tissue fatty acid composition and gut microbiota as a novel mechanism for the anti-inflammatory effect of omega-3 fatty acids. Given the excess of omega-6 and deficiency of omega-3 in the modern Western diet, the differential effects of tissue omega-6 and omega-3 fatty acids on gut microbiota and metabolic endotoxemia provide insight into the etiology and management of today's health epidemics.

  15. A host-microbiome interaction mediates the opposing effects of omega-6 and omega-3 fatty acids on metabolic endotoxemia

    PubMed Central

    Kaliannan, Kanakaraju; Wang, Bin; Li, Xiang-Yong; Kim, Kui-Jin; Kang, Jing X.

    2015-01-01

    Metabolic endotoxemia, commonly derived from gut dysbiosis, is a primary cause of chronic low grade inflammation that underlies many chronic diseases. Here we show that mice fed a diet high in omega-6 fatty acids exhibit higher levels of metabolic endotoxemia and systemic low-grade inflammation, while transgenic conversion of tissue omega-6 to omega-3 fatty acids dramatically reduces endotoxemic and inflammatory status. These opposing effects of tissue omega-6 and omega-3 fatty acids can be eliminated by antibiotic treatment and animal co-housing, suggesting the involvement of the gut microbiota. Analysis of gut microbiota and fecal transfer revealed that elevated tissue omega-3 fatty acids enhance intestinal production and secretion of intestinal alkaline phosphatase (IAP), which induces changes in the gut bacteria composition resulting in decreased lipopolysaccharide production and gut permeability, and ultimately, reduced metabolic endotoxemia and inflammation. Our findings uncover an interaction between host tissue fatty acid composition and gut microbiota as a novel mechanism for the anti-inflammatory effect of omega-3 fatty acids. Given the excess of omega-6 and deficiency of omega-3 in the modern Western diet, the differential effects of tissue omega-6 and omega-3 fatty acids on gut microbiota and metabolic endotoxemia provide insight into the etiology and management of today’s health epidemics. PMID:26062993

  16. Polar Direct Drive--Simulations and Results from OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Radha, P. B.

    2015-11-01

    Polar direct drive (PDD) is a valuable platform to study implosion dynamics at the National Ignition Facility (NIF). While hydrodynamic behavior is expected to scale between OMEGA and the NIF, coronal laser-plasma interactions that influence drive and shell preheat are expected to be different because of the larger coronal density scale lengths characteristic of the NIF. The goal of NIF experiments is to validate physics models (e.g., thermal transport and laser-plasma interactions relevant to energy coupling) at these longer scale lengths to gain confidence in hydrodynamic simulations of direct-drive implosions. Models in the hydrodynamic code DRACO, validated using OMEGA implosions, are used to design and interpret NIF experiments. The physics in these models, including cross-beam energy transfer and nonlocal transport, is discussed. Comparisons with observations including shell and ablation surface trajectory, temporally resolved scattered light and spectra, bang time, shell shape, time-resolved x-ray emission, and areal density are presented from OMEGA and NIF experiments. Excellent agreement is obtained on the backlit shell trajectories and scattered light, providing confidence in the modeling of the laser drive at the longer scale. Possible reasons for the discrepancy in the predicted trajectory of the ablation surface are discussed and planned experiments to address issues such as imprint and shock timing are presented. As will be shown, high-convergence implosions should be possible with custom phase plates relevant to PDD, improved single-beam smoothing, and laser pulse shaping. Such implosions are a necessary step toward a future direct-drive -ignition campaign. A path forward for direct drive on the NIF is presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  17. Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium tritium implosions on OMEGA

    SciTech Connect

    Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Yu. Glebov, V.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H.; Kessler, T. J.; Kosc, T. Z.; Loucks, S. J.; Marozas, J. A.; Marshall, F. J.; Maximov, A. V.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Nora, R.; Radha, P. B.; Regan, S. P.; Seka, W.; Shmayda, W. T.; Short, R.W.; Shvydky, A.; Skupsky, S.; Stoeckl, C.; Yaakobi, B.; Frenje, J. A.; Gatu-Johnson, M.; Petrasso, R. D.; Casey, D. T.

    2014-05-01

    Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of α ≅ 4, an implosion velocity of 3.8 × 10⁷ cm/s, and a laser intensity of ~10¹⁵ W/cm². These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.

  18. Simulations of Fuel Assembly and Fast-Electron Transport in Integrated Fast-Ignition Experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Solodov, A. A.; Theobald, W.; Anderson, K. S.; Shvydky, A.; Epstein, R.; Betti, R.; Myatt, J. F.; Stoeckl, C.; Jarrott, L. C.; McGuffey, C.; Qiao, B.; Beg, F. N.; Wei, M. S.; Stephens, R. B.

    2013-10-01

    Integrated fast-ignition experiments on OMEGA benefit from improved performance of the OMEGA EP laser, including higher contrast, higher energy, and a smaller focus. Recent 8-keV, Cu-Kα flash radiography of cone-in-shell implosions and cone-tip breakout measurements showed good agreement with the 2-D radiation-hydrodynamic simulations using the code DRACO. DRACO simulations show that the fuel assembly can be further improved by optimizing the compression laser pulse, evacuating air from the shell, and by adjusting the material of the cone tip. This is found to delay the cone-tip breakout by ~220 ps and increase the core areal density from ~80 mg/cm2 in the current experiments to ~500 mg/cm2 at the time of the OMEGA EP beam arrival before the cone-tip breakout. Simulations using the code LSP of fast-electron transport in the recent integrated OMEGA experiments with Cu-doped shells will be presented. Cu-doping is added to probe the transport of fast electrons via their induced Cu K-shell fluorescent emission. This material is based upon work supported by the Department of Energy National Nuclear Security Administration DE-NA0001944 and the Office of Science under DE-FC02-04ER54789.

  19. OMEGA navigation system status and future plans

    NASA Technical Reports Server (NTRS)

    Nolan, T. P.; Scull, D. C.

    1974-01-01

    OMEGA is described as a very low frequency (VLF) radio navigational system operating in the internationally allocated navigation band in the electromagentic spectrum between 10 and 14 kilohertz. Full system implementation with worldwide coverage from eight transmitting stations is planned for the latter 1970's. Experimental stations have operated since 1966 in support of system evaluation and test. These stations provided coverage over most of the North Atlantic, North American Continent, and eastern portions of the North Pacific. This coverage provided the fundamental basis for further development of the system and has been essential to the demonstrated feasibility of the one to two nautical mile root-mean-square system accuracy. OMEGA is available to users in all nations, both on ships and in aircraft.

  20. Cardioprotective mechanism of omega-3 polyunsaturated fatty acids.

    PubMed

    Endo, Jin; Arita, Makoto

    2016-01-01

    Omega-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid and docosahexaenoic acid, are widely regarded as cardioprotective. Several large-scale, randomized clinical trials have shown that dietary intake of omega-3 PUFAs improves the prognosis of patients with symptomatic heart failure or recent myocardial infarction. Therefore, dietary consumption of omega-3 PUFA is recommended in international guidelines for the general population to prevent the occurrence of cardiovascular diseases (CVDs). However, the precise mechanisms underlying the cardioprotective effects of omega-3 PUFAs are not fully understood. Omega-3 PUFAs can be incorporated into the phospholipid bilayer of cell membranes and can affect membrane fluidity, lipid microdomain formation, and signaling across membranes. Omega-3 PUFAs also modulate the function of membrane ion channels, such as Na and L-type Ca channels, to prevent lethal arrhythmias. Moreover, omega-3 PUFAs also prevent the conversion of arachidonic acid into pro-inflammatory eicosanoids by serving as an alternative substrate for cyclooxygenase or lipoxygenase, resulting in the production of less potent products. In addition, a number of enzymatically oxygenated metabolites derived from omega-3 PUFAs were recently identified as anti-inflammatory mediators. These omega-3 metabolites may contribute to the beneficial effects against CVDs that are attributed to omega-3 PUFAs.

  1. OMEGA Global Radionavigation. A Guide for Users.

    DTIC Science & Technology

    1983-11-01

    about stable and the earth’s surface was uniformly OMEGA station off- air periods (either scheduled conductive, the speed and phase propagation of...Alaska 30. La Reunion Island, France 3. Ascension Island, U.K. 31. Manama, Bahrain 4. Arequipa , Peru 32. Marcus Island, Japan 5. Attu, Alaska 33...37. Pago Pago, American Samoa 10. Buenos Aires , Argentina 38. Perth, Australia 11. Butt of Lewis, U.K. 39. Pretoria, South Africa 12. Cambridge

  2. Overview of Omega-3 Fatty Acid Therapies

    PubMed Central

    Bradberry, J. Chris; Hilleman, Daniel E.

    2013-01-01

    The triglyceride (TG)-lowering benefits of the very-long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are well documented. Available as prescription formulations and dietary supplements, EPA and DHA are recommended by the American Heart Association for patients with coronary heart disease and hypertriglyceridemia. Dietary supplements are not subject to the same government regulatory standards for safety, efficacy, and purity as prescription drugs are; moreover, supplements may contain variable concentrations of EPA and DHA and possibly other contaminants. Reducing low-density lipoprotein-cholesterol (LDL-C) levels remains the primary treatment goal in the management of dyslipidemia. Dietary supplements and prescription formulations that contain both EPA and DHA may lower TG levels, but they may also increase LDL-C levels. Two prescription formulations of long-chain omega-3 fatty acids are available in the U.S. Although prescription omega-3 acid ethyl esters (OM-3-A EEs, Lovaza) contain high-purity EPA and DHA, prescription icosapent ethyl (IPE, Vascepa) is a high-purity EPA agent. In clinical trials of statin-treated and non–statin-treated patients with hypertriglyceridemia, both OM-3-A EE and IPE lowered TG levels and other atherogenic markers; however, IPE did not increase LDL-C levels. Results of recent outcomes trials of long-chain omega-3 fatty acids, fibrates, and niacin have been disappointing, failing to show additional reductions in adverse cardiovascular events when combined with statins. Therefore, the REDUCE–IT study is being conducted to evaluate the effect of the combination of IPE and statins on cardiovascular outcomes in high-risk patients. The results of this trial are eagerly anticipated. PMID:24391388

  3. Laser fusion monthly -- August 1980

    SciTech Connect

    Ahlstrom, H.G.

    1980-08-01

    This report documents the monthly progress for the laser fusion research at Lawrence Livermore National Laboratory. First it gives facilities report for both the Shiva and Argus projects. Topics discussed include; laser system for the Nova Project; the fusion experiments analysis facility; optical/x-ray streak camera; Shiva Dante System temporal response; 2{omega}{sub 0} experiment; and planning for an ICF engineering test facility.

  4. Semileptonic Decays of Heavy Omega Baryons in a Quark Model

    SciTech Connect

    Muslema Pervin; Winston Roberts; Simon Capstick

    2006-03-24

    The semileptonic decays of {Omega}{sub c} and {Omega}{sub b} are treated in the framework of a constituent quark model developed in a previous paper on the semileptonic decays of heavy {Lambda} baryons. Analytic results for the form factors for the decays to ground states and a number of excited states are evaluated. For {Omega}{sub b} to {Omega}{sub c} the form factors obtained are shown to satisfy the relations predicted at leading order in the heavy-quark effective theory at the non-recoil point. A modified fit of nonrelativistic and semirelativistic Hamiltonians generates configuration-mixed baryon wave functions from the known masses and the measured {Lambda}{sub c}{sup +} {yields} {Lambda}e{sup +}{nu} rate, with wave functions expanded in both harmonic oscillator and Sturmian bases. Decay rates of {Omega}{sub b} to pairs of ground and excited {Omega}{sub c} states related by heavy-quark symmetry calculated using these configuration-mixed wave functions are in the ratios expected from heavy-quark effective theory, to a good approximation. Our predictions for the semileptonic elastic branching fraction of {Omega}{sub Q} vary minimally within the models we use. We obtain an average value of (84 {+-} 2%) for the fraction of {Omega}{sub c} {yields} {Xi}{sup (*)} decays to ground states, and 91% for the fraction of {Omega}{sub c} {yields} {Omega}{sup (*)} decays to the ground state {Omega}. The elastic fraction of {Omega}{sub b} {yields} {Omega}{sub c} ranges from about 50% calculated with the two harmonic-oscillator models, to about 67% calculated with the two Sturmian models.

  5. Final Report: Experimental Astrophysics on the Omega Laser

    SciTech Connect

    R. Paul Drake

    2005-08-15

    This report summarized results obtained in work supported by this research grant. In hydrodynamic instability experiments related to supernovae, we showed that initial conditions have a controlling effect on material interpenetration, and demonstrated new diagnostic techniques that will provide improved data. In radiative shock experiments, we demonstrated the ability to produce and detect radiative shocks that have collapsed spatially in consequence of radiative cooling.

  6. Omega-6 and omega-3 fatty acids predict accelerated decline of peripheral nerve function in older persons

    PubMed Central

    Lauretani, F.; Bandinelli, S.; Benedetta, B.; Cherubini, A.; Iorio, A. D.; Blè, A.; Giacomini, V.; Corsi, A. M.; Guralnik, J. M.; Ferrucci, L.

    2009-01-01

    Pre-clinical studies suggest that both omega-6 and omega-3 fatty acids have beneficial effects on peripheral nerve function. Rats feed a diet rich in polyunsaturated fatty acids (PUFAs) showed modification of phospholipid fatty acid composition in nerve membranes and improvement of sciatic nerve conduction velocity (NCV). We tested the hypothesis that baseline plasma omega-6 and omega-3 fatty acids levels predict accelerated decline of peripheral nerve function. Changes between baseline and the 3-year follow-up in peripheral nerve function was assessed by standard surface ENG of the right peroneal nerve in 384 male and 443 female participants of the InCHIANTI study (age range: 24–97 years). Plasma concentrations of selected fatty acids assessed at baseline by gas chromatography. Independent of confounders, plasma omega-6 fatty acids and linoleic acid were significantly correlated with peroneal NCV at enrollment. Lower plasma PUFA, omega-6 fatty acids, linoleic acid, ratio omega-6/omega-3, arachidonic acid and docosahexanoic acid levels were significantly predicted a steeper decline in nerve function parameters over the 3-year follow-up. Low plasma omega-6 and omega-3 fatty acids levels were associated with accelerated decline of peripheral nerve function with aging. PMID:17594339

  7. Omega Centauri Looks Radiant in Infrared

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Poster Version

    A cluster brimming with millions of stars glistens like an iridescent opal in this image from NASA's Spitzer Space Telescope. Called Omega Centauri, the sparkling orb of stars is like a miniature galaxy. It is the biggest and brightest of the 150 or so similar objects, called globular clusters, that orbit around the outside of our Milky Way galaxy. Stargazers at southern latitudes can spot the stellar gem with the naked eye in the constellation Centaurus.

    Globular clusters are some of the oldest objects in our universe. Their stars are over 12 billion years old, and, in most cases, formed all at once when the universe was just a toddler. Omega Centauri is unusual in that its stars are of different ages and possess varying levels of metals, or elements heavier than boron. Astronomers say this points to a different origin for Omega Centauri than other globular clusters: they think it might be the core of a dwarf galaxy that was ripped apart and absorbed by our Milky Way long ago.

    In this new view of Omega Centauri, Spitzer's infrared observations have been combined with visible-light data from the National Science Foundation's Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile. Visible-light data with a wavelength of .55 microns is colored blue, 3.6-micron infrared light captured by Spitzer's infrared array camera is colored green and 24-micron infrared light taken by Spitzer's multiband imaging photometer is colored red.

    Where green and red overlap, the color yellow appears. Thus, the yellow and red dots are stars revealed by Spitzer. These stars, called red giants, are more evolved, larger and dustier. The stars that appear blue were spotted in both visible and 3.6-micron-, or near-, infrared light. They are less evolved, like our own sun. Some of the red spots in the picture are distant galaxies beyond our own.

    Spitzer found very little dust

  8. Omega Centauri Looks Radiant in Infrared

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Poster Version

    A cluster brimming with millions of stars glistens like an iridescent opal in this image from NASA's Spitzer Space Telescope. Called Omega Centauri, the sparkling orb of stars is like a miniature galaxy. It is the biggest and brightest of the 150 or so similar objects, called globular clusters, that orbit around the outside of our Milky Way galaxy. Stargazers at southern latitudes can spot the stellar gem with the naked eye in the constellation Centaurus.

    Globular clusters are some of the oldest objects in our universe. Their stars are over 12 billion years old, and, in most cases, formed all at once when the universe was just a toddler. Omega Centauri is unusual in that its stars are of different ages and possess varying levels of metals, or elements heavier than boron. Astronomers say this points to a different origin for Omega Centauri than other globular clusters: they think it might be the core of a dwarf galaxy that was ripped apart and absorbed by our Milky Way long ago.

    In this new view of Omega Centauri, Spitzer's infrared observations have been combined with visible-light data from the National Science Foundation's Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile. Visible-light data with a wavelength of .55 microns is colored blue, 3.6-micron infrared light captured by Spitzer's infrared array camera is colored green and 24-micron infrared light taken by Spitzer's multiband imaging photometer is colored red.

    Where green and red overlap, the color yellow appears. Thus, the yellow and red dots are stars revealed by Spitzer. These stars, called red giants, are more evolved, larger and dustier. The stars that appear blue were spotted in both visible and 3.6-micron-, or near-, infrared light. They are less evolved, like our own sun. Some of the red spots in the picture are distant galaxies beyond our own.

    Spitzer found very little dust

  9. Dietary Omega-3 Fatty Acid, Ratio of Omega-6 to Omega-3 Intake, Inflammation, and Survival in Long-term Hemodialysis Patients

    PubMed Central

    Noori, Nazanin; Dukkipati, Ramanath; Kovesdy, Csaba P.; Sim, John J.; Feroze, Usama; Murali, Sameer B.; Bross, Rachelle; Benner, Debbie; Kopple, Joel D; Kalantar-Zadeh, Kamyar

    2011-01-01

    Background Mortality among long-term hemodialysis patients is high, mostly attributed to cardiovascular events, and may be related to chronic inflammation. We hypothesized that the anti-inflammatory benefits of higher dietary omega-3, compared to omega-6, poly-unsaturated fatty acids may modulate the inflammatory processes and reduce death risk. Study design Prospective cohort study using linear and Cox proportional regressions. Setting and Participants 145 hemodialysis patients from 8 DaVita dialysis clinics in Southern California during 2001-2007 Predictors Intake of dietary omega-3 and ratio of omega-6 to omega-3 using 3-day food record supplemented by dietary interview. Outcomes One-year change in serum C-reactive protein (CRP) and 6-year survival. Results Patients were 53±14 years old (mean±SD) and included 43% women and 42% African-Americans. Median (25th-75 percentile) of dietary omega-3 intake, ratio of omega-6 to omega-3 intake, baseline serum CRP, and change in CRP over one year were 1.1(0.8-1.6) g/day, 9.3(7.6-11.3), 3.1(0.8-6.8) mg/L, and +0.2(−0.4 to +0.8) mg/L, respectively. In regression models adjusted for case-mix, dietary calorie and fat intake, body mass index and history of hypertension, each 1-unit higher ratio of omega-6 to omega-3 intake was associated with 0.55 mg/L increase in serum CRP (p=0.03). In fully adjusted model, the death hazard ratios (95% confidence interval) for the 1st(1.7-<7.6) 2nd(7.6-<9.3), 3rd(9.3-<11.3) and 4th(11.3-17.4) quartiles of dietary omega-6 to omega-3 ratio were 0.39(0.14-1.18), 0.30(0.09-0.99), 0.67(0.25-1.79) and 1.00(reference), respectively (p-for-trend=0.06). Limitations Three-day food record may underestimate actual dietary fat intake at individual level. Conclusions Higher dietary omega-6 to omega-3 ratio appears associated with both worsening inflammation over time and a trend towards higher death risk in hemodialysis patients. Additional studies including interventional trials are needed to examine

  10. Green frequency-doubled laser-beam propagation in high-temperature hohlraum plasmas.

    PubMed

    Niemann, C; Berger, R L; Divol, L; Froula, D H; Jones, O; Kirkwood, R K; Meezan, N; Moody, J D; Ross, J; Sorce, C; Suter, L J; Glenzer, S H

    2008-02-01

    We demonstrate propagation and small backscatter losses of a frequency-doubled (2omega) laser beam interacting with inertial confinement fusion hohlraum plasmas. The electron temperature of 3.3 keV, approximately a factor of 2 higher than achieved in previous experiments with open geometry targets, approaches plasma conditions of high-fusion yield hohlraums. In this new temperature regime, we measure 2omega laser-beam transmission approaching 80% with simultaneous backscattering losses of less than 10%. These findings suggest that good laser coupling into fusion hohlraums using 2omega light is possible.

  11. Omega-6 to Omega-3 Fatty Acid Ratio in Patients with ADHD: A Meta-Analysis.

    PubMed

    LaChance, Laura; McKenzie, Kwame; Taylor, Valerie H; Vigod, Simone N

    2016-01-01

    Omega-3 and omega-6 fatty acids have been shown to be deficient in individuals with attention deficit/hyperactivity disorder compared to controls (Hawkey & Nigg, 2014). Clinical trials of omega-3 and omega-6 supplements as treatment for ADHD have demonstrated minimal efficacy (Bloch & Qawasmi, 2011; Gillies, Sinn, Lad, Leach, & Ross, 2011; Hawkey & Nigg, 2014; Puri & Martins, 2014; Sonuga-Barke et al., 2013). Existing trials have analyzed omega-3 and omega-6 separately although the tissue ratio of these fatty acids (n6/n3) may be more important than absolute levels of either. The objective of this study was to determine the relationship between blood n6/n3 and arachidonic acid to eicosapentaenoic acid (AA/EPA), to ADHD symptoms. A systematic literature review identified original articles measuring blood n6/n3 or AA/EPA ratio in children and youth with ADHD, compared to controls without ADHD. Three databases were searched. Blood n6/n3, and AA/EPA ratios were compared between individuals with ADHD and controls. Results were pooled across studies using quantitative synthesis. Five articles met inclusion criteria for the meta-analysis. The pooled mean difference between patients with ADHD and controls was 1.97 (0.90-3.04) for n6/n3 (n=5 studies, I(2) 83%) and 8.25 (5.94-10.56) for AA/EPA (n=3 studies, I(2) 0%). Children and youth with ADHD have elevated ratios of both blood n6/n3 and AA/EPA fatty acids compared to controls. Thus an elevated n6/n3, and more specifically AA/EPA, ratio may represent the underlying disturbance in essential fatty acid levels in patients with ADHD. These findings have implications for the development of future interventions using essential fatty acids to treat ADHD, and for the use of these ratios as biomarkers for titrating and monitoring ADHD treatment with essential fatty acids.

  12. A microcomputer-based low-cost Omega navigation system

    NASA Technical Reports Server (NTRS)

    Lilley, R. W.; Salter, R. J., Jr.

    1976-01-01

    The application of a low cost, commercially available microcomputer as the navigation processor for a simplified OMEGA navigation system is an area of current research. The interface of a low cost front end OMEGA sensor is described and an example of the phase processing software and navigation routines is given. Emphasis is placed on the description of results obtained with the software version of the OMEGA burst filter known as the memory aided phase locked loop.

  13. Two-dimensional simulations of the neutron yield in cryogenic deuterium-tritium implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Goncharov, V. N.; Radha, P. B.; Marozas, J. A.; Skupsky, S.; Boehly, T. R.; Sangster, T. C.; Meyerhofer, D. D.; McCrory, R. L.

    2010-10-01

    Maximizing the neutron yield to obtain energy gain is the ultimate goal for inertial confinement fusion. Nonuniformities seeded by target and laser perturbations can disrupt neutron production via the Rayleigh-Taylor instability growth. To understand the effects of perturbations on the neutron yield of cryogenic DT implosions on the Omega Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)], two-dimensional DRACO [P. B. Radha et al., Phys. Plasmas 12, 056307 (2005)] simulations have been performed to systematically investigate each perturbation source and their combined effects on the neutron-yield performance. Two sources of nonuniformity accounted for the neutron-yield reduction in DRACO simulations: target offset from the target chamber center and laser imprinting. The integrated simulations for individual shots reproduce the experimental yield-over-clean (YOC) ratio within a factor of 2 or better. The simulated neutron-averaged ion temperatures ⟨Ti⟩ is only about 10%-15% higher than measurements. By defining the temperature-over-clean, its relationship to YOC provides an indication of how much the hot-spot volume and density are perturbed with respect to the uniform situation. Typically, the YOC in OMEGA experiments is of the order of ˜5%. The simulation results suggest that YOC can be increased to the ignition hydroequivalent level of 15%-20% (with ⟨ρR⟩=200-300 mg/cm2) by maintaining a target offset of less than 10 μm and employing beam smoothing by spectral dispersion.

  14. NONLINEAR-OPTICS PHENOMENA Determining the coordinate dependence of some components of the cubic susceptibility tensor \\hat\\chi^{(3)}(z,\\omega,-\\omega,\\omega,\\omega) of a one-dimensionally inhomogeneous absorbing plate at an arbitrary frequency dispersion

    NASA Astrophysics Data System (ADS)

    Golubkov, A. A.; Makarov, Vladimir A.

    2010-12-01

    The possibility of unique reconstruction of the spatial profile of the cubic nonlinear susceptibility tensor component \\hat\\chi_{yyyy}^{(3)}(z,\\omega,-\\omega,\\omega,\\omega) of a one-dimensionally inhomogeneous plate whose medium has a symmetry plane m_y perpendicular to its surface is proved for the first time and the unique reconstruction algorithm is proposed. The amplitude complex coefficients of reflection and transmission (measured in some range of angles of incidence) as well as of conversion of an s-polarised plane signal monochromatic wave into two waves propagating on both sides of the plate make it possible to reconstruct the profile. These two waves result from nonlinear interaction of a signal wave with an intense plane wave incident normally on the plate. All the waves under consideration have the same frequency \\omega, and so its variation helps study the frequency dispersion of the cubic nonlinear susceptibility tensor component \\hat\\chi_{yyyy}^{(3)}(z,\\omega,-\\omega,\\omega,\\omega). For media with additional symmetry axes 2_z, 4_z, 6_z, or \\infty_z that are perpendicular to the plate surface, the proposed method can be used to reconstruct the profile and to examine the frequency dispersion of about one third of all independent complex components of the tensor \\hat\\chi^{(3)}.

  15. Dynamical coupled channels calculation of pion and omega meson production

    SciTech Connect

    Paris, Mark W.

    2009-02-15

    The dynamical coupled-channels approach developed at the Excited Baryon Analysis Center is extended to include the {omega}N channel to study {pi}- and {omega}-meson production induced by scattering pions and photons from the proton. Six intermediate channels, including {pi}N, {eta}N, {pi}{delta}, {sigma}N, {rho}N, and {omega}N, are employed to describe unpolarized and polarized data. Bare parameters in an effective hadronic Lagrangian are determined in a fit to the data for {pi}N{yields}{pi}N, {gamma}N{yields}{pi}N, {pi}{sup -}p{yields}{omega}n, and {gamma}p{yields}{omega}p reactions at center-of-mass energies from threshold to W<2.0 GeV. The T matrix determined in these fits is used to calculate the photon beam asymmetry for {omega}-meson production and the {omega}N{yields}{omega}N total cross section and {omega}N-scattering lengths. The calculated beam asymmetry is in good agreement with the observed in the range of energies near threshold to W < or approx. 2.0 GeV.

  16. Determining the coordinate dependence of some components of the cubic susceptibility tensor {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}) of a one-dimensionally inhomogeneous absorbing plate at an arbitrary frequency dispersion

    SciTech Connect

    Golubkov, A A; Makarov, Vladimir A

    2010-12-29

    The possibility of unique reconstruction of the spatial profile of the cubic nonlinear susceptibility tensor component {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}) of a one-dimensionally inhomogeneous plate whose medium has a symmetry plane m{sub y} perpendicular to its surface is proved for the first time and the unique reconstruction algorithm is proposed. The amplitude complex coefficients of reflection and transmission (measured in some range of angles of incidence) as well as of conversion of an s-polarised plane signal monochromatic wave into two waves propagating on both sides of the plate make it possible to reconstruct the profile. These two waves result from nonlinear interaction of a signal wave with an intense plane wave incident normally on the plate. All the waves under consideration have the same frequency {omega}, and so its variation helps study the frequency dispersion of the cubic nonlinear susceptibility tensor component {chi}-hat{sub yyyy}{sup (3)}(z, {omega}, -{omega}, {omega}, {omega}). For media with additional symmetry axes 2{sub z}, 4{sub z}, 6{sub z}, or {infinity}{sub z} that are perpendicular to the plate surface, the proposed method can be used to reconstruct the profile and to examine the frequency dispersion of about one third of all independent complex components of the tensor {chi}-hat{sup (3)}. (nonlinear-optics phenomena)

  17. The ion-channel laser

    SciTech Connect

    Whittum, D.H.; Sessler, A.M. ); Dawson, J.M. . Dept. of Physics)

    1990-01-01

    A relativistic electron beam propagating through a plasma in the ion-focused regime exhibits an electromagnetic instability at a resonant frequency {omega} {approximately} 2{gamma}{sup 2} {omega}{sub {beta}}. Growth is enhanced by optical guiding in the ion channel, which acts as dielectric waveguide, with fiber parameter V {approximately} 2 (I/I{sub A}){sup 1/2}. A 1-D theory for such an ion-channel laser'' is formulated, scaling laws are derived and numerical examples are given. Possible experimental evidence is noted. 23 refs., 1 fig., 1 tab.

  18. A Comparison of 1 T(Omega) and 10 T (Omega) High Resistance Standards Between NIST and Sandia

    SciTech Connect

    Jarrett, D.G.; Dziuba, R.F.; Kraft, M.E.

    1999-04-23

    NIST-built 10 T{Omega} and commercial 1 T{Omega} standard resistors were hand carried between NIST and Sandia for a high resistance comparison. The comparison tested the ruggedness of the new NIST-built standard resistors, provided a check of the scaling between the two laboratories, supported measurements to reestablish NIST calibration services at 10 T{Omega} and 100 T{Omega}, and demonstrated the possibility of establishing a NIST high resistance measurement assurance program (MAP). The comparison has demonstrated agreement on the order of 0.07% which is within the expanded uncertainties (coverage factor = 2) of NIST and Sandia at 1 T{Omega} and 10 T{Omega}.

  19. PRODUCTION OF HIGHER STRENGTH THIN WALLED GLOW DISCHARGE POLYMER SHELLS FOR CRYOGENIC EXPERIMENTS AT OMEGA

    SciTech Connect

    NIKROO,A; CZECHOWICZ,DG; CASTILLO,ER; PONTELANDOLFO,JM

    2002-04-01

    OAK A271 PRODUCTION OF HIGHER STRENGTH THIN WALLED GLOW DISCHARGE POLYMER SHELLS FOR CRYOGENIC EXPERIMENTS AT OMEGA. Thin walled polymer shells are needed for OMEGA cryogenic laser experiments. These capsules need to be about 900 {micro}m in diameter and as thin as possible (approx 1-2 {micro}m), while having enough strength to be filled with DT as fast as possible to about 1000 atm. The authors have found that by optimizing the coating parameters in the glow discharge polymer (GDP) deposition system, traditionally used for making ICF targets, they can routinely make robust, {approx} 1.5 {micro}m thick, 900 {micro}m diameter GDP shells with buckle strengths of over 0.3 atm. This is twice the strength of shells made prior to the optimization and is comparable to values quoted for polyimide shells. In addition, these shells were found to be approximately three times more permeable and over 20% denser than previously made GDP shells. The combination of higher strength and permeability is ideal for direct drive cryogenic targets at OMEGA. Shells as thin as 0.5 {micro}m have been made. In this paper, the authors discuss the shell fabrication process, effects of modifying various GDP deposition parameters on shell properties and chemical composition.

  20. Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA.

    PubMed

    Glebov, V Yu; Forrest, C; Knauer, J P; Pruyne, A; Romanofsky, M; Sangster, T C; Shoup, M J; Stoeckl, C; Caggiano, J A; Carman, M L; Clancy, T J; Hatarik, R; McNaney, J; Zaitseva, N P

    2012-10-01

    A new neutron time-of-flight (nTOF) detector with a bibenzyl crystal as a scintillator has been designed and manufactured for the National Ignition Facility (NIF). This detector will replace a nTOF20-Spec detector with an oxygenated xylene scintillator currently operational on the NIF to improve the areal-density measurements. In addition to areal density, the bibenzyl detector will measure the D-D and D-T neutron yield and the ion temperature of indirect- and direct-drive-implosion experiments. The design of the bibenzyl detector and results of tests on the OMEGA Laser System are presented.

  1. Effect of a diet enriched with omega-6 and omega-3 fatty acids on the pig liver transcriptome.

    PubMed

    Szostak, Agnieszka; Ogłuszka, Magdalena; Te Pas, Marinus F W; Poławska, Ewa; Urbański, Paweł; Juszczuk-Kubiak, Edyta; Blicharski, Tadeusz; Pareek, Chandra Shekhar; Dunkelberger, Jenelle R; Horbańczuk, Jarosław O; Pierzchała, Mariusz

    2016-01-01

    The optimal ratio of omega-6 to omega-3 polyunsaturated fatty acids (PUFAs) is important for keeping the homeostasis of biological processes and metabolism, yet the underlying biological mechanism is poorly understood. The objective of this study was to identify changes in the pig liver transcriptome induced by a diet enriched with omega-6 and omega-3 fatty acids and to characterize the biological mechanisms related to PUFA metabolism. Polish Landrace pigs (n = 12) were fed diet enriched with linoleic acid (LA, omega-6) and α-linolenic acid (ALA, omega-3) or standard diet as a control. The fatty acid profiling was assayed in order to verify how feeding influenced the fatty acid content in the liver, and subsequently next-generation sequencing (NGS) was used to identify differentially expressed genes (DEG) between transcriptomes between dietary groups. The biological mechanisms and pathway interaction networks were identified using DAVID and Cytoscape tools. Fatty acid profile analysis indicated a higher contribution of PUFAs in the liver for LA- and ALA-enriched diet group, particularly for the omega-3 fatty acid family, but not omega-6. Next-generation sequencing identified 3565 DEG, 1484 of which were induced and 2081 were suppressed by PUFA supplementation. A low ratio of omega-6/omega-3 fatty acids resulted in the modulation of fatty acid metabolism pathways and over-representation of genes involved in energy metabolism, signal transduction, and immune response pathways. In conclusion, a diet enriched with omega-6 and omega-3 fatty acids altered the transcriptomic profile of the pig liver and would influence animal health status.

  2. Effect of dietary intake of omega-3 and omega-6 fatty acids on severity of asthma in children.

    PubMed

    Hodge, L; Salome, C M; Hughes, J M; Liu-Brennan, D; Rimmer, J; Allman, M; Pang, D; Armour, C; Woolcock, A J

    1998-02-01

    We assessed the clinical and biochemical effects in asthmatic children of fish oil supplementation and a diet that increases omega-3 and reduces omega-6 fatty acids. Thirty nine asthmatic children aged 8-12 yrs participated in a double-blind, randomized, controlled trial for 6 months during which they received fish oil capsules plus canola oil and margarine (omega-3 group) or safflower oil capsules plus sunflower oil and margarine (omega-6 group). Plasma fatty acids, stimulated tumour necrosis factor alpha (TNFalpha) production, circulating eosinophil numbers and lung function were measured at baseline and after 3 and 6 months of dietary modification. Day and night symptoms, peak flow rates and medication use were recorded for 1 week prior to laboratory visits. Plasma phospholipid omega-3 fatty acids were significantly greater in the omega-3 group at 3 and 6 months compared to the omega-6 group (p<0.001). In the omega-3 group TNFalpha production fell significantly compared with baseline (p=0.026), but the magnitude of change between groups did not reach significance (p=0.075). There were no significant changes in clinical outcome measures. Dietary enrichment of omega-3 fatty acids over 6 months increased plasma levels of these fatty acids, reduced stimulated tumour necrosis factor alpha production, but had no effect on the clinical severity of asthma in these children.

  3. Progress of LMJ-relevant implosions experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Casner, A.; Philippe, F.; Tassin, V.; Seytor, P.; Monteil, M.-C.; Gauthier, P.; Park, H. S.; Robey, H.; Ross, J.; Amendt, P.; Girard, F.; Villette, B.; Reverdin, C.; Loiseau, P.; Caillaud, T.; Landoas, O.; Li, C. K.; Petrasso, R.; Seguin, F.; Rosenberg, M.; Renaudin, P.

    2013-11-01

    In preparation of the first ignition attempts on the Laser Mégajoule (LMJ), an experimental program is being pursued on OMEGA to investigate LMJ-relevant hohlraums. First, radiation temperature levels close to 300 eV were recently achieved in reduced-scale hohlraums with modest backscatter losses. Regarding the baseline target design for fusion experiments on LMJ, an extensive experimental database has also been collected for scaled implosions experiments in both empty and gas-filled rugby-shaped hohlraums. We acquired a full picture of hohlraum energetics and implosion dynamics. Not only did the rugby hohlraums show significantly higher x-ray drive energy over the cylindrical hohlraums, but symmetry control by power balance was demonstrated, as well as high-performance D2 implosions enabling the use of a complete suite of neutrons diagnostics. Charged particle diagnostics provide complementary insights into the physics of these x-ray driven implosions. An overview of these results demonstrates our ability to control the key parameters driving the implosion, lending more confidence in extrapolations to ignition-scale targets.

  4. The role of the tissue omega-6/omega-3 fatty acid ratio in regulating tumor angiogenesis.

    PubMed

    Kang, Jing X; Liu, Angela

    2013-06-01

    Angiogenesis is a necessary step in tumor growth and metastasis. It is well established that the metabolites of omega-6 and omega-3 fatty acids, which must be obtained through the diet and cannot be synthesized de novo in mammals, have differential effects on cellular processes. Omega-6 fatty acid (n-6 FA)-derived metabolites promote angiogenesis by increasing growth factor expression whereas omega-3 fatty acids (n-3 FA) have anti-angiogenic and antitumor properties. However, most studies thus far have failed to account for the role of the n-6 FA/n-3 FA ratio in angiogenesis and instead examined the absolute levels of n-6 and n-3 FA. This review highlights the biochemical interactions between n-6 and n-3 FA and focuses on how the n-6/n-3 FA ratio in tissues modulates tumor angiogenesis. We suggest that future work should consider the n-6/n-3 FA ratio to be a key element in experimental design and analysis. Furthermore, we recommend that clinical interventions should aim to both reduce n-6 metabolites and simultaneously increase n-3 FA intake.

  5. Observation of {chi}{sub c1} Decays into Vector Meson Pairs {phi}{phi}, {omega}{omega}, and {omega}{phi}

    SciTech Connect

    Ablikim, M.; An, Z. H.; Bai, J. Z.; Berger, N.; Bian, J. M.; Cai, X.; Cao, G. F.; Cao, X. X.; Chang, J. F.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, Y.; Chen, Y. B.; Chu, Y. P.; Dai, H. L.; Dai, J. P.; Deng, Z. Y.; Dong, L. Y.

    2011-08-26

    Using (106{+-}4)x10{sup 6} {psi}(3686) events accumulated with the BESIII detector at the BEPCII e{sup +}e{sup -} collider, we present the first measurement of decays of {chi}{sub c1} to vector meson pairs {phi}{phi}, {omega}{omega}, and {omega}{phi}. The branching fractions are measured to be (4.4{+-}0.3{+-}0.5)x10{sup -4}, (6.0{+-}0.3{+-}0.7)x10{sup -4}, and (2.2{+-}0.6{+-}0.2)x10{sup -5}, for {chi}{sub c1}{yields}{phi}{phi}, {omega}{omega}, and {omega}{phi}, respectively, which indicates that the hadron helicity selection rule is significantly violated in {chi}{sub cJ} decays. In addition, the measurement of {chi}{sub cJ}{yields}{omega}{phi} provides the first indication of the rate of doubly OZI-suppressed {chi}{sub cJ} decay. Finally, we present improved measurements for the branching fractions of {chi}{sub c0} and {chi}{sub c2} to vector meson pairs.

  6. Omega Navigation System Course Book. Volume 2

    DTIC Science & Technology

    1994-07-01

    71 H B, F E 46. Ascension, Is., UK -8 -14 G A, B, E 69. Tananarive, -19 48 D C, E Madagascar Southern 70. Brisbane, Australia -27 153 A, B C, G F Mid...Rellabftl Comeage S- 11k - 1 ISystem Availablity 7"" Ole Re N"fa Regabifty o owl I PS = PROBABILUTY THAT I I OMEGA CAN BE I - - USED FOR NAVIGATION W PsA...panel displays. The time-panel is a matrix of 288 squares, each corresponding to a unique time of the year. A red square in a cell time-panel

  7. North Atlantic OMEGA Navigation System Validation

    DTIC Science & Technology

    1980-07-21

    Coordinates 7-18 7-7 Aeroflot Flight Zone OMEGA Accuracies vs DME or DME /VOR Coordinates 7-18 7-8 Alabama Getty Measurements 7-20 7-9 British Respect...navigation equipment on board the aircraft during the tests consisted of TAC.N VOR/ DME , sextant and a driftmeter. The majority of flight hours were...measurement of two (2) distances from DME , or azimuth and distance for VOR/ DME with distances from the radio beacons of not more than 40 KM. During the

  8. BPS states in omega background and integrability

    NASA Astrophysics Data System (ADS)

    Bulycheva, Kseniya; Chen, Heng-yu; Gorsky, Alexander; Koroteev, Peter

    2012-10-01

    We reconsider string and domain wall central charges in {N} = 2 supersymmetric gauge theories in four dimensions in presence of the Omega background in the Nekrasov-Shatashvili (NS) limit. Existence of these charges entails presence of the corresponding topological defects in the theory — vortices and domain walls. In spirit of the 4d/2d duality we discuss the worldsheet low energy effective theory living on the BPS vortex in {N} =2 Supersymmetric Quantum Chromodynamics (SQCD). We discuss some aspects of the brane realization of the dualities between various quantum integrable models. A chain of such dualities enables us to check the AGT correspondence in the NS limit.

  9. Interpretation of symmetry experiments on Omega

    NASA Astrophysics Data System (ADS)

    Lours, Laurence; Bastian, Josiane; Monteil, Marie-Christine; Philippe, Franck; Jadaud, Jean-Paul

    2006-10-01

    The interpretation of the symmetry experiments performed on Omega in 2005 with 3 cone LMJ-like irradiation is presented here. The goal of this campaign was the characterization of the irradiation symmetry by X-ray imaging of the D2Ar capsule. Images of backlit implosion (as done in earlier campaigns with foam balls) and core emission were obtained on the same shot, and can be compared to FCI2 simulations. This set of shots comfirms former results with foam balls of a good symmetry control with 3 cones in empty hohlraums. The influence of the hohlraum shape on symmetry is also studied by comparison of cylindrical hohlraums vs rugby ones.

  10. Progress of Rugby Hohlraum Experiments on Omega

    NASA Astrophysics Data System (ADS)

    Philippe, Franck; Tassin, Veronique; Casner, Alexis; Gauthier, Pascal; Seytor, Patricia; Monteil, Marie-Christine; Park, Hye-Sook; Robey, Harry; Ross, Steven; Amendt, Peter; Girard, Frederic; Villette, Bruno; Reverdin, Charles; Loiseau, Pascal; Caillaud, Tony; Landoas, Olivier; Li, Chi Kang; Petrasso, Richard; Seguin, Fredrick; Rosenberg, Markus

    2011-10-01

    The rugby hohlraum concept is predicted to enable better coupling and higher gains in the indirect drive approach to ignition. A collaborative experimental program is currently pursued on OMEGA to test this concept in preparation for future megajoule-scale ignition designs. A direct comparison of gas-filled rugby hohlraums with classical cylinders was recently performed, showing a significant (up to ~40%) observed x-ray drive enhancement and neutron yields that are consistently higher in the rugby case. This work extends and confirms our previous findings in empty rugby hohlraums.

  11. OmegaCAM: The VST Camera

    NASA Astrophysics Data System (ADS)

    Cappellarao, E.

    2005-06-01

    OmegaCAM is the large-format CCD pixels imaging camera that has been designed to exploit the square degree field of view of the VST while sampling the excellent seeing of Paranal (Kuijken et al. 2002, The Messenger 110, 15). The instrument is built by a consortium which comprises institutes in the Netherlands, Germany and Italy, and is headed by PI Konrad Kuijken (Groningen and Leiden University) with co-PI's Ralf Bender (Munich USM/MPE) and Enrico Cappellaro (INAF Naples), and project management by Bernhard Muschielok and Reinhold Häfner (USM). The Optical Detector Team at ESO has designed and built the detector system.

  12. Omega Transmitter Outages January to December 1979.

    DTIC Science & Technology

    1980-10-01

    34.3 610 No. FAA-tI-1-113 FAACT #1.U OMEGA TRANSMITTER OUTAGES JANUARY TO DECEMBER 1919 Lorraine hzonca FEERAL AVIATION AIMNISTRATION TECINICAL CENTER...Normal During Normal Month Maint. Period Maint. Operation Maint. Operation Mar 3/6 - 3/26 (Argentina) 8156 264* 18.3 0.6* Apr 4/1 - 4/12 (Liberia) 691...0400 124 11.6 North Dakota 14 Aug 1200 to 3 Sep 2100 489 55.5 LaReunion 1 Jul 0000 to 14 Jul 2400 336 92.9 Argentina 6 Mar 0000 to 26 Mar 2400 504 59.6

  13. Commissioning of a multiple-frequency modulation smoothing by spectral dispersion demonstration system on OMEGA EP

    NASA Astrophysics Data System (ADS)

    Kruschwitz, B. E.; Kelly, J. H.; Dorrer, C.; Okishev, A. V.; Waxer, L. J.; Balonek, G.; Begishev, I. A.; Bittle, W.; Consentino, A.; Cuffney, R.; Hill, E.; Marozas, J. A.; Moore, M.; Roides, R. G.; Zuegel, J. D.

    2013-02-01

    A one-dimensional smoothing by spectral dispersion (SSD) demonstration system for smoothing focal-spot nonuniformities using multiple modulation frequencies (multi-FM SSD) was commissioned on one long-pulse beamline of OMEGA EP—the first use of such a system in a high-energy laser. System models of frequency modulation-to-amplitude modulation (FM-to-AM) conversion in the OMEGA EP beamline and final optics were used to develop an AM budget. The AM budget in turn provided a UV power limit of 0.85 TW, based on accumulation of B-integral in the final optics. The front end of the demonstration system utilized a National Ignition Facility preamplifier module (PAM) with a custom SSD grating inserted into the PAM's multipass amplifier section. The dispersion of the SSD grating was selected to cleanly propagate the dispersed SSD bandwidth through various pinholes in the system while maintaining sufficient focal-spot smoothing performance. A commissioning plan was executed that systematically introduced the new features of the demonstration system into OMEGA EP. Ultimately, the OMEGA EP beamline was ramped to the UV power limit with various pulse shapes. The front-end system was designed to provide flexibility in pulse shaping. Various combinations of pickets and nanosecond-scale drive pulses were demonstrated, with multi-FM SSD selectively applied to portions of the pulse. Analysis of the dispersion measured by the far-field diagnostics at the outputs of the infrared beamline and the frequency-conversion crystals indicated that the SSD modulation spectrum was maintained through both the beamline and the frequency-conversion process. At the completion of the plan, a series of equivalent-target-plane measurements with distributed phase plates installed were conducted that confirmed the expected timeintegrated smoothing of the focal spot.

  14. Terahertz generation from laser filaments in the presence of a static electric field in a plasma

    SciTech Connect

    Bhasin, Lalita; Tripathi, V. K.

    2011-12-15

    Two femtosecond laser pulses with frequencies {omega}{sub 1} and {omega}{sub 2} that undergo filamentation in a plasma couple nonlinearly in the presence of a transverse, static electric field to generate terahertz wave at the frequency {omega}{sub 1}-{omega}{sub 2}. The coupling is enhanced in the presence of the static electric field. We develop a theoretical model and observe over 30 times increase in the magnitude of normalized terahertz amplitude by applying a dc electric field ~50kV/cm.

  15. CVD Diamond Detectors for Current Mode Neutron Time-of-Flight Spectroscopy at OMEGA/NIF

    SciTech Connect

    Schmid, G J; Friensehner, A F; Glebov, V Y; Hargrove, D R; Hatchett, S P; Izumi, N; Lerche, R A; Phillips, T W; Sangster, T C; Sibernagel, C; Stoeckl, C

    2001-06-19

    As part of a laser fusion diagnostic development program, we have performed pulsed neutron and pulsed laser tests of a CVD diamond detector manufactured from DIAFILM, a commercial grade of CVD diamond. The laser tests were performed at the short pulse UV laser at Bechtel Nevada in Livermore, CA. The pulsed neutrons were provided by DT capsule implosions at the OMEGA laser fusion facility in Rochester, NY. From these tests, we have determined the impulse response to be 250 ps fwhm for an applied E-field of 500 V/mm. Additionally, we have determined the sensitivity to be 2.8 mA/W at 500 V/mm and 4.5 mA/W at 1000 V/mm (2 to 6x times higher than reported values for natural Type IIa diamond). These detector characteristics allow us to conceive of a neutron time-of-flight current mode spectrometer based on CVD diamond. Such an instrument would sit inside the laser fusion target chamber close to TCC, and would record neutron spectra fast enough such that backscattered neutrons and y rays from the target chamber wall would not be a concern. However, the data we have taken show that the Electromagnetic Pulse (EMP) noise could be a limiting factor in performance. Determining the degree to which this noise can be shielded will be an important subject of future tests.

  16. LLE Review Quarterly Report (April-June 1996). Volume 67

    SciTech Connect

    Skeldon, Mark D.

    1996-06-01

    This volume of the LLE Review, covering the period April-June 1996, contains articles detailing several nonlinear processes associated with lasers and their use, as well as an article describing the computer control systems necessary to maintain and operate a large laser system such as the 60-beam OMEGA laser. The specific topics discussed in this issue include stimulated scattering in laser plasmas, power exchange between interacting laser beams, charged particles interacting with a laser pulse, thermal equilibration of optically excited states, an overview of the laser control system software in OMEGA, and a technique for cancellation of the nonlinear phase accumulation in short-pulse lasers.

  17. LLE review: Quarterly report, April--June 1996. Volume 67

    SciTech Connect

    Skeldon, M.D.

    1996-11-01

    This volume contains articles detailing several nonlinear processes associated with lasers and their use, as well as an article describing the computer control systems necessary to maintain and operate a large laser system such as the 60-beam OMEGA laser. The specific topics discussed in this issue include stimulated scattering in laser plasmas, power exchange between interacting laser beams, charged particles interacting with a laser pulse, thermal equilibration of optically excited states, an overview of the laser control system software in OMEGA, and a technique for cancellation of the nonlinear phase accumulation in short-pulse lasers.

  18. Selected bibliography of OMEGA, VLF and LF techniques applied to aircraft navigation systems

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A bibliography is presented which includes references to the OMEGA navigation system, very low frequencies, time-frequency measurements, air traffic control, radio navigation, and applications of OMEGA.

  19. Serum Omega-6/Omega-3 Ratio and Risk Markers for Cardiovascular Disease in an Industrial Population of Delhi.

    PubMed

    Gupta, Ruby; Lakshmy, Ramakrishnan; Abraham, Ransi Ann; Reddy, Kolli Srinath; Jeemon, Panniyammakal; Prabhakaran, Dorairaj

    2013-09-01

    High omega-6/omega-3 ratio intake promotes development of many chronic diseases. Secondary prevention studies though have demonstrated a decline in progression of many such diseases after reducing the intake, specific biochemical indices of cardiovascular disease risk markers have not been evaluated. We have evaluated the circulating levels of omega-6/omega-3 ratio and its effect on cardiovascular risk markers in India. Present study was conducted in industrial setting where employees were randomly selected. Data on their demographic characteristics were collected using pre-tested questionnaire. Fasting blood samples were collected from all the participants. Serum was separated and stored at -80°C till the time of analysis. Lipids were estimated using standard kits. Fatty acids in serum were estimated by Gas chromatography. The identified Omega-3 fatty acid included were 18:3 (Alpha-linolenic acid), 20:5 (Eicosapentenoic acid) & 22:6 (Docosahexenoic acid). Among omega-6 included were 18:2 (linoleic acid), 18:3 (gamma-linolenic acid) & 20:4 (Arachidonic acid). Complete data was available for 176 participants (89% males and 11% females) with mean age of 47.23 ± 6.00 years. The bmi of the participants was 24.88 ± 3.43 Kg/m(2) and waist circumference was 91.50 ± 9.56 cm. The median of omega-6/omega-3 ratio in the study population was 36.69 (range: 6.21 - 183.69). The levels of total cholesterol, triglycerides, ldl-cholesterol and cholesterol/hdl ratio and apo B correlated significantly with omega-6/3 ratio. There was no correlation observed with hsCRP and LDL-particle size. A direct relationship of omega-6/omega-3 ratio with dyslipidemia was observed in our study.

  20. Cloning and characterization of a novel feline IFN-omega.

    PubMed

    Yang, Li-Min; Xue, Qing-Hua; Sun, Lei; Zhu, Yi-Ping; Liu, Wen-Jun

    2007-02-01

    The interferons (IFNs) are a large family of multifunctional secreted protein involved in antiviral defense, cell growth regulation, and immune activation. The human IFNs are used worldwide as antiviral drugs. Here, we present cDNAs encoding 13 novel feline IFN-omega (FeIFN-omega) subtypes that share 95%-99% amino acid sequence identity. FeIFN-omega2 and FeIFN-omega4 have seven additional amino acids at position 109 that are not present in other subtypes. Sequence identity of the present FeIFN proteins encoded by the 13 subtypes is approximately 57% compared with human IFN-omega (HuIFN-omega). All 13 FeIFN-omega subtypes were expressed in Escherichia coli using a periplasmic expression system. The antiviral activity of each product was evaluated in vitro. In addition, subtype FeIFN-omega2 was cytoplasm expressed in E. coli and secretion expressed in Pichia pastoris. The purified mature recombinant protein demonstrated significant antiviral activity on both homologous and heterologous animal cells in vitro.

  1. Measurement of the Spin of the Omega- Hyperon at Babar

    SciTech Connect

    Aubert, B.

    2006-07-05

    A measurement of the spin of the {Omega}{sup -} hyperon produced through the exclusive process {Xi}{sub c}{sup 0} {yields} {Omega}{sup -}K{sup +} is presented using a total integrated luminosity of 116 fb{sup -1} recorded with the BABAR detector at the e{sup +}e{sup -} asymmetric-energy B-Factory at SLAC. Under the assumption that the {Xi}{sub c}{sup 0} has spin 1/2, the angular distribution of the {Lambda} from {Omega}{sup -} {yields} {Lambda}K{sup -} decay is inconsistent with all half-integer {Omega}{sup -} spin values other than 3/2. Lower statistics data for the process {Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +} from a 230 fb{sup -1} sample are also found to be consistent with {Omega}{sup -} spin 3/2. If the {Xi}{sub c}{sup 0} spin were 3/2, an {Omega}{sup -} spin of 5/2 cannot be excluded.

  2. Prenatal omega-3 fatty acids: review and recommendations.

    PubMed

    Jordan, Robin G

    2010-01-01

    The influence of dietary omega-3 fatty acids on health outcomes is widely recognized. The adequate intake of omega-3 fatty acids docasahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in particular can increase gestation length and improve infant cognitive and visual performance. Adequate levels of omega-3 fatty acids have also been shown to reduce the incidence of preterm birth in some populations. Research on prenatal omega-3 intake and other outcomes, such as preeclampsia and fetal growth restriction, is inconclusive. Women in the United States consume low levels of omega-3 fatty acids compared to omega-6 fatty acids; this dietary pattern is associated with poor health outcomes. Omega-3 fatty acids are found primarily in fish, yet many pregnant women avoid fish because of concerns about potential mercury and polychlorinated biphenyl contamination. It is important for prenatal care providers to assess women's diets for omega-3 fatty acid intake and ensure that pregnant women are consuming between 200 and 300 mg daily from safe food sources. Purified fish, algal oil supplements, and DHA-enriched eggs are alternative sources for pregnant women who do not eat fish.

  3. Dietary omega-3 fatty acid intake and cardiovascular risk.

    PubMed

    Psota, Tricia L; Gebauer, Sarah K; Kris-Etherton, Penny

    2006-08-21

    Dietary omega-3 fatty acids decrease the risk of cardiovascular disease (CVD). Both epidemiologic and interventional studies have demonstrated beneficial effects of omega-3 fatty acids on many CVD end points, including all CVD (defined as all coronary artery disease [CAD], fatal and nonfatal myocardial infarction [MI], and stroke combined), all CAD, fatal and nonfatal MI, stroke, sudden cardiac death, and all-cause mortality. Much of the evidence comes from studies with fish oil and fish; to a lesser extent, data relate to plant-derived omega-3 fatty acids. Cardioprotective benefits have been observed with daily consumption of as little as 25 to 57 g (approximately 1 to 2 oz) of fish high in omega-3 fatty acids, an intake equivalent to >or=1 fish meal weekly or even monthly, with greater intakes decreasing risk further in a dose-dependent manner, up to about 5 servings per week. Fish, including farm-raised fish and their wild counterparts, are the major dietary sources of the longer-chain omega-3 fatty acids. Sources of plant-derived omega-3 fatty acids include flaxseed, flaxseed oil, walnuts, canola oil, and soybean oil. Because of the remarkable cardioprotective effects of omega-3 fatty acids, consumption of food sources that provide omega-3 fatty acids--especially the longer-chain fatty acids (>or=20 carbons) from marine sources--should be increased in the diet to decrease CVD risk significantly.

  4. Relativistic quark model for the Omega- electromagnetic form factors

    SciTech Connect

    G. Ramalho, K. Tsushima, Franz Gross

    2009-08-01

    We compute the Omega- electromagnetic form factors and the decuplet baryon magnetic moments using a quark model application of the Covariant Spectator Theory. Our predictions for the Omega- electromagnetic form factors can be tested in the future by lattice QCD simulations at the physical strange quark mass.

  5. A proposed microcomputer implementation of an Omega navigation processor

    NASA Technical Reports Server (NTRS)

    Abel, J. D.

    1976-01-01

    A microprocessor navigation systems using the Omega process is discussed. Several methods for correcting incoming sky waves are presented along with the hardware design which depends on a microcomputer. The control program is discussed, and block diagrams of the Omega processor and interface systems are presented.

  6. Antiarrhythmic effects of omega-3 fatty acids.

    PubMed

    Reiffel, James A; McDonald, Arline

    2006-08-21

    Fish oil, and omega-3 fatty acids in particular, have been found to reduce plasma levels of triglycerides and increase levels of high-density lipoprotein in patients with marked hypertriglyceridemia, and a pharmaceutical-grade preparation has recently received approval from the US Food and Drug Administration to market for this purpose. However, in both bench research studies and clinical trials, evidence for clinically significant antiarrhythmic properties has also been detected in association with omega-3 fatty acid intake. Arguably the most significant finding in this data set was the reduction in the incidence of sudden death in survivors of myocardial infarction in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI)-Prevenzione trial and the subsequent recommendation for administration of fish oil as part of the postinfarction regimen in Europe. This article reviews in detail the basic and clinical research studies of fish oil as an antiarrhythmic entity, the forms of preparation and/or administration that appear to possess these properties and those that do not, the types of arrhythmias (ventricular ectopy and atrial fibrillation as well as ventricular tachyarrhythmias) that have been beneficially affected by fish oil administration, and the presumed and known mechanisms by which the beneficial actions are exerted.

  7. Laser-driven magnetized liner inertial fusion

    DOE PAGES

    Davies, J. R.; Barnak, D. H.; Betti, R.; ...

    2017-06-05

    A laser-driven, magnetized liner inertial fusion (MagLIF) experiment is designed in this paper for the OMEGA Laser System by scaling down the Z point design to provide the first experimental data on MagLIF scaling. OMEGA delivers roughly 1000× less energy than Z, so target linear dimensions are reduced by factors of ~10. Magneto-inertial fusion electrical discharge system could provide an axial magnetic field of 10 T. Two-dimensional hydrocode modeling indicates that a single OMEGA beam can preheat the fuel to a mean temperature of ~200 eV, limited by mix caused by heat flow into the wall. One-dimensional magnetohydrodynamic (MHD) modelingmore » is used to determine the pulse duration and fuel density that optimize neutron yield at a fuel convergence ratio of roughly 25 or less, matching the Z point design, for a range of shell thicknesses. A relatively thinner shell, giving a higher implosion velocity, is required to give adequate fuel heating on OMEGA compared to Z because of the increase in thermal losses in smaller targets. Two-dimensional MHD modeling of the point design gives roughly a 50% reduction in compressed density, temperature, and magnetic field from 1-D because of end losses. Finally, scaling up the OMEGA point design to the MJ laser energy available on the National Ignition Facility gives a 500-fold increase in neutron yield in 1-D modeling.« less

  8. Laser-driven magnetized liner inertial fusion

    NASA Astrophysics Data System (ADS)

    Davies, J. R.; Barnak, D. H.; Betti, R.; Campbell, E. M.; Chang, P.-Y.; Sefkow, A. B.; Peterson, K. J.; Sinars, D. B.; Weis, M. R.

    2017-06-01

    A laser-driven, magnetized liner inertial fusion (MagLIF) experiment is designed for the OMEGA Laser System by scaling down the Z point design to provide the first experimental data on MagLIF scaling. OMEGA delivers roughly 1000× less energy than Z, so target linear dimensions are reduced by factors of ˜10. Magneto-inertial fusion electrical discharge system could provide an axial magnetic field of 10 T. Two-dimensional hydrocode modeling indicates that a single OMEGA beam can preheat the fuel to a mean temperature of ˜200 eV, limited by mix caused by heat flow into the wall. One-dimensional magnetohydrodynamic (MHD) modeling is used to determine the pulse duration and fuel density that optimize neutron yield at a fuel convergence ratio of roughly 25 or less, matching the Z point design, for a range of shell thicknesses. A relatively thinner shell, giving a higher implosion velocity, is required to give adequate fuel heating on OMEGA compared to Z because of the increase in thermal losses in smaller targets. Two-dimensional MHD modeling of the point design gives roughly a 50% reduction in compressed density, temperature, and magnetic field from 1-D because of end losses. Scaling up the OMEGA point design to the MJ laser energy available on the National Ignition Facility gives a 500-fold increase in neutron yield in 1-D modeling.

  9. Observation of in-medium modifications of the omega meson.

    PubMed

    Trnka, D; Anton, G; Bacelar, J C S; Bartholomy, O; Bayadilov, D; Beloglazov, Y A; Bogendörfer, R; Castelijns, R; Crede, V; Dutz, H; Ehmanns, A; Elsner, D; Ewald, R; Fabry, I; Fuchs, M; Essig, K; Funke, Ch; Gothe, R; Gregor, R; Gridnev, A B; Gutz, E; Höffgen, S; Hoffmeister, P; Horn, I; Hössl, J; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Klein, Frank; Klein, Fritz; Klempt, E; Konrad, M; Kopf, B; Kotulla, M; Krusche, B; Langheinrich, J; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Messchendorp, J G; Mertens, T; Metag, V; Morales, C; Nanova, M; Novotny, R; Ostrick, M; Pant, L M; van Pee, H; Pfeiffer, M; Roy, A; Radkov, A; Schadmand, S; Schmidt, Ch; Schmieden, H; Schoch, B; Shende, S; Suft, G; Sumachev, V V; Szczepanek, T; Süle, A; Thoma, U; Varma, R; Walther, D; Weinheimer, Ch; Wendel, Ch

    2005-05-20

    The photoproduction of omega mesons on nuclei has been investigated using the Crystal Barrel/TAPS experiment at the ELSA tagged photon facility in Bonn. The aim is to study possible in-medium modifications of the omega meson via the reaction gamma + A --> omega + X --> pi(0)gamma + X('). Results obtained for Nb are compared to a reference measurement on a LH2 target. While for recoiling, long-lived mesons (pi(0), eta, and eta;(')), which decay outside of the nucleus, a difference in the line shape for the two data samples is not observed, we find a significant enhancement towards lower masses for omega mesons produced on the Nb target. For momenta less than 500 MeV/c an in-medium omega meson mass of M(medium) = [722(+4)(-4)(stat)+35-5(syst)] MeV/c(2) has been deduced at an estimated average nuclear density of 0.6rho(0).

  10. Bioavailability of long-chain omega-3 fatty acids.

    PubMed

    Schuchardt, Jan Philipp; Hahn, Andreas

    2013-07-01

    Supplements have reached a prominent role in improving the supply of long-chain omega-3 fatty acids, such as Eicosapentaenoic acid (EPA 20:5n-3) and Docosahexaenoic acid (DHA 22:6n-3). Similar to other nutrients, the availability of omega-3 fatty acids is highly variable and determined by numerous factors. However, the question of omega-3 fatty acids bioavailability has long been disregarded, which may have contributed to the neutral or negative results concerning their effects in several studies. This review provides an overview of the influence of chemical binding form (free fatty acids bound in ethylesters, triacylglycerides or phospholipids), matrix effects (capsule ingestion with concomitant intake of food, fat content in food) or galenic form (i.e. microencapsulation, emulsification) on the bioavailability of omega-3 fatty acids. There is a need to systematically investigate the bioavailability of omega-3 fatty acids formulations, which might be a key to designing more effective studies in the future.

  11. Electromagnetic Tunneling and Resonances in Pseudochiral Omega Slabs.

    PubMed

    Razzaz, Faroq; Alkanhal, Majeed A S

    2017-02-06

    This paper presents theoretical investigation of the electromagnetic wave tunneling and anomalous transmission around the trapped modes in a pseudochiral omega slab. The dispersion relation, the conditions of the trapped modes, and the evanescent wave coupling and tunneling in two different reciprocal pseudochiral omega slab structures are derived. The Berreman's matrix method is applied to obtain the transmission coefficients across the pseudochiral omega slab. When the structure is perturbed, a resonance phenomenon is detected around the trapped modes. This resonance results in transmission anomalies (total transmission and total reflection) and dramatic field amplifications around the trapped modes. The number of the discrete trapped modes and then the resonance frequencies are prescribed by the parameters of the pseudochiral omega slab such as the value of the omega parameter and its orientation and the slab thickness.

  12. Electromagnetic Tunneling and Resonances in Pseudochiral Omega Slabs

    PubMed Central

    Razzaz, Faroq; Alkanhal, Majeed A. S.

    2017-01-01

    This paper presents theoretical investigation of the electromagnetic wave tunneling and anomalous transmission around the trapped modes in a pseudochiral omega slab. The dispersion relation, the conditions of the trapped modes, and the evanescent wave coupling and tunneling in two different reciprocal pseudochiral omega slab structures are derived. The Berreman’s matrix method is applied to obtain the transmission coefficients across the pseudochiral omega slab. When the structure is perturbed, a resonance phenomenon is detected around the trapped modes. This resonance results in transmission anomalies (total transmission and total reflection) and dramatic field amplifications around the trapped modes. The number of the discrete trapped modes and then the resonance frequencies are prescribed by the parameters of the pseudochiral omega slab such as the value of the omega parameter and its orientation and the slab thickness. PMID:28165058

  13. Omega-3 fatty acids in major depressive disorder.

    PubMed

    Freeman, Marlene P

    2009-01-01

    Patients with major depressive disorder have high rates of cardiovascular disease and other medical comorbidity. Omega-3 fatty acids, particularly those found in fish and seafood, have cardiovascular health benefits and may play an adjunctive role in the treatment of mood disorders. However, existing studies on omega-3 fatty acids in depression have limitations such as small sample sizes and a wide variance in study design, and results regarding efficacy are mixed. The preponderance of data from placebo-controlled treatment studies suggests that omega-3 fatty acids are a reasonable augmentation strategy for the treatment of major depressive disorder. More research is necessary before omega-3 supplements can be recommended as monotherapy for the treatment of depression. For many individuals with major depressive disorder, augmentation with omega-3 fatty acids should be considered, as general health benefits are well established and adjunctive use is low risk.

  14. Nonlinear absorption and harmonic generation of laser in a gas with anharmonic clusters

    SciTech Connect

    Kumar, Manoj; Tripathi, V. K.

    2013-02-15

    The nonlinear absorption and harmonic generation of intense short pulse laser in a gas embedded with anharmonic clusters are investigated theoretically. When the laser induced excursion of cluster electrons becomes comparable to cluster radius, the restoration force on electrons no longer remains linearly proportional to the excursion. As a consequence, the plasmon resonance is broadened, leading to broadband laser absorption. It also leads to second and third harmonic generations, at much higher level than the one due to ponderomotive nonlinearity. The harmonic yield is resonantly enhanced at the plasmon resonance {omega}={omega}{sub pe}/{radical}(3), where {omega} is the frequency of the laser and {omega}{sub pe} is the plasma frequency of cluster electrons.

  15. Omega-6 to Omega-3 Fatty Acid Ratio in Patients with ADHD: A Meta-Analysis

    PubMed Central

    LaChance, Laura; McKenzie, Kwame; Taylor, Valerie H.; Vigod, Simone N.

    2016-01-01

    Objective: Omega-3 and omega-6 fatty acids have been shown to be deficient in individuals with attention deficit/hyperactivity disorder compared to controls (Hawkey & Nigg, 2014). Clinical trials of omega-3 and omega-6 supplements as treatment for ADHD have demonstrated minimal efficacy (Bloch & Qawasmi, 2011; Gillies, Sinn, Lad, Leach, & Ross, 2011; Hawkey & Nigg, 2014; Puri & Martins, 2014; Sonuga-Barke et al., 2013). Existing trials have analyzed omega-3 and omega-6 separately although the tissue ratio of these fatty acids (n6/n3) may be more important than absolute levels of either. The objective of this study was to determine the relationship between blood n6/n3 and arachidonic acid to eicosapentaenoic acid (AA/EPA), to ADHD symptoms. Method: A systematic literature review identified original articles measuring blood n6/n3 or AA/EPA ratio in children and youth with ADHD, compared to controls without ADHD. Three databases were searched. Blood n6/n3, and AA/EPA ratios were compared between individuals with ADHD and controls. Results were pooled across studies using quantitative synthesis. Results: Five articles met inclusion criteria for the meta-analysis. The pooled mean difference between patients with ADHD and controls was 1.97 (0.90–3.04) for n6/n3 (n=5 studies, I2 83%) and 8.25 (5.94–10.56) for AA/EPA (n=3 studies, I2 0%). Conclusions: Children and youth with ADHD have elevated ratios of both blood n6/n3 and AA/EPA fatty acids compared to controls. Thus an elevated n6/n3, and more specifically AA/EPA, ratio may represent the underlying disturbance in essential fatty acid levels in patients with ADHD. These findings have implications for the development of future interventions using essential fatty acids to treat ADHD, and for the use of these ratios as biomarkers for titrating and monitoring ADHD treatment with essential fatty acids. PMID:27274744

  16. Simulation and analysis of time-gated monochromatic radiographs of cryogenic implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Epstein, R.; Stoeckl, C.; Goncharov, V. N.; McKenty, P. W.; Marshall, F. J.; Regan, S. P.; Betti, R.; Bittle, W.; Harding, D. R.; Hu, S. X.; Igumenshchev, I. V.; Jacobs-Perkins, D.; Janezic, R. T.; Kelly, J. H.; Kosc, T. Z.; Mileham, C.; Morse, S. F. B.; Radha, P. B.; Rice, B.; Sangster, T. C.; Shoup, M. J., III; Shmayda, W. T.; Sorce, C.; Ulreich, J.; Wittman, M. D.

    2017-06-01

    Spherical polymer shells containing cryogenic DT ice layers have been imploded on the OMEGA Laser System and radiographed using Si backlighter targets (hν = 1.865 keV) driven with 20-ps IR pulses from the OMEGA EP Laser System. We report on a series of implosions in which the deuterium-tritium (DT) shell is imaged for a range of convergence ratios and in-flight aspect ratios. The shadows of the converging DT ice and polymer shells are recorded while the self-emission is minimized using a time-resolved (40-ps) monochromatic crystal imaging system. The images acquired have been analyzed for the level of ablator mixing into the DT fuel (even 0.1% of carbon mix can be reliably inferred). Simulations are compared with measured x-ray radiographs to provide insight into the early time and stagnation stages of an implosion, to guide the modeling efforts to improve the target designs, and to guide the development of this and other imagining techniques, such as Compton radiography.

  17. Three-Dimensional Analysis of the Effects of Low-Mode Asymmetries on OMEGA Cryogenic Implosions

    NASA Astrophysics Data System (ADS)

    Anderson, K. S.; McKenty, P. W.; Shvydky, A.; Knauer, J. P.; Collins, T. J. B.; Marinak, M. M.

    2016-10-01

    Understanding the role of low-mode asymmetries is essential to characterizing inertial confinement fusion implosions. Asymmetries seeded by nonuniformities in laser drive, capsule manufacture, and target positioning lead to shell modulation as well as nonradial hydrodynamic flow in the hot spot at stagnation, which can adversely affect peak pressure and neutron yield. Full-sphere three-dimensional simulations are required to quantify the flow in the hot spot and its impact on hot-spot pressure and other observables. This paper will analyze results from HYDRA simulations of OMEGA cryogenic implosions modeling various sources of low-mode asymmetries (e.g., target offset, laser power imbalance, ice layer roughness) and show comparisons with experimental observables. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Numbers DE-NA0001944 and performed under the auspices of the LLNL under Contract No. DE-AC52-07NA27344.

  18. Convergent ablation measurements of plastic ablators in gas-filled rugby hohlraums on OMEGA

    NASA Astrophysics Data System (ADS)

    Casner, A.; Jalinaud, T.; Masse, L.; Galmiche, D.

    2015-10-01

    Indirect-drive implosions experiments were conducted on the Omega Laser Facility to test the performance of uniformly doped plastic ablators for Inertial Confinement Fusion. The first convergent ablation measurements in gas-filled rugby hohlraums are reported. Ignition relevant limb velocities in the range from 150 to 300 μm .n s-1 have been reached by varying the laser drive energy and the initial capsule aspect ratio. The measured capsule trajectory and implosion velocity are in good agreement with 2D integrated simulations and a zero-dimensional modeling of the implosions. We demonstrate experimentally the scaling law for the maximum implosion velocity predicted by the improved rocket model [Y. Saillard, Nucl. Fusion 46, 1017 (2006)] in the high-ablation regime case.

  19. Electron Positron Proton Spectrometer for use at Laboratory for Laser Energetics

    SciTech Connect

    Ayers, S L

    2010-04-07

    The Electron Positron Proton Spectrometer (EPPS) is mounted in a TIM (Ten-Inch Manipulator) system on the Omega-60 or Omega-EP laser facilities at the University of Rochester, Laboratory for Laser Energetics (LLE), when in use, see Fig. 1. The Spectrometer assembly, shown in Fig. 2, is constructed of a steel box containing magnets, surrounded by Lead 6% Antimony shielding with SS threaded insert, sitting on an Aluminum 6061-T6 plate.

  20. Laser-Plasma Interactions in High-Energy Density Plasmas

    SciTech Connect

    Constantin, C G; Baldis, H A; Schneider, M B; Hinkel, D E; Langdon, A B; Seka, W; Bahr, R; Depierreaux, S

    2005-08-24

    Laser-plasma interactions (LPI) have been studied experimentally in high-temperature, high-energy density plasmas. The studies have been performed using the Omega laser at the Laboratory for Laser Energetics (LLE), Rochester, NY. Up to 10 TW of power was incident upon reduced-scale hohlraums, distributed in three laser beam cones. The hot hohlraums fill quickly with plasma. Late in the laser pulse, most of the laser energy is deposited at the laser entrance hole, where most of the LPI takes place. Due to the high electron temperature, the stimulated Raman scattering (SRS) spectrum extends well beyond {omega}{sub 0}/2, due to the Bohm-Gross shift. This high-temperature, high-energy density regime provides a unique opportunity to study LPI beyond inertial confinement fusion (ICF) conditions.

  1. Three-dimensional modeling of direct-drive cryogenic implosions on OMEGA

    DOE PAGES

    Igumenshchev, I. V.; Goncharov, V. N.; Marshall, F. J.; ...

    2016-05-04

    The effects of large-scale (with Legendre modes ≲10) laser-imposed nonuniformities in direct-drive cryogenic implosions on the OMEGA laser system are investigated using three-dimension hydrodynamic simulations performed using a newly developed code ASTER. Sources of these nonuniformities include an illumination pattern produced by 60 OMEGA laser beams, capsule offsets (~10 to 20 μm), and imperfect pointing, energy balance, and timing of the beams (with typical σrms ~10 μm, 10%, and 5 ps, respectively). Two implosion designs using 26-kJ triple-picket laser pulses were studied: a nominal design, in which a 880-μm-diameter capsule is illuminated by the same-diameter beams, and a “R75” designmore » using a capsule of 900 μm in diameter and beams of 75% of this diameter. Simulations found that nonuniformities because of capsule offsets and beam imbalance have the largest effect on implosion performance. These nonuniformities lead to significant distortions of implosion cores resulting in an incomplete stagnation. The shape of distorted cores is well represented by neutron images, but loosely in x-rays. Simulated neutron spectra from perturbed implosions show large directional variations and up to ~ 2 keV variation of the hot spot temperature inferred from these spectra. The R75 design is more hydrodynamically efficient because of mitigation of crossed-beam energy transfer, but also suffers more from the nonuniformities. Furthermore, simulations predict a performance advantage of this design over the nominal design when the target offset and beam imbalance σrms are reduced to less than 5 μm and 5%, respectively.« less

  2. Three-dimensional modeling of direct-drive cryogenic implosions on OMEGA

    SciTech Connect

    Igumenshchev, I. V.; Goncharov, V. N.; Marshall, F. J.; Knauer, J. P.; Campbell, E. M.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu.; McCrory, R. L.; Regan, S. P.; Sangster, T. C.; Skupsky, S.; Stoeckl, C.

    2016-05-04

    The effects of large-scale (with Legendre modes ≲10) laser-imposed nonuniformities in direct-drive cryogenic implosions on the OMEGA laser system are investigated using three-dimension hydrodynamic simulations performed using a newly developed code ASTER. Sources of these nonuniformities include an illumination pattern produced by 60 OMEGA laser beams, capsule offsets (~10 to 20 μm), and imperfect pointing, energy balance, and timing of the beams (with typical σrms ~10 μm, 10%, and 5 ps, respectively). Two implosion designs using 26-kJ triple-picket laser pulses were studied: a nominal design, in which a 880-μm-diameter capsule is illuminated by the same-diameter beams, and a “R75” design using a capsule of 900 μm in diameter and beams of 75% of this diameter. Simulations found that nonuniformities because of capsule offsets and beam imbalance have the largest effect on implosion performance. These nonuniformities lead to significant distortions of implosion cores resulting in an incomplete stagnation. The shape of distorted cores is well represented by neutron images, but loosely in x-rays. Simulated neutron spectra from perturbed implosions show large directional variations and up to ~ 2 keV variation of the hot spot temperature inferred from these spectra. The R75 design is more hydrodynamically efficient because of mitigation of crossed-beam energy transfer, but also suffers more from the nonuniformities. Furthermore, simulations predict a performance advantage of this design over the nominal design when the target offset and beam imbalance σrms are reduced to less than 5 μm and 5%, respectively.

  3. Three-dimensional modeling of direct-drive cryogenic implosions on OMEGA

    SciTech Connect

    Igumenshchev, I. V.; Goncharov, V. N.; Marshall, F. J.; Knauer, J. P.; Campbell, E. M.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu.; McCrory, R. L.; Regan, S. P.; Sangster, T. C.; Skupsky, S.; Stoeckl, C.

    2016-05-04

    The effects of large-scale (with Legendre modes ≲10) laser-imposed nonuniformities in direct-drive cryogenic implosions on the OMEGA laser system are investigated using three-dimension hydrodynamic simulations performed using a newly developed code ASTER. Sources of these nonuniformities include an illumination pattern produced by 60 OMEGA laser beams, capsule offsets (~10 to 20 μm), and imperfect pointing, energy balance, and timing of the beams (with typical σrms ~10 μm, 10%, and 5 ps, respectively). Two implosion designs using 26-kJ triple-picket laser pulses were studied: a nominal design, in which a 880-μm-diameter capsule is illuminated by the same-diameter beams, and a “R75” design using a capsule of 900 μm in diameter and beams of 75% of this diameter. Simulations found that nonuniformities because of capsule offsets and beam imbalance have the largest effect on implosion performance. These nonuniformities lead to significant distortions of implosion cores resulting in an incomplete stagnation. The shape of distorted cores is well represented by neutron images, but loosely in x-rays. Simulated neutron spectra from perturbed implosions show large directional variations and up to ~ 2 keV variation of the hot spot temperature inferred from these spectra. The R75 design is more hydrodynamically efficient because of mitigation of crossed-beam energy transfer, but also suffers more from the nonuniformities. Furthermore, simulations predict a performance advantage of this design over the nominal design when the target offset and beam imbalance σrms are reduced to less than 5 μm and 5%, respectively.

  4. CVD Diamond Detectors for Current Mode Neutron Time-of-Flight Spectroscopy at OMEGA/NIF

    SciTech Connect

    G. J. Schmid; V. Yu. Glebov; A. V. Friensehner; D. R. Hargrove; S. P. Hatchett; N. Izumi; R. A. Lerche; T. W. Phillips; T. C. Sangster; C. Silbernagel; C. Stoecki

    2001-07-01

    We have performed pulsed neutron and pulsed laser tests of a CVD diamond detector manufactured from DIAFILM, a commercial grade of CVD diamond. The laser tests were performed at the short pulse UV laser at Bechtel Nevada in Livermore, CA. The pulsed neutrons were provided by DT capsule implosions at the OMEGA laser fusion facility in Rochester, NY. From these tests, we have determined the impulse response to be 250 ps fwhm for an applied E-field of 500 V/mm. Additionally, we have determined the sensitivity to be 2.4 mA/W at 500 V/mm and 4.0 mA/W at 1000 V/mm. These values are approximately 2 to 5x times higher than those reported for natural Type IIa diamond at similar E-field and thickness (1mm). These characteristics allow us to conceive of a neutron time-of-flight current mode spectrometer based on CVD diamond. Such an instrument would sit inside the laser fusion target chamber close to target chamber center (TCC), and would record neutron spectra fast enough such that backscattered neutrons and x-rays from the target chamber wall would not be a concern. The acquired neutron spectra could then be used to extract DD fuel areal density from the downscattered secondary to secondary ratio.

  5. Design of a Production Process to Enhance Optical Performance of 3(omega) Optics

    SciTech Connect

    Prasad, R R; Bruere, J R; Halpin, J; Lucero, P; Mills, S; Bernacil, M; Hackel, R P

    2003-11-01

    Using the Phoenix pre-production conditioning facility we have shown that raster scanning of 3{omega} optics using a XeF excimer laser and mitigation of the resultant damage sites with a CO{sub 2} laser can enhance their optical damage resistance. Several large-scale (43 cm x 43 cm) optics have been processed in this facility. A production facility capable of processing several large optics a week has been designed based on our experience in the pre-production facility. The facility will be equipped with UV conditioning lasers--351-nm XeF excimer lasers operating at 100 Hz and 23 ns. The facility will also include a CO{sub 2} laser for damage mitigation, an optics stage for raster scanning large-scale optics, a damage mapping system (DMS) that images large-scale optics and can detect damage sites or precursors as small as {approx} 15 {micro}m, and two microscopes to image damage sites with {approx} 5 {micro}m resolution. The optics will be handled in a class 100 clean room, within the facility that will be maintained at class 1000.

  6. Proton emission from cone-in-shell fast-ignition experiments at Omega

    SciTech Connect

    Sinenian, N.; Frenje, J. A.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Theobald, W.; Stoeckl, C.; Stephens, R. B.

    2012-11-15

    Measurements of energetic protons from cone-in-shell fast-igniton implosions at Omega have been conducted. In these experiments, charged-particle spectrometers were used to measure a significant population (>10{sup 13}) of energetic protons (7.5 MeV max.), indicating the presence of strong electric fields. These energetic protons, observed in directions both transverse and forward relative to the direction of the short-pulse laser beam, have been used to study aspects of coupling efficiency of the petawatt fast-ignitior beam. Approximately 5% of the laser energy coupled to hot electrons was lost to fast ions. Forward going protons were less energetic and showed no dependence on laser intensity or whether the cone tip was intact when the short-pulse laser was fired. Maximum energies of protons emitted transverse to the cone-in-shell target scale with incident on-target laser intensity (2-6 Multiplication-Sign 10{sup 18}W-cm{sup -2}), as described by the ponderomotive scaling ({proportional_to}I{sup 1/2}). It is shown that these protons are accelerated from the entire cone, rather than from the cone tip alone. These protons were used to estimate the lower limit on the hot-electron temperature, which was found to be hotter than the ponderomotive scaling by factors of 2-3.

  7. Multiple-view spectrally resolved x-ray imaging observations of polar-direct-drive implosions on OMEGA

    SciTech Connect

    Mancini, R. C.; Johns, H. M.; Joshi, T.; Mayes, D.; Nagayama, T.; Hsu, S. C.; Baumgaertel, J. A.; Cobble, J.; Krasheninnikova, N. S.; Bradley, P. A.; Hakel, P.; Murphy, T. J.; Schmitt, M. J.; Shah, R. C.; Tregillis, I. L.; Wysocki, F. J.

    2014-12-15

    We present spatially, temporally, and spectrally resolved narrow- and broad-band x-ray images of polar-direct-drive (PDD) implosions on OMEGA. These self-emission images were obtained during the deceleration phase and bang time using several multiple monochromatic x-ray imaging instruments fielded along two or three quasi-orthogonal lines-of-sight, including equatorial and polar views. The instruments recorded images based on K-shell lines from a titanium tracer located in the shell as well as continuum emission. These observations constitute the first such data obtained for PDD implosions. The image data show features attributed to laser imprinting and zero-order hydrodynamics. Equatorial-view images show a “double bun” structure that is consistent with synthetic images obtained from post-processing 2D and 3D radiation-hydrodynamic simulations of the experiment. Polar-view images show a pentagonal, petal pattern that correlates with the PDD laser illumination used on OMEGA, thus revealing a 3D aspect of PDD OMEGA implosions not previously observed. Differences are noted with respect to a PDD experiment performed at National Ignition Facility.

  8. Symmetry control using beam phasing in ~0.2 NIF scale high temperature Hohlraum experiment on OMEGA

    SciTech Connect

    Delamater, Norman D; Wilson, Goug C; Kyrala, George A; Seifter, Achim; Hoffman, N M; Dodd, E; Glebov, V

    2009-01-01

    Results are shown from recent experiments at the Omega laser facility, using 40 Omega beams driving the hohlraum with 3 cones from each side and up to 19.5 kJ of laser energy. Beam phasing is achieved by decreasing the energy separately in each of the three cones, by 3 kJ, for a total drive energy of 16.5kJ. This results in a more asymmetric drive, which will vary the shape of the imploded symmetry capsule core from round to oblate or prolate in a systematic and controlled manner. These results would be the first demonstration of beam phasing for implosions in such 'high temperature' (275 eV) hohlraums at Omega. Dante measurements confirmed the predicted peak drive temperatures of 275 eV. Implosion core time dependent x-ray images were obtained from framing camera data which show the expected change in symmetry due to beam phasing and which also agree well with post processed hydro code calculations. Time resolved hard x-ray data has been obtained and it was found that the hard x-rays are correlated mainly with the low angle 21{sup o} degree cone.

  9. Hubble Space Telescope Image of Omega Nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In this sturning image provided by the Hubble Space Telescope (HST), the Omega Nebula (M17) resembles the fury of a raging sea, showing a bubbly ocean of glowing hydrogen gas and small amounts of other elements such as oxygen and sulfur. The nebula, also known as the Swan Nebula, is a hotbed of newly born stars residing 5,500 light-years away in the constellation Sagittarius. The wavelike patterns of gas have been sculpted and illuminated by a torrent of ultraviolet radiation from the young massive stars, which lie outside the picture to the upper left. The ultraviolet radiation is carving and heating the surfaces of cold hydrogen gas clouds. The warmed surfaces glow orange and red in this photograph. The green represents an even hotter gas that masks background structures. Various gases represented with color are: sulfur, represented in red; hydrogen, green; and oxygen blue.

  10. BVRI CCD photometry of Omega Centauri

    SciTech Connect

    Alcaino, G.; Liller, W.

    1987-12-01

    Color-magnitude diagrams (CMDs) of V vs B-V, V vs V-I, and V vs B-I have been constructed based on 179 BVRI CCD frames of two adjoining 4x2.5-arcmin fields in Omega Cen (NGC 5139) obtained with the 1.54-m Danish La Silla telescope. The spread in the main sequences noted in the three CMDs indicates that the wide range in chemical composition among the evolved stars in this cluster persists as well in the unevolved stars. This result suggests that the abundance variations are primordial. A difference in magnitude between the turnoff and the horizontal branch of 3.8 + or - 0.15 is found which is greater than a previous value. 38 references.

  11. [Antiinflammatory therapy in ostheoarthritis including omega 3 and omega 6 fatty acids].

    PubMed

    Dzielska-Olczak, Małgorzata; Nowak, Jerzy Z

    2012-05-01

    Osteoarthritis (ostheoarthrosis, OA) is characterized by progressive destruction of articular cartilage, remodeling of the periarticular bone and inflammation of the synovial membrane. In patients occur joints pain, impaired joints motion and disability. The results of many studies indicate an inflammation as foundation of this disease. The management of OA include a combination of pharmacological treatments and nonpharmacological interventions. Pharmacological treatments include used paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs) and chondroprotectives (glucosamine, chondroitin sulfate and so on). NSAIDs long-term use associated with serious adverse effects. OA symptoms are effectively reduced by nutrients such omega 3 and omega 6 fatty acids (PUFAs as EPA, DHA), which decrease the need for non-steroidal drugs and may less adverse events. They exerts, particularly EPA, anti-inflammatory effect, inhibit catabolic processes, stimulate the anabolic process in the cartilage in the joint. Many different evidence validate that omega 3 alleviate the progression of osteoarthritis and have exciting therapeutic potential for preventing cartilage degradation associated with chronic inflammatory in joints.

  12. Modification of the omega-meson lifetime in nuclear matter.

    PubMed

    Kotulla, M; Trnka, D; Mühlich, P; Anton, G; Bacelar, J C S; Bartholomy, O; Bayadilov, D; Beloglazov, Y A; Bogendörfer, R; Castelijns, R; Crede, V; Dutz, H; Ehmanns, A; Elsner, D; Ewald, R; Fabry, I; Fuchs, M; Essig, K; Funke, Ch; Gothe, R; Gregor, R; Gridnev, A B; Gutz, E; Höffgen, S; Hoffmeister, P; Horn, I; Hössl, J; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Klein, Frank; Klein, Fritz; Klempt, E; Konrad, M; Kopf, B; Krusche, B; Langheinrich, J; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Messchendorp, J G; Mertens, T; Metag, V; Mosel, U; Nanova, M; Novotny, R; Ostrick, M; Pant, L M; van Pee, H; Pfeiffer, M; Roy, A; Radkov, A; Schadmand, S; Schmidt, Ch; Schmieden, H; Schoch, B; Shende, S; Suft, G; Sumachev, V V; Szczepanek, T; Süle, A; Thoma, U; Varma, R; Walther, D; Weinheimer, Ch; Wendel, Ch

    2008-05-16

    Information on hadron properties in the nuclear medium has been derived from the photoproduction of omega mesons on the nuclei C, Ca, Nb, and Pb using the Crystal Barrel/TAPS detector at the ELSA tagged photon facility in Bonn. The dependence of the omega-meson cross section on the nuclear mass number has been compared with three different types of models: a Glauber analysis, a Boltzmann-Uehling-Uhlenbeck analysis of the Giessen theory group, and a calculation by the Valencia theory group. In all three cases, the inelastic omega width is found to be 130-150 MeV/c(2) at normal nuclear matter density for an average 3-momentum of 1.1 GeV/c. In the rest frame of the omega meson, this inelastic omega width corresponds to a reduction of the omega lifetime by a factor approximately 30. For the first time, the momentum dependent omegaN cross section has been extracted from the experiment and is in the range of 70 mb.

  13. Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability

    PubMed Central

    Christensen, Jeppe Hagstrup

    2011-01-01

    Omega-3 polyunsaturated fatty acids (PUFA) may modulate autonomic control of the heart because omega-3 PUFA is abundant in the brain and other nervous tissue as well as in cardiac tissue. This might partly explain why omega-3 PUFA offer some protection against sudden cardiac death (SCD). The autonomic nervous system is involved in the pathogenesis of SCD. Heart rate variability (HRV) can be used as a non-invasive marker of cardiac autonomic control and a low HRV is a predictor for SCD and arrhythmic events. Studies on HRV and omega-3 PUFA have been performed in several populations such as patients with ischemic heart disease, patients with diabetes mellitus, patients with chronic renal failure, and in healthy subjects as well as in children. The studies have demonstrated a positive association between cellular content of omega-3 PUFA and HRV and supplementation with omega-3 PUFA seems to increase HRV which could be a possible explanation for decreased risk of arrhythmic events and SCD sometimes observed after omega-3 PUFA supplementation. However, the results are not consistent and further research is needed. PMID:22110443

  14. Production and Decay of Omega_c^0

    SciTech Connect

    Aubert, B

    2007-03-21

    We present an analysis of inclusive {Omega}{sub c}{sup 0} baryon production and decays in 230.5 fb{sup -1} of data recorded with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the Stanford Linear Accelerator Center. {Omega}{sub c}{sup 0} baryons are reconstructed in four final states ({Omega}{sup -}{pi}{sup +}, {Omega}{sup -}{pi}{sup +}{pi}{sup 0}, {Omega}{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -}, {Xi}{sup -}K{sup -}{pi}{sup +}{pi}{sup +}) and the ratios of branching fractions for these final states are measured. We also measure the momentum spectrum of the {Omega}{sub c}{sup 0} baryons in the e{sup +}e{sup -} center-of-mass frame. From the spectrum, they observe {Omega}{sub c}{sup 0} production from B decays and in c{bar c} events, and extract the two rates of production.

  15. The Role of Omega-3 Fatty Acids in Diets.

    PubMed

    Gomez-Candela, C; Roldan Puchalt, M C; Palma Milla, S; Lopez Plaza, B; Bermejo, L

    2015-01-01

    The article is a summary of Dra. Carmen Gómez Candela's presentation at the Science in Nutrition 3rd International Congress in Milan, March 2014. The article covers omega-3 fatty acids use in different medical areas and several institutions' opinions in relation to the topic. Omega-3 acids are essential fatty acids. A certain amount of omega-3 is needed in our daily diet; however, the usual consumption is generally less than the recommended amount. Changes in dietary patterns in the course of history have led to deficit levels of omega-3 in the human body. Currently, there is increasing evidence of the benefits of omega-3 in different medical specialities. There are still some gaps regarding its role in illnesses such as dementia, psychiatric disorders, and inflammatory diseases. Nevertheless, stronger evidence is being proved in cardiovascular diseases and cancer. This article provides a reflection on possible ways to increase omega-3 daily consumption and the constraints associated with food with high contents of heavy metals, which, in turn, are also rich in omega-3s.

  16. New portrait of Omega Nebula's glistening watercolours

    NASA Astrophysics Data System (ADS)

    2009-07-01

    The Omega Nebula, sometimes called the Swan Nebula, is a dazzling stellar nursery located about 5500 light-years away towards the constellation of Sagittarius (the Archer). An active star-forming region of gas and dust about 15 light-years across, the nebula has recently spawned a cluster of massive, hot stars. The intense light and strong winds from these hulking infants have carved remarkable filigree structures in the gas and dust. When seen through a small telescope the nebula has a shape that reminds some observers of the final letter of the Greek alphabet, omega, while others see a swan with its distinctive long, curved neck. Yet other nicknames for this evocative cosmic landmark include the Horseshoe and the Lobster Nebula. Swiss astronomer Jean-Philippe Loys de Chéseaux discovered the nebula around 1745. The French comet hunter Charles Messier independently rediscovered it about twenty years later and included it as number 17 in his famous catalogue. In a small telescope, the Omega Nebula appears as an enigmatic ghostly bar of light set against the star fields of the Milky Way. Early observers were unsure whether this curiosity was really a cloud of gas or a remote cluster of stars too faint to be resolved. In 1866, William Huggins settled the debate when he confirmed the Omega Nebula to be a cloud of glowing gas, through the use of a new instrument, the astronomical spectrograph. In recent years, astronomers have discovered that the Omega Nebula is one of the youngest and most massive star-forming regions in the Milky Way. Active star-birth started a few million years ago and continues through today. The brightly shining gas shown in this picture is just a blister erupting from the side of a much larger dark cloud of molecular gas. The dust that is so prominent in this picture comes from the remains of massive hot stars that have ended their brief lives and ejected material back into space, as well as the cosmic detritus from which future suns form. The

  17. Search for lepton flavor violating decays tau+/--->l+/-omega.

    PubMed

    Aubert, B; Bona, M; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes Pegna, D; Lynch, G; Orimoto, T J; Osipenkov, I L; Ronan, M T; Tackmann, K; Tanabe, T; Wenzel, W A; Del Amo Sanchez, P; Hawkes, C M; Soni, N; Watson, A T; Koch, H; Schroeder, T; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Barrett, M; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Gary, J W; Liu, F; Long, O; Shen, B C; Vitug, G M; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Echenard, B; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Ayad, R; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Watson, J E; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Nash, J A; Panduro Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Béquilleux, J; D'Orazio, A; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, G; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; Losecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Sekula, S J; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Leruste, Ph; Malclès, J; Ocariz, J; Perez, A; Prendki, J; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Biesiada, J; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Roethel, W; Wilson, F F; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; White, R M; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; Nelson, S; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Yi, K; Young, C C; Ziegler, V; Burchat, P R; Edwards, A J; Majewski, S A; Miyashita, T S; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Pan, B; Saeed, M A; Zain, S B; Spanier, S M; Wogsland, B J; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H

    2008-02-22

    A search for lepton flavor violating decays of a tau to a lighter-mass charged lepton and an omega vector meson is performed using 384.1 fb(-1) of e(+)e(-) annihilation data collected with the BABAR detector at the Stanford Linear Accelerator Center PEP-II storage ring. No signal is found, and the upper limits on the branching ratios are determined to be B(tau(+/-)-->e;{+/-}omega)<1.1 x10 (-7) and B(tau(+/-)-->micro(+/-)omega)<1.0 x 10(-7) at 90% confidence level.

  18. A Comparison of Composite Reliability Estimators: Coefficient Omega Confidence Intervals in the Current Literature

    ERIC Educational Resources Information Center

    Padilla, Miguel A.; Divers, Jasmin

    2016-01-01

    Coefficient omega and alpha are both measures of the composite reliability for a set of items. Unlike coefficient alpha, coefficient omega remains unbiased with congeneric items with uncorrelated errors. Despite this ability, coefficient omega is not as widely used and cited in the literature as coefficient alpha. Reasons for coefficient omega's…

  19. A Comparison of Composite Reliability Estimators: Coefficient Omega Confidence Intervals in the Current Literature

    ERIC Educational Resources Information Center

    Padilla, Miguel A.; Divers, Jasmin

    2016-01-01

    Coefficient omega and alpha are both measures of the composite reliability for a set of items. Unlike coefficient alpha, coefficient omega remains unbiased with congeneric items with uncorrelated errors. Despite this ability, coefficient omega is not as widely used and cited in the literature as coefficient alpha. Reasons for coefficient omega's…

  20. LLE (Laboratory for Laser Energetics) review

    SciTech Connect

    Kumpan, S.A.

    1990-01-01

    This volume of the LLE Review, covering the period April--June 1990, contains articles in two main sections, Progress in Laser Fusion and Advanced Technology Developments. The first article presents the theoretical interpretation of the glass-ablator cryogenic-implosion experiments recently conducted on OMEGA. It is followed by an article describing the analysis of neutron time-of-flight data taken during DT and DD experiments; and a discussion of the improvements to laser diagnostics that now provide for precise control of the OMEGA laser is given. This paper contains a report on the development of transparent conductive coatings for KDP crystals, and a discussion of the study of the transient-surface Debye-Waller effect in materials irradiated with an ultrafast laser.

  1. Optical diagnostic suite (schlieren, interferometry, and grid image refractometry) on OMEGA EP using a 10-ps, 263-nm probe beam

    SciTech Connect

    Froula, D. H.; Boni, R.; Bedzyk, M.; Craxton, R. S.; Ehrne, F.; Ivancic, S.; Jungquist, R.; Shoup, M. J.; Theobald, W.; Weiner, D.; Kugland, N. L.; Rushford, M. C.

    2012-10-15

    A 10-ps, 263-nm (4{omega}) laser is being built to probe plasmas produced on the OMEGA EP [J. H. Kelly, L. J. Waxer, V. Bagnoud, I. A. Begishev, J. Bromage, B. E. Kruschwitz, T. E. Kessler, S. J. Loucks, D. N. Maywar, R. L. McCrory et al., J. Phys. IV France 133, 75-80 (2006)]. A suite of optical diagnostics (schlieren, interferometry, and grid image refractometry) has been designed to diagnose and characterize a wide variety of plasmas. Light scattered by the probe beam is collected by an f/4 catadioptric telescope and a transport system is designed to image with a near-diffraction-limited resolution ({approx}1 -{mu}m full width at half maximum) over a 5-mm field of view to a diagnostic table. The transport system provides a contrast greater than 1 : 10{sup 4} with respect to all wavelengths outside of the 263 {+-} 2 nm measurement range.

  2. Anti-inflammatory Effects of Omega 3 and Omega 6 Polyunsaturated Fatty Acids in Cardiovascular Disease and Metabolic Syndrome.

    PubMed

    Tortosa-Caparrós, Esther; Navas-Carrillo, Diana; Marín, Francisco; Orenes-Piñero, Esteban

    2016-01-08

    A lipid excess produces a systemic inflammation process due to tumor necrosis factor-α, interleukin-6 and C-reactive protein synthesis. Simultaneously, this fat excess promotes the appearance of insulin resistance. All this contributes to the development of atherosclerosis and increases the risk of cardiovascular diseases. On the other hand, polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid and docosahexaenoic acid (omega 3), and arachidonic acid (omega 6) have shown anti-inflammatory properties. Lately, an inverse relationship between omega-3 fatty acids, inflammation, obesity and cardiovascular diseases has been demonstrated. To check fatty acids effect, the levels of some inflammation biomarkers have been analyzed. Leptin, adiponectin and resistin represent a group of hormones associated with the development of cardiovascular diseases, obesity, type 2 diabetes mellitus and insulin resistance and are modified in obese-overweight people comparing to normal weight people. Omega-3 PUFAs have been shown to decrease the production of inflammatory mediators, having a positive effect in obesity and diabetes mellitus type-2. Moreover, they significantly decrease the appearance of cardiovascular disease risk factors. Regarding omega-6 PUFA, there is controversy whether their effects are pro- or anti-inflammatory. The aim of this manuscript is to provide a comprehensive overview about the role of omega-3 and omega-6 PUFAs in cardiovascular diseases and metabolic syndrome.

  3. Fatty acid composition in major depression: decreased omega 3 fractions in cholesteryl esters and increased C20: 4 omega 6/C20:5 omega 3 ratio in cholesteryl esters and phospholipids.

    PubMed

    Maes, M; Smith, R; Christophe, A; Cosyns, P; Desnyder, R; Meltzer, H

    1996-04-26

    Recently, there were some reports that major depression may be accompanied by alterations in serum total cholesterol, cholesterol ester and omega 3 essential fatty acid levels and by an increased C20: 4 omega 6/C20: 5 omega 3, i.e., arachidonic acid/eicosapentaenoic, ratio. The present study aimed to examine fatty acid composition of serum cholesteryl esters and phospholipids in 36 major depressed, 14 minor depressed and 24 normal subjects. Individual saturated (e.g., C14:0; C16:0, C18:0) and unsaturated (e.g., C18:1, C18:2, C20:4) fatty acids in phospholipid and cholesteryl ester fractions were assayed and the sums of the percentages of omega 6 and omega 3, saturated, branched chain and odd chain fatty acids, monoenes as well as the ratios omega 6/omega 3 and C20:4 omega 6/C20:5 omega 3 were calculated. Major depressed subjects had significantly higher C20:4 omega 6/C20:5 omega 3 ratio in both serum cholesteryl esters and phospholipids and a significantly increased omega 6/omega 3 ratio in cholesteryl ester fraction than healthy volunteers and minor depressed subjects. Major depressed subjects had significantly lower C18:3 omega 3 in cholesteryl esters than normal controls. Major depressed subjects showed significantly lower total omega 3 polyunsaturated fatty acids in cholesteryl esters and significantly lower C20:5 omega 3 in serum cholesteryl esters and phospholipids than minor depressed subjects and healthy controls. These findings suggest an abnormal intake or metabolism of essential fatty acids in conjunction with decreased formation of cholesteryl esters in major depression.

  4. High dietary ratio of omega-6 to omega-3 polyunsaturated acids during pregnancy and prevalence of post-partum depression.

    PubMed

    da Rocha, Camilla M M; Kac, Gilberto

    2012-01-01

    Observational studies suggest association between low concentrations of omega-3 family fatty acids and greater risk for post-partum depression (PPD). The objective was to investigate the effect of unbalanced dietary intake of omega-6/omega-3 ratio >9:1 in the prevalence for PPD. The study comprises a prospective cohort with four waves of follow-up during pregnancy and one following delivery. PPD was evaluated according to the Edinburgh Post-partum Depression Scale (PPD ≥ 11) in 106 puerperae between 2005 and 2007, in Rio de Janeiro, Brazil. Independent variables included socio-demographic, obstetric, pre-pregnancy body mass index (BMI) and dietary intake data, which were obtained by means of a food frequency questionnaire in the first trimester of pregnancy. Statistical analysis involved calculation of PPD prevalence and multivariate Poisson regression with robust variance. PPD prevalence amounted to 26.4% [n = 28; confidence interval (CI) 95%: 18.0-34.8], and higher prevalences of PPD were observed in women who consumed an omega-6/omega-3 ratio >9:1 (60.0%) and in those with pre-pregnancy BMI <18.5 kg/m(2) (66.7%). These variables held as factors associated to PPD in the multivariate model, elevating the chances of occurrence of the outcome in 2.50 (CI 95%: 1.21-5.14) and 4.01 times (CI 95%: 1.96-8.20), respectively. Analyses were adjusted for age, schooling, pre-pregnancy BMI, lipids consumption and time elapsed since delivery. It verified an association between omega-6/omega-3 ratio above 9:1, the levels recommended by the Institute of Medicine, and the prevalence of PPD. These results add to the evidence regarding the importance of omega-6 and omega-3 fatty acids in the regulation of mental health mechanisms. © 2010 Blackwell Publishing Ltd.

  5. Differentiating prescription omega-3-acid ethyl esters (P-OM3) from dietary-supplement omega-3 fatty acids.

    PubMed

    Brunton, Stephen; Collins, Nancy

    2007-05-01

    A reliable means of treating hyper-triglyceridemia is the use of large doses of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Modest levels of EPA and DHA may be obtained from food, particularly fatty fish. This article is intended to review clinically relevant differences between dietary-supplement omega-3 fatty acids and prescription omega-3-acid ethyl esters (P-OM3). PubMed and the Food and Drug Administration (FDA) Website were searched for articles published between 1995 and 2007 that contained the terms fish oil, fatty acids, n-3 fatty acids, omega fatty acids, docosahexaenoic acid, or eicosapentaenoic acid. Articles discussing sources, recommended intake, and differences among various formulations of omega-3 fatty acids were selected for review. A limitation to this review is the lack of head-to-head clinical trials using P-OM3 and dietary-supplement omega-3 fatty acids. Many types of nonprescription dietary supplements of omega-3 fatty acids are available; however, the efficacy, quality, and safety of these products are open to question because they are not regulated by the same standards as pharmaceutical agents. P-OM3 is the only omega-3 fatty acid product (Omacor capsules) approved by the US FDA available in the United States as an adjunct to diet to reduce very high (> or = 500 mg/dL) triglyceride levels in adult patients. P-OM3 can be used with confidence by practitioners who want to provide therapeutic doses of omega-3 fatty acids in a preparation that has been documented to be both safe and effective.

  6. Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium–tritium implosions on OMEGA

    SciTech Connect

    Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H.; and others

    2014-05-15

    Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of α ≃ 4, an implosion velocity of 3.8 × 10{sup 7} cm/s, and a laser intensity of ∼10{sup 15} W/cm{sup 2}. These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.

  7. The omega-Meson Mass and the Nucleon Size in Nucleiauthor{Haruki KurasawaandToshio Suzuki(*)

    NASA Astrophysics Data System (ADS)

    Nakaichi-Maeda, S.; Akaishi, Y.

    1990-12-01

    Modification of the nucleon size in nuclear medium is discussed in terms of the omega-meson mass. Vacuum polarization changes the omega-meson mass in nuclear medium and modifies the mean square change radius of the proton by 3(1/m_{omega}({*) 2}-1/m_{omega}(2) ), where m_{omega}(*) and m_{omega} denote the omega-meson mass in nuclear medium and in free space, respectively.

  8. Homoclinic {omega}-explosion and domains of hyperbolicity

    SciTech Connect

    Sten'kin, O V; Shil'nikov, L P

    1998-04-30

    The existence of domains of hyperbolicity is proved for general one-parameter families of multidimensional systems that undergo a homoclinic {omega}-explosion and the structure of the hyperbolic sets is studied for such families.

  9. Omega-3 fatty acids: a growing ocean of choices.

    PubMed

    Fares, Hassan; Lavie, Carl J; DiNicolantonio, James J; O'Keefe, James H; Milani, Richard V

    2014-02-01

    There has been increasing interest in the health benefits of supplemental and/or dietary omega-3 polyunsaturated fatty acids (PUFAs), particularly in their role in disease prevention. This interest escalated once their effects on cardiovascular health were observed from numerous observational studies in populations whose diet consisted mainly of fish. Research has since been undertaken on omega-3 PUFAs to investigate their health benefits in a vast array of medical conditions, including primary and secondary prevention. This article discusses the evidence and controversies concerning omega-3 PUFAs in various health conditions. In addition to the effects on cardiovascular health, omega-3 PUFAs have been shown to prevent the development of dementia, reduce systemic inflammatory diseases, prevent prostate cancer, and possibly have a role in the treatment of depression and bipolar disorder.

  10. Bacterial formation of omega-muricholic acid in rats.

    PubMed Central

    Sacquet, E C; Raibaud, P M; Mejean, C; Riottot, M J; Leprince, C; Leglise, P C

    1979-01-01

    In the feces of conventional rats, the amount of omega-muricholic and hyodeoxycholic acids vary according to the diet. To understand this phenomenon, we investigated the bacterial formation of these bile acids. The present paper reports the first isolation, from conventional rat feces, of a strain of Clostridium group III which transforms beta-muricholic acid, the main bile acid in germfree rats, into omega-muricholic acid. PMID:485143

  11. Dynamical coupled channel approach to omega meson production

    SciTech Connect

    Mark Paris

    2007-09-10

    The dynamical coupled channel approach of Matsuyama, Sato, and Lee is used to study the $\\omega$--meson production induced by pions and photons scattering from the proton. The parameters of the model are fixed in a two-channel (\\omega N,\\pi N) calculation for the non-resonant and resonant contributions to the $T$ matrix by fitting the available unpolarized differential cross section data. The polarized photon beam asymmetry is predicted and compared to existing data.

  12. MANGANESE ABUNDANCES IN THE GLOBULAR CLUSTER {omega} CENTAURI

    SciTech Connect

    Cunha, Katia; Smith, Verne V.; Bergemann, Maria; Suntzeff, Nicholas B.; Lambert, David L.

    2010-07-01

    We present manganese abundances in 10 red giant members of the globular cluster {omega} Centauri; eight stars are from the most metal-poor population (RGB MP and RGB MInt1) while two targets are members of the more metal-rich groups (RGB MInt2 and MInt3). This is the first time Mn abundances have been studied in this peculiar stellar system. The LTE values of [Mn/Fe] in {omega} Cen overlap those of Milky Way stars in the metal-poor {omega} Cen populations ([Fe/H] {approx}-1.5 to -1.8), however unlike what is observed in Milky Way halo and disk stars, [Mn/Fe] declines in the two more metal-rich RGB MInt2 and MInt3 targets. Non-LTE calculations were carried out in order to derive corrections to the LTE Mn abundances. The non-LTE results for {omega} Cen in comparison with the non-LTE [Mn/Fe] versus [Fe/H] trend obtained for the Milky Way confirm and strengthen the conclusion that the manganese behavior in {omega} Cen is distinct. These results suggest that low-metallicity supernovae (with metallicities {<=} -2) of either Type II or Type Ia dominated the enrichment of the more metal-rich stars in {omega} Cen. The dominance of low-metallicity stars in the chemical evolution of {omega} Cen has been noted previously in the s-process elements where enrichment from metal-poor asymptotic giant branch stars is indicated. In addition, copper, which also has metallicity-dependent yields, exhibits lower values of [Cu/Fe] in the RGB MInt2 and MInt3 {omega} Cen populations.

  13. Mitigating Sleep Loss: Assessment of Omega-3 Fatty Acids

    DTIC Science & Technology

    2011-04-15

    from EEG and cytokines support the hypothesis that the improved perfroamnce is due to reduced inflammatory activity with Omega supplementation . These...treatment found that Omega-3 supplementation improved this metric. 10 | P a g e Distribution Statement A: Approved for public release... supplementation led to significantly better accuracy on both parameters for both tasks, Fs (8,219) > 2.79, ps < .01, but only marginally faster

  14. Ambiguity resolution in systems using Omega for position location

    NASA Technical Reports Server (NTRS)

    Frenkel, G.; Gan, D. G.

    1974-01-01

    The lane ambiguity problem prevents the utilization of the Omega system for many applications such as locating buoys and balloons. The method of multiple lines of position introduced herein uses signals from four or more Omega stations for ambiguity resolution. The coordinates of the candidate points are determined first through the use of the Newton iterative procedure. Subsequently, a likelihood function is generated for each point, and the ambiguity is resolved by selecting the most likely point. The method was tested through simulation.

  15. Two-dimensional simulations of the neutron yield in cryogenic deuterium-tritium implosions on OMEGA

    SciTech Connect

    Hu, S. X.; Goncharov, V. N.; Radha, P. B.; Marozas, J. A.; Skupsky, S.; Boehly, T. R.; Sangster, T. C.; Meyerhofer, D. D.; McCrory, R. L.

    2010-10-15

    Maximizing the neutron yield to obtain energy gain is the ultimate goal for inertial confinement fusion. Nonuniformities seeded by target and laser perturbations can disrupt neutron production via the Rayleigh-Taylor instability growth. To understand the effects of perturbations on the neutron yield of cryogenic DT implosions on the Omega Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)], two-dimensional DRACO[P. B. Radha et al., Phys. Plasmas 12, 056307 (2005)] simulations have been performed to systematically investigate each perturbation source and their combined effects on the neutron-yield performance. Two sources of nonuniformity accounted for the neutron-yield reduction in DRACO simulations: target offset from the target chamber center and laser imprinting. The integrated simulations for individual shots reproduce the experimental yield-over-clean (YOC) ratio within a factor of 2 or better. The simulated neutron-averaged ion temperatures is only about 10%-15% higher than measurements. By defining the temperature-over-clean, its relationship to YOC provides an indication of how much the hot-spot volume and density are perturbed with respect to the uniform situation. Typically, the YOC in OMEGA experiments is of the order of {approx}5%. The simulation results suggest that YOC can be increased to the ignition hydroequivalent level of 15%-20% (with <{rho}R>=200-300 mg/cm{sup 2}) by maintaining a target offset of less than 10 {mu}m and employing beam smoothing by spectral dispersion.

  16. The role of omega-3 fatty acids in mood disorders.

    PubMed

    Stahl, Lauren A; Begg, Denovan P; Weisinger, Richard S; Sinclair, Andrew J

    2008-01-01

    Research has established that docosahexaenoic acid (DHA), a long-chain omega-3 polyunsaturated fatty acid (PUFA), plays a fundamental role in brain structure and function. Epidemiological and cross-sectional studies have also identified a role for long-chain omega-3 PUFA, which includes DHA, eicosapentaenoic acid, and docosapentaenoic acid, in the etiology of depression. In the past ten years, there have been 12 intervention studies conducted using various preparations of longchain omega-3 PUFA in unipolar and bipolar depression. The majority of these studies administered long-chain omega-3 PUFA as an adjunct therapy. The studies have been conducted over 4 to 16 weeks of intervention and have often included small cohorts. In four out of the seven studies conducted in depressed individuals and in two out of the five studies in bipolar patients, individuals have reported a positive outcome following supplementation with ethyl-eicosapentaenoic acid or fish oil containing long-chain omega-3 PUFA. In the three trials that researched the influence of DHA-rich preparations, no significant effects were reported. The mechanisms that have been invoked to account for the benefits of long-chain omega-3 PUFA in depression include reductions in prostaglandins derived from arachidonic acid, which lead to decreased brain-derived neurotrophic factor levels and/or alterations in blood flow to the brain.

  17. The reliability of multidimensional neuropsychological measures: from alpha to omega.

    PubMed

    Watkins, Marley W

    To demonstrate that Coefficient omega, a model-based estimate, is more a more appropriate index of reliability than coefficient alpha for the multidimensional scales that are commonly employed by neuropsychologists. As an illustration, a structural model of an overarching general factor and four first-order factors for the WAIS-IV based on the standardization sample of 2200 participants was identified and omega coefficients were subsequently computed for WAIS-IV composite scores. Alpha coefficients were ≥ .90 and omega coefficients ranged from .75 to .88 for WAIS-IV factor index scores, indicating that the blend of general and group factor variance in each index score created a reliable multidimensional composite. However, the amalgam of variance from general and group factors did not allow the precision of Full Scale IQ (FSIQ) and factor index scores to be disentangled. In contrast, omega hierarchical coefficients were low for all four factor index scores (.10-.41), indicating that most of the reliable variance of each factor index score was due to the general intelligence factor. In contrast, the omega hierarchical coefficient for the FSIQ score was .84. Meaningful interpretation of WAIS-IV factor index scores as unambiguous indicators of group factors is imprecise, thereby fostering unreliable identification of neurocognitive strengths and weaknesses, whereas the WAIS-IV FSIQ score can be interpreted as a reliable measure of general intelligence. It was concluded that neuropsychologists should base their clinical decisions on reliable scores as indexed by coefficient omega.

  18. Omega-3 Fatty Acids and Skeletal Muscle Health.

    PubMed

    Jeromson, Stewart; Gallagher, Iain J; Galloway, Stuart D R; Hamilton, D Lee

    2015-11-19

    Skeletal muscle is a plastic tissue capable of adapting and mal-adapting to physical activity and diet. The response of skeletal muscle to adaptive stimuli, such as exercise, can be modified by the prior nutritional status of the muscle. The influence of nutrition on skeletal muscle has the potential to substantially impact physical function and whole body metabolism. Animal and cell based models show that omega-3 fatty acids, in particular those of marine origin, can influence skeletal muscle metabolism. Furthermore, recent human studies demonstrate that omega-3 fatty acids of marine origin can influence the exercise and nutritional response of skeletal muscle. These studies show that the prior omega-3 status influences not only the metabolic response of muscle to nutrition, but also the functional response to a period of exercise training. Omega-3 fatty acids of marine origin therefore have the potential to alter the trajectory of a number of human diseases including the physical decline associated with aging. We explore the potential molecular mechanisms by which omega-3 fatty acids may act in skeletal muscle, considering the n-3/n-6 ratio, inflammation and lipidomic remodelling as possible mechanisms of action. Finally, we suggest some avenues for further research to clarify how omega-3 fatty acids may be exerting their biological action in skeletal muscle.

  19. FEM simulation of static loading test of the Omega beam

    NASA Astrophysics Data System (ADS)

    Bílý, Petr; Kohoutková, Alena; Jedlinský, Petr

    2017-09-01

    The paper deals with a FEM simulation of static loading test of the Omega beam. Omega beam is a precast prestressed high-performance concrete element with the shape of Greek letter omega. Omega beam was designed as a self-supporting permanent formwork member for construction of girder bridges. FEM program ATENA Science was exploited for simulation of load-bearing test of the beam. The numerical model was calibrated using the data from both static loading test and tests of material properties. Comparison of load-displacement diagrams obtained from the experiment and the model was conducted. Development of cracks and crack patterns were compared. Very good agreement of experimental data and the FEM model was reached. The calibrated model can be used for design of optimized Omega beams in the future without the need of expensive loading tests. The calibrated material model can be also exploited in other types of FEM analyses of bridges constructed with the use of Omega beams, such as limit state analysis, optimization of shear connectors, prediction of long-term deflections or prediction of crack development.

  20. Study of the decay B0bar -> D* omega pi

    SciTech Connect

    Aubert, B.

    2006-04-24

    We report on a study of the decay {bar B}{sup 0} {yields} D*{sup +}{omega}{pi}{sup -} with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million B{bar B} decays, we measure the branching fraction {Beta}({bar B}{sup 0} {yields} D*{sup +}{omega}{pi}{sup -}) = (2.88 {+-} 0.21(stat.) {+-} 0.31(syst.)) x 10{sup -3}. We study the invariant mass spectrum of the {omega}{pi}{sup -} system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in {tau}{sup -} {yields} {omega}{pi}{sup -} {nu}{sub {tau}}. We also measure the polarization of the D*{sup +} as a function of the {omega}{pi}{sup -} mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D*{sup +} to be {Lambda}{sub L}/{Lambda} = 0.654 {+-} 0.042(stat.) {+-} 0.016(syst.). This is in agreement with the expectations from heavy-quark effective theory and factorization assuming that the decay proceeds as {bar B}{sup 0} {yields} D*{sup +}{rho}(1450), {rho}(1450) {yields} {omega}{pi}{sup -}.

  1. Omega-3 fatty acids: cardiovascular benefits, sources and sustainability.

    PubMed

    Lee, John H; O'Keefe, James H; Lavie, Carl J; Harris, William S

    2009-12-01

    The evidence for the cardioprotective nature of omega-3 fatty acids is abundant, and currently available data indicate that patients with known coronary heart disease should consume at least 1 g daily of long-chain omega-3 fatty acids from either oily fish or fish-oil supplements, and that individuals without disease should consume at least 250-500 mg daily. However, this area of research poses two questions. Firstly, which is the best source of omega-3 fatty acids-fish or fish-oil supplements? Secondly, are recommendations for omega-3 supplementation warranted in view of the rapid depletion of world fish stocks? The argument that eating fish is better than taking fish-oil supplements stems from the fact that several important nutrients, such as vitamin D, selenium, and antioxidants, are missing from the supplements. However, three major prevention trials have clearly indicated that omega-3 fatty acid capsules confer cardiovascular benefits and, therefore, that both are cardioprotective. Sustainable sources of omega-3 fatty acids will need to be identified if long-term cardiovascular risk reduction is to be achieved at the population level.

  2. Omega-3 Fatty Acids and Skeletal Muscle Health

    PubMed Central

    Jeromson, Stewart; Gallagher, Iain J.; Galloway, Stuart D. R.; Hamilton, D. Lee

    2015-01-01

    Skeletal muscle is a plastic tissue capable of adapting and mal-adapting to physical activity and diet. The response of skeletal muscle to adaptive stimuli, such as exercise, can be modified by the prior nutritional status of the muscle. The influence of nutrition on skeletal muscle has the potential to substantially impact physical function and whole body metabolism. Animal and cell based models show that omega-3 fatty acids, in particular those of marine origin, can influence skeletal muscle metabolism. Furthermore, recent human studies demonstrate that omega-3 fatty acids of marine origin can influence the exercise and nutritional response of skeletal muscle. These studies show that the prior omega-3 status influences not only the metabolic response of muscle to nutrition, but also the functional response to a period of exercise training. Omega-3 fatty acids of marine origin therefore have the potential to alter the trajectory of a number of human diseases including the physical decline associated with aging. We explore the potential molecular mechanisms by which omega-3 fatty acids may act in skeletal muscle, considering the n-3/n-6 ratio, inflammation and lipidomic remodelling as possible mechanisms of action. Finally, we suggest some avenues for further research to clarify how omega-3 fatty acids may be exerting their biological action in skeletal muscle. PMID:26610527

  3. Mitigation of cross-beam energy transfer in symmetric implosions on OMEGA using wavelength detuning

    DOE PAGES

    Edgell, D. H.; Follett, R. K.; Igumenshchev, I. V.; ...

    2017-06-13

    The effects of frequency detuning laser beams in direct-drive symmetric implosions were investigated with a 3-D cross-beam energy transfer (CBET) model. Our model shows that interactions between beams with relative angles between 45° and 90° are most significant for CBET in OMEGA direct-drive implosions. There is no net exchange in power between beams but there is significant redistribution of power from the ingoing central portion of the beam profile to the outgoing edge as it is exiting the plasma, reducing the total absorbed power. Furthermore, redistribution of laser power because of CBET increases the root-mean-square (rms) absorption nonuniformity by anmore » order of magnitude. CBET mitigation by shifting relative wavelengths of three groups of laser beams fed by each of the different beamlines was modeled. At an on-target wavelength shift of Δλ ~ 10 Å, the total laser absorption was maximized, and the rms absorption nonuniformity was near minimum. In order to completely decouple the three groups of beams from each other requires wavelength shifts Δλ > 30 Å.« less

  4. Mitigation of cross-beam energy transfer in symmetric implosions on OMEGA using wavelength detuning

    NASA Astrophysics Data System (ADS)

    Edgell, D. H.; Follett, R. K.; Igumenshchev, I. V.; Myatt, J. F.; Shaw, J. G.; Froula, D. H.

    2017-06-01

    The effects of frequency detuning laser beams in direct-drive symmetric implosions were investigated with a 3-D cross-beam energy transfer (CBET) model. The model shows that interactions between beams with relative angles between 45° and 90° are most significant for CBET in OMEGA direct-drive implosions. There is no net exchange in power between beams, but there is significant redistribution of power from the ingoing central portion of the beam profile to the outgoing edge as it is exiting the plasma, reducing the total absorbed power. Redistribution of laser power because of CBET increased the root-mean-square (rms) absorption nonuniformity by an order of magnitude. CBET mitigation by shifting relative wavelengths of three groups of laser beams fed by each of the different beamlines was modeled. At an on-target wavelength shift of Δλ ˜ 10 Å, the total laser absorption was maximized, and the rms absorption nonuniformity was near minimum. To completely decouple the three groups of beams from each other requires wavelength shifts Δλ > 30 Å.

  5. The 1-D Campaign on OMEGA: A Systematic Approach to Find the Optimum Path to Ignition

    NASA Astrophysics Data System (ADS)

    Betti, R.; Bose, A.; Christopherson, A. R.; Campbell, E. M.; Collins, T. J. B.; Knauer, J. P.; Maximov, A. V.; Radha, P. B.; Regan, S. P.; Shang, W.; Stoeckll, C.

    2016-10-01

    A methodology is devised to make progress toward achieving ignition starting from a wellunderstood implosion. This technique uses several metrics that rely on trends in experimental observables rather than absolute values and their agreement with simulations. The flexibility of the OMEGA laser makes it ideal to implement such a platform. For direct-drive inertial fusion, this methodology is being implemented starting from high-adiabat, low-convergence implosions of DT cryogenic capsules. The first implosions of this campaign use single-parameter scans to determine trends in the experimental observables used to identify degradation mechanisms affecting implosion performance. In this implosion, short-wavelength perturbations or hot-electron preheat are turned on and off by using (a) laser smoothing on/off keeping identical laser pulse shapes and (b) low/high intensities keeping the shock timing fixed. Another pair of shots with identical laser pulse shapes but different payloads (DT and CH) is used to characterize the preheat level. The first results of this systematic approach are presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  6. Streaked x-ray spectrometer having a discrete selection of Bragg geometries for Omega

    SciTech Connect

    Millecchia, M.; Regan, S. P.; Bahr, R. E.; Romanofsky, M.; Sorce, C.

    2012-10-15

    The streaked x-ray spectrometer (SXS) is used with streak cameras [D. H. Kalantar, P. M. Bell, R. L. Costa, B. A. Hammel, O. L. Landen, T. J. Orzechowski, J. D. Hares, and A. K. L. Dymoke-Bradshaw, in 22nd International Congress on High-Speed Photography and Photonics, edited by D. L. Paisley and A. M. Frank (SPIE, Bellingham, WA, 1997), Vol. 2869, p. 680] positioned with a ten-inch manipulator on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] and OMEGA EP [L. J. Waxer et al., Presented at CLEO/QELS 2008, San Jose, CA, 4-9 May 2008 (Paper JThB1)] for time-resolved, x-ray spectroscopy of laser-produced plasmas in the 1.4- to 20-keV photon-energy range. These experiments require measuring a portion of this photon-energy range to monitor a particular emission or absorption feature of interest. The SXS relies on a pinned mechanical reference system to create a discrete set of Bragg reflection geometries for a variety of crystals. A wide selection of spectral windows is achieved accurately and efficiently using this technique. It replaces the previous spectrometer designs that had a continuous Bragg angle adjustment and required a tedious alignment calibration procedure. The number of spectral windows needed for the SXS was determined by studying the spectral ranges selected by OMEGA users over the last decade. These selections are easily configured in the SXS using one of the 25 discrete Bragg reflection geometries and one of the six types of Bragg crystals, including two curved crystals.

  7. Streaked x-ray spectrometer having a discrete selection of Bragg geometries for Omega.

    PubMed

    Millecchia, M; Regan, S P; Bahr, R E; Romanofsky, M; Sorce, C

    2012-10-01

    The streaked x-ray spectrometer (SXS) is used with streak cameras [D. H. Kalantar, P. M. Bell, R. L. Costa, B. A. Hammel, O. L. Landen, T. J. Orzechowski, J. D. Hares, and A. K. L. Dymoke-Bradshaw, in 22nd International Congress on High-Speed Photography and Photonics, edited by D. L. Paisley and A. M. Frank (SPIE, Bellingham, WA, 1997), Vol. 2869, p. 680] positioned with a ten-inch manipulator on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] and OMEGA EP [L. J. Waxer et al., Presented at CLEO∕QELS 2008, San Jose, CA, 4-9 May 2008 (Paper JThB1)] for time-resolved, x-ray spectroscopy of laser-produced plasmas in the 1.4- to 20-keV photon-energy range. These experiments require measuring a portion of this photon-energy range to monitor a particular emission or absorption feature of interest. The SXS relies on a pinned mechanical reference system to create a discrete set of Bragg reflection geometries for a variety of crystals. A wide selection of spectral windows is achieved accurately and efficiently using this technique. It replaces the previous spectrometer designs that had a continuous Bragg angle adjustment and required a tedious alignment calibration procedure. The number of spectral windows needed for the SXS was determined by studying the spectral ranges selected by OMEGA users over the last decade. These selections are easily configured in the SXS using one of the 25 discrete Bragg reflection geometries and one of the six types of Bragg crystals, including two curved crystals.

  8. New approach to omega PPCs (Propagation Corrections)

    NASA Astrophysics Data System (ADS)

    Morris, Peter B.; Gupta, Radha R.

    1989-11-01

    The currently available propagation correction (PPC) model algorithm maintained by the U.S. Coast Guard Omega Navigation System Center was developed in 1980. Although an improvement over the earlier 1974 algorithm, the 1980 PCC model exhibits a number of deficiencies. To correct these deficiencies, a new approach to modeling PPCs is presented. This model incorporates semi-empirical forms directly into the time-dependent portions of the model, thus insuring that the PPC predictions are directly data-driven and data collected during path transition conditions may be used for model calibration. A geomagnetic conductivity sub-model is described which provides effective phase velocity and excitation factor phase functional forms for day or night path segments with given geomagnetic bearing, geomagnetic latitude, and ground conductivity. This sub-model describes all space-dependent quantities (on which phase depends) except for the spatially anomalous ionospheres of the auroral and polar regions. A diurnal sub-model is described in which the diurnal phase behavior on a propagation path is treated as a sum of discrete phase changes on path segments having ionospheric reflection heights determined from classical Chapman photoionization models. In addition, onset and recovery times for sunrise and sunset are characterized by several parameters which can be adjusted to fit observed data.

  9. Plasma omega-3 and omega-6 concentrations and risk of cutaneous basal and squamous cell carcinomas in Australian adults.

    PubMed

    Wallingford, Sarah C; Hughes, Maria Celia; Green, Adèle C; van der Pols, Jolieke C

    2013-10-01

    Laboratory-based evidence suggests that omega-3 and omega-6 polyunsaturated fatty acids may affect skin photocarcinogenesis, but epidemiologic evidence is inconsistent. In 1,191 White Australian adults, we prospectively investigated associations between baseline plasma concentrations of omega-3 and omega-6 fatty acids and cutaneous basal cell carcinomas (BCC) and squamous cell carcinomas (SCC). Relative risks (RR) and 95% confidence intervals (CI) were estimated on the basis of number of histologically confirmed tumors diagnosed during follow-up (1997-2007). Plasma eicosapentaenoic acid (EPA) concentrations and omega-3/-6 ratio showed significant inverse associations with SCC tumors, comparing higher tertiles with the lowest, in age- and sex-adjusted models (Ptrend = 0.02 and 0.03, respectively) which weakened after adjustment for past sun exposure. Associations between EPA and SCC were stronger among participants with a history of skin cancer at baseline (n = 378; highest vs. lowest tertile: RR = 0.50; 95% CI, 0.28-0.92; Ptrend = 0.01). Total omega-6 was inversely associated with BCC tumors in multivariate models (P = 0.04; highest vs. lowest tertile: RR = 0.71; 95% CI, 0.51-0.99), and more strongly in the subgroup with past skin cancer. Linoleic and linolenic acids were also inversely associated with BCC occurrence in this subgroup. When fatty acids were analyzed as continuous variables, however, there was no evidence of any linear or nonlinear associations. This study provides some support for reduced skin cancer risk with high plasma concentrations of omega-3 and omega-6 fatty acids, but results depended on how fatty acid data were modeled. Further investigation of these associations in larger datasets is needed.

  10. Omega-3 and omega-6 content of medicinal foods for depressed patients: implications from the Iranian Traditional Medicine

    PubMed Central

    Tavakkoli-Kakhki, Mandana; Motavasselian, Malihe; Mosaddegh, Mahmoud; Esfahani, Mohammad Mahdi; Kamalinejad, Mohammad; Nematy, Mohsen; Eslami, Saeid

    2014-01-01

    Objectives: Considering the increasing prevalence of depression in modern societies and the positive effects of omega-3 polyunsaturated fatty acids on depression, this study aims to investigate the omega-3 and omega-6 content of various foodstuffs, prescribed or prohibited by Iranian Traditional Medicine (ITM). Materials and Methods: Firstly, reliable sources of Iranian Traditional Medicine were reviewed in order to identify the prescribed and prohibited foodstuffs for depressed patients. Afterwards, according to the online database of United States Department of Agriculture (URL: http://ndb.nal.usda.gov/ndb/search/list), the ratio of linoleic acid to alpha linolenic acid (as representatives of omega-6 and omega-3, respectively) was identified in each foodstuff. Finally, the ratios of omega-6 to omega-3 were compared between seven food groups of vegetables, fruits, dry goods, high protein products, dairies, breads, and spices. Results: Based on the resources of Iranian Traditional Medicine, the following foods are prescribed for depressed patients: basil, coriander, spinach, lettuce, squash, peppermint, dill, chicory, celery, beet, quince, cucumber, watermelon, grape, peach, pomegranate, banana, apple, currant, pistachio, dried fig, almond, egg, chicken, lamb, trout, milk, bread without bran, saffron, oregano, and coriander seeds. On the other hand, cabbage, eggplant, onion, garlic, broad beans, lentils, beef, whole wheat bread, and mustard are prohibited. It should be noted that omega-3 content in some prescribed foods is more than that of the prohibited ones. Conclusion: The present study showed that mint, basil, spinach, lettuce, squash, lamb, saffron, oregano, cucumber, pistachio, milk, and also wild trout can be considered as medicinal foods for depressed patients. PMID:25068136

  11. Omega-3 and omega-6 content of medicinal foods for depressed patients: implications from the Iranian Traditional Medicine.

    PubMed

    Tavakkoli-Kakhki, Mandana; Motavasselian, Malihe; Mosaddegh, Mahmoud; Esfahani, Mohammad Mahdi; Kamalinejad, Mohammad; Nematy, Mohsen; Eslami, Saeid

    2014-07-01

    Considering the increasing prevalence of depression in modern societies and the positive effects of omega-3 polyunsaturated fatty acids on depression, this study aims to investigate the omega-3 and omega-6 content of various foodstuffs, prescribed or prohibited by Iranian Traditional Medicine (ITM). Firstly, reliable sources of Iranian Traditional Medicine were reviewed in order to identify the prescribed and prohibited foodstuffs for depressed patients. Afterwards, according to the online database of United States Department of Agriculture (URL: http://ndb.nal.usda.gov/ndb/search/list), the ratio of linoleic acid to alpha linolenic acid (as representatives of omega-6 and omega-3, respectively) was identified in each foodstuff. Finally, the ratios of omega-6 to omega-3 were compared between seven food groups of vegetables, fruits, dry goods, high protein products, dairies, breads, and spices. Based on the resources of Iranian Traditional Medicine, the following foods are prescribed for depressed patients: basil, coriander, spinach, lettuce, squash, peppermint, dill, chicory, celery, beet, quince, cucumber, watermelon, grape, peach, pomegranate, banana, apple, currant, pistachio, dried fig, almond, egg, chicken, lamb, trout, milk, bread without bran, saffron, oregano, and coriander seeds. On the other hand, cabbage, eggplant, onion, garlic, broad beans, lentils, beef, whole wheat bread, and mustard are prohibited. It should be noted that omega-3 content in some prescribed foods is more than that of the prohibited ones. The present study showed that mint, basil, spinach, lettuce, squash, lamb, saffron, oregano, cucumber, pistachio, milk, and also wild trout can be considered as medicinal foods for depressed patients.

  12. Demonstration of the highest deuterium-tritium areal density using multiple-picket cryogenic designs on OMEGA.

    PubMed

    Goncharov, V N; Sangster, T C; Boehly, T R; Hu, S X; Igumenshchev, I V; Marshall, F J; McCrory, R L; Meyerhofer, D D; Radha, P B; Seka, W; Skupsky, S; Stoeckl, C; Casey, D T; Frenje, J A; Petrasso, R D

    2010-04-23

    The performance of triple-picket deuterium-tritium cryogenic target designs on the OMEGA Laser System [T. R. Boehly, Opt. Commun. 133, 495 (1997)] is reported. These designs facilitate control of shock heating in low-adiabat inertial confinement fusion targets. Areal densities up to 300 mg/cm2 (the highest ever measured in cryogenic deuterium-tritium implosions) are inferred in the experiments with an implosion velocity approximately 3x10(7) cm/s driven at peak laser intensities of 8x10(14) W/cm2. Extension of these designs to ignition on the National Ignition Facility [J. A. Paisner, Laser Focus World 30, 75 (1994)] is presented.

  13. Omega-3 Fatty Acids and Cardiovascular Disease: A Case for Omega-3 Index as a New Risk Factor

    PubMed Central

    Harris, William S.

    2007-01-01

    The omega-3 fatty acids (FAs) found in fish and fish oils (eicosapentaenoic and docosahexaenoic acids, EPA and DHA) have been reported to have a variety of beneficial effects in cardiovascular diseases. Ecological and prospective cohort studies as well as randomized, controlled trials have supported the view that the effects of these FAs are clinically-relevant. They operate via several mechanisms, all beginning with the incorporation of EPA and DHA into cell membranes. From here, these omega-3 FA alter membrane physical characteristics and the activity of membrane-bound proteins, and once released by intracellular phospholipases, can interact with ion channels, be converted into a wide variety of bioactive eicosanoids, and serve as ligands for several nuclear transcription factors thereby altering gene expression. In as much as blood levels are a strong reflection of dietary intake, it is proposed that an omega-3 FA biomarker, the omega-3 index (erythrocyte EPA+DHA) be considered at least a marker, if not a risk factor, for coronary heart disease, especially sudden cardiac death. The omega-3 index fulfils many of the requirements for a risk factor including consistent epidemiological evidence, a plausible mechanism of action, a reproducible assay, independence from classical risk factors, modifiability, and most importantly, the demonstration that raising tissue levels will reduce risk for cardiac events. For these and a number of other reasons, the omega-3 index compares very favourably with other risk factors for sudden cardiac death. PMID:17324586

  14. Balancing proportions of competing omega-3 and omega-6 highly unsaturated fatty acids (HUFA) in tissue lipids.

    PubMed

    Bibus, Doug; Lands, Bill

    2015-08-01

    People eating different balances of omega-3 and omega-6 nutrients develop predictably different proportions of competing highly unsaturated fatty acids (HUFA) in their tissue lipids. While epidemiological studies have associated wide differences in HUFA balance with disease severity, some clinical studies that did not examine wide differences failed to confirm the association. We examined the degree to which the relative amount of arachidonic acid, the major precursor of omega-6 eicosanoids, differs among people who have widely different dietary intakes of omega-3 and omega-6 nutrients. Gas chromatographic analyses of human blood samples describe the balance among n-3 and n-6 HUFA for different individuals. The proportion of the omega-6 arachidonic acid, from which potent eicosanoids are formed, is not constant. It ranges from 30% to 70% of HUFA while the competing n-3 HUFA range from 60% to 10% of HUFA. Significant differences in clinical outcomes between control and intervention groups have been seen when using dietary interventions that shift the balance of n-3 and n-6 nutrients far enough to create a biologically significant difference in the HUFA balance.

  15. Omega-3 and Omega-6 Fatty Acids Act as Inhibitors of the Matrix Metalloproteinase-2 and Matrix Metalloproteinase-9 Activity.

    PubMed

    Nicolai, Eleonora; Sinibaldi, Federica; Sannino, Gianpaolo; Laganà, Giuseppina; Basoli, Francesco; Licoccia, Silvia; Cozza, Paola; Santucci, Roberto; Piro, Maria Cristina

    2017-08-01

    Polyunsaturated fatty acids have been reported to play a protective role in a wide range of diseases characterized by an increased metalloproteinases (MMPs) activity. The recent finding that omega-3 and omega-6 fatty acids exert an anti-inflammatory effect in periodontal diseases has stimulated the present study, designed to determine whether such properties derive from a direct inhibitory action of these compounds on the activity of MMPs. To this issue, we investigated the effect exerted by omega-3 and omega-6 fatty acids on the activity of MMP-2 and MMP-9, two enzymes that actively participate to the destruction of the organic matrix of dentin following demineralization operated by bacteria acids. Data obtained (both in vitro and on ex-vivo teeth) reveal that omega-3 and omega-6 fatty acids inhibit the proteolytic activity of MMP-2 and MMP-9, two enzymes present in dentin. This observation is of interest since it assigns to these compounds a key role as MMPs inhibitors, and stimulates further study to better define their therapeutic potentialities in carious decay.

  16. Advances in the Manufacture of Omega-scale Double-shell Targets

    NASA Astrophysics Data System (ADS)

    Bono, M.

    2005-10-01

    The double-shell ignition target design consists of a low-Z outer shell that absorbs hohlraum-generated x-rays, implodes, and collides with a high-Z inner shell containing DT fuel. Efforts are continuing to field scaled ignition-like double shells on the Omega laser facility over a range of inner-shell Z. Previous ignition-like double-shell implosions on Omega used a low-Z CH inner shell [1]. The current target contains a higher-Z glass inner shell of diameter 216 microns, which is supported by SiO2 aerogel inside a Br-doped CH ablator shell of diameter 550 microns. Fielding double-shell targets has historically been limited by the ability to successfully fabricate them, but several technological advances have recently been made in the manufacturing process. The inner capsule will be cast in SiO2 aerogel of density 50 mg/cc, whose outer contour will be machined concentric to the inner capsule. This piece will then be assembled between two hemispherical ablator shells that mate at a step-joint with an adhesive-filled gap of thickness 100 nm. Three-dimensional tomographs made of each target using an x-ray micro-tomography system will allow precise characterization of the targets. [1] P. Amendt et al., Phys. Rev. Lett. 94, 065004 (2005).

  17. Time history prediction of direct-drive implosions on the Omega facility

    SciTech Connect

    Laffite, S.; Bourgade, J. L.; Caillaud, T.; Girard, F.; Landoas, O.; Lemaire, S.; Masse, L.; Masson-Laborde, P. E.; Philippe, F.; Reverdin, C.; Tassin, V.; Delettrez, J. A.; Glebov, V. Yu.; Marshall, F. J.; Michel, D. T.; Seka, W.; Frenje, J. A.; Joshi, T.; Mancini, R. C.; Legay, G.

    2016-01-15

    We present in this article direct-drive experiments that were carried out on the Omega facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. Two different pulse shapes were tested in order to vary the implosion stability of the same target whose parameters, dimensions and composition, remained the same. The direct-drive configuration on the Omega facility allows the accurate time-resolved measurement of the scattered light. We show that, provided the laser coupling is well controlled, the implosion time history, assessed by the “bang-time” and the shell trajectory measurements, can be predicted. This conclusion is independent on the pulse shape. In contrast, we show that the pulse shape affects the implosion stability, assessed by comparing the target performances between prediction and measurement. For the 1-ns square pulse, the measured neutron number is about 80% of the prediction. For the 2-step 2-ns pulse, we test here that this ratio falls to about 20%.

  18. Monochromatic backlighting of direct-drive cryogenic DT implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Stoeckl, C.; Epstein, R.; Betti, R.; Bittle, W.; Delettrez, J. A.; Forrest, C. J.; Glebov, V. Yu.; Goncharov, V. N.; Harding, D. R.; Igumenshchev, I. V.; Jacobs-Perkins, D. W.; Janezic, R. T.; Kelly, J. H.; Kosc, T. Z.; McCrory, R. L.; Michel, D. T.; Mileham, C.; McKenty, P. W.; Marshall, F. J.; Morse, S. F. B.; Regan, S. P.; Radha, P. B.; Rice, B.; Sangster, T. C.; Shoup, M. J.; Shmayda, W. T.; Sorce, C.; Theobald, W.; Ulreich, J.; Wittman, M. D.; Meyerhofer, D. D.; Frenje, J. A.; Gatu Johnson, M.; Petrasso, R. D.

    2017-05-01

    Backlighting is a powerful technique to observe the flow of cold and dense material in high-energy-density-plasma experiments. High-performance, direct-drive cryogenic deuterium-tritium (DT) implosions are a challenging backlighting configuration because of the low opacity of the DT shell, the high shell velocity, the small size of the stagnating shell, and the very bright self-emission of the hot core. A crystal imaging system with a Si Heα backlighter at 1.865 keV driven by ˜20-ps short pulses from OMEGA EP was developed to radiograph the OMEGA cryogenic implosions. The high throughput of the crystal imaging system makes it possible to record high-quality images with good photon statistics and a spatial resolution of ˜15 μm at 10% to 90% modulation. This imager has been used to study the evolution of preimposed mass-density perturbations in the ablator, to quantify the perturbations caused by the stalk that is used to mount the target, and to study the mix caused by laser imprint or small-scale debris on the target surface. Because of the very low opacity of DT relative to carbon, even 0.1% of mix of carbon into the DT ice can be reliably inferred from the images. With the current implosion designs, mix is only observed for an adiabat below α = 4.

  19. Time history prediction of direct-drive implosions on the Omega facility

    DOE PAGES

    Laffite, S.; Bourgade, J. L.; Caillaud, T.; ...

    2016-01-14

    We present in this article direct-drive experiments that were carried out on the Omega facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. Two different pulse shapes were tested in order to vary the implosion stability of the same target whose parameters, dimensions and composition, remained the same. The direct-drive configuration on the Omega facility allows the accurate time-resolvedmeasurement of the scattered light. We show that, provided the laser coupling is well controlled, the implosion time history, assessed by the “bang-time” and the shell trajectory measurements, can be predicted. This conclusion is independent on the pulse shape. Inmore » contrast, we show that the pulse shape affects the implosion stability, assessed by comparing the target performances between prediction and measurement. For the 1-ns square pulse, the measuredneutron number is about 80% of the prediction. Lastly, for the 2-step 2-ns pulse, we test here that this ratio falls to about 20%.« less

  20. The Equation-of-State Dependence of Nonuniformity Growth in Cryogenic-DT Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Goncharov, V. N.; Boehly, T. R.; Skupsky, S.; Sangster, T. C.; Meyerhofer, D. D.; McCrory, R. L.

    2010-11-01

    This work reports on the analysis of low-adiabat, cryogenic deuterium--tritium (DT), high-compression implosion experimentsootnotetext V. N. Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010). performed on OMEGA using 2-D DRACO simulations.ootnotetext S. X. Hu et al., ``Two-Dimensional Simulations of the Neutron-Yield in Cryogenic-DT Implosions on OMEGA,'' submitted to Phys. Plasmas. The growth of various target and laser perturbations has been investigated using 2-D radiation-hydrodynamic simulations with different fuel equation-of-states (EOS) such as the SESAME-EOS, the Thomas--Fermi model, as well as the FPEOS tableootnotetext S. X. Hu et al., Phys. Rev. Lett. 104, 235003 (2010). recently created by the path-integral Monte Carlo method. It has been shown that uniform 1-D hydro simulations using the FPEOS table predicted ˜20% lower neutron yield than the SESAME-EOS case.^3 In this work, we will present the dependence of RT growth and neutron-yield reduction on these different equation of states from 2-D hydro simulations. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

  1. High Omega-3 Polyunsaturated Fatty Acids in fat-1 Mice Reduce Inflammatory Pain.

    PubMed

    Zhang, Enji; Kim, Jwa-Jin; Shin, Nara; Yin, Yuhua; Nan, Yongshan; Xu, Yinshi; Hong, Jinpyo; Hsu, Tzung Min; Chung, Woosuk; Ko, Youngkwon; Lee, Wonhyung; Lim, Kyu; Kim, Dong Woon; Lee, Sun Yeul

    2017-06-01

    Omega-3 and omega-6 polyunsaturated fatty acids (PUFAs), such as α-linolenic and linoleic acids, are essential fatty acids in mammals, because they cannot be synthesized de novo. However, fat-1 transgenic mice can synthesize omega-3 PUFAs from omega-6 PUFAs without dietary supplementation of omega-3, leading to abundant omega-3 PUFA accumulation in various tissues. In this study, we used fat-1 transgenic mice to investigate the role of omega-3 PUFAs in response to inflammatory pain. A high omega-3 PUFA tissue content attenuated formalin-induced pain sensitivity, microglial activation, inducible nitric oxide synthase expression, and the phosphorylation of NR2B, a subunit of the N-methyl-d-aspartate (NMDA) receptor. Our findings suggest that elevated omega-3 PUFA levels inhibit NMDA receptor activity in the spinal dorsal horn and modulate inflammatory pain transmission by regulating signal transmission at the spinal dorsal horn, leading to the attenuation of chemically induced inflammatory pain.

  2. Lowered omega3 polyunsaturated fatty acids in serum phospholipids and cholesteryl esters of depressed patients.

    PubMed

    Maes, M; Christophe, A; Delanghe, J; Altamura, C; Neels, H; Meltzer, H Y

    1999-03-22

    Depression is associated with a lowered degree of esterification of serum cholesterol, an increased C20:4omega6/C20:5omega3 ratio and decreases in omega3 fractions in fatty acids (FAs) or in the red blood cell membrane. The aims of the present study were to examine: (i) serum phospholipid and cholesteryl ester compositions of individual saturated fatty acids (SFAs), monounsaturated FAs (MUFAs) and polyunsaturated FAs (PUFAs) in major depressed patients vs. healthy volunteers; (ii) the relationships between the above FAs and lowered serum zinc (Zn), a marker of the inflammatory response in depression; and (iii) the effects of subchronic treatment with antidepressants on FAs in depression. The composition of the FAs was determined by means of thin layer chromatography in conjunction with gas chromatography. Lipid concentrations were assayed by enzymatic colorimetric methods. The oxidative potential index (OPI) of FAs was computed in 34 major depressed inpatients and 14 normal volunteers. Major depression was associated with: increased MUFA and C22:5omega3 proportions and increased C20:4omega6/C20:5omega3 and C22:5omega6/C22:6omega3 ratios; lower C22:4omega6, C20:5omega3 and C22:5omega3 fractions in phospholipids; lower C18:3omega3, C20:5omega3 and total (sigma)omega3 FAs, and higher C20:4omega6/C20:5omega3 and sigmaomega6/sigmaomega3 ratios in cholesteryl esters; lower serum concentrations of phospholipids and cholesteryl esters; and a decreased OPI. In depression, there were significant and positive correlations between serum Zn and C20:5omega3 and C22:6omega3 fractions in phospholipids; and significant inverse correlations between serum Zn and the sigmaomega6/sigmaomega3, C20:4omega6/C20:5omega3, and C22:5omega6/C22:6omega3 ratios in phospholipids. There was no significant effect of antidepressive treatment on any of the FAs. The results show that, in major depression, there is a deficiency of omega3 PUFAs and a compensatory increase in MUFAs and C22:5omega6 in

  3. Separation of dietary omega-3 and omega-6 fatty acids in food by capillary electrophoresis.

    PubMed

    Soliman, Laiel C; Donkor, Kingsley K; Church, John S; Cinel, Bruno; Prema, Dipesh; Dugan, Michael E R

    2013-10-01

    A lower dietary omega-6/omega-3 (n-6/n-3) fatty acid ratio (<4) has been shown to be beneficial in preventing a number of chronic illnesses. Interest exists in developing more rapid and sensitive analytical methods for profiling fatty acid levels in foods. An aqueous CE method was developed for the simultaneous determination of 15 n-3 and n-6 relevant fatty acids. The effect of pH and concentration of buffer, type and concentration of organic modifier, and additive on the separation was investigated in order to determine the best conditions for the analysis. Baseline separations of the 15 fatty acids were achieved using 40 mM borate buffer at pH 9.50 containing 50 mM SDS, 10 mM β-cyclodextrin, and 10% acetonitrile. The developed CE method has LODs of <5 mg/L and good linearity (R(2) > 0.980) for all fatty acids studied. The proposed method was successfully applied to the determination of n-3 and n-6 fatty acids in flax seed, Udo® oils and a selection of grass-fed and grain-fed beef muscle samples.

  4. Helping women to good health: breast cancer, omega-3/omega-6 lipids, and related lifestyle factors.

    PubMed

    de Lorgeril, Michel; Salen, Patricia

    2014-03-27

    In addition to genetic predisposition and sex hormone exposure, physical activity and a healthy diet play important roles in breast cancer (BC). Increased intake of omega-3 fatty acids (n-3) associated with decreased omega-6 (n-6), resulting in a higher n-3/n-6 ratio compared with the western diet, are inversely associated with BC risk, as shown by Yang et al. in their meta-analysis in BMC Cancer. High consumption of polyphenols and organic foods increase the n-3/n-6 ratio, and in turn may decrease BC risk. Intake of high fiber foods and foods with low glycemic index decreases insulin resistance and diabetes risk, and in turn may decrease BC risk. The modernized Mediterranean diet is an effective strategy for combining these recommendations, and this dietary pattern reduces overall cancer risk and specifically BC risk. High-risk women should also eliminate environmental endocrine disruptors, including those from foods. Drugs that decrease the n-3/n-6 ratio or that are suspected of increasing BC or diabetes risk should be used with great caution by high-risk women and women wishing to decrease their BC risk.Please see related article: http://www.biomedcentral.com/1471-2407/14/105/abstract.

  5. Unbalanced omega-6/omega-3 ratio in red meat products in China

    PubMed Central

    Yu, Ming; Gao, Qianqian; Wang, Yan; Zhang, Wei; Li, Lin; Wang, Ying; Dai, Yifan

    2013-01-01

    Dietary meats play a crucial role in human health. The objective of this survey was to determine the fatty acid content and omega-6/omega-3 polyunsaturated fatty acids (n-6/n-3 PUFA) ratio of fresh red meat (beef and pork) from four cities (Shanghai, Nanjing, Yinchuan and Hohhot) in China. The results showed that the n-6/n-3 PUFA ratio from all the samples ranged from 6 to 23. The total n-6 PUFA concentrations ranged from 290.54 mg/100 g in beef from Nanjing to 1601.48 mg/100 g in pork from Hohhot, whereas the total concentrations of n-3 PUFA ranged from 46.34 mg/100 g in beef from Nanjing to 96.03 mg/100 g in pork from Nanjing. The results indicated that the n-6/n-3 ratio in the red meat from all four regions is unbalanced and is much higher than that (< 5:1) recommended by the WHO/FAO. The total amount of n-3 PUFA was far lower than the required daily dose. Therefore, potential solutions to increase the n-3 PUFA content in meat products or to provide alternative source of n-3 PUFA should be explored. PMID:24086169

  6. Omega-6 and omega-3 oxylipins are implicated in soybean oil-induced obesity in mice.

    PubMed

    Deol, Poonamjot; Fahrmann, Johannes; Yang, Jun; Evans, Jane R; Rizo, Antonia; Grapov, Dmitry; Salemi, Michelle; Wanichthanarak, Kwanjeera; Fiehn, Oliver; Phinney, Brett; Hammock, Bruce D; Sladek, Frances M

    2017-10-02

    Soybean oil consumption is increasing worldwide and parallels a rise in obesity. Rich in unsaturated fats, especially linoleic acid, soybean oil is assumed to be healthy, and yet it induces obesity, diabetes, insulin resistance, and fatty liver in mice. Here, we show that the genetically modified soybean oil Plenish, which came on the U.S. market in 2014 and is low in linoleic acid, induces less obesity than conventional soybean oil in C57BL/6 male mice. Proteomic analysis of the liver reveals global differences in hepatic proteins when comparing diets rich in the two soybean oils, coconut oil, and a low-fat diet. Metabolomic analysis of the liver and plasma shows a positive correlation between obesity and hepatic C18 oxylipin metabolites of omega-6 (ω6) and omega-3 (ω3) fatty acids (linoleic and α-linolenic acid, respectively) in the cytochrome P450/soluble epoxide hydrolase pathway. While Plenish induced less insulin resistance than conventional soybean oil, it resulted in hepatomegaly and liver dysfunction as did olive oil, which has a similar fatty acid composition. These results implicate a new class of compounds in diet-induced obesity-C18 epoxide and diol oxylipins.

  7. Laser Compression of Nanocrystalline Tantalum

    NASA Astrophysics Data System (ADS)

    Lu, Chia-Hui; Maddox, Brian; Remington, Bruce; Bringa, Eduardo; Kawasaki, Megumi; Langdon, Terence; Park, Hye-Sook; Kad, Bimal; Meyers, Marc

    2011-06-01

    Nanocrystlline tantalum was prepared by HPT (High Pressure Torsion) from monocrystalline [100] stock yielding a grain size of 70 nm. It was subjected to laser driven compression at energy levels of ~ 350 J to ~ 850 J in the Omega facility (LLE, U. of Rochester) yielding pressures as high as ~180 GPa. The laser beam created a crater of significant depth (~100 μm). Transmission electron microscopy (TEM) revealed dislocations in the grains but no twins in contrast with monocrystalline tantalum. Hardness measurements were conducted and show the same trend as single crystalline tantalum. The grain size was found to increase close to the energy deposition surface.

  8. Laser compression of nanocrystalline tantalum

    NASA Astrophysics Data System (ADS)

    Lu, Chia-Hui; Maddox, Brian; Remington, B.; Bringa, Eduardo M.; Kawasaki, Megumi; Langdon, Terence; Park, Hye-Sook; Kad, Bimal; Meyers, Marc

    2012-03-01

    Nanocrystalline tantalum was prepared by high pressure torsion from monocrystalline [100] stock, yielding a grain size of 70nm. It was subjected to laser driven compression at energy levels of ~ 350 J to ~ 850 J in the Omega facility (LLE, U. of Rochester) with corresponding pressures as high as ~ 170 GPa. The laser beam created a crater of significant depth (~ 100 µm). Transmission electron microscopy (TEM) revealed dislocations in the grains but no twins in contrast with monocrystalline tantalum. Hardness measurements were conducted and show the same trend as single crystalline tantalum. The grain size was found to increase close to the energy deposition surface due to the thermomechanical excursion.

  9. Omega-3 Fatty acids and airway hyperresponsiveness in asthma.

    PubMed

    Mickleborough, Timothy D; Ionescu, Alina A; Rundell, Kenneth W

    2004-12-01

    Despite the progress that has been made in the treatment of asthma, the prevalence and burden of this disease has continued to increase. Exercise is a powerful trigger of asthma symptoms and reversible airflow obstruction and may result in the avoidance of physical activity by patients with asthma, resulting in detrimental consequences to their health. Approximately 90% of patients with asthma are hyperresponsive to exercise and experience exercise-induced bronchoconstriction (EIB). While pharmacologic treatment of asthma is usually highly effective, medications often have significant side-effects or exhibit tachyphylaxis. Alternative therapies for treatment (complementary medicine) that reduce the dose requirements of pharmacologic interventions would be beneficial, and could potentially reduce the public health burden of this disease. There is accumulating evidence that dietary modification has potential to influence the severity of asthma and reduce the prevalence and incidence of this condition. A possible contributing factor to the increased incidence of asthma in Western societies may be the consumption of a proinflammatory diet. In the typical Western diet, 20- to 25-fold more omega- 6 polyunsaturated fatty acids (PUFA) than omega-3 PUFA are consumed, which causes the release of proinflammatory arachidonic acid metabolites (leukotrienes and prostanoids). This review analyzes the existing literature on omega-3 PUFA supplementation as a potential modifier of airway hyperresponsiveness in asthma and includes studies concerning the efficacy of omega-3 PUFA supplementation in EIB. While clinical data evaluating the effect of omega-3 PUFA supplementation in asthma has been equivocal, it has recently been shown that pharmaceutical-grade fish oil (omega-3 PUFA) supplementation reduces airway hyperresponsiveness after exercise, medication use, and proinflammatory mediator generation in nonatopic elite athletes with EIB. These findings are provocative and suggest that

  10. Phase-matched four-wave mixing of sub-100-TW/ cm2 femtosecond laser pulses in isolated air-guided modes of a hollow photonic-crystal fiber.

    PubMed

    Konorov, S O; Serebryannikov, E E; Akimov, D A; Ivanov, A A; Alfimov, M V; Zheltikov, A M

    2004-12-01

    Hollow-core photonic-crystal fibers are shown to allow propagation and nonlinear-optical frequency conversion of high-intensity ultrashort laser pulses in the regime of isolated guided modes confined in the hollow gas-filled fiber core. With a specially designed dispersion of such modes, the 3omega=2omega+2omega-omega four-wave mixing of fundamental (omega) and second-harmonic (2omega) sub-100- TW/ cm(2) femtosecond pulses of a Cr:forsterite laser can be phase matched in a hollow photonic-crystal fiber within a spectral band of more than 10 nm, resulting in the efficient generation of femtosecond pulses in a well-resolved higher-order air-guided mode of 417-nm radiation.

  11. Hubble Space Telescope Image of Omega Nebula

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This sturning image, taken by the newly installed Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST), is an image of the center of the Omega Nebula. It is a hotbed of newly born stars wrapped in colorful blankets of glowing gas and cradled in an enormous cold, dark hydrogen cloud. The region of nebula shown in this photograph is about 3,500 times wider than our solar system. The nebula, also called M17 and the Swan Nebula, resides 5,500 light-years away in the constellation Sagittarius. The Swan Nebula is illuminated by ultraviolet radiation from young, massive stars, located just beyond the upper-right corner of the image. The powerful radiation from these stars evaporates and erodes the dense cloud of cold gas within which the stars formed. The blistered walls of the hollow cloud shine primarily in the blue, green, and red light emitted by excited atoms of hydrogen, nitrogen, oxygen, and sulfur. Particularly striking is the rose-like feature, seen to the right of center, which glows in the red light emitted by hydrogen and sulfur. As the infant stars evaporate the surrounding cloud, they expose dense pockets of gas that may contain developing stars. One isolated pocket is seen at the center of the brightest region of the nebula. Other dense pockets of gas have formed the remarkable feature jutting inward from the left edge of the image. The color image is constructed from four separate images taken in these filters: blue, near infrared, hydrogen alpha, and doubly ionized oxygen. Credit: NASA, H. Ford (JHU), G. Illingworth (USCS/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.

  12. Hubble Space Telescope Image of Omega Nebula

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This sturning image, taken by the newly installed Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST), is an image of the center of the Omega Nebula. It is a hotbed of newly born stars wrapped in colorful blankets of glowing gas and cradled in an enormous cold, dark hydrogen cloud. The region of nebula shown in this photograph is about 3,500 times wider than our solar system. The nebula, also called M17 and the Swan Nebula, resides 5,500 light-years away in the constellation Sagittarius. The Swan Nebula is illuminated by ultraviolet radiation from young, massive stars, located just beyond the upper-right corner of the image. The powerful radiation from these stars evaporates and erodes the dense cloud of cold gas within which the stars formed. The blistered walls of the hollow cloud shine primarily in the blue, green, and red light emitted by excited atoms of hydrogen, nitrogen, oxygen, and sulfur. Particularly striking is the rose-like feature, seen to the right of center, which glows in the red light emitted by hydrogen and sulfur. As the infant stars evaporate the surrounding cloud, they expose dense pockets of gas that may contain developing stars. One isolated pocket is seen at the center of the brightest region of the nebula. Other dense pockets of gas have formed the remarkable feature jutting inward from the left edge of the image. The color image is constructed from four separate images taken in these filters: blue, near infrared, hydrogen alpha, and doubly ionized oxygen. Credit: NASA, H. Ford (JHU), G. Illingworth (USCS/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.

  13. A New Neutron Time-of-Flight Detector for DT Yield and Ion-Temperature Measurements on OMEGA

    NASA Astrophysics Data System (ADS)

    Glebov, V. Yu.; Forrest, C. J.; Knauer, J. P.; Regan, S. P.; Sangster, T. C.; Stoeckl, C.

    2015-11-01

    A new neutron time-of-flight (nTOF) detector for DT yield and ion-temperature measurements in DT implosions on the OMEGA Laser System was designed, fabricated, tested, and calibrated. The goal of this detector is to provide a second line of sight for DT yield and ion-temperature measurements in the 1 ×1012 to 1014 yield range. The nTOF detector consists of a 40-mm-diam, 20-mm-thick BC-422Q(1%) scintillator coupled with a one-stage Photek PMT-140 photomultiplier tube. To avoid PMT saturation at high yields a neutral density filter ND1 is inserted between the scintillator and PMT. Both the scintillator and PMT are shielded from hard x rays by 5 mm of lead on all sides and 10 mm in the direction of the target. The nTOF detector is located at 15.8 m from target chamber center in the OMEGA Target Bay. The design details and calibration results of this nTOF detector in DT implosions on OMEGA will be presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  14. Measurements of shock-front structure in multi-species plasmas on OMEGA

    NASA Astrophysics Data System (ADS)

    Rinderknecht, Hans G.; Park, H.-S.; Ross, J. S.; Wilks, S. C.; Amendt, P. A.; Heeter, R. F.; Katz, J.; Hoffman, N. M.; Vold, E.; Taitano, W.; Simakov, A.; Chacon, L.

    2016-10-01

    The structure of a shock front in a plasma with multiple ion species is measured for the first time in experiments on the OMEGA laser. Thomson scattering of a 263.25 nm probe beam is used to diagnose electron density, electron and ion temperature, ion species concentration, and flow velocity in strong shocks (M 5) propagating through low-density (ρ 0.1 mg/cc) plasmas composed of H(98%)+Ne(2%) and H(98%)+C(2%). Separation of the ion species within the shock front is inferred. Although shocks play an important role in ICF and astrophysical plasmas, the intrinsically kinetic nature of the shock front indicates the need for experiments to benchmark hydrodynamic models. Comparison with PIC, Vlasov-Fokker-Planck, and multi-component hydrodynamic simulations will be presented. This work performed under auspices of U.S. DOE by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  15. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF

    SciTech Connect

    Zylstra, A. B. Gatu Johnson, M.; Frenje, J. A.; Séguin, F. H.; Rinderknecht, H. G.; Rosenberg, M. J.; Sio, H. W.; Li, C. K.; Petrasso, R. D.; McCluskey, M.; Mastrosimone, D.; Glebov, V. Yu.; Forrest, C.; Stoeckl, C.; Sangster, T. C.

    2014-06-15

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility [T. Boehly et al., Opt. Commun. 133, 495 (1997)]. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is currently capable of measuring the yield to ∼±10% accuracy, and mean neutron energy to ∼±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burn can be measured. Future improvements to reduce the neutron energy uncertainty to ±15−20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ∼±25−40 km/s.

  16. Three-dimensional modeling of capsule implosions in OMEGA tetrahedral hohlraums

    SciTech Connect

    Schnittman, J. D.; Craxton, R. S.

    2000-07-01

    Tetrahedral hohlraums have been proposed as a means for achieving the highly uniform implosions needed for ignition with inertial confinement fusion (ICF) [J. D. Schnittman and R. S. Craxton, Phys. Plasmas 3, 3786 (1996)]. Recent experiments on the OMEGA laser system have achieved good drive uniformity consistent with theoretical predictions [J. M. Wallace et al., Phys. Rev. Lett. 82, 3807 (1999)]. To better understand these experiments and future investigations of high-convergence ICF implosions, the three-dimensional (3-D) view-factor code BUTTERCUP has been expanded to model the time-dependent radiation transport in the hohlraum and the hydrodynamic implosion of the capsule. Additionally, a 3-D postprocessor has been written to simulate x-ray images of the imploded core. Despite BUTTERCUP's relative simplicity, its predictions for radiation drive temperatures, fusion yields, and core deformation show close agreement with experiment. (c) 2000 American Institute of Physics.

  17. Three-dimensional modeling of capsule implosions in OMEGA tetrahedral hohlraums

    NASA Astrophysics Data System (ADS)

    Schnittman, J. D.; Craxton, R. S.

    2000-07-01

    Tetrahedral hohlraums have been proposed as a means for achieving the highly uniform implosions needed for ignition with inertial confinement fusion (ICF) [J. D. Schnittman and R. S. Craxton, Phys. Plasmas 3, 3786 (1996)]. Recent experiments on the OMEGA laser system have achieved good drive uniformity consistent with theoretical predictions [J. M. Wallace et al., Phys. Rev. Lett. 82, 3807 (1999)]. To better understand these experiments and future investigations of high-convergence ICF implosions, the three-dimensional (3-D) view-factor code BUTTERCUP has been expanded to model the time-dependent radiation transport in the hohlraum and the hydrodynamic implosion of the capsule. Additionally, a 3-D postprocessor has been written to simulate x-ray images of the imploded core. Despite BUTTERCUP's relative simplicity, its predictions for radiation drive temperatures, fusion yields, and core deformation show close agreement with experiment.

  18. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF.

    PubMed

    Zylstra, A B; Gatu Johnson, M; Frenje, J A; Séguin, F H; Rinderknecht, H G; Rosenberg, M J; Sio, H W; Li, C K; Petrasso, R D; McCluskey, M; Mastrosimone, D; Glebov, V Yu; Forrest, C; Stoeckl, C; Sangster, T C

    2014-06-01

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility [T. Boehly et al., Opt. Commun. 133, 495 (1997)]. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is currently capable of measuring the yield to ~±10% accuracy, and mean neutron energy to ~±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burn can be measured. Future improvements to reduce the neutron energy uncertainty to ±15-20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ~±25-40 km/s.

  19. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF

    DOE PAGES

    Zylstra, A. B.; Gatu Johnson, M.; Frenje, J. A.; ...

    2014-06-04

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is capable of measuring the yield to ~±10% accuracy, and mean neutron energy to ~±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burn can be measured. Future improvements to reduce the neutron energymore » uncertainty to ±15-20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ~±25-40 km/s.« less

  20. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF

    NASA Astrophysics Data System (ADS)

    Zylstra, A. B.; Gatu Johnson, M.; Frenje, J. A.; Séguin, F. H.; Rinderknecht, H. G.; Rosenberg, M. J.; Sio, H. W.; Li, C. K.; Petrasso, R. D.; McCluskey, M.; Mastrosimone, D.; Glebov, V. Yu.; Forrest, C.; Stoeckl, C.; Sangster, T. C.

    2014-06-01

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility [T. Boehly et al., Opt. Commun. 133, 495 (1997)]. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is currently capable of measuring the yield to ˜±10% accuracy, and mean neutron energy to ˜±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burn can be measured. Future improvements to reduce the neutron energy uncertainty to ±15-20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ˜±25-40 km/s.

  1. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF

    SciTech Connect

    Zylstra, A. B.; Gatu Johnson, M.; Frenje, J. A.; Séguin, F. H.; Rinderknecht, H. G.; Rosenberg, M. J.; Sio, H. W.; Li, C. K.; Petrasso, R. D.; McCluskey, M.; Mastrosimone, D.; Glebov, V. Yu.; Forrest, C.; Stoeckl, C.; Sangster, T. C.

    2014-06-04

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is capable of measuring the yield to ~±10% accuracy, and mean neutron energy to ~±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burn can be measured. Future improvements to reduce the neutron energy uncertainty to ±15-20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ~±25-40 km/s.

  2. Monte Carlo validation experiments for the gas Cherenkov detectors at the National Ignition Facility and Omega

    SciTech Connect

    Rubery, M. S.; Horsfield, C. J.; Herrmann, H.; Kim, Y.; Mack, J. M.; Young, C.; Evans, S.; Sedillo, T.; McEvoy, A.; Caldwell, S. E.; Grafil, E.; Stoeffl, W.; Milnes, J. S.

    2013-07-15

    The gas Cherenkov detectors at NIF and Omega measure several ICF burn characteristics by detecting multi-MeV nuclear γ emissions from the implosion. Of primary interest are γ bang-time (GBT) and burn width defined as the time between initial laser-plasma interaction and peak in the fusion reaction history and the FWHM of the reaction history respectively. To accurately calculate such parameters the collaboration relies on Monte Carlo codes, such as GEANT4 and ACCEPT, for diagnostic properties that cannot be measured directly. This paper describes a series of experiments performed at the High Intensity γ Source (HIγS) facility at Duke University to validate the geometries and material data used in the Monte Carlo simulations. Results published here show that model-driven parameters such as intensity and temporal response can be used with less than 50% uncertainty for all diagnostics and facilities.

  3. Omega-3 fatty acids in inflammation and autoimmune diseases.

    PubMed

    Simopoulos, Artemis P

    2002-12-01

    Among the fatty acids, it is the omega-3 polyunsaturated fatty acids (PUFA) which possess the most potent immunomodulatory activities, and among the omega-3 PUFA, those from fish oil-eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)--are more biologically potent than alpha-linolenic acid (ALA). Some of the effects of omega-3 PUFA are brought about by modulation of the amount and types of eicosanoids made, and other effects are elicited by eicosanoid-independent mechanisms, including actions upon intracellular signaling pathways, transcription factor activity and gene expression. Animal experiments and clinical intervention studies indicate that omega-3 fatty acids have anti-inflammatory properties and, therefore, might be useful in the management of inflammatory and autoimmune diseases. Coronary heart disease, major depression, aging and cancer are characterized by an increased level of interleukin 1 (IL-1), a proinflammatory cytokine. Similarly, arthritis, Crohn's disease, ulcerative colitis and lupus erythematosis are autoimmune diseases characterized by a high level of IL-1 and the proinflammatory leukotriene LTB(4) produced by omega-6 fatty acids. There have been a number of clinical trials assessing the benefits of dietary supplementation with fish oils in several inflammatory and autoimmune diseases in humans, including rheumatoid arthritis, Crohn's disease, ulcerative colitis, psoriasis, lupus erythematosus, multiple sclerosis and migraine headaches. Many of the placebo-controlled trials of fish oil in chronic inflammatory diseases reveal significant benefit, including decreased disease activity and a lowered use of anti-inflammatory drugs.

  4. Omega-3 fatty acids and cognitive function in women

    PubMed Central

    Robinson, Jennifer G; Ijioma, Nkechinyere; Harris, William

    2010-01-01

    Omega-3 fatty acids (FAs) could play an important role in maintaining cognitive function in aging individuals. The omega-3 FA docosahexaenoic acid is a major constituent of neuronal membranes and, along with the other long-chain omega-3 FAs from fish such as eicosapentaentoic acid, has been shown to have a wide variety of beneficial effects on neuronal functioning, inflammation, oxidation and cell death, as well as on the development of the characteristic pathology of Alzheimer’s disease. Omega-3 FAs may prevent vascular dementia via salutary effects on lipids, inflammation, thrombosis and vascular function. Epidemiologic studies have generally supported a protective association between fish and omega-3 FA levels and cognitive decline. Some of the small, short-term, randomized trials of docosahexaenoic acid and/or eicosapentaentoic acid supplementation have found positive effects on some aspects of cognition in older adults who were cognitively intact or had mild cognitive impairment, although little effect was found in participants with Alzheimer’s disease. Large, long-term trials in this area are needed. PMID:20088735

  5. Stimulated Brillouin scattering of the beat wave of two lasers in a plasma

    SciTech Connect

    Panwar, Anuraj; Sharma, A. K.

    2009-09-15

    Stimulated Brillouin scattering of two collinear lasers in a plasma is investigated. Lasers exert a longitudinal ponderomotive force on electrons, imparting them oscillatory axial velocity at the beat frequency. This velocity acts as a driver for parametric excitation of an ion acoustic wave (omega,k-vector) and a noncollinear sideband electromagnetic wave (omega{sup '},k-vector{sup '}). The driver velocity v-vector{sub 0-} couples to the sideband wave to exert a ponderomotive force at (omega,k-vector) on the electrons, driving the ion acoustic wave. The density perturbation of ion acoustic wave beats with v-vector{sub 0-} to produce a nonlinear current at (omega{sup '},k-vector{sup '}), driving the sideband. In the case of finite spot size Gaussian laser beams, the beat wave has a Gaussian profile and excites an ion acoustic wave (omega,k-vector) and a backscattered TM mode (omega{sup '},k-vector{sub z}{sup '}). The growth rate scales as the product of amplitudes of the lasers and maximizes at optimum values of scattering angles. The parametric instability of difference frequency driver is stronger than the sum frequency driver.

  6. Capsule Implosion Symmetry in OMEGA Tetrahedral Hohlraums

    NASA Astrophysics Data System (ADS)

    Schnittman, J. D.; Craxton, R. S.; Pollaine, S. M.; Turner, R. E.; Wallace, J. M.; Murphy, T. J.; Delamater, N. D.; Oertel, J. A.; Hauer, A. A.; Klare, K. A.

    1998-11-01

    The 3-D time-dependent capsule implosion symmetry has been calculated for spherical hohlraums with four laser entrance holes. The code BUTTERCUP calculates the locations of beam spots on the hohlraum wall and includes a model for the absorption and x-ray conversion of the laser energy. The gold wall is heated by 1-D radiation diffusion, and radiation transport is carried out with a 3-D view-factor algorithm. A simple hydrodynamic calculation of the imploding capsule gives the resulting 3-D time-dependent drive symmetry. The predicted radiation uniformity incident on the capsule is very good ( ~1% rms) throughout the laser pulse. Experimental images of the capsule show round implosions with convergence ratios of 10 for standard capsules,(T. J. Murphy, Bull. Am. Phys. Soc. 42), 2008 (1997). in agreement with predictions. Radiation temperatures and capsule trajectories are calculated and show good agreement with experiment. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460.

  7. Cardiac mortality is associated with low levels of omega-3 and omega-6 fatty acids in the heart of cadavers with a history of coronary heart disease.

    PubMed

    Chattipakorn, Nipon; Settakorn, Jongkolnee; Petsophonsakul, Petnoi; Suwannahoi, Padiphat; Mahakranukrauh, Pasuk; Srichairatanakool, Somdet; Chattipakorn, Siriporn C

    2009-10-01

    The benefits of omega-3 (ie, eicosapentaenoic acid and docosahexaenoic acid [DHA]) and omega-6 (ie, linoleic acid and arachidonic acid [AA]) fatty acids on reducing cardiac mortality are still debated. In this study, we tested the hypothesis that high levels of omega-3 and omega-6 fatty acids in heart tissues are associated with low cardiac mortality in Thai cadavers. One hundred fresh cadavers were examined in this study. The cause of death, history of coronary heart disease (CHD), and fish consumption habits were obtained from death certificates, cadaver medical record profiles, and a questionnaire to a person who lived with the subject before death. In each cadaver, biopsies of cardiac tissues were taken from the interventricular septum for measurement of fatty acid. Of the 100 cadavers (average age, 69 +/- 13 years), 60 were men. The frequency of fish consumption was directly associated with omega-3 and omega-6 fatty acids in heart tissues (P < .01). History of CHD and cause of death (cardiac vs noncardiac) were not significantly associated with levels of omega-3 or omega-6 fatty acids. However, in cadavers with a history of CHD, high levels of omega-3 and omega-6, particularly DHA and AA, were associated with low cardiac mortality (P < .05). Fish consumption is associated with levels of omega-3 and omega-6 fatty acids in heart tissues. Although omega-3 and omega-6 fatty acids are not associated with cardiac mortality in the overall studied population, their low levels (especially DHA and AA) in heart tissues are associated with high cardiac mortality in cadavers with a history of CHD.

  8. Measurements of the Effect of Adiabat on Shell Decompression in Direct-Drive Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Michel, D. T.; Hu, S. X.; Radha, P. B.; Davis, A. K.; Craxton, R. S.; Glebov, V. Yu.; Goncharov, V. N.; Igumenshchev, I. V.; Stoeckl, C.; Froula, D. H.

    2016-10-01

    Measurements of the effect of adiabat (α) on the shell thickness were performed in direct-drive implosions. The maximum in-flight shell thickness was obtained using a novel technique where the outer and inner surfaces of the shell were simultaneously measured using self-emission images of the imploding target. When reducing the shell's adiabat from α = 6 to α = 4.5 , the shell thickness was measured to decrease from 75 μm to 60 μm, but when decreasing the adiabat further (α = 1.8), the shell thickness was measured to increase to 75 μm. The measured shell thickness, shell trajectories, neutron bang time, and neutron yield were reproduced by two-dimensional simulations that include laser imprint, nonlocal thermal transport, cross-beam energy transfer, and first-principles equation-of-state models. These results show that the decompression of the shell measured for low-adiabat implosions was a result of laser imprint. Additional information on the evolution of the density profile was obtained using x-ray radiography. The backlighter was created with six of the 60 OMEGA laser beams, with the pointings and energies of other beams adjusted to maintain a uniform implosion. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  9. A Compact, TIM-Based, Pulsed-Power System for Magnetized Target Experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Gotchev, O. V.; Barbero, M. D.; Jang, N. W.; Knauer, J. P.; Betti, R.

    2006-10-01

    By magnetizing the target and then compressing the magnetic flux to levels sufficient to inhibit thermal transport in the hot spot, one can trigger ignition in massive cryogenic shells imploded with low velocity. The reduction in thermal-conduction losses leads to increased hot-spot temperatures at lower implosion velocities, thus relaxing the energy requirements for ignition. This work describes a compact, pulsed-power system for the generation of a macroscopic seed magnetic field and its integration into such flux-compression experiments on OMEGA. Magnetohydrodynamic simulations predict compression of a 10-T seed field to multimegagauss values. A fast (100-ns) current pulse (up to 60 kA), driven by a TIM-based energy-delivery system, is discharged into a low-mass, double coil that surrounds the laser target. A working prototype has generated a >11-T seed field utilizing a <100-J capacitor bank, laser-triggered spark gap, and a low-impedance (<1-φ) stripline. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-92SF19460. N. W. Jang et al., ``Theory and Simulation of Laser-Driven Magnetic Field Compression,'' this conference.

  10. Non-Equilibrium Electron And Ion Temperature Measurements In Omega Direct-Drive Implosions

    SciTech Connect

    Koch, J. A.; Miles, A.; Hsing, W.; Lee, R. W.; Scott, H.; Stewart, R.; Tommasini, R.; Frenje, J.; Li, C.; Petrasso, R.; Glebov, V.

    2009-09-10

    We have performed experiments at the Omega Laser Facility at the University of Rochester/Laboratory for Laser Energetics to measure time-resolved electron temperature (Te) and ion temperature (Ti) in high-temperature implosions. These experiments use direct laser drive on thin glass shells filled with a mixture of D, {sup 3}He, Kr, and Xe, and use neutron and proton emission to diagnose Ti and x-ray emission to diagnose Te. The Kr dopant serves as an optically-thin tracer for Te measurements via K-shell spectroscopy, while the Xe dopant enhances radiation losses and serves as an energy sink due to ionization. Important results include the observation of an order-of-magnitude increase in areal density with a low concentration of Xe, the observation of double-peaked Ti and x-ray emission time profiles indicative of separate shock and compression phases, and generally good agreement with hydrodynamic simulations of the temperature histories. We describe the experiments, the results, and the supporting hydrodynamics simulations.

  11. Promotion of prostatic metastatic migration towards human bone marrow stoma by Omega 6 and its inhibition by Omega 3 PUFAs

    PubMed Central

    Brown, M D; Hart, C A; Gazi, E; Bagley, S; Clarke, N W

    2006-01-01

    Epidemiological studies have shown not only a relationship between the intake of dietary lipids and an increased risk of developing metastatic prostate cancer, but also the type of lipid intake that influences the risk of metastatic prostate cancer. The Omega-6 poly-unsaturated fatty acid, Arachidonic acid, has been shown to enhance the proliferation of malignant prostate epithelial cells and increase the risk of advanced prostate cancer. However, its role in potentiating the migration of cancer cells is unknown. Here we show that arachidonic acid at concentrations ⩽5 μM is a potent stimulator of malignant epithelial cellular invasion, which is able to restore invasion toward hydrocortisone-deprived adipocyte-free human bone marrow stroma completely. This observed invasion is mediated by the arachidonic acid metabolite prostaglandin E2 and is inhibited by the Omega-3 poly-unsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid at a ratio of 1 : 2 Omega-3 : Omega-6, and by the COX-2 inhibitor NS-398. These results identify a mechanism by which arachidonic acid may potentiate the risk of metastatic migration and secondary implantation in vivo, a risk which can be reduced with the uptake of Omega-3 poly-unsaturated fatty acids. PMID:16523199

  12. Cooperative formation of omega-muricholic acid by intestinal microorganisms.

    PubMed Central

    Eyssen, H; De Pauw, G; Stragier, J; Verhulst, A

    1983-01-01

    Three anaerobic bacteria, isolated from the ceca of rats and mice, converted, through a concerted mechanism, beta-muricholic acid, the predominant bile acid in germfree rats, into omega-muricholic acid. One isolate was a Eubacterium lentum strain; the second and third isolates were tentatively identified as atypical Fusobacterium sp. strains. The conversion of beta-muricholic acid into omega-muricholic acid proceeded in two steps: E. lentum oxidized the 6 beta-hydroxyl group of beta-muricholic acid to a 6-oxo group, which was reduced by either of the two other species to a 6 alpha-hydroxyl group, yielding omega-muricholic acid. This transformation occurred both in vitro and in gnotobiotic rats. Monoassociation of germfree rats with the E. lentum strain gave rise to an unidentified fecal bile acid, probably a derivative of beta-muricholic acid having a double bond in the side chain. PMID:6824314

  13. Evidence for the decay X(3872) -> J/\\psi\\omega

    SciTech Connect

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-08-11

    We present a study of the decays B{sup 0,+} --> J/{psi}{pi}{sup +}{pi}{sup -}{pi}{sup 0}K{sup 0,+}, using 467x10{sup 6} B{anti B} pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) --> J/{psi}{omega}, with product branching fractions B(B{sup +} --> X(3872)K{sup +}) x B(X(3872) --> J/{psi}{omega}) = [0.6 {+-} 0.2(stat) {+-} 0.1(syst)] x 10{sup -5}, and B(B{sup 0} --> X(3872)K{sup 0}) x B(X(3872) --> J/{psi}{omega}) = [0.6 {+-} 0.3(stat) {+-} 0.1(syst)] x 10{sup -5}. A detailed study of the {pi}{sup +}{pi}{sup -}{pi}{sup 0} mass distribution from X(3872) decay favors a negative-parity assignment.

  14. Constraining omega and bias from the Stromlo-APM survey

    SciTech Connect

    Loveday, J.

    1995-05-01

    Galaxy redshift surveys provide a distorted picture of the universe due to the non-Hubble component of galaxy motions. By measuring such distortions in the linear regime one can constrain the quantity {beta} = {Omega}{sup 0.6} where {Omega} is the cosmological density parameter and b is the (linear) bias factor for optically-selected galaxies. In this paper we estimate {beta} from the Stromlo-APM redshift survey by comparing the amplitude of the direction-averaged redshift space correlation function to the real space correlation function. We find a 95% confidence upper limit of {beta} = 0.75, with a `best estimate` of {beta} {approx} 0.48. A bias parameter b {approx} 2 is thus required if {Omega} {equivalent_to} 1. However, higher-order correlations measured from the APM galaxy survey indicate a low value for the bias parameter b {approx} 1, requiring that Q {approx_lt} 0.6.

  15. Rapid lipid enrichment in omega3 fatty acids: liver data.

    PubMed

    Carpentier, Yvon A; Peltier, Sebastien; Portois, Laurence; Sener, Abdullah; Malaisse, Willy J

    2008-03-01

    The bolus intravenous injection of a novel medium-chain triglyceride:fish oil emulsion to normal subjects was recently reported to enrich within 60 min the phospholipid content of leucocytes and platelets in long-chain polyunsaturated omega3 fatty acids. The present study, conducted in second generation omega3-depleted rats, aims at investigating whether such a procedure may also increase within 60 min the phospholipid content of omega3 fatty acids in cells located outwards of the bloodstream, in this case liver cells, and whether this coincides with correction of the perturbation in the liver triglyceride fatty acid content and profile otherwise prevailing in these rats. The results indicate that such is indeed the case and further suggest a cause-to-effect relationship between the two events.

  16. Search for Lepton Flavor Violating Decays Tau+- to L+- Omega

    SciTech Connect

    Schenk, S.; /Heidelberg U.

    2011-11-30

    This paper reports on a search for lepton flavor violating decays of a {tau} lepton to a lighter-mass charged lepton and an {omega} vector meson. The data sample corresponds to an integrated luminosity of 384 fb{sup -1} recorded by the BaBar experiment at the SLAC PEP-II asymmetric-energy B Factory. No evidence for a signal is found and the upper limits on the branching ratios are determined to be B({tau}{sup {+-}} {yields} e{sup {+-}}{omega}) < 1.1 x 10{sup -7} and B({tau}{sup {+-}} {yields} {mu}{sup {+-}}{omega}) < 1.0 x 10{sup -7} at 90% confidence level.

  17. Recent field test results using OMEGA transmissions for clock synchronization

    NASA Technical Reports Server (NTRS)

    Chi, A. R.; Wardrip, S. C.

    1974-01-01

    The results are presented of clock synchronization experiments using OMEGA transmissions from North Dakota on 13.10 kHz and 12.85 kHz. The OMEGA transmissions were monitored during April 1974 from NASA tracking sites located at Madrid, Spain; Canary Island; and Winkfield, England. The sites are located at distances between 6600 kilometers (22,100 microseconds) to 7300 kilometers (24,400 microseconds) from North Dakota. The data shows that cycle identification of the received signals was accomplished. There are, however, discrepancies between the measured and calculated propagation delay values which have not been explained, but seem to increase with distance between the receiver and the transmitter. The data also indicates that three strategically located OMEGA transmitting stations may be adequate to provide worldwide coverage for clock synchronization to within plus or minus two (2) microseconds.

  18. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic). 721.10214 Section 721.10214... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...

  19. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic). 721.10214 Section 721.10214... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...

  20. 40 CFR 721.10214 - Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic). 721.10214 Section 721.10214... Poly(oxyalkylenediyl),.alpha.-substituted carbomonocycle-.omega.-substituted carbomonocycle (generic... identified generically as poly(oxyalkylenediyl),.alpha.-substituted...