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Sample records for nif target area

  1. NIF target area design support. Final summary report

    International Nuclear Information System (INIS)

    Tokheim, R.E.; Seaman, L.; Curran, D.R.

    1996-02-01

    SRI International continued support work for the National Ignition Facility, Chamber Dynamics Group at Lawrence Livermore National Laboratory (LLNL). The work entailed computational modeling of shrapnel and debris generation from copper shine shields, hohlraum, and stainless steel cryogenic support tubes for 1.8 MJ and 1.0 MJ no-yield and 20 MJ yield shots. Also, the authors addressed the effects of shrapnel at the first wall. Computations for 1.8 MJ showed an ionized gold hohlraum, but about half solid and half ionized copper shine shields, when material cell phase boundaries were maintained. This debris generation represents a potential threat to the first wall and debris shields. Further work is required to translate these results into particle size distributions based on computed strain rates. The authors used simple algorithms for x-ray loading of frost layers protecting the target support to compute peak stress attenuation. They developed algorithmic formulas for predicting damage in candidate first wall materials and they found damage algorithms for fused-silica debris shield material. They obtained very preliminary computational results at 20 MJ for predicting shrapnel mass and particle density at the first wall in spherical polar coordinate space with the hohlraum axis as the polar direction

  2. Development of IFE target systems on the NIF

    International Nuclear Information System (INIS)

    Schultz, K.R.; Fagaly, R.L.; Bernat, T.; Meier, W.; Petzoldt, R.; Foreman, L.

    1995-01-01

    The Target Systems session of the Workshop on NIF Experiments for IFE developed a list of critical issues for inertial fusion energy (IFE) target systems, and considered the potential of the National Ignition Facility (NIF) to help in the resolution of these issues and in the development of IFE target systems. This paper describes the IFE Target System issues, categorized into target fabrication issues and target transport issues, describes potential NIF IFE target systems experiments, considers the impact of these experiments on the NIF and discusses the development required before these experiments could be done. Most target systems issues must be resolved by development in the laboratory, not in the NIF, and some must be resolved before the NIF can be successful. However, experiments done in the NIF could play a valuable role in developing target systems for IFE. These experiments should have modest impact on the basic design of the NIF, but could require several hundred dedicated, high yield shots

  3. Current progress in NIF target concepts

    International Nuclear Information System (INIS)

    Gobby, P.L.; Foreman, L.R.; Thoma, D.J.; Jacobson, L.A.; Hollis, R.V.; Barrera, J.; Mitchell, M.A.; Salazar, M.A.; Salzer, L.J.

    1996-01-01

    Target concepts for the National Ignition Facility (NIF) require progress in the art and science of target fabrication. Three distinct issues are addressed: beryllium fuel capsules, foam-buffered direct drive, and high-density gas-filled hohlraums. In all cases experiments on the existing Nova laser at LLNL are either in progress or planned for the near future to test the various concepts. Consequently, target fabrication must be able to deliver targets appropriate for each

  4. NIF Ignition Target 3D Point Design

    Energy Technology Data Exchange (ETDEWEB)

    Jones, O; Marinak, M; Milovich, J; Callahan, D

    2008-11-05

    We have developed an input file for running 3D NIF hohlraums that is optimized such that it can be run in 1-2 days on parallel computers. We have incorporated increasing levels of automation into the 3D input file: (1) Configuration controlled input files; (2) Common file for 2D and 3D, different types of capsules (symcap, etc.); and (3) Can obtain target dimensions, laser pulse, and diagnostics settings automatically from NIF Campaign Management Tool. Using 3D Hydra calculations to investigate different problems: (1) Intrinsic 3D asymmetry; (2) Tolerance to nonideal 3D effects (e.g. laser power balance, pointing errors); and (3) Synthetic diagnostics.

  5. NIF Target Assembly Metrology Methodology and Results

    Energy Technology Data Exchange (ETDEWEB)

    Alger, E. T. [General Atomics, San Diego, CA (United States); Kroll, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dzenitis, E. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Montesanti, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hughes, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Swisher, M. [IAP, Livermore, CA (United States); Taylor, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Segraves, K. [IAP, Livermore, CA (United States); Lord, D. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Castro, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Edwards, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-01-01

    During our inertial confinement fusion (ICF) experiments at the National Ignition Facility (NIF) we require cryogenic targets at the 1-cm scale to be fabricated, assembled, and metrologized to micron-level tolerances. During assembly of these ICF targets, there are physical dimensmetrology is completed using optical coordinate measurement machines that provide repeatable measurements with micron precision, while also allowing in-process data collection for absolute accuracy in assembly. To date, 51 targets have been assembled and metrologized, and 34 targets have been successfully fielded on NIF relying on these metrology data. In the near future, ignition experiments on NIF will require tighter tolerances and more demanding target assembly and metrology capability. Metrology methods, calculations, and uncertainty estimates will be discussed. Target diagnostic port alignment, target position, and capsule location results will be reviewed for the 2009 Energetics Campaign. The information is presented via control charts showing the effect of process improvements that were made during target production. Certain parameters, including capsule position, met the 2009 campaign specifications but will have much tighter requirements in the future. Finally, in order to meet these new requirements assembly process changes and metrology capability upgrades will be necessary.

  6. Target diagnostic system for the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Leeper, R.J.; Chandler, G.A.; Cooper, G.W.; Derzon, M.S.

    1996-01-01

    A review of recent progress on the design of a diagnostic system proposed for ignition target experiments on the National Ignition Facility (NIF) will be presented. This diagnostic package contains an extensive suite of optical, x-ray, gamma-ray, and neutron diagnostics that enable measurements of the performance of both direct and indirect driven NIF targets. The philosophy used in designing all of the diagnostics in the set has emphasized redundant and independent measurement of fundamental physical quantities relevant to the operation of the NIF target. A unique feature of these diagnostics is that they are being designed to be capable of operating, in the high radiation, EMP, and debris backgrounds expected on the NIF facility. The diagnostic system proposed can be categorized into three broad areas: laser characterization, hohlraum characterization, and capsule performance diagnostics. The operating principles of a representative instrument from each class of diagnostic employed in this package will be summarized and illustrated with data obtained in recent prototype diagnostic tests

  7. Target Diagnostics Supports NIF's Path to Ignition

    International Nuclear Information System (INIS)

    Shelton, R.

    2011-01-01

    The physics requirements derived from the National Ignition Facility (NIF) experimental campaigns are leading to a wide variety of target diagnostics. Software development for the control and analysis of these diagnostics is included in the NIF Integrated Computer Control System, Diagnostic Control System and Data Visualization. These projects implement the configuration, controls, data analysis and visual representation of most of these diagnostics. To date, over 40 target diagnostics have been developed to support NIF experiments. In 2011 diagnostics were developed or enhanced to measure Ignition performance in a high neutron yield environment. Performance is optimized around four key variables: Adiabat (a) which is the strength and timing of four shocks delivered to the target, Velocity (V) of the imploding target, Mix (M) is the uniformity of the burn, and the Shape (S) of the imploding Deuterium Tritium (DT) hot spot. The diagnostics used to measure each of these parameters is shown in figure 1. Adiabat is measured using the Velocity Interferometer System for Any Reflector (VISAR) diagnostic consisting of three streak cameras. To provide for more accurate adiabat measurements the VISAR streak cameras were enhanced in FY11 with a ten comb fiducial signal controller to allow for post shot correction of the streak camera sweep non-linearity. Mix is measured by the Neutron Time of Flight (NTOF) and Radiochemical Analysis of Gaseous Samples (RAGS) diagnostics. To accommodate high neutron yield shots, NTOF diagnostic controls are being modified to use Mach Zehnder interferometer signals to allow the digitizers to be moved from near the target chamber to the neutron shielded diagnostic mezzanine. In December 2011 the first phase of RAGS diagnostic commissioning will be completed. This diagnostic will analyze the tracers that are added to NIF target capsules that undergo nuclear reactions during the shot. These gases are collected and purified for nuclear counting by

  8. NIF target fill, transport and insertion cryostat

    International Nuclear Information System (INIS)

    Warren, R.

    1994-01-01

    A cryostat to support the fielding of a cryogenic target within the NIF is described. The present design is predicated upon fuel layer symmetry being achieved with the β layering process and modifications needed for other fuel symmetrization processes are discussed. These include the vertically differentially heated capsule with a uniform liquid layer stabilized by a surface tension gradient, foam supported liquid layers and solid D 2 or HD layers symmetrized by bulk irradiation from a laser source. The cold sinks to be incorporated in these techniques could, in principal, be cooled with the high pressure helium envisioned for the heat sink rings of the present design. Supplementary laser access would be provided for differential heating of the capsule for surface tension gradient stabilization of a liquid layer or bulk heating of a solid layer. The cryostat in each of these cases would look substantially the same as in the present case with the only significant differences being in the details of the design in the immediate vicinity of the target

  9. Backscatter measurements for NIF ignition targets (invited).

    Science.gov (United States)

    Moody, J D; Datte, P; Krauter, K; Bond, E; Michel, P A; Glenzer, S H; Divol, L; Niemann, C; Suter, L; Meezan, N; MacGowan, B J; Hibbard, R; London, R; Kilkenny, J; Wallace, R; Kline, J L; Knittel, K; Frieders, G; Golick, B; Ross, G; Widmann, K; Jackson, J; Vernon, S; Clancy, T

    2010-10-01

    Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of ∼15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.

  10. Backscatter measurements for NIF ignition targets (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Moody, J. D.; Datte, P.; Krauter, K.; Bond, E.; Michel, P. A.; Glenzer, S. H.; Divol, L.; Suter, L.; Meezan, N.; MacGowan, B. J.; Hibbard, R.; London, R.; Kilkenny, J.; Wallace, R.; Knittel, K.; Frieders, G.; Golick, B.; Ross, G.; Widmann, K.; Jackson, J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); and others

    2010-10-15

    Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of {approx}15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.

  11. Backscatter measurements for NIF ignition targets (invited)

    International Nuclear Information System (INIS)

    Moody, J. D.; Datte, P.; Krauter, K.; Bond, E.; Michel, P. A.; Glenzer, S. H.; Divol, L.; Suter, L.; Meezan, N.; MacGowan, B. J.; Hibbard, R.; London, R.; Kilkenny, J.; Wallace, R.; Knittel, K.; Frieders, G.; Golick, B.; Ross, G.; Widmann, K.; Jackson, J.

    2010-01-01

    Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near backscatter imager (NBI) instrument separately measure the stimulated Brillouin and stimulated Raman scattered light. Both instruments work in conjunction to determine the total backscattered power to an accuracy of ∼15%. In order to achieve the power accuracy we have added time-resolution to the NBI for the first time. This capability provides a temporally resolved spatial image of the backscatter which can be viewed as a movie.

  12. Advances in target design and fabrication for experiments on NIF

    Directory of Open Access Journals (Sweden)

    Obrey K.

    2013-11-01

    Full Text Available The ability to build target platforms for National Ignition Facility (NIF is a key feature in LANL's (Los Alamos National Laboratory Target Fabrication Program. We recently built and manufactured the first LANL targets to be fielded on NIF in March 2011. Experiments on NIF require precision component manufacturing and accurate knowledge of the materials used in the targets. The characterization of foams and aerogels, the Be ignition capsule, and machining unique components are of main material focus. One important characterization metric the physics' have determined is that the knowledge of density gradients in foams is important. We are making strides in not only locating these density gradients in aerogels and foams as a result of how they are manufactured and machined but also quantifying the density within the foam using 3D confocal micro x-ray fluorescence (μXRF imaging and 3D x-ray computed tomography (CT imaging. In addition, collaborative efforts between General Atomics (GA and LANL in the characterization of the NIF Ignition beryllium capsule have shown that the copper in the capsule migrates radially from the capsule center.

  13. Quantifying design trade-offs of beryllium targets on NIF

    Science.gov (United States)

    Yi, S. A.; Zylstra, A. B.; Kline, J. L.; Loomis, E. N.; Kyrala, G. A.; Shah, R. C.; Perry, T. S.; Kanzleiter, R. J.; Batha, S. H.; MacLaren, S. A.; Ralph, J. E.; Masse, L. P.; Salmonson, J. D.; Tipton, R. E.; Callahan, D. A.; Hurricane, O. A.

    2017-10-01

    An important determinant of target performance is implosion kinetic energy, which scales with the capsule size. The maximum achievable performance for a given laser is thus related to the largest capsule that can be imploded symmetrically, constrained by drive uniformity. A limiting factor for symmetric radiation drive is the ratio of hohlraum to capsule radii, or case-to-capsule ratio (CCR). For a fixed laser energy, a larger hohlraum allows for driving bigger capsules symmetrically at the cost of reduced peak radiation temperature (Tr). Beryllium ablators may thus allow for unique target design trade-offs due to their higher ablation efficiency at lower Tr. By utilizing larger hohlraum sizes than most modern NIF designs, beryllium capsules thus have the potential to operate in unique regions of the target design parameter space. We present design simulations of beryllium targets with a large CCR = 4.3 3.7 . These are scaled surrogates of large hohlraum low Tr beryllium targets, with the goal of quantifying symmetry tunability as a function of CCR. This work performed under the auspices of the U.S. DOE by LANL under contract DE-AC52- 06NA25396, and by LLNL under Contract DE-AC52-07NA27344.

  14. 3D studies of the NIF symmetry tuning targets

    Science.gov (United States)

    Milovich, J.; Jones, O.; Edwards, M.; Weber, S.; Dewald, E.; Landen, O.; Marinak, M.

    2009-11-01

    Minimizing radiation drive asymmetries is necessary for a successful ignition campaign. Since the ignition capsule symmetry is most sensitive to the foot (first 2 ns) and the peak of the laser pulse, two different targets will be fielded on the NIF: re-emit and symmetry capsules (Sym-Caps). The first measures the incoming flux asymmetries during the foot by observing the re-radiated flux of a high-Z ball in place of the ignition capsule. The Sym-Caps resemble the ignition target with the frozen DT layer replaced by an equivalent mass of ablator material, thus preserving the hydrodynamic implosion properties. By measuring the x-ray self-emission near peak compression the ignition capsule core shape can be tuned. Simulations with 2D radiation-hydrodynamic simulations codes omit 3D effects in the hohlraum such as diagnostic holes, capsule roughness, shot-to-shot variations caused by laser beam power imbalances and pointing errors. We study these effects by performing 3D simulations using HYDRA and found that tuning the laser pulse using a finite number of shots is not substantially compromised.

  15. D2 and DT Liquid-Layer Target Shots on NIF

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Curtis [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alger, Ethan [General Atomics, San Diego, CA (United States); Bhandarkar, Suhas [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Boehm, Kurt [General Atomics, San Diego, CA (United States); Braun, Tom [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Espinosaloza, Francisco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haid, Benjamin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Heredia, Ricardo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kline, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kozioziemski, Bernard [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kroll, Jeremy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Malone, Daniel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nikroo, Abbas [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Opsahl, Patrick [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sater, James [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zylstra, Alex [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-22

    Experiments at the National Ignition Facility (NIF) using targets containing a Deuterium-Tritium (DT) fuel layer have, until recently, required that a high-quality layer of solid deuterium-tritium (herein referred to as an "ice-layer") be formed in the capsule. The development of a process to line the inner surface of a target capsule with a foam layer of a thickness that is typical of icelayers has resulted in the ability to field targets with liquid layers wetting the foam. Successful fielding of liquid-layer targets on NIF required not only a foam lined capsule, but also changes to the capsule filling process and the manner with which the inventory is maintained in the capsule. Additionally, changes to target heater power and the temperature drops across target components were required in order to achieve the desired range of shot temperatures. These changes, and the target's performance during four target shots on NIF will be discussed.

  16. Laser coupling to reduced-scale targets at Nif Early Light

    Energy Technology Data Exchange (ETDEWEB)

    Hinkel, D.E.; Schneider, M.B.; Young, B.K.; Holder, J.P.; Langdon, A.B.; Bonanno, G.; Bower, D.E.; Bruns, H.C.; Campbell, K.M.; Celeste, J.R.; Compton, S.; Costa, R.L.; Dewald, E.L.; Dixit, S.N.; Eckart, M.J.; Eder, D.C.; Edwards, M.J.; Ellis, A.D.; Emig, J.A.; Froula, D.H.; Glenzer, S.H.; Hargrove, D.; Haynam, C.A.; Heeter, R.F.; Henesian, M.A.; Holtmeier, G.; James, D.L.; Jancaitis, K.S.; Kalantar, K.H.; Kamperschroer, J.H.; Kauffman, R.L.; Kimbrough, J.; Kirkwood, R.K.; Koniges, A.E.; Landen, O.L.; Landon, M.; Lee, F.D.; MacGowan, B.J.; Mackinnon, A.J.; Manes, K.R.; Marshall, C.; May, M.J.; McDonald, J.W.; Menapace, J.; Moses, S.E.I.; Munro, D.H.; Murray, J.R.; Niemann, C.; Power, G.D.; Rekow, V.; Ruppe, J.A.; Schein, J.; Shepherd, R.; Singh, M.S.; Springer, P.T.; Still, C.H.; Suter, L.J.; Tietbohl, G.L.; Turner, R.E.; VanWonterghem, B.M.; Wallace, R.J.; Warrick, A.; Weber, F.; Wegner, P.J.; Williams, E.A.; Young, P.E. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Baldis, H.A. [California at Davis Univ., CA (United States); Pellinen, D.; Watts, P. [Bechtel Nevada Corporation, Livermore, CA (United States)

    2006-06-15

    Deposition of maximum laser energy into a small, high-Z enclosure in a short laser pulse creates a hot environment. Such targets were recently included in an experimental campaign using the first four of the 192 beams of the National Ignition Facility (NIF) under construction at the University of California Lawrence Livermore National Laboratory. These targets demonstrate good laser coupling, reaching a radiation temperature of 340 eV. In addition, the Raman backscatter spectrum contains features consistent with Brillouin backscatter of Raman forward scatter. Also, NIF Early Light diagnostics indicate that 20% of the direct backscatter from these reduced-scale targets is in the polarization orthogonal to that of the incident light. (authors)

  17. Enhancing Ignition Probability and Fusion Yield in NIF Indirect Drive Targets with Applied Magnetic Fields

    Science.gov (United States)

    Perkins, L. John; Logan, B. Grant; Ho, Darwin; Zimmerman, George; Rhodes, Mark; Blackfield, Donald; Hawkins, Steven

    2017-10-01

    Imposed magnetic fields of tens of Tesla that increase to greater than 10 kT (100 MGauss) under capsule compression may relax conditions for ignition and propagating burn in indirect-drive ICF targets. This may allow attainment of ignition, or at least significant fusion energy yields, in presently-performing ICF targets on the National Ignition Facility that today are sub-marginal for thermonuclear burn through adverse hydrodynamic conditions at stagnation. Results of detailed 2D radiation-hydrodynamic-burn simulations applied to NIF capsule implosions with low-mode shape perturbations and residual kinetic energy loss indicate that such compressed fields may increase the probability for ignition through range reduction of fusion alpha particles, suppression of electron heat conduction and stabilization of higher-mode RT instabilities. Optimum initial applied fields are around 50 T. Off-line testing has been performed of a hohlraum coil and pulsed power supply that could be integrated on NIF; axial fields of 58T were obtained. Given the full plasma structure at capsule stagnation may be governed by 3-D resistive MHD, the formation of closed magnetic field lines might further augment ignition prospects. Experiments are now required to assess the potential of applied magnetic fields to NIF ICF ignition and burn. Work performed under auspices of U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

  18. High-resolution 3D simulations of NIF ignition targets performed on Sequoia with HYDRA

    Science.gov (United States)

    Marinak, M. M.; Clark, D. S.; Jones, O. S.; Kerbel, G. D.; Sepke, S.; Patel, M. V.; Koning, J. M.; Schroeder, C. R.

    2015-11-01

    Developments in the multiphysics ICF code HYDRA enable it to perform large-scale simulations on the Sequoia machine at LLNL. With an aggregate computing power of 20 Petaflops, Sequoia offers an unprecedented capability to resolve the physical processes in NIF ignition targets for a more complete, consistent treatment of the sources of asymmetry. We describe modifications to HYDRA that enable it to scale to over one million processes on Sequoia. These include new options for replicating parts of the mesh over a subset of the processes, to avoid strong scaling limits. We consider results from a 3D full ignition capsule-only simulation performed using over one billion zones run on 262,000 processors which resolves surface perturbations through modes l = 200. We also report progress towards a high-resolution 3D integrated hohlraum simulation performed using 262,000 processors which resolves surface perturbations on the ignition capsule through modes l = 70. These aim for the most complete calculations yet of the interactions and overall impact of the various sources of asymmetry for NIF ignition targets. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

  19. NIF pointing and centering systems and target alignment using a 351 nm laser source

    International Nuclear Information System (INIS)

    Boege, S.J.; Bliss, E.S.; Chocol, C.J.; Holdener, F.R.; Miller, J.L.; Toeppen, J.S.; Vann, C.S.; Zacharias, R.A.

    1996-10-01

    The operational requirements of the National Ignition Facility (NIF) place tight constraints upon its alignment system. In general, the alignment system must establish and maintain the correct relationships between beam position, beam angle, laser component clear apertures, and the target. At the target, this includes adjustment of beam focus to obtain the correct spot size. This must be accomplished for all beamlines in a time consistent with planned shot rates and yet, in the front end and main laser, beam control functions cannot be initiated until the amplifiers have sufficiently cooled so as to minimize dynamic thermal distortions during and after alignment and wavefront optimization. The scope of the task dictates an automated system that implements parallel processes. We describe reticle choices and other alignment references, insertion of alignment beams, principles of operation of the Chamber Center Reference System 2048 and Target Alignment Sensor, and the anticipated alignment sequence that will occur between shots

  20. Laser coupling to reduced-scale targets at NIF Early Light

    International Nuclear Information System (INIS)

    Hinkel, D E; Schneider, M B; Young, B K; Holder, J P; Langdon, A B; Baldis, H A; Bonanno, G; Bower, D E; Bruns, H C; Campbell, K M; Celeste, J R; Compton, S; Costa, R L; Dewald, E L; Dixit, S N; Eckart, M J; Eder, D C; Edwards, M J; Ellis, A D; Emig, J A; Froula, D H; Glenzer, S H; Hargrove, D; Haynam, C A; Heeter, R F; Henesian, M A; Holtmeier, G; James, D L; Jancaitis, K S; Kalantar, D H; Kamperschroer, J H; Kauffman, R L; Kimbrough, J; Kirkwood, R K; Koniges, A E; Landen, O L; Landon, M; Lee, F D; MacGowan, B J; Mackinnon, A J; Manes, K R; Marshall, C; May, M J; McDonald, J W; Menapace, J; Moses, S I; Munro, D H; Murray, J R; Niemann, C; Pellinen, D; Power, G D; Rekow, V; Ruppe, J A; Schein, J; Shepherd, R; Singh, M S; Springer, P; Still, C H; Suter, L J; Tietbohl, G L; Turner, R E; VanWonterghem, B M; Wallace, R J; Warrick, A; Watts, P; Weber, F; Wegner, P J; Williams, E A; Young, P E

    2005-01-01

    Deposition of maximum laser energy into a small, high-Z enclosure in a short laser pulse creates a hot environment. Such targets were recently included in an experimental campaign using the first four of the 192 beams of the National Ignition Facility [J. A. Paisner, E. M. Campbell, and W. J. Hogan, Fusion Technology 26 26, 755 (1994)], under construction at the University of California Lawrence Livermore National Laboratory. These targets demonstrate good laser coupling, reaching a radiation temperature of 340 eV. In addition, the Raman backscatter spectrum contains features consistent with Brillouin backscatter of Raman forward scatter [A. B. Langdon and D. E. Hinkel, Physical Review Letters 89, 015003 (2002)]. Also, NIF Early Light diagnostics indicate that 20% of the direct backscatter from these reduced-scale targets is in the polarization orthogonal to that of the incident light

  1. Controlled expression of nif and isc iron-sulfur protein maturation components reveals target specificity and limited functional replacement between the two systems.

    Science.gov (United States)

    Dos Santos, Patricia C; Johnson, Deborah C; Ragle, Brook E; Unciuleac, Mihaela-Carmen; Dean, Dennis R

    2007-04-01

    The nitrogen-fixing organism Azotobacter vinelandii contains at least two systems that catalyze formation of [Fe-S] clusters. One of these systems is encoded by nif genes, whose products supply [Fe-S] clusters required for maturation of nitrogenase. The other system is encoded by isc genes, whose products are required for maturation of [Fe-S] proteins that participate in general metabolic processes. The two systems are similar in that they include an enzyme for the mobilization of sulfur (NifS or IscS) and an assembly scaffold (NifU or IscU) upon which [Fe-S] clusters are formed. Normal cellular levels of the Nif system, which supplies [Fe-S] clusters for the maturation of nitrogenase, cannot also supply [Fe-S] clusters for the maturation of other cellular [Fe-S] proteins. Conversely, when produced at the normal physiological levels, the Isc system cannot supply [Fe-S] clusters for the maturation of nitrogenase. In the present work we found that such target specificity for IscU can be overcome by elevated production of NifU. We also found that NifU, when expressed at normal levels, is able to partially replace the function of IscU if cells are cultured under low-oxygen-availability conditions. In contrast to the situation with IscU, we could not establish conditions in which the function of IscS could be replaced by NifS. We also found that elevated expression of the Isc components, as a result of deletion of the regulatory iscR gene, improved the capacity for nitrogen-fixing growth of strains deficient in either NifU or NifS.

  2. Mini-chamber, an advanced protection concept for NIF

    International Nuclear Information System (INIS)

    Peterson, P.F.; Scott, J.M.

    1996-01-01

    Inertial confinement fusion (ICF) target debris and ablated near-target materials pose the primary threat to the National Ignition Facility (NIF) final optics debris shields, as well as a major challenge in future inertial fusion energy (IFE) power plants. This work discusses a NIF 'mini-chamber,' designed to mitigate the debris threat. Although the NIF base-line design protects against debris using a frost-protected target positioner and refractory first-wall coatings, the mini-chamber provides important flexibility in three areas: debris-shield protection from beyond-design basis shots (i.e. heavy hohlraums, special diagnostics, shields); fielding of large experiments with significant surface ablation; and studying key ablation and gas-dynamics issues for liquid-wall IFE power plants. Key mini-chamber modeling results are presented, followed by discussion of equipment requirements for fielding a NIF mini-chamber. 7 refs., 3 figs

  3. X-ray flux and X-ray burn through experiments on reduced-scale targets at the Nif and OMEGA lasers

    International Nuclear Information System (INIS)

    Schneider, M.B.; Hinkel, D.E.; Young, B.K.; Holder, J.P.; Langdon, A.B.; Bower, D.E.; Bruns, H.C.; Campbell, K.M.; Celeste, J.R.; Compton, S.; Costa, R.L.; Dewald, E.L.; Dixit, S.N.; Eckart, M.J.; Eder, D.C.; Edwards, M.J.; Ellis, A.D.; Emig, J.A.; Froula, D.H.; Glebov, V.; Glenzer, S.H.; Hargrove, D.; Haynam, C.A.; Heeter, R.F.; Henesian, M.A.; Holtmeier, G.; James, D.L.; Jancaitis, K.S.; Kalantar, D.H.; Kamperschroer, J.H.; Kauffman, R.L.; Kimbrough, J.; Kirkwood, R.; Koniges, A.E.; Landen, O.L.; Landon, M.; Lee, F.D.; MacGowan, B.J.; Mackinnon, A.J.; Manes, K.R.; Marshall, C.; May, M.J.; McDonald, J.W.; Menapace, J.; Moon, S.J.; Moses, E.I.; Munro, D.H.; Murray, J.R.; Niemann, C.; Piston, K.; Power, G.D.; Rekow, V.; Ruppe, J.A.; Schein, J.; Shepherd, R.; Singh, M.S.; Sorce, C.; Springer, P.T.; Still, C.H.; Suter, L.J.; Tietbohl, G.L.; Turner, R.E.; Van Wonterghem, B.M.; Wallace, R.J.; Warrick, A.; Weber, F.; Wegner, P.J.; Williams, E.A.; Young, P.E.; Baldis, H.A.; Constantin, C.G.; Bahr, R.; Roberts, S.; Seka, W.; Stoeckl, C.; Pellinen, D.; Watts, P.

    2006-01-01

    An experimental campaign to maximize radiation drive in small-scale hohlraums has been carried out at the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (Livermore, USA) and at the OMEGA laser at the Laboratory for Laser Energetics (Rochester, USA). The small-scale hohlraums, laser energy, laser pulse, and diagnostics were similar at both facilities but the geometries were very different. The NIF experiments used on-axis laser beams whereas the OMEGA experiments used 19 beams in three beam cones. In the cases when the lasers coupled well and produced similar radiation drive, images of X-ray burn-through and laser deposition indicate the pattern of plasma filling is very different. The OMEGA targets fill faster than the NIF targets, which helps explain the time behavior of the X-ray fluences. (authors)

  4. X-ray flux and X-ray burn through experiments on reduced-scale targets at the Nif and OMEGA lasers

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.B.; Hinkel, D.E.; Young, B.K.; Holder, J.P.; Langdon, A.B.; Bower, D.E.; Bruns, H.C.; Campbell, K.M.; Celeste, J.R.; Compton, S.; Costa, R.L.; Dewald, E.L.; Dixit, S.N.; Eckart, M.J.; Eder, D.C.; Edwards, M.J.; Ellis, A.D.; Emig, J.A.; Froula, D.H.; Glebov, V.; Glenzer, S.H.; Hargrove, D.; Haynam, C.A.; Heeter, R.F.; Henesian, M.A.; Holtmeier, G.; James, D.L.; Jancaitis, K.S.; Kalantar, D.H.; Kamperschroer, J.H.; Kauffman, R.L.; Kimbrough, J.; Kirkwood, R.; Koniges, A.E.; Landen, O.L.; Landon, M.; Lee, F.D.; MacGowan, B.J.; Mackinnon, A.J.; Manes, K.R.; Marshall, C.; May, M.J.; McDonald, J.W.; Menapace, J.; Moon, S.J.; Moses, E.I.; Munro, D.H.; Murray, J.R.; Niemann, C.; Piston, K.; Power, G.D.; Rekow, V.; Ruppe, J.A.; Schein, J.; Shepherd, R.; Singh, M.S.; Sorce, C.; Springer, P.T.; Still, C.H.; Suter, L.J.; Tietbohl, G.L.; Turner, R.E.; Van Wonterghem, B.M.; Wallace, R.J.; Warrick, A.; Weber, F.; Wegner, P.J.; Williams, E.A.; Young, P.E. [Lawrence Livermore National Lab., Livermore, CA (United States); Baldis, H.A.; Constantin, C.G. [California at Davis Univ., CA (United States); Bahr, R.; Roberts, S.; Seka, W.; Stoeckl, C. [Laboratory for Laser Energetics, Rochester, NY (United States); Pellinen, D.; Watts, P. [Bechtel Nevada Corporation, Livermore, CA (United States)

    2006-06-15

    An experimental campaign to maximize radiation drive in small-scale hohlraums has been carried out at the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (Livermore, USA) and at the OMEGA laser at the Laboratory for Laser Energetics (Rochester, USA). The small-scale hohlraums, laser energy, laser pulse, and diagnostics were similar at both facilities but the geometries were very different. The NIF experiments used on-axis laser beams whereas the OMEGA experiments used 19 beams in three beam cones. In the cases when the lasers coupled well and produced similar radiation drive, images of X-ray burn-through and laser deposition indicate the pattern of plasma filling is very different. The OMEGA targets fill faster than the NIF targets, which helps explain the time behavior of the X-ray fluences. (authors)

  5. Automated alignment of the Advanced Radiographic Capability (ARC) target area at the National Ignition Facility

    Science.gov (United States)

    Roberts, Randy S.; Awwal, Abdul A. S.; Bliss, Erlan S.; Heebner, John E.; Leach, Richard R.; Orth, Charles D.; Rushford, Michael C.; Lowe-Webb, Roger R.; Wilhelmsen, Karl C.

    2015-09-01

    The Advanced Radiographic Capability (ARC) at the National Ignition Facility (NIF) is a petawatt-class, short-pulse laser system designed to provide x-ray backlighting of NIF targets. ARC uses four NIF beamlines to produce eight beamlets to create a sequence of eight images of an imploding fuel capsule using backlighting targets and diagnostic instrumentation. ARC employs a front end that produces two pulses, chirps the pulses out to 2 ns, and then injects the pulses into the two halves of each of four NIF beamlines. These pulses are amplified by NIF pre- and main amplifiers and transported to compressor vessels located in the NIF target area. The pulses are then compressed and pointed into the NIF target chamber where they impinge upon an array of backlighters. The interaction of the ARC laser pulses and the backlighting material produces bursts of high-energy x-rays that illuminate an imploding fuel capsule. The transmitted x-rays are imaged by diagnostic instrumentation to produce a sequence of radiograph images. A key component of the success of ARC is the automatic alignment system that accomplishes the precise alignment of the beamlets to avoid damaging equipment and to ensure that the beamlets are directed onto the tens-of-microns scale backlighters. In this paper, we describe the ARC automatic alignment system, with emphasis on control loops used to align the beampaths. We also provide a detailed discussion of the alignment image processing, because it plays a critical role in providing beam centering and pointing information for the control loops.

  6. National Ignition Facility subsystem design requirements target area auxiliary subsystem SSDR 1.8.6

    International Nuclear Information System (INIS)

    Reitz, T.

    1996-01-01

    This Subsystem Design Requirement (SSDR) establishes the performance, design, development, and test requirements for the Target Area Auxiliary Subsystems (WBS 1.8.6), which is part of the NIF Target Experimental System (WBS 1.8). This document responds directly to the requirements detailed in NIF Target Experimental System SDR 003 document. Key elements of the Target Area Auxiliary Subsystems include: WBS 1.8.6.1 Local Utility Services; WBS 1.8.6.2 Cable Trays; WBS 1.8.6.3 Personnel, Safety, and Occupational Access; WBS 1.8.6.4 Assembly, Installation, and Maintenance Equipment; WBS 1.8.6.4.1 Target Chamber Service System; WBS 1.8.6.4.2 Target Bay Service Systems

  7. Investigation of the possibility of gamma-ray diagnostic imaging of target compression at NIF.

    Science.gov (United States)

    Lemieux, Daniel A; Baudet, Camille; Grim, Gary P; Barber, H Bradford; Miller, Brian W; Fasje, David; Furenlid, Lars R

    2011-09-23

    The National Ignition Facility at Lawrence Livermore National Laboratory is the world's leading facility to study the physics of igniting plasmas. Plasmas of hot deuterium and tritium, undergo d(t,n)α reactions that produce a 14.1 MeV neutron and 3.5 MeV a particle, in the center of mass. As these neutrons pass through the materials surrounding the hot core, they may undergo subsequent (n,x) reactions. For example, (12)C(n,n'γ)(12)C reactions occur in remnant debris from the polymer ablator resulting in a significant fluence of 4.44 MeV gamma-rays. Imaging of these gammas will enable the determination of the volumetric size and symmetry of the ablation; large size and high asymmetry is expected to correlate with poor compression and lower fusion yield. Results from a gamma-ray imaging system are expected to be complimentary to a neutron imaging diagnostic system already in place at the NIF. This paper describes initial efforts to design a gamma-ray imaging system for the NIF using the existing neutron imaging system as a baseline for study. Due to the cross-section and expected range of ablator areal densities, the gamma flux should be approximately 10(-3) of the neutron flux. For this reason, care must be taken to maximize the efficiency of the gamma-ray imaging system because it will be gamma starved. As with the neutron imager, use of pinholes and/or coded apertures are anticipated. Along with aperture and detector design, the selection of an appropriate scintillator is discussed. The volume of energy deposition of the interacting 4.44 MeV gamma-rays is a critical parameter limiting the imaging system spatial resolution. The volume of energy deposition is simulated with GEANT4, and plans to measure the volume of energy deposition experimentally are described. Results of tests on a pixellated LYSO scintillator are also presented.

  8. Update on design simulations for NIF ignition targets, and the roll-up of all specifications into an error budget

    International Nuclear Information System (INIS)

    Haan, S.W.; Herrmann, M.C.; Salmonson, J.D.; Amendt, P.A.; Callahan, D.A.; Dittrich, T.R.; Edwards, M.J.; Jones, O.S.; Marinak, M.M.; Munro, D.H.; Pollaine, S.M.; Spears, B.K.; Suter, L.J.

    2007-01-01

    Targets intended to produce ignition on NIF are being simulated and the simulations are used to set specifications for target fabrication and other program elements. Recent design work has focused on designs that assume only 1.0 MJ of laser energy instead of the previous 1.6 MJ. To perform with less laser energy, the hohlraum has been redesigned to be more efficient than previously, and the capsules are slightly smaller. Three hohlraum designs are being examined: gas fill, SiO 2 foam fill, and SiO 2 lined. All have a cocktail wall, and shields mounted between the capsule and the laser entrance holes. Two capsule designs are being considered. One has a graded doped Be(Cu) ablator, and the other graded doped CH(Ge). Both can perform acceptably with recently demonstrated ice layer quality, and with recently demonstrated outer surface roughness. Complete tables of specifications are being prepared for both targets, to be completed this fiscal year. All the specifications are being rolled together into an error budget indicating adequate margin for ignition with the new designs. The dominant source of error is hohlraum asymmetry at intermediate modes 4-8, indicating the importance of experimental techniques to measure and control this asymmetry. (authors)

  9. Impact of neutron and gamma radiation on the design of NIF diagnostics and target-bay systems

    Energy Technology Data Exchange (ETDEWEB)

    Eder, D.C.; Song, P.M.; Latkowski, J.F.; Reyes, S.; O' Brien, D.W.; Lee, F.D.; Young, B.K.; Koch, J.A.; Moran, M.J.; Watts, P.W.; Kimbrough, J.R.; Ng, E.W.; Landen, O.L.; MacGowan, B.J. [Lawrence Livermore National Lab., Livermore, CA (United States)

    2006-06-15

    The design of a wide range of components in and near the target bay of the National Ignition Facility (NIF) must allow for significant radiation from neutrons and gammas. Detailed 3-dimensional Monte Carlo simulations are critical to determine neutron and gamma fluxes for all target-bay components to allow optimization of location and auxiliary shielding. Demonstration of ignition poses unique challenges because of the large range (about 3 orders of magnitude) in the yield for any given attempt at ignition. Some diagnostics will provide data independent of yield, while others will provide data for lower yields and only survive high yields with little or no damage. In addition, for a given yield there is a more than 10 orders of magnitude range in neutron and gamma fluxes depending on location in the facility. For example, sensitive components in the diagnostic mezzanines and switchyards require auxiliary shielding for high-yield shots even though they are greater than 17 meters from target chamber center (TCC) and shielded by the 2 m-thick target-bay wall. In contrast, there are components 0.2 to 2 m from TCC with little or no shielding. For these components, particular attention is being made to use low-activation material because of the extremely high neutron loading levels. Many of the components closest to target center are designed to be single use to reduce worker dose from having to refurbish highly activated components. The cryogenic target positioner is an example where activation and ease of component replacement is an important part of the design. We are developing a design process for all target-bay systems that will assure reliable operation for the full range of planned yields. (authors)

  10. Impact of neutron and gamma radiation on the design of NIF diagnostics and target-bay systems

    Science.gov (United States)

    Eder, D. C.; Song, P. M.; Latkowski, J. F.; Reyes, S.; O'Brien, D. W.; Lee, F. D.; Young, B. K.; Koch, J. A.; Moran, M. J.; Watts, P. W.; Kimbrough, J. R.; Ng, E. W.; Landen, O. L.; MacGowan, B. J.

    2006-06-01

    The design of a wide range of components in and near the target bay of the National Ignition Facility (NIF) must allow for significant radiation from neutrons and gammas. Detailed 3D Monte Carlo simulations are critical to determine neutron and gamma fluxes for all target-bay components to allow optimization of location and auxiliary shielding. Demonstration of ignition poses unique challenges because of the large range (˜ 3 orders of magnitude) in the yield for any given attempt at ignition. Some diagnostics will provide data independent of yield, while others will provide data for lower yields and only survive high yields with little or no damage. In addition, for a given yield there is a more than 10 orders of magnitude range in neutron and gamma fluxes depending on location in the facility. For example, sensitive components in the diagnostic mezzanines and switchyards require auxiliary shielding for high-yield shots even though they are greater than 17 meters from target chamber center (TCC) and shielded by the 2 m-thick target-bay wall. In contrast, there are components 0.2 to 2 m from TCC with little or no shielding. For these components, particular attention is being made to use low-activation material because of the extremely high neutron loading levels. Many of the components closest to target center are designed to be single use to reduce worker dose from having to refurbish highly activated components. The cryogenic target positioner is an example where activation and ease of component replacement is an important part of the design. We are developing a design process for all target-bay systems that will assure reliable operation for the full range of planned yields.

  11. Design of the target area for the National Ignition Facility

    International Nuclear Information System (INIS)

    Foley, R.J.; Karpenko, V.P.; Adams, C.H.

    1997-01-01

    The preliminary design of the target area for the National Ignition Facility has been completed. The target area is required to meet a challenging set of engineering system design requirements and user needs. The target area must provide the appropriate conditions before, during, and after each shot. The repeated introduction of large amounts of laser energy into the chamber and subsequent target emissions represent new design challenges for ICF facility design. Prior to each shot, the target area must provide the required target illumination, target chamber vacuum, diagnostics, and optically stable structures. During the shot, the impact of the target emissions on the target chamber, diagnostics, and optical elements is minimized and the workers and public are protected from excessive prompt radiation doses. After the shot, residual radioactivation is managed to allow the required accessibility. Diagnostic data is retrieved, operations and maintenance activities are conducted, and the facility is ready for the next shot. The target area subsystems include the target chamber, target positioner, structural systems, target diagnostics, environmental systems, and the final optics assembly. The engineering design of the major elements of the target area requires a unique combination of precision engineering, structural analysis, opto-mechanical design, random vibration suppression, thermal stability, materials engineering, robotics, and optical cleanliness. The facility has been designed to conduct both x- ray driven targets and to be converted at a later date for direct drive experiments. The NIF has been configured to provide a wide range of experimental environments for the anticipated user groups of the facility. The design status of the major elements of the target area is described

  12. Prospects for high-gain, high yield NIF targets driven by 2w (green) light

    International Nuclear Information System (INIS)

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

    2003-01-01

    A laser ablation/ionization mass spectrometer system is described for the direct analysis of solids, particles, and fibers. The system uses a quadrupole ion trap operated in an ion-storage (IS) mode, coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). The sample is inserted radially into the ring electrode and an imaging system allows direct viewing and selected analysis of the sample. Measurements identified trace contaminants of Ag, Sn, and Sb in a Pb target with single laser-shot experiments. Resolution (m/Δm) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described

  13. Color separation gratings for diverting the unconverted light away from the NIF target

    International Nuclear Information System (INIS)

    Dixit, S.N.; Rushford, M.C.; Thomas, I.M.; Herman, S.M.; Britten, J.A.; Shore, B.W.; Perry, M.D.

    1997-01-01

    Most of the glass laser based inertial confinement fusion systems around the world today employ non-linear frequency conversion for converting the 1.053 micrometer light at the fundamental frequency (referred to as 1ω light) to either its second harmonic (called 2ω) at 527 nm or to its third harmonic (called 3ω) at 351 nm. Shorter wavelengths are preferred for laser fusion because of the improved coupling of the laser light to the fusion targets due to reduced fast electron production at shorter wavelengths. The frequency conversion process, however, is only about 60-70% efficient and the residual 30-40% of the energy remains at 1ω and 2ω frequencies. Color separation gratings (CSGs) offer a versatile approach to reducing and possibly eliminating the unconverted light at the target region. A CSG consists of a three- level lamellar grating designed so that nearly all of the 3ω light passes through undiffracted while the residual 1ω and 2ω energy is diverted into higher diffraction orders. The diffraction angle is determined solely by the grating period. We have demonstrated the concept of using a color separation grating. We fabricated a 345 micrometer period CSG in fused silica using lithographic processes and wet etching. The measured far field indicates that greater than 95% of the incident light is preserved in the 3ω zeroth order while less than 5% of unconverted 1ω and 2ω light is remaining in the zeroth order. We would like to add that diffractive optics fabricated in fused silica by wet etching in hydrofluoric acid should have high damage threshold. Our experience suggests that the damage threshold of the etched substrate is at least as high as the unetched part. 6 refs., 4 figs., 1 tab

  14. Target experimental area and systems of the Us national ignition facility

    International Nuclear Information System (INIS)

    Tobin, M.; Van Wonterghem, B.; MacGowan, B.J.; Hibbard, W.; Kalantar, D.; Lee, F.D.; Pittenger, L.; Wong, K.

    2000-01-01

    One of the major goals of the US National Ignition Facility is the demonstration of laser driven fusion ignition and burn of targets by inertial confinement and provide capability for a wide variety of high energy density physics experiments. The NIF target area houses the optical systems required to focus the 192 beamlets to a target precisely positioned at the center of the 10 meter diameter, 10-cm thick aluminum target chamber. The chamber serves as mounting surface for the 48 final optics assemblies, the target alignment and positioning equipment, and the target diagnostics. The internal surfaces of the chamber are protected by louvered steel beam dumps. The target area also provides the necessary shielding against target emission and environmental protection equipment. Despite its complexity, the design provides the flexibility to accommodate the needs of the various NIF user groups, such as direct and indirect drive irradiation geometries, modular final optics design, capability to handle cryogenic targets, and easily re-configurable diagnostic instruments. Efficient target area operations are ensured by using line-replaceable designs for systems requiring frequent inspection, maintenance and reconfiguration, such as the final optics, debris shields, phase plates and the diagnostic instruments. A precision diagnostic instrument manipulator (DIMS) allows fast removal and precise repositioning of diagnostic instruments. In addition we will describe several activities to enhance the target chamber availability, such as the target debris mitigation, the use of standard experimental configurations and the development of smart shot operations planning tools. (authors)

  15. Target experimental area and systems of the U.S. National Ignition Facility

    International Nuclear Information System (INIS)

    Tobin, M; Van Wonterghem, B; MacGowan, B J; Hibbard, W; Kalantar, D; Lee, F D; Pittenger, L; Wong, K

    1999-01-01

    One of the major goals of the US National Ignition Facility is the demonstration of laser driven fusion ignition and burn of targets by inertial confinement and provide capability for a wide variety of high energy density physics experiments. The NIF target area houses the optical systems required to focus the 192 beamlets to a target precisely positioned at the center of the 10 meter diameter, 10-cm thick aluminum target chamber. The chamber serves as mounting surface for the 48 final optics assemblies, the target alignment and positioning equipment, and the target diagnostics. The internal surfaces of the chamber are protected by louvered steel beam dumps. The target area also provides the necessary shielding against target emission and environmental protection equipment. Despite its complexity, the design provides the flexibility to accommodate the needs of the various NIF user groups, such as direct and indirect drive irradiation geometries, modular final optics design, capability to handle cryogenic targets, and easily re-configurable diagnostic instruments. Efficient target area operations are ensured by using line-replaceable designs for systems requiring frequent inspection, maintenance and reconfiguration, such as the final optics, debris shields, phase plates and the diagnostic instruments. A precision diagnostic instrument manipulator (DIMS) allows fast removal and precise repositioning of diagnostic instruments. In addition the authors describe several activities to enhance the target chamber availability, such as the target debris mitigation, the use of standard experimental configurations and the development of smart shot operations planning tools

  16. Molecular Ecology of nifH Genes and Transcripts Along a Chronosequence in Revegetated Areas of the Tengger Desert.

    Science.gov (United States)

    Wang, Jin; Bao, Jing-Ting; Li, Xin-Rong; Liu, Yu-Bing

    2016-01-01

    The colonization and succession of diazotrophs are essential for the development of organic soil layers in desert. We examined the succession of diazotrophs in the well-established revegetated areas representing a chronosequence of 0 year (control), 22 years (restored artificially since 1981), 57 years (restored artificially since 1956), and more than 100 years (restored naturally) to determine the community assembly and active expression of diazotrophs. The pyrosequencing data revealed that Alphaproteobacteria-like diazotrophs predominated in the topsoil of our mobile dune site, while cyanobacterial diazotrophs predominated in the revegetated sites. The cyanobacterial diazotrophs were primarily composed of the heterocystous genera Anabaena, Calothrix, Cylindrospermum, Nodularia, Nostoc, Trichormus, and Mastigocladus. Almost all the nifH sequences belonged to the Cyanobacteria phylum (all the relative abundance values >99.1 %) at transcript level and all the active cyanobacterial diazotrophs distributed in the families Nostocaceae and Rivulariaceae. The most dominant active cyanobacterial genus was Cylindrospermum in all the samples. The rank abundance and community analyses demonstrated that most of the diazotrophic diversity originated from the "rare" species, and all the DNA-based diazotrophic libraries were richer and more diverse than their RNA-based counterparts in the revegetated sites. Significant differences in the diazotrophic community and their active population composition were observed among the four research sites. Samples from the 1981-revegetating site (predominated by cyanobacterial crusts) showed the highest nitrogenase activity, followed by samples from the naturally revegetating site (predominated by lichen crusts), the 1956-revegetating site (predominated by moss crusts), and the mobile dune site (without crusts). Collectively, our data highlight the importance of nitrogen fixation by the primary successional desert topsoil and suggest

  17. National NIF Diagnostic Program Interim Management Plan

    International Nuclear Information System (INIS)

    Warner, B

    2002-01-01

    The National Ignition Facility (NIF) has the mission of supporting Stockpile Stewardship and Basic Science research in high-energy-density plasmas. To execute those missions, the facility must provide diagnostic instrumentation capable of observing and resolving in time events and radiation emissions characteristic of the plasmas of interest. The diagnostic instrumentation must conform to high standards of operability and reliability within the NIF environment. These exacting standards, together with the facility mission of supporting a diverse user base, has led to the need for a central organization charged with delivering diagnostic capability to the NIF. The National NIF Diagnostics Program (NNDP) has been set up under the aegis of the NIF Director to provide that organization authority and accountability to the wide user community for NIF. The funds necessary to perform the work of developing diagnostics for NIF will be allocated from the National NIF Diagnostics Program to the participating laboratories and organizations. The participating laboratories and organizations will design, build, and commission the diagnostics for NIF. Restricted availability of funding has had an adverse impact, unforeseen at the time of the original decision to projectize NIF Core Diagnostics Systems and Cryogenic Target Handing Systems, on the planning and initiation of these efforts. The purpose of this document is to provide an interim project management plan describing the organizational structure and management processes currently in place for NIF Core Diagnostics Systems. Preparation of a Program Execution Plan for NIF Core Diagnostics Systems has been initiated and a current draft is provided as Attachment 1 to this document. The National NIF Diagnostics Program Interim Management Plan provides a summary of primary design criteria and functional requirements, current organizational structure, tracking and reporting procedures, and current planning estimates of project scope

  18. Optical alignment techniques for line-imaging velocity interferometry and line-imaging self-emulsion of targets at the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Malone, Robert M.; Frogget, Brent C.; Kaufman, Morris I.; Tunnell, Thomas W.; Guyton, Robert L.; Reinbachs, Imants P.; Watts, Phillip W.

    2007-01-01

    The National Ignition Facility (NIF) requires optical diagnostics for measuring shock velocities in shock physics experiments. The Velocity Interferometer System for Any Reflector (VISAR) measures shock velocities, shock breakout times, and emission of 1- to 5-mm targets at a location remote to the NIF target chamber. Three optical systems using the same vacuum chamber port each have a total track of 69 feet. All optical lenses are on kinematic mounts or sliding rails, enabling pointing accuracy of the optical axis to be checked. Counter-propagating laser beams (orange and red) align these diagnostics to a listing of tolerances. The orange alignment laser is introduced at the entrance to the two-level interferometer table and passes forward through the optical systems to the recording streak cameras. The red alignment laser is introduced in front of the recording streak cameras and passes in the reverse direction through all optical elements, out of the interferometer table, eventually reaching the target chamber center. Red laser wavelength is selected to be at the 50 percent reflection point of a special beamsplitter used to separate emission light from the Doppler-shifted interferometer light. Movable aperture cards, placed before and after lens groups, show the spread of alignments spots created by the orange and red alignment lasers. Optical elements include 1- to 15-inch-diameter mirrors, lenses with up to 10.5-inch diameters, beamsplitters, etalons, dove prisms, filters, and pellicles. Alignment of more than 75 optical elements must be verified before each target shot. Archived images from eight alignment cameras prove proper alignment before each shot

  19. NIF Operations Management Plan, August 2011

    Energy Technology Data Exchange (ETDEWEB)

    Van Wonterghem, Bruno M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility (NIF)

    2014-01-30

    Lawrence Livermore National Laboratory’s (LLNL) National Ignition Facility (NIF) is a key component of the National Nuclear Security Administration’s (NNSA) Stockpile Stewardship Program, whose purpose is to maintain the safety, reliability, and effectiveness of our nation’s nuclear stockpile without underground nuclear testing. The NIF is crucial to the Stockpile Stewardship Program because it is the only facility that can create the conditions of extreme temperature and pressure—conditions that exist only in stars or in exploding nuclear weapons—that are relevant to understanding how our modern nuclear weapons operate. As such, the NIF’s primary mission is to attain fusion ignition in the laboratory. Fusion ignition not only supports Stockpile Stewardship needs, but also provides the basis for future decisions about fusion’s potential as a long-term energy source. Additionally, NIF provides scientists with access to high-energy-density regimes that can yield new insight and understanding in the areas of astrophysics, hydrodynamics, material properties, plasma physics, and radiative properties. The use of the NIF to support the Stockpile Stewardship Program and the advancement of basic high-energy-density science understanding is planned and managed through program-level execution plans and NIF directorate-level management teams. An example of a plan is the National Ignition Campaign Execution Plan. The NIF Operations Management Plan provides an overview of the NIF Operations organization and describes how the NIF is supported by the LLNL infrastructure and how it is safely and responsibly managed and operated. Detailed information on NIF management of the organization is found in a series of supporting plans, policies, and procedures. A list of related acronyms can be found in Appendix A of this document. The purpose of this document is to provide a roadmap of how the NIF Operations organization functions. It provides a guide to understanding the

  20. NIF capsule performance modeling

    Directory of Open Access Journals (Sweden)

    Weber S.

    2013-11-01

    Full Text Available Post-shot modeling of NIF capsule implosions was performed in order to validate our physical and numerical models. Cryogenic layered target implosions and experiments with surrogate targets produce an abundance of capsule performance data including implosion velocity, remaining ablator mass, times of peak x-ray and neutron emission, core image size, core symmetry, neutron yield, and x-ray spectra. We have attempted to match the integrated data set with capsule-only simulations by adjusting the drive and other physics parameters within expected uncertainties. The simulations include interface roughness, time-dependent symmetry, and a model of mix. We were able to match many of the measured performance parameters for a selection of shots.

  1. February 2017 - NIF Highlights

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, K. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-13

    February was a very productive month with only 20 shot days on the calendar. There were 41 target shots performed for the HED, ICF, and the Discovery Science (DS) program. The DS program had a week dedicated to their experiments that was extraordinarily fruitful: 14 target shots were performed for five independent teams, each of whom had a unique experimental platform to field. The teams and the facility worked extraordinarily well to pull off this feat! Additionally, the facility developed high-energy laser operations on a demonstration quad to investigate taking NIF to a new level of performance, and the ICF program demonstrated a 40% increase in the yield from a capsule that had a new, 5-μm-diameter fill tube that apparently mitigates some of the issues that have affected implosions to date. Details follow below.

  2. The role of the NIF in the development of inertial fusion energy

    International Nuclear Information System (INIS)

    Logan, B.G.

    1995-01-01

    Recent decisions by DOE to proceed with the National Ignition Facility (NIF) and the first half of the Induction Systems Linac Experiments (ILSE) can provide the scientific basis for inertial fusion ignition and high-repetition heavy-ion driver physics, respectively. Both are critical to Inertial Fusion Energy (IFE). A conceptual design has been completed for a 1.8-MJ, 500-TW, 0.35-microm-solid-state laser system, the NIF. The NIF will demonstrate inertial fusion ignition and gain for national security applications, and for IFE development. It will support science applications using high-power lasers. The demonstration of inertial fusion ignition and gain, along with the parallel demonstration of the feasibility of an efficient, high-repetition-rate driver, would provide the basis for a follow-on Engineering Test Facility (ETF) identified in the National Energy Policy Act of 1992. The ETF would provide an integrated testbed for the development and demonstration of the technologies needed for IFE power plants. In addition to target physics of ignition, the NIF will contribute important data on IFE target chamber issues, including neutron damage, activation, target debris clearing, operational experience in many areas prototypical to future IFE power plants, and an opportunity to provide tests of candidate low-cost IFE targets and injection systems. An overview of the NIF design and the target area environments relevant to conducting IFE experiments are described in Section 2. In providing this basic data for IFE, the NIF will provide confidence that an ETF can be successful in the integration of drivers, target chambers, and targets for IFE

  3. Environment-Dependent Distribution of the Sediment nifH-Harboring Microbiota in the Northern South China Sea

    Science.gov (United States)

    Yang, Jinying; Li, Jing; Luan, Xiwu; Zhang, Yunbo; Gu, Guizhou; Xue, Rongrong; Zong, Mingyue; Klotz, Martin G.

    2013-01-01

    The South China Sea (SCS), the largest marginal sea in the Western Pacific Ocean, is a huge oligotrophic water body with very limited influx of nitrogenous nutrients. This suggests that sediment microbial N2 fixation plays an important role in the production of bioavailable nitrogen. To test the molecular underpinning of this hypothesis, the diversity, abundance, biogeographical distribution, and community structure of the sediment diazotrophic microbiota were investigated at 12 sampling sites, including estuarine, coastal, offshore, deep-sea, and methane hydrate reservoirs or their prospective areas by targeting nifH and some other functional biomarker genes. Diverse and novel nifH sequences were obtained, significantly extending the evolutionary complexity of extant nifH genes. Statistical analyses indicate that sediment in situ temperature is the most significant environmental factor influencing the abundance, community structure, and spatial distribution of the sediment nifH-harboring microbial assemblages in the northern SCS (nSCS). The significantly positive correlation of the sediment pore water NH4+ concentration with the nifH gene abundance suggests that the nSCS sediment nifH-harboring microbiota is active in N2 fixation and NH4+ production. Several other environmental factors, including sediment pore water PO43− concentration, sediment organic carbon, nitrogen and phosphorus levels, etc., are also important in influencing the community structure, spatial distribution, or abundance of the nifH-harboring microbial assemblages. We also confirmed that the nifH genes encoded by archaeal diazotrophs in the ANME-2c subgroup occur exclusively in the deep-sea methane seep areas, providing for the possibility to develop ANME-2c nifH genes as a diagnostic tool for deep-sea methane hydrate reservoir discovery. PMID:23064334

  4. Sensorimotor nucleus NIf is necessary for auditory processing but not vocal motor output in the avian song system.

    Science.gov (United States)

    Cardin, Jessica A; Raksin, Jonathan N; Schmidt, Marc F

    2005-04-01

    Sensorimotor integration in the avian song system is crucial for both learning and maintenance of song, a vocal motor behavior. Although a number of song system areas demonstrate both sensory and motor characteristics, their exact roles in auditory and premotor processing are unclear. In particular, it is unknown whether input from the forebrain nucleus interface of the nidopallium (NIf), which exhibits both sensory and premotor activity, is necessary for both auditory and premotor processing in its target, HVC. Here we show that bilateral NIf lesions result in long-term loss of HVC auditory activity but do not impair song production. NIf is thus a major source of auditory input to HVC, but an intact NIf is not necessary for motor output in adult zebra finches.

  5. Construction of the NIFS campus information network, NIFS-LAN

    Energy Technology Data Exchange (ETDEWEB)

    Tsuda, Kenzo; Yamamoto, Takashi; Kato, Takeo; Nakamura, Osamu; Watanabe, Kunihiko; Watanabe, Reiko; Tsugawa, Kazuko; Kamimura, Tetsuo

    2000-10-01

    The advanced NIFS campus information network, NIFS-LAN, was designed and constructed as an informational infrastructure in 1996, 1997 and 1998 fiscal year. NIFS-LAN was composed of three autonomous clusters classified from research purpose; Research Information cluster, Large Helical Device Experiment cluster and Large-Scale Computer Simulation Research cluster. Many ATM(Asychronous Transfer Mode) switching systems and switching equipments were used for NIFS-LAN. Here, the outline of NIFS-LAN is described. (author)

  6. Magnetic Fields on the National Ignition Facility (MagNIF)

    International Nuclear Information System (INIS)

    Mason, D.; Folta, J.

    2016-01-01

    A magnetized target capability on the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) has been investigated. Stakeholders' needs and project feasibility analysis were considered in order to down-select from a wide variety of different potential magnetic field magnitudes and volumes. From the large range of different target platforms, laser configurations, and diagnostics configurations of interest to the stakeholders, the gas-pipe platform has been selected for the first round of magnetized target experiments. Gas pipe targets are routinely shot on the NIF and provide unique value for external collaborators. High-level project goals have been established including an experimentally relevant 20Tesla magnetic field magnitude. The field will be achieved using pulsed power-driven coils. A system architecture has been proposed. The pulsed power drive system will be located in the NIF target bay. This decision provides improved maintainability and mitigates equipment safety risks associated with explosive failure of the drive capacitor. High-level and first-level subsystem requirements have been established. Requirements have been included for two distinct coil designs - full solenoid and quasi-Helmholtz. A Failure Modes and Effects Analysis (FMEA) has been performed and documented. Additional requirements have been derived from the mitigations included in the FMEA document. A project plan is proposed. The plan includes a first phase of electromagnetic simulations to assess whether the design will meet performance requirements, then a second phase of risk mitigation projects to address the areas of highest technical risk. The duration from project kickoff to the first magnetized target shot is approximately 29 months.

  7. Magnetic Fields on the National Ignition Facility (MagNIF)

    Energy Technology Data Exchange (ETDEWEB)

    Mason, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Folta, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-08-12

    A magnetized target capability on the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) has been investigated. Stakeholders’ needs and project feasibility analysis were considered in order to down-select from a wide variety of different potential magnetic field magnitudes and volumes. From the large range of different target platforms, laser configurations, and diagnostics configurations of interest to the stakeholders, the gas-pipe platform has been selected for the first round of magnetized target experiments. Gas pipe targets are routinely shot on the NIF and provide unique value for external collaborators. High-level project goals have been established including an experimentally relevant 20Tesla magnetic field magnitude. The field will be achieved using pulsed power-driven coils. A system architecture has been proposed. The pulsed power drive system will be located in the NIF target bay. This decision provides improved maintainability and mitigates equipment safety risks associated with explosive failure of the drive capacitor. High-level and first-level subsystem requirements have been established. Requirements have been included for two distinct coil designs – full solenoid and quasi-Helmholtz. A Failure Modes and Effects Analysis (FMEA) has been performed and documented. Additional requirements have been derived from the mitigations included in the FMEA document. A project plan is proposed. The plan includes a first phase of electromagnetic simulations to assess whether the design will meet performance requirements, then a second phase of risk mitigation projects to address the areas of highest technical risk. The duration from project kickoff to the first magnetized target shot is approximately 29 months.

  8. IMS Mitigation Target Areas - 2010 [ds673

    Data.gov (United States)

    California Natural Resource Agency — Mitigation Target Areas (MTA) were developed by the California Department of Fish and Game for the Interim Mitigation Strategy (IMS). The MTAs are an identification...

  9. New approaches to the preparation of PαMS beads as mandrels for NIF-scale target capsules

    International Nuclear Information System (INIS)

    Cook, R.; Buckley, S.R.; Fearon, E.; Letts, S.A.

    1999-01-01

    The authors report on a new method using heated density gradient columns for preparing spherical poly(αmethylstyrene) (PαMS) bead mandrels for inertial confinement fusion spherical shell targets. Using 1,2 propane diol/glycerol mixtures, stable density gradient columns for supporting PαMS beads can be prepared at temperatures as high as 150 C. At these temperatures plasticized commercial beads become fluid and spherical, however loss of the plasticizer and very low molecular weight components of the bead due to limited solubility in the column fluid leads to surface finish problems. The authors also present results on PαMS beads prepared in an aqueous bath batch mode. Using these techniques beads with maximum out-of-rounds less than 5 microm have been produced

  10. Tests and calibration of NIF neutron time of flight detectors.

    Science.gov (United States)

    Ali, Z A; Glebov, V Yu; Cruz, M; Duffy, T; Stoeckl, C; Roberts, S; Sangster, T C; Tommasini, R; Throop, A; Moran, M; Dauffy, L; Horsefield, C

    2008-10-01

    The National Ignition Facility (NIF) neutron time of flight (NTOF) diagnostic will measure neutron yield and ion temperature in all NIF campaigns in DD, DT, and THD(*) implosions. The NIF NTOF diagnostic is designed to measure neutron yield from 1x10(9) to 2x10(19). The NTOF consists of several detectors of varying sensitivity located on the NIF at about 5 and 20 m from the target. Production, testing, and calibration of the NIF NTOF detectors have begun at the Laboratory for Laser Energetics (LLE). Operational tests of the NTOF detectors were performed on several facilities including the OMEGA laser at LLE and the Titan laser at Lawrence Livermore National Laboratory. Neutron calibrations were carried out on the OMEGA laser. Results of the NTOF detector tests and calibration will be presented.

  11. NIF diagnostic damage and design issues

    International Nuclear Information System (INIS)

    Landen, N.

    1999-01-01

    The NIF target environment is evaluated with respect to target and diagnostic debris and with respect to instrument survivability in the presence of target debris and radiation. Quantitative estimates are arrived at by extrapolating from Nova and Omega experience using simple scaling arguments. Specifically, we evaluate the closest distance of approach of various components of DIM-based diagnostics such as target mounted pinhole arrays, open detectors, filters, x-ray optics, and spectrometers. We also include constraints on achieving adequate signal-to-noise on x-ray diagnostics. Four of the most important conclusions are as follows: (1) The required full NIF stand-off distance for heavily filtered detectors (e.g. multi-keV x-ray and particle detectors) as determined by concerns of diagnostic debris and diagnostic survivability to debris and radiation is no more than 100 cm. (2) Target mounted pinhole arrays and slits mounted a few cm from chamber center at NIF will survive long enough to record data and should be an acceptable source of shrapnel debris. (3) DIM-based instrument stand-off distances are compatible with achieving the same photon statistics (or better with ongoing improvements in detector resolution and noise) than available with current Nova and Omega SIM- or TIM-based instrumentation. Section II reviews target and diagnostic debris with respect to final optics. Section III reviews debris and radiation with respect to all diagnostic components. The following laser scaling between Nova/Omega and NIF is used throughout unless otherwise specified: laser energy E = 100x, drive duration τ = 6x and hence for a given laser intensity or hohlraum temperature, target size r approximately √(E/τ) = 4x. The 100x increase in E accounts for the fact that many Nova shots were performed with only 20 kJ and all LLNL Omega shots were performed with only 15 kJ

  12. Status of NIF mirror technologies for completion of the NIF facility

    International Nuclear Information System (INIS)

    Stolz, C.J.

    2008-01-01

    The 1600 mirrors required for the National Ignition Facility (NIF) are now coated with the last optics currently being installed. The combined surface area of the NIF mirrors is almost 450 square meters, roughly 3.4 times greater than the surface area of the two Keck primary mirrors. Additionally, the power handling specification of NIF mirrors is 19 orders of magnitude greater than that of the Keck mirrors. The NIF laser will be at least 40x greater energy than the previous LLNL fusion laser called NOVA. To manufacture these mirrors, a number of new technologies (electrolytic in-situ dressing, ion figuring, source stabilization) were used that were not available for previous fusion laser optics. Post deposition technologies designed to increase laser resistance (off-line laser conditioning, solarization, air knives) have also been utilized. This paper summarizes the differences in technologies used to manufacture NIF mirrors from those used for previous fusion lasers and examines potential future technologies that would enable higher fluence operations and extend lifetimes

  13. Optimization of the NIF ignition point design hohlraum

    International Nuclear Information System (INIS)

    Callahan, D A; Hinkel, D E; Berger, R L; Divol, L; Dixit, S N; Edwards, M J; Haan, S W; Jones, O S; Lindl, J D; Meezan, N B; Michel, P A; Pollaine, S M; Suter, L J; Town, R P J; Bradley, P A

    2008-01-01

    In preparation for the start of NIF ignition experiments, we have designed a porfolio of targets that span the temperature range that is consistent with initial NIF operations: 300 eV, 285 eV, and 270 eV. Because these targets are quite complicated, we have developed a plan for choosing the optimum hohlraum for the first ignition attempt that is based on this portfolio of designs coupled with early NIF experiements using 96 beams. These early experiments will measure the laser plasma instabilities of the candidate designs and will demonstrate our ability to tune symmetry in these designs. These experimental results, coupled with the theory and simulations that went into the designs, will allow us to choose the optimal hohlraum for the first NIF ignition attempt

  14. Optimization of the NIF ignition point design hohlraum

    Science.gov (United States)

    Callahan, D. A.; Hinkel, D. E.; Berger, R. L.; Divol, L.; Dixit, S. N.; Edwards, M. J.; Haan, S. W.; Jones, O. S.; Lindl, J. D.; Meezan, N. B.; Michel, P. A.; Pollaine, S. M.; Suter, L. J.; Town, R. P. J.; Bradley, P. A.

    2008-05-01

    In preparation for the start of NIF ignition experiments, we have designed a porfolio of targets that span the temperature range that is consistent with initial NIF operations: 300 eV, 285 eV, and 270 eV. Because these targets are quite complicated, we have developed a plan for choosing the optimum hohlraum for the first ignition attempt that is based on this portfolio of designs coupled with early NIF experiements using 96 beams. These early experiments will measure the laser plasma instabilities of the candidate designs and will demonstrate our ability to tune symmetry in these designs. These experimental results, coupled with the theory and simulations that went into the designs, will allow us to choose the optimal hohlraum for the first NIF ignition attempt.

  15. The National Ignition Facility (NIF) as a User Facility

    Science.gov (United States)

    Keane, Christopher; NIF Team

    2013-10-01

    The National Ignition Facility (NIF) has made significant progress towards operation as a user facility. Through June 2013, NIF conducted over 1200 experiments in support of ICF, HED science, and development of facility capabilities. The NIF laser has met or achieved all specifications and a wide variety of diagnostic and target fabrication capabilities are in place. A NIF User Group and associated Executive Board have been formed. Two User Group meetings have been conducted since formation of the User Group. NIF experiments in fundamental science have provided important new results. NIF ramp compression experiments have been conducted using diamond and iron, with EOS results obtained at pressures up to approximately 50 Mbar and 8 Mbar, respectively. Initial experiments in supernova hydrodynamics, the fundamental physics of the Rayleigh-Taylor instability, and equation of state in the Gbar pressure regime have also been conducted. This presentation will discuss the fundamental science program at NIF, including the proposal solicitation and scientific review processes and other aspects of user facility operation. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

  16. Target area acquisition and control system survivability for the National Ignition Facility

    International Nuclear Information System (INIS)

    Hagans, K.; Stathis, P.; Wiedwald, J.; Campbell, D.

    1994-06-01

    The hardening of instruments to survive NIF target emission environments presents a significant challenge. Neutron flux is predicted to be as much as six orders of magnitude greater than the highest achieved neutron flux on NOVA. Not withstanding the high prompt radiation fields, the specifications for the instruments are demanding; requiring high resolution imaging and sub nanosecond transient measurements. We present an analysis of the sensitivity of the proposed NIF instrumentation design to EMP, X-rays, gamma rays, and neutrons. Major components assessed include fiber optic cable transport, high bandwidth cable and charge coupled detector (CCD) imaging systems

  17. Target support for inertial confinement fusion

    International Nuclear Information System (INIS)

    Schultz, K.R.

    1995-08-01

    General Atomics (GA) plays an important industrial support role for the US Inertial Confinement Fusion (ICF) program in the area of target technology. This includes three major activities: target fabrication support, target handling systems development, and target chamber design. The work includes target fabrication for existing ICF experiments, target and target system development for future experiments, and target research and target chamber design for experiments on future machines, such as the National Ignition Facility (NIF)

  18. Large area solid target neutron source

    International Nuclear Information System (INIS)

    Crawford, J.C.; Bauer, W.

    1974-01-01

    A potentially useful neutron source may result from the combination of a solid deuterium-tritium loaded target with the large area, high energy ion beams from ion sources being developed for neutral beam injection. The resulting neutron source would have a large radiating area and thus produce the sizable experimental volume necessary for future studies of bulk and synergistic surface radiation effects as well as experiments on engineering samples and small components. With a 200 keV D + T + beam and 40 kW/cm 2 power dissipation on a 200 cm 2 target spot, a total neutron yield of about 4 x 10 15 n/sec may be achieved. Although the useable neutron flux from this source is limited to 1 to 2 x 10 13 n/cm 2 /sec, this flux can be produced 3 cm in front of the target and over about 300 cm 3 of experimental volume. Problems of total power dissipation, sputtering, isotopic flushing and thermal dissociation are reviewed. Neutron flux profiles and potential experimental configurations are presented and compared to other neutron source concepts. (U.S.)

  19. Characterization of nifB, nifS, and nifU genes in the cyanobacterium Anabaena variabilis: NifB is required for the vanadium-dependent nitrogenase.

    OpenAIRE

    Lyons, E M; Thiel, T

    1995-01-01

    Anabaena variabilis ATCC 29413 is a heterotrophic, nitrogen-fixing cyanobacterium containing both a Mo-dependent nitrogenase encoded by the nif genes and V-dependent nitrogenase encoded by the vnf genes. The nifB, nifS, and nifU genes of A. variabilis were cloned, mapped, and partially sequenced. The fdxN gene was between nifB and nifS. Growth and acetylene reduction assays using wild-type and mutant strains indicated that the nifB product (NifB) was required for nitrogen fixation not only by...

  20. Preliminary report: NIF laser bundle review

    International Nuclear Information System (INIS)

    Tietbohl, G.L.; Larson, D.W.; Erlandson, A.C.

    1995-01-01

    As requested in the guidance memo 1 , this committe determined whether there are compelling reasons to recommend a change from the NIF CDR baseline laser. The baseline bundle design based on a tradeoff between cost and technical risk, which is replicated four times to create the required 192 beams. The baseline amplifier design uses bottom loading 1x4 slab and flashlamp cassettes for amplifier maintenance and large vacuum enclosures (2.5m high x 7m wide in cross-section for each of the two spatial filters in each of the four bundles. The laser beams are arranged in two laser bays configured in a u-shape around the target area. The entire bundle review effort was performed in a very short time (six weeks) and with limited resources (15 personnel part-time). This should be compared to the effort that produced the CDR design (12 months, 50 to 100 personnel). This committee considered three alternate bundle configurations (2x2, 4x2, and 4x4 bundles), and evaluated each bundle against the baseline design using the seven requested issues in the guidance memo: Cost; schedule; performance risk; maintainability/operability; hardware failure cost exposure; activation; and design flexibility. The issues were reviewed to identify differences between each alternate bundle configuration and the baseline

  1. The National Ignition Facility (NIF): A path to fusion energy

    International Nuclear Information System (INIS)

    Moses, Edward I.

    2008-01-01

    Fusion energy has long been considered a promising, clean, nearly inexhaustible source of energy. Power production by fusion micro-explosions of inertial confinement fusion (ICF) targets has been a long-term research goal since the invention of the first laser in 1960. The National Ignition Facility (NIF) is poised to take the next important step in the journey by beginning experiments researching ICF ignition. Ignition on NIF will be the culmination of over 30 years of ICF research on high-powered laser systems such as the Nova laser at Lawrence Livermore National Laboratory (LLNL) and the OMEGA laser at the University of Rochester, as well as smaller systems around the world. NIF is a 192-beam Nd-glass laser facility at LLNL that is more than 90% complete. The first cluster of 48 beams is operational in the laser bay, the second cluster is now being commissioned, and the beam path to the target chamber is being installed. The Project will be completed in 2009, and ignition experiments will start in 2010. When completed, NIF will produce up to 1.8 MJ of 0.35-μm light in highly shaped pulses required for ignition. It will have beam stability and control to higher precision than any other laser fusion facility. Experiments using one of the beams of NIF have demonstrated that NIF can meet its beam performance goals. The National Ignition Campaign (NIC) has been established to manage the ignition effort on NIF. NIC has all of the research and development required to execute the ignition plan and to develop NIF into a fully operational facility. NIF will explore the ignition space, including direct drive, 2ω ignition, and fast ignition, to optimize target efficiency for developing fusion as an energy source. In addition to efficient target performance, fusion energy requires significant advances in high-repetition-rate lasers and fusion reactor technology. The Mercury laser at LLNL is a high-repetition-rate Nd-glass laser for fusion energy driver development. Mercury

  2. The national ignition facility (NIF) : A path to fusion energy

    International Nuclear Information System (INIS)

    Moses, E. I.

    2007-01-01

    Fusion energy has long been considered a promising clean, nearly inexhaustible source of energy. Power production by fusion micro-explosions of inertial confinement fusion (ICF) targets has been a long term research goal since the invention of the first laser in 1960. The NIF is poised to take the next important step in the journey by beginning experiments researching ICF ignition. Ignition on NIF will be the culmination of over thirty years of ICF research on high-powered laser systems such as the Nova laser at LLNL and the OMEGA laser at the University of Rochester as well as smaller systems around the world. NIF is a 192 beam Nd-glass laser facility at LLNL that is more than 90% complete. The first cluster of 48 beams is operational in the laser bay, the second cluster is now being commissioned, and the beam path to the target chamber is being installed. The Project will be completed in 2009 and ignition experiments will start in 2010. When completed NIF will produce up to 1.8 MJ of 0.35 μm light in highly shaped pulses required for ignition. It will have beam stability and control to higher precision than any other laser fusion facility. Experiments using one of the beams of NIF have demonstrated that NIF can meet its beam performance goals. The National Ignition Campaign (NIC) has been established to manage the ignition effort on NIF. NIC has all of the research and development required to execute the ignition plan and to develop NIF into a fully operational facility. NIF will explore the ignition space, including direct drive, 2ω ignition, and fast ignition, to optimize target efficiency for developing fusion as an energy source. In addition to efficient target performance, fusion energy requires significant advances in high repetition rate lasers and fusion reactor technology. The Mercury laser at LLNL is a high repetition rate Nd-glass laser for fusion energy driver development. Mercury uses state-o-the art technology such as ceramic laser slabs and light

  3. Automated optics inspection analysis for NIF

    Energy Technology Data Exchange (ETDEWEB)

    Kegelmeyer, Laura M., E-mail: kegelmeyer1@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA (United States); Clark, Raelyn; Leach, Richard R.; McGuigan, David; Kamm, Victoria Miller; Potter, Daniel; Salmon, J. Thad; Senecal, Joshua; Conder, Alan; Nostrand, Mike; Whitman, Pamela K. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2012-12-15

    The National Ignition Facility (NIF) is a high-energy laser facility comprised of 192 beamlines that house thousands of optics. These optics guide, amplify and tightly focus light onto a tiny target for fusion ignition research and high energy density physics experiments. The condition of these optics is key to the economic, efficient and maximally energetic performance of the laser. Our goal, and novel achievement, is to find on the optics any imperfections while they are tens of microns in size, track them through time to see if they grow and if so, remove the optic and repair the single site so the entire optic can then be re-installed for further use on the laser. This paper gives an overview of the image analysis used for detecting, measuring, and tracking sites of interest on an optic while it is installed on the beamline via in situ inspection and after it has been removed for maintenance. In this way, the condition of each optic is monitored throughout the optic's lifetime. This overview paper will summarize key algorithms and technical developments for custom image analysis and processing and highlight recent improvements. (Associated papers will include more details on these issues.) We will also discuss the use of OI Analysis for daily operation of the NIF laser and its extension to inspection of NIF targets.

  4. Automated optics inspection analysis for NIF

    International Nuclear Information System (INIS)

    Kegelmeyer, Laura M.; Clark, Raelyn; Leach, Richard R.; McGuigan, David; Kamm, Victoria Miller; Potter, Daniel; Salmon, J. Thad; Senecal, Joshua; Conder, Alan; Nostrand, Mike; Whitman, Pamela K.

    2012-01-01

    The National Ignition Facility (NIF) is a high-energy laser facility comprised of 192 beamlines that house thousands of optics. These optics guide, amplify and tightly focus light onto a tiny target for fusion ignition research and high energy density physics experiments. The condition of these optics is key to the economic, efficient and maximally energetic performance of the laser. Our goal, and novel achievement, is to find on the optics any imperfections while they are tens of microns in size, track them through time to see if they grow and if so, remove the optic and repair the single site so the entire optic can then be re-installed for further use on the laser. This paper gives an overview of the image analysis used for detecting, measuring, and tracking sites of interest on an optic while it is installed on the beamline via in situ inspection and after it has been removed for maintenance. In this way, the condition of each optic is monitored throughout the optic's lifetime. This overview paper will summarize key algorithms and technical developments for custom image analysis and processing and highlight recent improvements. (Associated papers will include more details on these issues.) We will also discuss the use of OI Analysis for daily operation of the NIF laser and its extension to inspection of NIF targets.

  5. Comparison of the Three NIF Ablators

    Energy Technology Data Exchange (ETDEWEB)

    Kritcher, A. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Clark, D. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haan, S. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Yi, S. A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zylstra, A. B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ralph, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Weber, C. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-11-01

    Indirect drive implosion experiments on NIF have now been performed using three different ablator materials: glow discharge polymer (GDP) or CH, high density carbon (HDC, which we also refer to as diamond), and sputtered beryllium (Be). It has been appreciated for some time that each of these materials has specific advantages and disadvantages as an ICF ablator.[1-4] In light of experiments conducted on NIF in the last few years, how do these ablators compare? Given current understanding, is any ablator more or less likely to reach ignition on NIF? Has the understanding of their respective strengths and weaknesses changed since NIF experiments began? How are those strengths and weaknesses highlighted by implosion designs currently being tested or planned for testing soon? This document aims to address these questions by combining modern simulation results with a survey of the current experimental data base. More particularly, this document is meant to fulfill an L2 Milestone for FY17 to “Document our understanding of the relative advantages and disadvantages of CH, HDC, and Be designs.” Note that this document does not aim to recommend a down-selection of the current three ablator choices. It is intended only to gather and document the current understanding of the differences between these ablators and thereby inform the choices made in planning future implosion experiments. This document has two themes: (i) We report on a reanalysis project in which post-shot simulations were done on a common basis for layered shots using each ablator. This included data from keyholes, 2D ConA, and so forth, from each campaign, leading up to the layered shots. (“Keyholes” are shots dedicated to measuring the shock timing in a NIF target, as described in Ref. 5. “2DConAs” are backlit implosions in which the symmetry of the implosion is measured between about half and full convergence, as described in Ref. 6.) This set of common-basis postshot simulations is compared to

  6. Fault tolerance of the NIF power conditioning system

    International Nuclear Information System (INIS)

    Larson, D.W.; Anderson, R.; Boyes, J.

    1995-01-01

    The tolerance of the circuit topology proposed for the National Ignition Facility (NIF) power conditioning system to specific fault conditions is investigated. A new pulsed power circuit is proposed for the NIF which is simpler and less expensive than previous ICF systems. The inherent fault modes of the new circuit are different from the conventional approach, and must be understood to ensure adequate NIF system reliability. A test-bed which simulates the NIF capacitor module design was constructed to study the circuit design. Measurements from test-bed experiments with induced faults are compared with results from a detailed circuit model. The model is validated by the measurements and used to predict the behavior of the actual NIF module during faults. The model can be used to optimize fault tolerance of the NIF module through an appropriate distribution of circuit inductance and resistance. The experimental and modeling results are presented, and fault performance is compared with the ratings of pulsed power components. Areas are identified which require additional investigation

  7. NIF Ambient Vibration Measurements

    International Nuclear Information System (INIS)

    Noble, C.R.; Hoehler, M.S.; S.C. Sommer

    1999-01-01

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B

  8. NIF-type iron-sulfur cluster assembly system is duplicated and distributed in the mitochondria and cytosol of Mastigamoeba balamuthi.

    Science.gov (United States)

    Nývltová, Eva; Šuták, Robert; Harant, Karel; Šedinová, Miroslava; Hrdy, Ivan; Paces, Jan; Vlček, Čestmír; Tachezy, Jan

    2013-04-30

    In most eukaryotes, the mitochondrion is the main organelle for the formation of iron-sulfur (FeS) clusters. This function is mediated through the iron-sulfur cluster assembly machinery, which was inherited from the α-proteobacterial ancestor of mitochondria. In Archamoebae, including pathogenic Entamoeba histolytica and free-living Mastigamoeba balamuthi, the complex iron-sulfur cluster machinery has been replaced by an ε-proteobacterial nitrogen fixation (NIF) system consisting of two components: NifS (cysteine desulfurase) and NifU (scaffold protein). However, the cellular localization of the NIF system and the involvement of mitochondria in archamoebal FeS assembly are controversial. Here, we show that the genes for both NIF components are duplicated within the M. balamuthi genome. One paralog of each protein contains an amino-terminal extension that targets proteins to mitochondria (NifS-M and NifU-M), and the second paralog lacks a targeting signal, thereby reflecting the cytosolic form of the NIF machinery (NifS-C and NifU-C). The dual localization of the NIF system corresponds to the presence of FeS proteins in both cellular compartments, including detectable hydrogenase activity in Mastigamoeba cytosol and mitochondria. In contrast, E. histolytica possesses only single genes encoding NifS and NifU, respectively, and there is no evidence for the presence of the NIF machinery in its reduced mitochondria. Thus, M. balamuthi is unique among eukaryotes in that its FeS cluster formation is mediated through two most likely independent NIF machineries present in two cellular compartments.

  9. Molecular evolution of the nif gene cluster carrying nifI1 and nifI2 genes in the Gram-positive phototrophic bacterium Heliobacterium chlorum.

    Science.gov (United States)

    Enkh-Amgalan, Jigjiddorj; Kawasaki, Hiroko; Seki, Tatsuji

    2006-01-01

    A major nif cluster was detected in the strictly anaerobic, Gram-positive phototrophic bacterium Heliobacterium chlorum. The cluster consisted of 11 genes arranged within a 10 kb region in the order nifI1, nifI2, nifH, nifD, nifK, nifE, nifN, nifX, fdx, nifB and nifV. The phylogenetic position of Hbt. chlorum was the same in the NifH, NifD, NifK, NifE and NifN trees; Hbt. chlorum formed a cluster with Desulfitobacterium hafniense, the closest neighbour of heliobacteria based on the 16S rRNA phylogeny, and two species of the genus Geobacter belonging to the Deltaproteobacteria. Two nifI genes, known to occur in the nif clusters of methanogenic archaea between nifH and nifD, were found upstream of the nifH gene of Hbt. chlorum. The organization of the nif operon and the phylogeny of individual and concatenated gene products showed that the Hbt. chlorum nif operon carrying nifI genes upstream of the nifH gene was an intermediate between the nif operon with nifI downstream of nifH (group II and III of the nitrogenase classification) and the nif operon lacking nifI (group I). Thus, the phylogenetic position of Hbt. chlorum nitrogenase may reflect an evolutionary stage of a divergence of the two nitrogenase groups, with group I consisting of the aerobic diazotrophs and group II consisting of strictly anaerobic prokaryotes.

  10. Final report for NIF chamber dynamics studies

    International Nuclear Information System (INIS)

    Burnham, A; Peterson, P F; Scott, J M

    1998-01-01

    The National Ignition Facility (NIF), a 1.8 MJ, 192 laser beam facility, will have anticipated fusion yields of up to 20 MJ from D-T pellets encased in a gold hohlraum target. The energy emitted from the target in the form of x rays, neutrons, target debris kinetic energy, and target shrapnel will be contained in a 5 m. radius spherical target chamber. various diagnostics will be stationed around the target at varying distances from the target. During each shot, the target will emit x rays that will vaporize nearby target facing surfaces including those of the diagnostics, the target positioner, and other chamber structures. This ablated vapor will be transported throughout the chamber, and will eventually condense and deposit on surfaces in the chamber, including the final optics debris shields. The research at the University of California at Berkeley relates primarily to the NIF chamber dynamics. The key design issues are the ablation of the chamber structures, transport of the vapor through the chamber and the condensation or deposition processes of those vaporized materials. An understanding of these processes is essential in developing a concept for protecting the fina optics debris shields from an excessive coating (> 10 A) of target debris and ablated material, thereby prolonging their lifetime between change-outs. At Berkeley, we have studied the physical issues of the ablation process and the effects of varying materials, the condensation process of the vaporized material, and design schemes that can lower the threat posed to the debris shields by these processes. The work or portions of the work completed this year have been published in several papers and a dissertation [l-5

  11. Stability analysis of directly driven Nif capsules

    Energy Technology Data Exchange (ETDEWEB)

    Goncharov, V.N.; Skupsky, S.; McKenty, P.W.; Delettrez, J.A.; Town, R.P.J. [Rochester Univ., NY (United States). Lab. for Laser Energetics; Cherfils-Clerouin, C. [CEA/DAM-Ile de France, DIF, 91 - Bruyeres Le Chatel (France)

    2000-07-01

    An analytical model is presented to study perturbation evolution at the ablation and inner surfaces of the imploding shell. The model describes the ablative Rayleigh-Taylor and Bell-Plesset instabilities. The initial conditions for the model are determined by using existing theories of laser imprint, ablative Richtmyer-Meshkov instability, 'feed-out' and by performing a series of 2-D ORCHID simulations. The model and simulations show that the direct-drive cryogenic {alpha} = 3 NIF capsules remain intact during the implosion if laser nonuniformities are smoothed by 2-D SSD used in the current direct-drive target designs. (authors)

  12. Progress towards polar-drive ignition for the NIF

    Science.gov (United States)

    McCrory, R. L.; Betti, R.; Boehly, T. R.; Casey, D. T.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Frenje, J. A.; Froula, D. H.; Gatu-Johnson, M.; Glebov, V. Yu.; Goncharov, V. N.; Harding, D. R.; Hohenberger, M.; Hu, S. X.; Igumenshchev, I. V.; Kessler, T. J.; Knauer, J. P.; Li, C. K.; Marozas, J. A.; Marshall, F. J.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Nilson, P. M.; Padalino, S. J.; Petrasso, R. D.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Séguin, F. H.; Seka, W.; Short, R. W.; Shvydky, A.; Skupsky, S.; Soures, J. M.; Stoeckl, C.; Theobald, W.; Yaakobi, B.; Zuegel, J. D.

    2013-11-01

    The University of Rochester's Laboratory for Laser Energetics (LLE) performs direct-drive inertial confinement fusion (ICF) research. LLE's Omega Laser Facility is used to study direct-drive ICF ignition concepts, developing an understanding of the underlying physics that feeds into the design of ignition targets for the National Ignition Facility (NIF). The baseline symmetric-illumination, direct-drive-ignition target design consists of a 1.5 MJ multiple-picket laser pulse that generates four shock waves (similar to the NIF baseline indirect-drive design) and is predicted to produce a one-dimensional (1D) gain of 48. LLE has developed the polar-drive (PD) illumination concept (for NIF beams in the x-ray-drive configuration) to allow the pursuit of direct-drive ignition without significant reconfiguration of the beam paths on the NIF. Some less-invasive changes in the NIF infrastructure will be required, including new phase plates, polarization rotators, and a PD-specific beam-smoothing front end. A suite of PD ignition designs with implosion velocities from 3.5 to 4.3 × 107 cm s-1 are predicted to have significant 2D gains (Collins et al 2012 Bull. Am. Phys. Soc. 57 155). Verification of the physics basis of these simulations is a major thrust of direct-drive implosion experiments on both OMEGA and the NIF. Many physics issues are being examined with symmetric beam irradiation on OMEGA, varying the implosion parameters over a wide region of design space. Cryogenic deuterium-tritium target experiments with symmetric irradiation have produced areal densities of ˜0.3 g cm-2, ion temperatures over 3 keV, and neutron yields in excess of 20% of the ‘clean’ 1D predicted value. The inferred Lawson criterion figure of merit (Betti R. et al 2010 Phys. Plasmas 17 058102) has increased from 1.7 atm s (IAEA 2010) to 2.6 atm s.

  13. NIF optics phase gradient specfication

    International Nuclear Information System (INIS)

    Williams, W.; Auerbach, J.; Hunt, J.; Lawson, L.; Manes, K.; Orth, C.; Sacks, R.; Trenholme, J.; Wegner, P.

    1997-01-01

    A root-mean-square (rms) phase gradient specification seems to allow a good connection between the NIP optics quality and focal spot requirements. Measurements on Beamlet optics individually, and as a chain, indicate they meet the assumptions necessary to use this specification, and that they have a typical rms phase gradient of ∼80 angstrom/cm. This may be sufficient for NIP to meet the proposed Stockpile Stewardship Management Program (SSMP) requirements of 80% of a high- power beam within a 200-250 micron diameter spot. Uncertainties include, especially, the scale length of the optics phase noise, the ability of the adaptive optic to correct against pump-induced distortions and optics noise, and the possibility of finding mitigation techniques against whole-beam self-focusing (e.g. a pre- correction optic). Further work is needed in these areas to better determine the NIF specifications. This memo is a written summary of a presentation on this topic given by W. Williams 24 April 1997 to NIP and LS ampersand T personnel

  14. NIF Discovery Science Eagle Nebula

    Science.gov (United States)

    Kane, Jave; Martinez, David; Pound, Marc; Heeter, Robert; Casner, Alexis; Villette, Bruno; Mancini, Roberto

    2017-10-01

    The University of Maryland and and LLNL are investigating the origin and dynamics of the famous Pillars of the Eagle Nebula and similar parsec-scale structures at the boundaries of HII regions in molecular hydrogen clouds. The National Ignition Facility (NIF) Discovery Science program Eagle Nebula has performed NIF shots to study models of pillar formation. The shots feature a new long-duration x-ray source, in which multiple hohlraums mimicking a cluster of stars are driven with UV light in series for 10 to 15 ns each to create a 30 to 60 ns output x-ray pulse. The source generates deeply nonlinear hydrodynamics in the Eagle science package, a structure of dense plastic and foam mocking up a molecular cloud containing a dense core. Omega EP and NIF shots have validated the source concept, showing that earlier hohlraums do not compromise later ones by preheat or by ejecting ablated plumes that deflect later beams. The NIF shots generated radiographs of shadowing-model pillars, and also showed evidence that cometary structures can be generated. The velocity and column density profiles of the NIF shadowing and cometary pillars have been compared with observations of the Eagle Pillars made at the millimeter-wave BIMA and CARMA observatories. Prepared by LLNL under Contract DE-AC52-07NA27344.

  15. Tests and Calibration of the NIF Neutron Time of Flight Detectors

    International Nuclear Information System (INIS)

    Ali, Z.A.; Glebov, V.Yu.; Cruz, M.; Duffy, T.; Stoeckl, C.; Roberts, S.; Sangster, T.C.; Tommasini, R.; Throop, A; Moran, M.; Dauffy, L.; Horsefield, C.

    2008-01-01

    The National Ignition Facility (NIF) Neutron Time of Flight (NTOF) diagnostic will measure neutron yield and ion temperature in all NIF campaigns in DD, DT, and THD (D = deuterium, T = tritium, H = hydrogen) implosions. The NIF NTOF diagnostic is designed to measure neutron yield from 10 9 to 2 x 10 19 . The NTOF consists of several detectors of varying sensitivity located on the NIF at about 5 m and 20 m from the target. Production, testing, and calibration of the NIF NTOF detectors have begun at the Laboratory for Laser Energetics (LLE). Operational tests of the NTOF detectors were performed on several facilities including the OMEGA laser at LLE and the Titan laser at Lawrence Livermore National Laboratory (LLNL). Neutron calibrations were carried out on the OMEGA laser. Results of the NTOF detectors tests and calibration will be presented

  16. Review of laser mega joule target area: Design and processes

    International Nuclear Information System (INIS)

    Geitzholz, M.; Lanternier, C.

    2006-01-01

    The Laser Mega Joule (LMJ) target area is currently designed to achieve ignition and significant fusion gain in laboratory. LMJ will be composed of 240 identical large 370 mm * 370 mm square laser beams. These beams will focus 2 mega-joules of energy at the wavelength of 351 nm on the center of an experiment chamber. Design studies for target equipment are well advanced, target chamber and target holder (concrete) works have already begun. A detailed overview of the target area equipment is presented: target chamber, frame, diagnostic inserter manipulator, final optic assembly, dual diagnostic and laser reference, non cryogenic target positioner. Recent technical and architectural choices are detailed including safety transfers and alignment processes (target, laser and diagnostic). All this target equipment allows us to optimize shot chrono-gram, from target metrology to the shot, including calibration process. (authors)

  17. Radiation Target Area Sample Environmental Chamber (RTASEC), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Payload Systems Inc. proposes the Radiation Target Area Sample Environmental Chamber (RTASEC) as an innovative approach enabling radiobiologists to investigate the...

  18. NIF Maintenance Plan March 2011

    Energy Technology Data Exchange (ETDEWEB)

    Van Wonterghem, Bruno M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-01-30

    Ensuring the reliability of the NIF, including its support systems and utilities, is essential to ensuring the availability of the NIF in its support of laser operations. This document identifies the policies and procedures necessary to perform and support the maintenance of the NIF’s systems. These systems are all encompassing and include the facility, beampath, Line Replaceable Units (LRUs), Safety Interlock System (SIS), and diagnostics and utilities that create the environments within the beampath consisting of vacuum, argon, or clean dry air.

  19. Transport Simulations for Fast Ignition on NIF

    Energy Technology Data Exchange (ETDEWEB)

    Strozzi, D J; Tabak, M; Grote, D P; Cohen, B I; Shay, H D; Town, R J; Kemp, A J; Key, M

    2009-10-26

    We are designing a full hydro-scale cone-guided, indirect-drive FI coupling experiment, for NIF, with the ARC-FIDO short-pulse laser. Current rad-hydro designs with limited fuel jetting into cone tip are not yet adequate for ignition. Designs are improving. Electron beam transport simulations (implicit-PIC LSP) show: (1) Magnetic fields and smaller angular spreads increase coupling to ignition-relevant 'hot spot' (20 um radius); (2) Plastic CD (for a warm target) produces somewhat better coupling than pure D (cryogenic target) due to enhanced resistive B fields; and (3) The optimal T{sub hot} for this target is {approx} 1 MeV; coupling falls by 3x as T{sub hot} rises to 4 MeV.

  20. Improving privacy protection in the area of behavioural targeting

    NARCIS (Netherlands)

    Zuiderveen Borgesius, F.J.

    2014-01-01

    This PhD thesis discusses how European law could improve privacy protection in the area of behavioural targeting. Behavioural targeting, also referred to as online profiling, involves monitoring people’s online behaviour, and using the collected information to show people individually targeted

  1. National Ignition Facility (NIF) FY2015 Facility Use Plan

    Energy Technology Data Exchange (ETDEWEB)

    Folta, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wisoff, Jeff [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-12-18

    Major features of the FY2015 NIF Use Plan include: • Performing a record number of layered DT experiments with 28 planned compared with 15 in FY2014. Executing the first plutonium experiments on the NIF in support of the Science Campaigns. • Over 300 targets shots, a 57% increase compared to FY14. This is a stretch goal defined in the 120-Day Study document, and relies upon the success of many shot-rate improvement actions, as well as on the distribution of shot type selected by the users. While the Plan is consistent with this goal, the increased proportion of layered DT experiments described above reduces the margin against this goal. • Commissioning of initial ARC capability, which will support both SSP-HED and SSPICF programs. • Increase in days allocated to Discovery Science to a level that supports an ongoing program for academic use of NIF and an annual solicitation for new proposals. • Six Facility Maintenance and Reconfiguration (FM&R) periods totaling 30 days dedicated to major facility maintenance and modifications. • Utilization of the NIF Facility Advisory Schedule Committee (FASC) to provide stakeholder review and feedback on the NIF schedule. The Use Plan assumes a total FY2015 LLNL NIF Operations funding in MTE 10.7 of $229.465M and in MTE 10.3 of 47.0M. This Use Plan will be revised in the event of significant changes to the FY2015 funding or if NNSA provides FY2016 budget guidance significantly reduced compared to FY2015.

  2. Fast neutron dose equivalent rates in heavy ion target areas

    International Nuclear Information System (INIS)

    Fulmer, C.B.; Butler, H.M.; Ohnesorge, W.F.; Mosko, S.W.

    1978-01-01

    At heavy ion accelerators, personnel access to areas near the target is sometimes important for successful performance of experiments. Radiation levels determine the amount of time that can be spent in these areas without exceeding maximum permissible exposures. Inasmuch as the fast neutrons contribute the major part of the Rem dose rates in these areas, knowledge of the fast neutron levels is important for planning permissive entry to target areas. Fast neutron dose rates were measured near thick medium mass targets bombarded with beams of C, N, O, and Ne ions. beam energies ranged from 3 to 16 MeV/amu. Dose rates (mrem/h) 1 meter from the target 90 degrees from the beam direction range from approx. 0.05 at MeV/amu to approx. 50 at 16 MeV/amu. These data should be helpful in planning permissive entry to heavy ion target areas

  3. Fast neutron dose equivalent rates in heavy ion target areas

    Energy Technology Data Exchange (ETDEWEB)

    Fulmer, C.B.; Butler, H.M.; Ohnesorge, W.F.; Mosko, S.W.

    1978-01-01

    At heavy ion accelerators, personnel access to areas near the target is sometimes important for successful performance of experiments. Radiation levels determine the amount of time that can be spent in these areas without exceeding maximum permissible exposures. Inasmuch as the fast neutrons contribute the major part of the Rem dose rates in these areas, knowledge of the fast neutron levels is important for planning permissive entry to target areas. Fast neutron dose rates were measured near thick medium mass targets bombarded with beams of C, N, O, and Ne ions. beam energies ranged from 3 to 16 MeV/amu. Dose rates (mrem/h) 1 meter from the target 90 degrees from the beam direction range from approx. 0.05 at MeV/amu to approx. 50 at 16 MeV/amu. These data should be helpful in planning permissive entry to heavy ion target areas.

  4. NIF Laser Line Replaceable Units (LRUs)

    International Nuclear Information System (INIS)

    Larson, D W

    2003-01-01

    The National Ignition Facility (NIF) is designed with its high value optical systems in cassettes called Line Replaceable Units (LRUs). Virtually all of the NIF's active components are assembled in one of the ∼4000 electrical and optical LRUs that serve between two and eight of NIF's 192 laser beam lines. Many of these LRUs are optomechanical assemblies that are roughly the size of a telephone booth. The primary design challenges for this hardware include meeting stringent mechanical precision, stability and cleanliness requirements. Pre-production units of each LRU type have been fielded on the first bundle of NIF and used to demonstrate that NIF meets its performance objectives. This presentation provides an overview of the NIF LRUs, their design and production plans for building out the remaining NIF bundles

  5. NIF total neutron yield diagnostic

    International Nuclear Information System (INIS)

    Cooper, Gary W.; Ruiz, Carlos L.

    2001-01-01

    We have designed a total neutron yield diagnostic for the National Ignition Facility (NIF) which is based on the activation of In and Cu samples. The particular approach that we have chosen is one in which we calibrate the entire counting system and which we call the ''F factor'' method. In this method, In and/or Cu samples are exposed to known sources of DD and DT neutrons. The activated samples are then counted with an appropriate system: a high purity Ge detector for In and a NaI coincidence system for Cu. We can then calculate a calibration factor, which relates measured activity to total neutron yield. The advantage of this approach is that specific knowledge of such quantities as cross sections and detector efficiencies is not needed. Unless the actual scattering environment of the NIF can be mocked up in the calibration experiment, the F factor will have to be modified using the results of a numerical simulation of the NIF scattering environment. In this article, the calibration factor methodology will be discussed and experimental results for the calibration factors will be presented. Total NIF neutron yields of 10 9 --10 19 can be measured with this method assuming a 50 cm stand-off distance can be employed for the lower yields

  6. NIF Rugby High Foot Campaign from the design side

    Science.gov (United States)

    Leidinger, J.-P.; Callahan, D. A.; Berzak-Hopkins, L. F.; Ralph, J. E.; Amendt, P.; Hinkel, D. E.; Michel, P.; Moody, J. D.; Ross, J. S.; Rygg, J. R.; Celliers, P.; Clouët, J.-F.; Dewald, E. L.; Kaiser, P.; Khan, S.; Kritcher, A. L.; Liberatore, S.; Marion, D.; Masson-Laborde, P.-E.; Milovich, J. L.; Morice, O.; Pak, A. E.; Poujade, O.; Strozzi, D.; Hurricane, O. A.

    2016-05-01

    The NIF Rugby High Foot campaign results, with 8 shots to date, are compared with the 2D FCI2 design simulations. A special emphasis is placed on the predictive features and on those areas where some work is still required to achieve the best possible modelling of these MJ-class experiments.

  7. NIF unconverted light and its influence on DANTE measurements.

    Science.gov (United States)

    Girard, Frederic; Suter, Larry; Landen, Otto; Munro, Dave; Regan, Sean; Kline, John

    2009-06-01

    NIF laser facility produces 1053 nm light and a fundamental requirement for NIF is to give up to 1.8 MJ of 351 nm light for target physics experiments. The 351 nm light is provided by frequency tripling the 1053 nm light in nonlinear crystals in the final optics assembly, just before the laser light enters the target chamber. Since this tripling process is not 100% efficient, unconverted light from the conversion process also enters the chamber. This unconverted light does not directly hit the target but it can strike target support structures at average intensities of few TW/cm2 where it can generate unwanted, background soft x-rays that are measured by the soft x-ray diagnostic DANTE installed on the NIF target chamber. This diagnostic quantifies the x-radiation intensity inside the hohlraum by measuring the x-ray flux coming from the target's laser entrance hole. Due to its centimeter wide field of view, it integrates x-ray emission from both the flux exiting a hohlraum laser entrance hole and from the target support structure irradiated by residual 1omega and 2omega unconverted light. This work gives quantitative evaluations of the unconverted light for the first time and the effects on DANTE measurements for the future NIF tuning experiment called "Shock timing." Emission spectra are significantly modified leading to an overestimation of radiative temperature during the foot of the laser pulse since background x-rays are predominant in first two DANTE channel measurements. Mitigations of these effects by coating silicon paddle with plastic, using a smaller collimator to reduce DANTE field of view or eliminating DANTE channels in the analysis have been investigated.

  8. COATING AND MANDREL EFFECTS ON FABRICATION OF GLOW DISCHARGE POLYMER NIF SCALE INDIRECT DRIVE CAPSULES

    International Nuclear Information System (INIS)

    NIKROO, A.; PONTELANDOLFO, J.M.; CASTILLO, E.R.

    2002-01-01

    OAK A271 COATING AND MANDREL EFFECTS ON FABRICATION OF GLOW DISCHARGE POLYMER NIF SCALE INDIRECT DRIVE CAPSULES. Targets for the National Ignition Facility (NIF) need to be about 200 (micro)m thick and 2 mm in diameter. These dimensions are well beyond those currently fabricated on a routine basis. They have investigated fabrication of near NIF scale targets using the depolymerizable mandrel technique. Poly-alpha-methylstyrene (PAMS) mandrels, about 2 mm in diameter, of varying qualities were coated with as much as 125 (micro)m of glow discharge polymer (GDP). The surface finish of the final shells was examined using a variety of techniques. A clear dependence of the modal spectrum of final GDP shell on the quality of the initial PAMS mandrels was observed. isolated features were found to be the greatest cause for a shell not meeting the NIF standard

  9. Optomechanical considerations for the VISAR diagnostic at the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Morris I. Kaufman, John R. Celeste, Brent C. Frogget, Tony L. Lee, Brian J. GacGowan, Robert M. Malone, Edmund W. Ng, Tom W. Tunnell, Phillip W. Watts

    2006-01-01

    The National Ignition Facility (NIF) requires optical diagnostics for measuring shock velocities in shock physics experiments. The velocity interferometer for any reflector measures shock velocities at a location remote to the NIF target chamber. Our team designed two systems, one for a polar port orientation, and the other to accommodate two equatorial ports. The polar-oriented design requires a 48-m optical relay to move the light from inside the target chamber to a separately housed measurement and laser illumination station. The currently operational equatorial design requires a much shorter relay of 21 m. Both designs posed significant optomechanical challenges due to the long optical path length, large quantity of optical elements, and stringent NIF requirements. System design had to tightly control the use of lubricants and materials, especially those inside the vacuum chamber; tolerate earthquakes and radiation; and consider numerous other tolerance, alignment, and steering adjustment issues. To ensure compliance with NIF performance requirements, we conducted a finite element analysis

  10. The genome of Paenibacillus sabinae T27 provides insight into evolution, organization and functional elucidation of nif and nif-like genes.

    Science.gov (United States)

    Li, Xinxin; Deng, Zhiping; Liu, Zhanzhi; Yan, Yongliang; Wang, Tianshu; Xie, Jianbo; Lin, Min; Cheng, Qi; Chen, Sanfeng

    2014-08-27

    Most biological nitrogen fixation is catalyzed by the molybdenum nitrogenase. This enzyme is a complex which contains the MoFe protein encoded by nifDK and the Fe protein encoded by nifH. In addition to nifHDK, nifHDK-like genes were found in some Archaea and Firmicutes, but their function is unclear. We sequenced the genome of Paenibacillus sabinae T27. A total of 4,793 open reading frames were predicted from its 5.27 Mb genome. The genome of P. sabinae T27 contains fifteen nitrogen fixation (nif) genes, including three nifH, one nifD, one nifK, four nifB, two nifE, two nifN, one nifX and one nifV. Of the 15 nif genes, eight nif genes (nifB, nifH, nifD, nifK, nifE, nifN, nifX and nifV) and two non-nif genes (orf1 and hesA) form a complete nif gene cluster. In addition to the nif genes, there are nitrogenase-like genes, including two nifH-like genes and five pairs of nifDK-like genes. IS elements on the flanking regions of nif and nif-like genes imply that these genes might have been obtained by horizontal gene transfer. Phylogenies of the concatenated 8 nif gene (nifB, nifH, nifD, nifK, nifE, nifN, nifX and nifV) products suggest that P. sabinae T27 is closely related to Frankia. RT-PCR analysis showed that the complete nif gene cluster is organized as an operon. We demonstrated that the complete nif gene cluster under the control of σ70-dependent promoter enabled Escherichia coli JM109 to fix nitrogen. Also, here for the first time we demonstrated that unlike nif genes, the transcriptions of nifHDK-like genes were not regulated by ammonium and oxygen, and nifH-like or nifD-like gene could not restore the nitrogenase activity of Klebsiella pneumonia nifH- and nifD- mutant strains, respectively, suggesting that nifHDK-like genes were not involved in nitrogen fixation. Our data and analysis reveal the contents and distribution of nif and nif-like genes and contribute to the study of evolutionary history of nitrogen fixation in Paenibacillus. For the first time we

  11. The National Ignition Facility (NIF) Diagnostic Set at the Completion of the National Ignition Campaign (NIC) September 2013

    Energy Technology Data Exchange (ETDEWEB)

    Kilkenny, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bell, P. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bradley, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bleuel, D. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Caggiano, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dewald, E. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hsing, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kalantar, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kauffman, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Moody, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shaughnessy, D. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shelton, R. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Yeamans, C. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Batha, S. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Grim, G. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Herrmann, H. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Merrill, F. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Leeper, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sangster, T. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Edgell, D. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glebov, V. Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Regan, S. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Frenje, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gatu-Johnson, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Petrasso, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rindernecht, H. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zylstra, A. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cooper, G. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ruiz, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-05

    At the completion of the National Ignition Campaign NIF had about 36 different types of diagnostics. These were based on several decades of development on Nova and OMEGA and involved the whole US ICF community. A plan for a limited of NIF Diagnostics was documented by the Joint Central Diagnostic Team in the NIF Conceptual Design Report in 1994. These diagnostics and many more were installed diagnostics by two decades later. We give a short description of each of the 36 different types of NIC diagnostics grouped by the function of the diagnostics, namely target drive, target response and target assembly, stagnation and burn. A comparison of NIF diagnostics with the Nova diagnostics shows that the NIF diagnostic capability is broadly equivalent to that of Nova’s in 1999. NIF diagnostics have a much greater degree of automation and rigor than Nova’s and the NIF diagnostic suite incorporates some scientific innovation compared to Nova and OMEGA namely one much higher speed x-ray imager. Directions for future NIF diagnostics are discussed.

  12. Federated access to heterogeneous information resources in the Neuroscience Information Framework (NIF).

    Science.gov (United States)

    Gupta, Amarnath; Bug, William; Marenco, Luis; Qian, Xufei; Condit, Christopher; Rangarajan, Arun; Müller, Hans Michael; Miller, Perry L; Sanders, Brian; Grethe, Jeffrey S; Astakhov, Vadim; Shepherd, Gordon; Sternberg, Paul W; Martone, Maryann E

    2008-09-01

    The overarching goal of the NIF (Neuroscience Information Framework) project is to be a one-stop-shop for Neuroscience. This paper provides a technical overview of how the system is designed. The technical goal of the first version of the NIF system was to develop an information system that a neuroscientist can use to locate relevant information from a wide variety of information sources by simple keyword queries. Although the user would provide only keywords to retrieve information, the NIF system is designed to treat them as concepts whose meanings are interpreted by the system. Thus, a search for term should find a record containing synonyms of the term. The system is targeted to find information from web pages, publications, databases, web sites built upon databases, XML documents and any other modality in which such information may be published. We have designed a system to achieve this functionality. A central element in the system is an ontology called NIFSTD (for NIF Standard) constructed by amalgamating a number of known and newly developed ontologies. NIFSTD is used by our ontology management module, called OntoQuest to perform ontology-based search over data sources. The NIF architecture currently provides three different mechanisms for searching heterogeneous data sources including relational databases, web sites, XML documents and full text of publications. Version 1.0 of the NIF system is currently in beta test and may be accessed through http://nif.nih.gov.

  13. At the interface of the auditory and vocal motor systems: NIf and its role in vocal processing, production and learning.

    Science.gov (United States)

    Lewandowski, Brian; Vyssotski, Alexei; Hahnloser, Richard H R; Schmidt, Marc

    2013-06-01

    Communication between auditory and vocal motor nuclei is essential for vocal learning. In songbirds, the nucleus interfacialis of the nidopallium (NIf) is part of a sensorimotor loop, along with auditory nucleus avalanche (Av) and song system nucleus HVC, that links the auditory and song systems. Most of the auditory information comes through this sensorimotor loop, with the projection from NIf to HVC representing the largest single source of auditory information to the song system. In addition to providing the majority of HVC's auditory input, NIf is also the primary driver of spontaneous activity and premotor-like bursting during sleep in HVC. Like HVC and RA, two nuclei critical for song learning and production, NIf exhibits behavioral-state dependent auditory responses and strong motor bursts that precede song output. NIf also exhibits extended periods of fast gamma oscillations following vocal production. Based on the converging evidence from studies of physiology and functional connectivity it would be reasonable to expect NIf to play an important role in the learning, maintenance, and production of song. Surprisingly, however, lesions of NIf in adult zebra finches have no effect on song production or maintenance. Only the plastic song produced by juvenile zebra finches during the sensorimotor phase of song learning is affected by NIf lesions. In this review, we carefully examine what is known about NIf at the anatomical, physiological, and behavioral levels. We reexamine conclusions drawn from previous studies in the light of our current understanding of the song system, and establish what can be said with certainty about NIf's involvement in song learning, maintenance, and production. Finally, we review recent theories of song learning integrating possible roles for NIf within these frameworks and suggest possible parallels between NIf and sensorimotor areas that form part of the neural circuitry for speech processing in humans. Copyright © 2013 Elsevier

  14. Progress towards polar-drive ignition for the NIF

    International Nuclear Information System (INIS)

    McCrory, R.L.; Betti, R.; Boehly, T.R.; Collins, T.J.B.; Craxton, R.S.; Delettrez, J.A.; Edgell, D.H.; Epstein, R.; Froula, D.H.; Glebov, V.Yu.; Goncharov, V.N.; Harding, D.R.; Hohenberger, M.; Hu, S.X.; Igumenshchev, I.V.; Kessler, T.J.; Knauer, J.P.; Casey, D.T.; Frenje, J.A.; Gatu-Johnson, M.

    2013-01-01

    The University of Rochester's Laboratory for Laser Energetics (LLE) performs direct-drive inertial confinement fusion (ICF) research. LLE's Omega Laser Facility is used to study direct-drive ICF ignition concepts, developing an understanding of the underlying physics that feeds into the design of ignition targets for the National Ignition Facility (NIF). The baseline symmetric-illumination, direct-drive–ignition target design consists of a 1.5 MJ multiple-picket laser pulse that generates four shock waves (similar to the NIF baseline indirect-drive design) and is predicted to produce a one-dimensional (1D) gain of 48. LLE has developed the polar-drive (PD) illumination concept (for NIF beams in the x-ray–drive configuration) to allow the pursuit of direct-drive ignition without significant reconfiguration of the beam paths on the NIF. Some less-invasive changes in the NIF infrastructure will be required, including new phase plates, polarization rotators, and a PD-specific beam-smoothing front end. A suite of PD ignition designs with implosion velocities from 3.5 to 4.3 × 10 7 cm s −1 are predicted to have significant 2D gains (Collins et al 2012 Bull. Am. Phys. Soc. 57 155). Verification of the physics basis of these simulations is a major thrust of direct-drive implosion experiments on both OMEGA and the NIF. Many physics issues are being examined with symmetric beam irradiation on OMEGA, varying the implosion parameters over a wide region of design space. Cryogenic deuterium–tritium target experiments with symmetric irradiation have produced areal densities of ∼0.3 g cm −2 , ion temperatures over 3 keV, and neutron yields in excess of 20% of the ‘clean’ 1D predicted value. The inferred Lawson criterion figure of merit (Betti R. et al 2010 Phys. Plasmas 17 058102) has increased from 1.7 atm s (IAEA 2010) to 2.6 atm s. (paper)

  15. Targeting global protected area expansion for imperiled biodiversity.

    Science.gov (United States)

    Venter, Oscar; Fuller, Richard A; Segan, Daniel B; Carwardine, Josie; Brooks, Thomas; Butchart, Stuart H M; Di Marco, Moreno; Iwamura, Takuya; Joseph, Liana; O'Grady, Damien; Possingham, Hugh P; Rondinini, Carlo; Smith, Robert J; Venter, Michelle; Watson, James E M

    2014-06-01

    Governments have agreed to expand the global protected area network from 13% to 17% of the world's land surface by 2020 (Aichi target 11) and to prevent the further loss of known threatened species (Aichi target 12). These targets are interdependent, as protected areas can stem biodiversity loss when strategically located and effectively managed. However, the global protected area estate is currently biased toward locations that are cheap to protect and away from important areas for biodiversity. Here we use data on the distribution of protected areas and threatened terrestrial birds, mammals, and amphibians to assess current and possible future coverage of these species under the convention. We discover that 17% of the 4,118 threatened vertebrates are not found in a single protected area and that fully 85% are not adequately covered (i.e., to a level consistent with their likely persistence). Using systematic conservation planning, we show that expanding protected areas to reach 17% coverage by protecting the cheapest land, even if ecoregionally representative, would increase the number of threatened vertebrates covered by only 6%. However, the nonlinear relationship between the cost of acquiring land and species coverage means that fivefold more threatened vertebrates could be adequately covered for only 1.5 times the cost of the cheapest solution, if cost efficiency and threatened vertebrates are both incorporated into protected area decision making. These results are robust to known errors in the vertebrate range maps. The Convention on Biological Diversity targets may stimulate major expansion of the global protected area estate. If this expansion is to secure a future for imperiled species, new protected areas must be sited more strategically than is presently the case.

  16. Target area for Nova upgrade: Containing ignition and beyond

    International Nuclear Information System (INIS)

    Tobin, M.T.; Smith, J.R.; Campbell, D.; Wong, D.K.; Sullivan, J.A.; Pendergrass, J.; Weinstein, B.; Klein, M.

    1991-01-01

    The Lawrence Livermore National Laboratory (LLNL) is developing a conceptual design for upgrading the Nova laser from ∼ 50 kJ to ∼ 1.8 MJ of laser energy at a wavelength of 351 nm. Anticipated target performance includes achieving ignition and possibly fusion yields to 20 MJ. The target area design represents a unique challenge since it will be operating in a regime where first wall ablation and optics damage are major issues for the first time in an ICF facility. Here we describe potential performance criteria for the facility and anticipated yield-dependent x-ray, neutron, shrapnel, and debris environments. We also briefly describe the different systems that make up the target area and discuss some of the design issues. The insignificant environmental impact Nova Upgrade (NU) operations is anticipated to have on the laboratory and surrounding area is discussed. Finally, alternate design options are described along with their potential benefits

  17. Harmonizing outdoor recreation and bird conservation targets in protected areas

    NARCIS (Netherlands)

    Pouwels, Rogier; Sierdsema, Henk; Foppen, Ruud P.B.; Henkens, René J.H.G.; Opdam, Paul F.M.; Eupen, van Michiel

    2017-01-01

    In protected areas managers have to achieve conservation targets while providing opportunities for outdoor recreation. This dual mandate causes conflicts in choosing between management options. Furthermore, the persistence of a protected species within the management unit often depends on how

  18. NIF Double Shell outer/inner shell collision experiments

    Science.gov (United States)

    Merritt, E. C.; Loomis, E. N.; Wilson, D. C.; Cardenas, T.; Montgomery, D. S.; Daughton, W. S.; Dodd, E. S.; Desjardins, T.; Renner, D. B.; Palaniyappan, S.; Batha, S. H.; Khan, S. F.; Smalyuk, V.; Ping, Y.; Amendt, P.; Schoff, M.; Hoppe, M.

    2017-10-01

    Double shell capsules are a potential low convergence path to substantial alpha-heating and ignition on NIF, since they are predicted to ignite and burn at relatively low temperatures via volume ignition. Current LANL NIF double shell designs consist of a low-Z ablator, low-density foam cushion, and high-Z inner shell with liquid DT fill. Central to the Double Shell concept is kinetic energy transfer from the outer to inner shell via collision. The collision determines maximum energy available for compression and implosion shape of the fuel. We present results of a NIF shape-transfer study: two experiments comparing shape and trajectory of the outer and inner shells at post-collision times. An outer-shell-only target shot measured the no-impact shell conditions, while an `imaging' double shell shot measured shell conditions with impact. The `imaging' target uses a low-Z inner shell and is designed to perform in similar collision physics space to a high-Z double shell but can be radiographed at 16keV, near the viable 2DConA BL energy limit. Work conducted under the auspices of the U.S. DOE by LANL under contract DE-AC52-06NA25396.

  19. Behavioral Model of High Performance Camera for NIF Optics Inspection

    International Nuclear Information System (INIS)

    Hackel, B M

    2007-01-01

    The purpose of this project was to develop software that will model the behavior of the high performance Spectral Instruments 1000 series Charge-Coupled Device (CCD) camera located in the Final Optics Damage Inspection (FODI) system on the National Ignition Facility. NIF's target chamber will be mounted with 48 Final Optics Assemblies (FOAs) to convert the laser light from infrared to ultraviolet and focus it precisely on the target. Following a NIF shot, the optical components of each FOA must be carefully inspected for damage by the FODI to ensure proper laser performance during subsequent experiments. Rapid image capture and complex image processing (to locate damage sites) will reduce shot turnaround time; thus increasing the total number of experiments NIF can conduct during its 30 year lifetime. Development of these rapid processes necessitates extensive offline software automation -- especially after the device has been deployed in the facility. Without access to the unique real device or an exact behavioral model, offline software testing is difficult. Furthermore, a software-based behavioral model allows for many instances to be running concurrently; this allows multiple developers to test their software at the same time. Thus it is beneficial to construct separate software that will exactly mimic the behavior and response of the real SI-1000 camera

  20. Recent advances in indirect drive ICF target physics

    International Nuclear Information System (INIS)

    Hammel, B.A.

    2002-01-01

    The National Ignition Facility (NIF), currently under construction, will be used for the study of ignition physics in inertially confined targets, as well as basic and applied research in the field of high energy density science. In preparing for ignition on the NIF, the Lawrence Livermore National Laboratory's Inertial Confinement Fusion Program, in collaboration with Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), the Laboratory for Laser Energetics (LLE), General Atomics (GA), and the Commissariat a l'Energie Atomique (CEA), is working to refine ignition designs, develop improved experimental methods, and fabricate and test cryogenic targets required for ignition. This paper will briefly review NIF construction progress, and summarize advances in these areas. (author)

  1. Advances in inertial confinement fusion at the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Moses, Edward I.

    2010-01-01

    The 192-beam National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational and conducting experiments. NIF, the flagship facility of the U.S. Inertial Confinement Fusion (ICF) Program, will achieve high-energy-density conditions never previously obtained in the laboratory-temperatures over 100 million K, densities of 1000 g/cm 3 , and pressures exceeding 100 billion atmospheres. Such conditions exist naturally only in the interiors of the stars and during thermonuclear burn. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. To date, the NIF laser has demonstrated all pulse shape, beam quality, energy, and other specifications required to meet the ignition challenge. On March 10, 2009, the NIF laser delivered 1.1 MJ of ultraviolet laser energy to target chamber center, approximately 30 times more energy than any previous facility. The ignition program at NIF is the National Ignition Campaign (NIC), a national collaboration for ignition experimentation with participation from General Atomics, LLNL, Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the University of Rochester Laboratory for Laser Energetics (LLE). The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on fusion as a viable energy option. A particular energy concept under investigation is the LIFE (Laser Inertial Fusion Energy) scheme. The LIFE engine is inherently safe, minimizes proliferation concerns associated with the nuclear fuel cycle, and can provide a sustainable carbon-free energy generation solution in the 21st century. This talk will describe NIF and its potential as a user facility and an experimental platform for high-energy-density science, NIC, and the LIFE approach for clean, sustainable energy.

  2. Advances in Inertial Confinement Fusion at the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Moses, E.

    2009-01-01

    The 192-beam National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational and conducting experiments. NIF, the flagship facility of the U.S. Inertial Confinement Fusion (ICF) Program, will achieve high-energy-density conditions never previously obtained in the laboratory - temperatures over 100 million K, densities of 1,000 g/cm3, and pressures exceeding 100 billion atmospheres. Such conditions exist naturally only in the interiors of the stars and during thermonuclear burn. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. To date, the NIF laser has demonstrated all pulse shape, beam quality, energy, and other specifications required to meet the ignition challenge. On March 10, 2009, the NIF laser delivered 1.1 MJ of ultraviolet laser energy to target chamber center, approximately 30 times more energy than any previous facility. The ignition program at NIF is the National Ignition Campaign (NIC), a national collaboration for ignition experimentation with participation from General Atomics, LLNL, Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the University of Rochester Laboratory for Laser Energetics (LLE). The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on fusion as a viable energy option. A particular energy concept under investigation is the LIFE (Laser Inertial Fusion Energy) scheme. The LIFE engine is inherently safe, minimizes proliferation concerns associated with the nuclear fuel cycle, and can provide a sustainable carbon-free energy generation solution in the 21st century. This talk will describe NIF and its potential as a user facility and an experimental platform for high-energy-density science, NIC, and the LIFE approach for clean, sustainable energy.

  3. Tilted bending magnet for SPS target area TCC2

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    A slow-extracted proton beam from the SPS goes to the underground target zone TCC2. The part of the primary beam which traverses target T4 is recuperated and transported over some 800 m, for further use in the North Area High Intensity facility (NAHIF). The curved and sloped trajectory required 4 of the bending magnets to be tilted. Here we see one of them being attended by Gilbert Françon in hall 867, ready for installation in TCC2.

  4. FANTM, the First Article NIF Test Module

    International Nuclear Information System (INIS)

    HAMMON, JUD; HARJES, HENRY C.; MOORE, WILLIAM B.S.; SMITH, DAVID L.; WILSON, J. MICHAEL

    1999-01-01

    Designing and developing the 1.7 to 2.1-MJ Power Conditioning System (PCS), that will power the flashlamps of the main and power amplifiers for the National Ignition Facility (NIF) lasers, is one of several responsibilities assumed by Sandia National Labs (SNL) in support of the NIF Project. Maxwell Physics International has been a partner in this process. The NIF is currently being constructed at Lawrence Livermore National Labs (LLNL). The test facility that has evolved over the last three years to satisfy the project requirements is called FANTM, for the First Article NIF Test Module. It was built at SNL and operated for about 17,000 shots to demonstrate component performance expectations over the lifetime of NIF. A few modules similar to the one shown in Fig. 1 will be used initially in the amplifier test phase of the project. The final full NIF system will require at least 192 of them in four capacitor bays. This paper briefly summarizes the final design of the FANTM facility and compares its performance with the predictions of circuit simulations for both normal operation and fault-mode response. Applying both the measured and modeled power pulse waveforms as input to a physics-based, semi-empirical amplifier gain code indicates that the 20-capacitor PCS can satisfy the NIF requirement for an average gain coefficient of 5.00 %/cm and can exceed 5.20 %/cm with 24 capacitors

  5. Progress on establishing guidelines for National Ignition Facility (NIF) experiments to extend debris shield lifetime

    International Nuclear Information System (INIS)

    Tobin, M.; Eder, D.; Braun, D.; MacGowan, B.

    2002-01-01

    The survivability of the debris shields on the National Ignition Facility (NIF) are a key factor for the affordable operation of the facility. The improvements required over Nova debris shields are described. Estimates of debris shield lifetimes in the presence of target emissions with 4-8 J/cm 2 laser fluences indicate lifetimes that may contribute unacceptably to operations costs for NIF. We are developing detailed suggested guidance for target and experiment designers for NIF to assist in minimizing the damage to, and therefore the cost of, maintaining NIF debris shields. The guidance suggests a target mass quantity that as particulate on the debris shields (300 mg) may be within current operating budgets. It also suggests the amount of material that should become shrapnel on a shot (10 mg). Finally, it suggests the level of non-volatile residue (NVR) that would threaten the sol-gel coatings on the debris shields (1 μg/cm 2 ). We review the experimentation on the Nova chamber that included measuring quantities of particulate on debris shields by element and capturing shrapnel pieces in aerogel samples mounted in the chamber. We also describe computations of X-ray emissions from a likely NIF target and the associated ablation expected from this X-ray exposure on supporting target hardware. We describe progress in assessing the benefits of a pre-shield and the possible impact on the guidance for target experiments on NIF. Plans for possible experimentation on Omega and other facilities to improve our understanding of target emissions and their impacts are discussed. Our discussion of planned future work provides a forum to invite possible collaboration with the IFE community

  6. Analysis of hohlraum energetics of the SG series and the NIF experiments with energy balance model

    Directory of Open Access Journals (Sweden)

    Guoli Ren

    2017-01-01

    Full Text Available The basic energy balance model is applied to analyze the hohlraum energetics data from the Shenguang (SG series laser facilities and the National Ignition Facility (NIF experiments published in the past few years. The analysis shows that the overall hohlraum energetics data are in agreement with the energy balance model within 20% deviation. The 20% deviation might be caused by the diversity in hohlraum parameters, such as material, laser pulse, gas filling density, etc. In addition, the NIF's ignition target designs and our ignition target designs given by simulations are also in accordance with the energy balance model. This work confirms the value of the energy balance model for ignition target design and experimental data assessment, and demonstrates that the NIF energy is enough to achieve ignition if a 1D spherical radiation drive could be created, meanwhile both the laser plasma instabilities and hydrodynamic instabilities could be suppressed.

  7. AA, radiation shielding curtain along the target area

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    At the far left is the beam tube for the high-intensity proton beam from the 26 GeV PS. The tube ends in a thin window and the proton beam continues in air through a hole in the shielding blocks (see also 8010308), behind which the target (see 7905091, 7905094)was located. After the target followed the magnetic horn, focusing the antiprotons, and the first part of the injection line with a proton dump. The antiprotons, deflected by a magnet, left the target area through another shielding wall, to make their way to the AA ring. Laterally, this sequence of components was shielded with movable, suspended, concrete blocks: the "curtain". Balasz Szeless, who had constructed it, is standing at its side.

  8. Rare isotope accelerator—conceptual design of target areas

    Science.gov (United States)

    Bollen, Georg; Baek, Inseok; Blideanu, Valentin; Lawton, Don; Mantica, Paul F.; Morrissey, David J.; Ronningen, Reginald M.; Sherrill, Bradley S.; Zeller, Albert; Beene, James R.; Burgess, Tom; Carter, Kenneth; Carrol, Adam; Conner, David; Gabriel, Tony; Mansur, Louis; Remec, Igor; Rennich, Mark; Stracener, Dan; Wendel, Mark; Ahle, Larry; Boles, Jason; Reyes, Susana; Stein, Werner; Heilbronn, Lawrence

    2006-06-01

    The planned rare isotope accelerator facility RIA in the US would become the most powerful radioactive beam facility in the world. RIA's driver accelerator will be a device capable of providing beams from protons to uranium at energies of at least 400 MeV per nucleon, with beam power up to 400 kW. Radioactive beam production relies on both the in-flight separation of fast beam fragments and on the ISOL technique. In both cases the high beam power poses major challenges for target technology and handling and on the design of the beam production areas. This paper will give a brief overview of RIA and discuss aspects of ongoing conceptual design work for the RIA target areas.

  9. Rare Isotope Accelerator - Conceptual Design of Target Areas

    Energy Technology Data Exchange (ETDEWEB)

    Bollen, Georg [Michigan State University, East Lansing; Baek, Inseok [Michigan State University, East Lansing; Blideanu, Valentin [CEA, Saclay, France; Lawton, Don [Michigan State University, East Lansing; Mantica, Paul F. [Michigan State University, East Lansing; Morrissey, David J. [Michigan State University, East Lansing; Ronningen, Reginald M. [Michigan State University, East Lansing; Sherrill, Bradley S. [Michigan State University, East Lansing; Zeller, Albert [Michigan State University, East Lansing; Beene, James R [ORNL; Burgess, Tom [Oak Ridge National Laboratory (ORNL); Carter, Kenneth [Oak Ridge National Laboratory (ORNL); Carrol, Adam [Oak Ridge National Laboratory (ORNL); Conner, David [ORNL; Gabriel, Tony A [ORNL; Mansur, Louis K [ORNL; Remec, Igor [ORNL; Rennich, Mark J [ORNL; Stracener, Daniel W [ORNL; Wendel, Mark W [ORNL; Ahle, Larry [Lawrence Livermore National Laboratory (LLNL); Boles, Jason [Lawrence Livermore National Laboratory (LLNL); Reyes, Susana [Lawrence Livermore National Laboratory (LLNL); Stein, Werner [Lawrence Livermore National Laboratory (LLNL); Heilbronn, Lawrence [Lawrence Berkeley National Laboratory (LBNL)

    2006-01-01

    The planned rare isotope accelerator facility RIA in the US would become the most powerful radioactive beam facility in the world. RIA s driver accelerator will be a device capable of providing beams from protons to uranium at energies of at least 400MeV per nucleon, with beam power up to 400 kW. Radioactive beam production relies on both the in-flight separation of fast beam fragments and on the ISOL technique. In both cases the high beam power poses major challenges for target technology and handling and on the design of the beam production areas. This paper will give a brief overview of RIA and discuss aspects of ongoing conceptual design work for the RIA target areas.

  10. Rare isotope accelerator - conceptual design of target areas

    International Nuclear Information System (INIS)

    Bollen, Georg; Baek, Inseok; Blideanu, Valentin; Lawton, Don; Mantica, Paul F.; Morrissey, David J.; Ronningen, Reginald M.; Sherrill, Bradley S.; Zeller, Albert; Beene, James R; Burgess, Tom; Carter, Kenneth; Carrol, Adam; Conner, David; Gabriel, Tony A; Mansur, Louis K; Remec, Igor; Rennich, Mark J; Stracener, Daniel W; Wendel, Mark W; Ahle, Larry; Boles, Jason; Reyes, Susana; Stein, Werner; Heilbronn, Lawrence

    2006-01-01

    The planned rare isotope accelerator facility RIA in the US would become the most powerful radioactive beam facility in the world. RIA's driver accelerator will be a device capable of providing beams from protons to uranium at energies of at least 400MeV per nucleon, with beam power up to 400 kW. Radioactive beam production relies on both the in-flight separation of fast beam fragments and on the ISOL technique. In both cases the high beam power poses major challenges for target technology and handling and on the design of the beam production areas. This paper will give a brief overview of RIA and discuss aspects of ongoing conceptual design work for the RIA target areas

  11. Rare isotope accelerator-conceptual design of target areas

    Energy Technology Data Exchange (ETDEWEB)

    Bollen, Georg [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States)]. E-mail: bollen@nscl.msu.edu; Baek, Inseok; Blideanu, Valentin; Lawton, Don; Mantica, Paul F.; Morrissey, David J.; Ronningen, Reginald M.; Sherrill, Bradley S.; Zeller, Albert [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Beene, James R.; Burgess, Tom; Carter, Kenneth; Carrol, Adam; Conner, David; Gabriel, Tony; Mansur, Louis; Remec, Igor; Rennich, Mark; Stracener, Dan; Wendel, Mark [Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States); Ahle, Larry; Boles, Jason; Reyes, Susana; Stein, Werner [Lawrence Livermore Laboratory, Livermore, CA 94550 (United States); Heilbronn, Lawrence [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2006-06-23

    The planned rare isotope accelerator facility RIA in the US would become the most powerful radioactive beam facility in the world. RIA's driver accelerator will be a device capable of providing beams from protons to uranium at energies of at least 400 MeV per nucleon, with beam power up to 400 kW. Radioactive beam production relies on both the in-flight separation of fast beam fragments and on the ISOL technique. In both cases the high beam power poses major challenges for target technology and handling and on the design of the beam production areas. This paper will give a brief overview of RIA and discuss aspects of ongoing conceptual design work for the RIA target areas.

  12. Orchestrating Shots for the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Mathisen, D G; Bettenhausen, R C; Beeler, R G; Bowers, G A; Carey, R W; Casavant, D D; Cline, B D; Demaret, R D; Domyancic, D M; Elko, S D; Fisher, J M; Krammen, J E; Lagin, L J; Ludwigsen, A P; Patterson, R W; Sanchez, R J; Stout, E A

    2005-01-01

    The National Ignition Facility (NIF), currently under construction at the Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8 Megajoule, 500-Terawatt, ultra-violet laser system together with a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. When completed, NIF will be the world's largest and most energetic laser experimental system, providing an international center to study inertial confinement fusion and physics of matter at extreme densities and pressures. The NIF is operated by the Integrated Computer Control System (ICCS), which is a layered architecture of over 700 lower-level front-end processors attached to nearly 60,000 control points and coordinated by higher-level supervisory subsystems in the main control room. A shot automation framework has been developed and deployed during the past year to orchestrate and automate shots performed at the NIF using the ICCS. The Shot Automation framework is designed to automate 4-8 hour shot sequences, that includes deriving shot goals from an experiment definition, set up of the laser and diagnostics, automatic alignment of laser beams, and a countdown to charge and fire the lasers. These sequences consist of set of preparatory verification shots, leading to amplified system shots followed by post-shot analysis and archiving. The framework provides for a flexible, model-based work-flow execution, driven by scripted automation called macro steps. The shot director software is the orchestrating component of a very flexible automation layer which allows us to define, coordinate and reuse simpler automation sequences. This software provides a restricted set of shot life cycle state transitions to 26 collaboration supervisors that automate 8-laser beams (bundle) and a common set of shared resources. Each collaboration supervisor commands approximately 10 subsystem shot supervisors that perform automated control and status verification

  13. Enhanced NIF neutron activation diagnostics.

    Science.gov (United States)

    Yeamans, C B; Bleuel, D L; Bernstein, L A

    2012-10-01

    The NIF neutron activation diagnostic suite relies on removable activation samples, leading to operational inefficiencies and a fundamental lower limit on the half-life of the activated product that can be observed. A neutron diagnostic system measuring activation of permanently installed samples could remove these limitations and significantly enhance overall neutron diagnostic capabilities. The physics and engineering aspects of two proposed systems are considered: one measuring the (89)Zr/(89 m)Zr isomer ratio in the existing Zr activation medium and the other using potassium zirconate as the activation medium. Both proposed systems could improve the signal-to-noise ratio of the current system by at least a factor of 5 and would allow independent measurement of fusion core velocity and fuel areal density.

  14. OMEGA ICF experiments and preparations for direct drive on NIF

    International Nuclear Information System (INIS)

    McCrory, R.L.; Bahr, R.E.; Betti, R.

    2001-01-01

    Direct-drive laser-fusion ignition experiments rely on detailed understanding and control of irradiation uniformity, the Rayleigh-Taylor instability, and target fabrication. LLE is investigating various theoretical aspects of a direct-drive NIF ignition target based on an 'all-DT' design: a spherical target of ∼3.4-mm diameter, 1 to 2 μm of CH wall thickness, and an ∼340-μm DT-ice layer near the triple point of DT (∼19 K). OMEGA experiments are designed to address the critical issues related to direct-drive laser fusion and to provide the necessary data to validate the predictive capability of LLE computer codes. The cryogenic targets to be used on OMEGA are hydrodynamically equivalent to those planned for the NIF. The current experimental studies on OMEGA address the essential components of direct-drive laser fusion: irradiation uniformity and laser imprinting, Rayleigh-Taylor growth and saturation, compressed core performance and shell fuel mixing, laser plasma interactions and their effect on target performance, and cryogenic target fabrication and handling. (author)

  15. Producing KDP and DKDP crystals for the NIF laser

    International Nuclear Information System (INIS)

    Atherton, L. J.; Burnham, A. K.; Combs, R. C.; Couture, S. A.; De Yoreo, J. J.; Hawley-Fedder, R. A.; Montesant, R. C.; Robey, H. F.; Runkel, M.; Staggs, M.; Wegner, P. J.; Yan, M.; Zaitseva, N. P.

    1999-01-01

    The cost and physics requirements of the NIF have established two important roles for potassium dihydrogen phosphate (KDP) crystals. 1. To extract more laser energy per unit of flashlamp light and laser glass, the NIF has adopted a multipass architecture as shown in Figure 1. Light is injected in the transport spatial filter, first traverses the power amplifiers, and then is directed to main amplifiers, where it makes four passes before being redirected through the power amplifiers towards the target. To enable the multipass of the main amplifiers, a KDP-containing Pockels cell rotates the polarization of the beam to make it either transmit through or reflect off a polarizer held at Brewster's angle within the main laser cavity. If transmitted, the light reflects off a mirror and makes another pass through the cavity. If reflected, it proceeds through the power amplifier to the target. the original seed crystal as the pyramid faces grow. Unfortunately, this pyramidal growth is very slow, and it takes about two years to grow a crystal to NIF size. To provide more programmatic flexibility and reduce costs in the long run, we have developed an alternative technology commonly called rapid growth. Through a combination of higher temperatures and higher supersaturation of the growth solution, a NIF-size boule can be grown in 1 to 2 months from a small ''point'' seed. However, growing boules of adequate size is not sufficient. Care must be taken to prevent inclusions of growth solution and incorporation of atomically substituted 2. Implosions for ICF work far better at shorter wavelengths due to less generation of hot electrons, which preheat the fuel and make it harder to compress. Compromising between optic lifetime and implosion efficiency, both Nova and the NIF operate at a tripled frequency of the 1053-nm fundamental frequency of a neodymium glass laser. This tripling is accomplished by two crystals, one made of KDP and one made of deuterated KDP (DKDP). The first

  16. Advances in NIF Shock Timing Experiments

    Science.gov (United States)

    Robey, Harry

    2012-10-01

    Experiments are underway to tune the shock timing of capsule implosions on the National Ignition Facility (NIF). These experiments use a modified cryogenic hohlraum geometry designed to precisely match the performance of ignition hohlraums. The targets employ a re-entrant Au cone to provide optical access to multiple shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of all four shocks is diagnosed with VISAR (Velocity Interferometer System for Any Reflector). Experiments are now routinely conducted in a mirrored keyhole geometry, which allows for simultaneous diagnosis of the shock timing at both the hohlraum pole and equator. Further modifications are being made to improve the surrogacy to ignition hohlraums by replacing the standard liquid deuterium (D2) capsule fill with a deuterium-tritium (DT) ice layer. These experiments will remove any possible surrogacy difference between D2 and DT as well as incorporate the physics of shock release from the ice layer, which is absent in current experiments. Experimental results and comparisons with numerical simulation are presented.

  17. TARGET - NEW PAYMENT SYSTEM FOR THE EURO AREA

    Directory of Open Access Journals (Sweden)

    ELENA VIOLETA DRĂGOI

    2015-04-01

    Full Text Available At EU level, the funds transfer systems have undergone significant changes starting with the introduction of euro. The launch of the euro, the emergence of new technologies, introduction of financial innovations and the globalization have led to reorganization of funds transfer systems` infrastructure. The paper aims to offer an analysis of actual payment system for Euro area, a trans-European funds transfer system with gross settlement in real-time for payments in euro TARGET- to increase economical and operational efficiency of payments and also to reduce the risks in the electronic funds transfer system by creating efficient and secure payment systems.

  18. THE LOW BACKSCATTERING TARGETS CLASSIFICATION IN URBAN AREAS

    Directory of Open Access Journals (Sweden)

    L. Shi

    2012-07-01

    Full Text Available The Polarimetric and Interferometric Synthetic Aperture Radar (POLINSAR is widely used in urban area nowadays. Because of the physical and geometric sensitivity, the POLINSAR is suitable for the city classification, power-lines detection, building extraction, etc. As the new X-band POLINSAR radar, the china prototype airborne system, XSAR works with high spatial resolution in azimuth (0.1 m and slant range (0.4 m. In land applications, SAR image classification is a useful tool to distinguish the interesting area and obtain the target information. The bare soil, the cement road, the water and the building shadow are common scenes in the urban area. As it always exists low backscattering sign objects (LBO with the similar scattering mechanism (all odd bounce except for shadow in the XSAR images, classes are usually confused in Wishart-H-Alpha and Freeman-Durden methods. It is very hard to distinguish those targets only using the general information. To overcome the shortage, this paper explores an improved algorithm for LBO refined classification based on the Pre-Classification in urban areas. Firstly, the Pre-Classification is applied in the polarimetric datum and the mixture class is marked which contains LBO. Then, the polarimetric covariance matrix C3 is re-estimated on the Pre-Classification results to get more reliable results. Finally, the occurrence space which combining the entropy and the phase-diff standard deviation between HH and VV channel is used to refine the Pre-Classification results. The XSAR airborne experiments show the improved method is potential to distinguish the mixture classes in the low backscattering objects.

  19. Oxygen sensitivity of the nifLA promoter of Klebsiella pneumoniae.

    OpenAIRE

    Kong, Q T; Wu, Q L; Ma, Z F; Shen, S C

    1986-01-01

    Oxygen sensitivity of the nifLA promoter of Klebsiella pneumoniae has been demonstrated. Studies on the oxygen regulation of nifB-lacZ and nifH-lacZ fusions in the presence of the nifLA operon, which contains either an intact or a deleted nifL gene, indicate that possibly both the nifL promoter and the nifL product are responsible for nif repression by oxygen.

  20. Summary of Disposable Debris Shields (DDS) Analysis for Development of Solid Debris Collection at NIF

    International Nuclear Information System (INIS)

    Shaughnessy, D.A.; Moody, K.J.; Grant, P.M.; Lewis, L.A.; Hutcheon, I.D.; Lindvall, R.; Gostic, J.M.

    2011-01-01

    Collection of solid debris from the National Ignition Facility (NIF) is being developed both as a diagnostic tool and as a means for measuring nuclear reaction cross sections relevant to the Stockpile Stewardship Program and nuclear astrophysics. The concept is straightforward; following a NIF shot, the debris that is produced as a result of the capsule and hohlraum explosion would be collected and subsequently extracted from the chamber. The number of nuclear activations that occurred in the capsule would then be measured through a combination of radiation detection and radiochemical processing followed by mass spectrometry. Development of the catcher is challenging due to the complex environment of the NIF target chamber. The collector surface is first exposed to a large photon flux, followed by the debris wind that is produced. The material used in the catcher must be mechanically strong in order to withstand the large amount of energy it is exposed to, as well as be chemically compatible with the form and composition of the debris. In addition, the location of the catcher is equally important. If it is positioned too close to the center of the target chamber, it will be significantly ablated, which could interfere with the ability of the debris to reach the surface and stick. If it is too far away, the fraction of the debris cloud collected will be too small to result in a statistically significant measurement. Material, geometric configuration, and location must all be tested in order to design the optimal debris collection system for NIF. One of the first ideas regarding solid debris collection at NIF was to use the disposable debris shields (DDS), which are fielded over the final optics assemblies (FOA) 7 m away from the center of the target chamber. The DDS are meant to be replaced after a certain number of shots, and if the shields could be subsequently analyzed after removal, it would serve as a mechanism for fielding a relatively large collection area

  1. Challenges to develop nitrogen-fixing cereals by direct nif-gene transfer.

    Science.gov (United States)

    Curatti, Leonardo; Rubio, Luis M

    2014-08-01

    Some regions of the developing world suffer low cereal production yields due to low fertilizer inputs, among other factors. Biological N2 fixation, catalyzed by the prokaryotic enzyme nitrogenase, is an alternative to the use of synthetic N fertilizers. The molybdenum nitrogenase is an O2-labile metalloenzyme composed of the NifDK and NifH proteins, which biosyntheses require a number of nif gene products. A challenging strategy to increase cereal crop productivity in a scenario of low N fertilization is the direct transfer of nif genes into cereals. The sensitivity of nitrogenase to O2 and the apparent complexity of nitrogenase biosynthesis are the main barriers identified so far. Expression of active NifH requires the products of nifM, nifH, and possibly nifU and nifS, whereas active NifDK requires the products of nifH, nifD, nifK, nifB, nifE, nifN, and possibly nifU, nifS, nifQ, nifV, nafY, nifW and nifZ. Plastids and mitochondria are potential subcellular locations for nitrogenase. Both could provide the ATP and electrons required for nitrogenase to function but they differ in their internal O2 levels and their ability to incorporate ammonium into amino acids. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Near Field Intensity Trends of Main Laser Alignment Images in the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Leach, R R; Beltsar, I; Burkhart, S; Lowe-Webb, R; Kamm, V M; Salmon, T; Wilhelmsen, K

    2015-01-22

    The National Ignition Facility (NIF) utilizes 192 high-energy laser beams focused with enough power and precision on a hydrogen-filled spherical, cryogenic target to potentially initiate a fusion reaction. NIF has been operational for six years; during that time, thousands of successful laser firings or shots have been executed. Critical instrument measurements and camera images are carefully recorded for each shot. The result is a massive and complex database or ‘big data’ archive that can be used to investigate the state of the laser system at any point in its history or to locate and track trends in the laser operation over time. In this study, the optical light throughput for more than 1600 NIF shots for each of the 192 main laser beams and 48 quads was measured over a three year period from January 2009 to October 2012. The purpose was to verify that the variation in the transmission of light through the optics over time performed within design expectations during this time period. Differences between average or integrated intensity from images recorded by the input sensor package (ISP) and by the output sensor package (OSP) in the NIF beam-line were examined. A metric is described for quantifying changes in the integrated intensity measurements and was used to view potential trends. Results are presented for the NIF input and output sensor package trends and changes over the three year time-frame.

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

    International Nuclear Information System (INIS)

    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.

    2013-01-01

    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.

    Science.gov (United States)

    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. Science of NIF scale capsule development (activities for FY97)

    International Nuclear Information System (INIS)

    Hamilton, K.E.; Buckley, S.R.; Cook, R.R.

    1997-01-01

    The focus of this work is the production of 2-mm PαMS mandrels by microencapsulation for use as National Ignition Facility (NIF) laser targets. It is our findings thus far that the processing techniques used previously for the 0.5-mm and 1.0-mm targets are no longer useful for preparation of the larger targets for a few fundamental reasons. The driving force for sphericity (from the minimization of interracial energy) decreases as the radius of curvature increases. Simultaneously, the mechanical robustness /stability of the water-oil-water emulsion droplets decreases as the droplet size increases. The impact of these physical conditions and the possibilities of circumventing these limitations have been examined while attempting to meet the NIF shell power spectrum criteria. Identifying the key parameters in the transition (solidification) from a w-o-w droplet to a solid polymer shell has been understood implicitly to be the paramount goal. It is believed through the knowledge gained that it will be possible to minimize the deleterious forces and maximize shell sphericity. At this point it is believed that properties intrinsic to the polymer (i.e., PαMS) such as its solution behavior and evolution of film stresses control the overall shell sphericity

  6. Science of NIF scale capsule development (activities for FY97)

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, K.E.; Buckley, S.R.; Cook, R.R.

    1997-11-12

    The focus of this work is the production of 2-mm P{alpha}MS mandrels by microencapsulation for use as National Ignition Facility (NIF) laser targets. It is our findings thus far that the processing techniques used previously for the 0.5-mm and 1.0-mm targets are no longer useful for preparation of the larger targets for a few fundamental reasons. The driving force for sphericity (from the minimization of interracial energy) decreases as the radius of curvature increases. Simultaneously, the mechanical robustness /stability of the water-oil-water emulsion droplets decreases as the droplet size increases. The impact of these physical conditions and the possibilities of circumventing these limitations have been examined while attempting to meet the NIF shell power spectrum criteria. Identifying the key parameters in the transition (solidification) from a w-o-w droplet to a solid polymer shell has been understood implicitly to be the paramount goal. It is believed through the knowledge gained that it will be possible to minimize the deleterious forces and maximize shell sphericity. At this point it is believed that properties intrinsic to the polymer (i.e., P{alpha}MS) such as its solution behavior and evolution of film stresses control the overall shell sphericity.

  7. NIF ICCS network design and loading analysis

    International Nuclear Information System (INIS)

    Tietbohl, G; Bryant, R

    1998-01-01

    The National Ignition Facility (NIF) is housed within a large facility about the size of two football fields. The Integrated Computer Control System (ICCS) is distributed throughout this facility and requires the integration of about 40,000 control points and over 500 video sources. This integration is provided by approximately 700 control computers distributed throughout the NIF facility and a network that provides the communication infrastructure. A main control room houses a set of seven computer consoles providing operator access and control of the various distributed front-end processors (FEPs). There are also remote workstations distributed within the facility that allow provide operator console functions while personnel are testing and troubleshooting throughout the facility. The operator workstations communicate with the FEPs which implement the localized control and monitoring functions. There are different types of FEPs for the various subsystems being controlled. This report describes the design of the NIF ICCS network and how it meets the traffic loads that will are expected and the requirements of the Sub-System Design Requirements (SSDR's). This document supersedes the earlier reports entitled Analysis of the National Ignition Facility Network, dated November 6, 1996 and The National Ignition Facility Digital Video and Control Network, dated July 9, 1996. For an overview of the ICCS, refer to the document NIF Integrated Computer Controls System Description (NIF-3738)

  8. NIFS symposium: toward the research of fusion burning plasmas

    International Nuclear Information System (INIS)

    Itoh, Sanae

    1993-07-01

    NIFS symposium, entitled 'Toward the research of Fusion Burning Plasmas - Present status and Future Strategy' was held at NIFS on July 15th 1992. This NIFS symposium covers various topics related to burning plasma, e.g., JET DT experiment, Plan for DT experiment on TFTR as well as the future trends among researchers. To study the critical issues and trends of future research, a questionnaire was sent to about 100 researchers. This report presents such activities in the NIFS symposium. (author)

  9. Report on the B-Fields at NIF Workshop Held at LLNL October 12-13, 2015

    International Nuclear Information System (INIS)

    Fournier, K. B.; Moody, J. D.

    2015-01-01

    A national ICF laboratory workshop on requirements for a magnetized target capability on NIF was held by NIF at LLNL on October 12 and 13, attended by experts from LLNL, SNL, LLE, LANL, GA, and NRL. Advocates for indirect drive (LLNL), magnetic (Z) drive (SNL), polar direct drive (LLE), and basic science needing applied B (many institutions) presented and discussed requirements for the magnetized target capabilities they would like to see. 30T capability was most frequently requested. A phased operation increasing the field in steps experimentally can be envisioned. The NIF management will take the inputs from the scientific community represented at the workshop and recommend pulse-powered magnet parameters for NIF that best meet the collective user requests. In parallel, LLNL will continue investigating magnets for future generations that might be powered by compact laser-B-field generators (Moody, Fujioka, Santos, Woolsey, Pollock). The NIF facility engineers will start to analyze compatibility of the recommended pulsed magnet parameters (size, field, rise time, materials) with NIF chamber constraints, diagnostic access, and final optics protection against debris in FY16. The objective of this assessment will be to develop a schedule for achieving an initial Bfield capability. Based on an initial assessment, room temperature magnetized gas capsules will be fielded on NIF first. Magnetized cryo-ice-layered targets will take longer (more compatibility issues). Magnetized wetted foam DT targets (Olson) may have somewhat fewer compatibility issues making them a more likely choice for the first cryo-ice-layered target fielded with applied Bz.

  10. Intragenic complementation by the nifJ-coded protein of Klebsiella pneumoniae.

    OpenAIRE

    Stacey, G; Zhu, J; Shah, V K; Shen, S C; Brill, W J

    1982-01-01

    A single mutation, nifC1005 (Jin et al. Sci. Sin. 23:108-118, 1980), located between nifH and nifJ in the nif cluster of Klebsiella pneumoniae, genetically complemented mutations in each of the 17 known nif genes. This suggested that the mutation is located in a new nif gene. We showed by complementation analyses that only 3 of 12 nifJ mutations tested were complemented by nifC1005. Nitrogenase activity in cell extracts of the mutant with nifC1005 as well as NifJ- mutants was stimulated by th...

  11. Configuring NIF for direct drive experiments

    International Nuclear Information System (INIS)

    Eimerl, D.; Rothenberg, J.; Key, M.

    1995-01-01

    The National Ignition Facility (NIF) is a proposed 1.8 MJ laser facility for carrying out experiments in inertial confinement fusion, currently designed for indirect drive experiments. The direct drive approach is being pursued at the 30 kJ Omega facility at the University of Rochester. In this paper we discuss the modifications to the NIF laser that would be required for both indirect and direct drive experiments. A primary concern is the additional cost of adding direct drive capability to the facility

  12. Hierarchical material models for fragmentation modeling in NIF-ALE-AMR

    International Nuclear Information System (INIS)

    Fisher, A C; Masters, N D; Koniges, A E; Anderson, R W; Gunney, B T N; Wang, P; Becker, R; Dixit, P; Benson, D J

    2008-01-01

    Fragmentation is a fundamental process that naturally spans micro to macroscopic scales. Recent advances in algorithms, computer simulations, and hardware enable us to connect the continuum to microstructural regimes in a real simulation through a heterogeneous multiscale mathematical model. We apply this model to the problem of predicting how targets in the NIF chamber dismantle, so that optics and diagnostics can be protected from damage. The mechanics of the initial material fracture depend on the microscopic grain structure. In order to effectively simulate the fragmentation, this process must be modeled at the subgrain level with computationally expensive crystal plasticity models. However, there are not enough computational resources to model the entire NIF target at this microscopic scale. In order to accomplish these calculations, a hierarchical material model (HMM) is being developed. The HMM will allow fine-scale modeling of the initial fragmentation using computationally expensive crystal plasticity, while the elements at the mesoscale can use polycrystal models, and the macroscopic elements use analytical flow stress models. The HMM framework is built upon an adaptive mesh refinement (AMR) capability. We present progress in implementing the HMM in the NIF-ALE-AMR code. Additionally, we present test simulations relevant to NIF targets

  13. Hierarchical material models for fragmentation modeling in NIF-ALE-AMR

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, A C; Masters, N D; Koniges, A E; Anderson, R W; Gunney, B T N; Wang, P; Becker, R [Lawrence Livermore National Laboratory, PO Box 808, Livermore, CA 94551 (United States); Dixit, P; Benson, D J [University of California San Diego, 9500 Gilman Dr., La Jolla. CA 92093 (United States)], E-mail: fisher47@llnl.gov

    2008-05-15

    Fragmentation is a fundamental process that naturally spans micro to macroscopic scales. Recent advances in algorithms, computer simulations, and hardware enable us to connect the continuum to microstructural regimes in a real simulation through a heterogeneous multiscale mathematical model. We apply this model to the problem of predicting how targets in the NIF chamber dismantle, so that optics and diagnostics can be protected from damage. The mechanics of the initial material fracture depend on the microscopic grain structure. In order to effectively simulate the fragmentation, this process must be modeled at the subgrain level with computationally expensive crystal plasticity models. However, there are not enough computational resources to model the entire NIF target at this microscopic scale. In order to accomplish these calculations, a hierarchical material model (HMM) is being developed. The HMM will allow fine-scale modeling of the initial fragmentation using computationally expensive crystal plasticity, while the elements at the mesoscale can use polycrystal models, and the macroscopic elements use analytical flow stress models. The HMM framework is built upon an adaptive mesh refinement (AMR) capability. We present progress in implementing the HMM in the NIF-ALE-AMR code. Additionally, we present test simulations relevant to NIF targets.

  14. National Ignition Facility subsystem design requirements NIF site improvements SSDR 1.2.1

    International Nuclear Information System (INIS)

    Kempel, P.; Hands, J.

    1996-01-01

    This Subsystem Design Requirements (SSDR) document establishes the performance, design, and verification requirements associated with the NIF Project Site at Lawrence Livermore National Laboratory (LLNL) at Livermore, California. It identifies generic design conditions for all NIF Project facilities, including siting requirements associated with natural phenomena, and contains specific requirements for furnishing site-related infrastructure utilities and services to the NIF Project conventional facilities and experimental hardware systems. Three candidate sites were identified as potential locations for the NIF Project. However, LLNL has been identified by DOE as the preferred site because of closely related laser experimentation underway at LLNL, the ability to use existing interrelated infrastructure, and other reasons. Selection of a site other than LLNL will entail the acquisition of site improvements and infrastructure additional to those described in this document. This SSDR addresses only the improvements associated with the NIF Project site located at LLNL, including new work and relocation or demolition of existing facilities that interfere with the construction of new facilities. If the Record of Decision for the PEIS on Stockpile Stewardship and Management were to select another site, this SSDR would be revised to reflect the characteristics of the selected site. Other facilities and infrastructure needed to support operation of the NIF, such as those listed below, are existing and available at the LLNL site, and are not included in this SSDR. Office Building. Target Receiving and Inspection. General Assembly Building. Electro- Mechanical Shop. Warehousing and General Storage. Shipping and Receiving. General Stores. Medical Facilities. Cafeteria services. Service Station and Garage. Fire Station. Security and Badging Services

  15. 3(omega) Power Balance Procedure on the NIF

    International Nuclear Information System (INIS)

    Glenzer, S; Jones, O; Speck, D R; Munro, D; Lerche, R; Salmon, T; Bliss, E; Gates, A; Boyd, B; Auerbach, J; Williams, W; Saroyan, A; Kalantar, D; MacGowan, B; Zacharias, R; Hayman, C; Sacks, R

    2001-01-01

    This document defines the detailed NIF full system shot procedure to obtain 8% power balance as specified by the SDR002 3.2.1.04. Because the 48 quads of the NIF will be set up over a period of five years, obtaining power balance will naturally be accomplished in two steps. First, as each quad is brought online, the four laser beams within each quad will be tuned by setting the PABTS splitter ratios so that each beam will give the same laser power on target during low energy square pulse shots. During the quad activation period all of the technical tools and procedures will be developed that are needed for attaining full laser power balance. After the initial settings of the 48 PABTS, if no other tuning is done the overall NIF power balance is expected to be about <15%. In the second step, an iteration procedure with approximately 18 full laser system shots will be needed to obtain 8% power balance by tuning out the remaining systematic differences among the quads to an acceptable small difference of 2% rms (at 3ω). This rms difference is smaller than the expected variation of the injection energy or the amplifier gain, and is also of the same order as the laser energy diagnostic accuracy. Therefore, 8% power balance will require a number of precision measurements that will need accurate calibrations combined with a laser performance model that accounts and corrects for variations of the injection energy and the amplifier gain. This document is intended to specify the procedure and the flow-down of requirements from the system design requirement of 8% power balance. It is further intended to help guide the laser shot planning, the laser controls, and the laser performance operations model groups. It should provide input relevant to power balance tuning for the development of an operations model that includes post-shot analysis (as described in NIF-0046491), shot planning (as described in this memo), and pre-shot analysis

  16. NIF small optics laser damage test specifications

    International Nuclear Information System (INIS)

    Sheehan, L

    1999-01-01

    The Laser Damage Group is currently conducting tests on small optics samples supplied for initial evaluation of potential NIF suppliers. This document is meant to define the specification of laser-induced damage for small optics and the test methods used to collect the data. A rating system which will be applied for vendor selection is presented

  17. Recent advances in indirect drive ICF target physics at LLNL

    International Nuclear Information System (INIS)

    Hammel, B.A.; Bernat, T.P.; Collins, G.W.; Haan, S.; Landen, O.L.; MacGowan, B.J.; Suter, L.J.

    1999-01-01

    In preparation for ignition on the National Ignition Facility, the Lawrence Livermore National Laboratory's Inertial Confinement Fusion Program, working in collaboration with Los Alamos National Laboratory, Commissariat a l'Energie Atomique (CEA), and Laboratory for Laser Energetics at the University of Rochester, has performed a broad range of experiments on the Nova and Omega lasers to test the fundamentals of the NIF target designs. These studies have refined our understanding of the important target physics, and have led to many of the specifications for the NIF laser and the cryogenic ignition targets. Our recent work has been focused in the areas of hohlraum energetics, symmetry, shock physics, and target design optimization and fabrication. (author)

  18. The nif Gene Operon of the Methanogenic Archaeon Methanococcus maripaludis

    Science.gov (United States)

    Kessler, Peter S.; Blank, Carrine; Leigh, John A.

    1998-01-01

    Nitrogen fixation occurs in two domains, Archaea and Bacteria. We have characterized a nif (nitrogen fixation) gene cluster in the methanogenic archaeon Methanococcus maripaludis. Sequence analysis revealed eight genes, six with sequence similarity to known nif genes and two with sequence similarity to glnB. The gene order, nifH, ORF105 (similar to glnB), ORF121 (similar to glnB), nifD, nifK, nifE, nifN, and nifX, was the same as that found in part in other diazotrophic methanogens and except for the presence of the glnB-like genes, also resembled the order found in many members of the Bacteria. Using transposon insertion mutagenesis, we determined that an 8-kb region required for nitrogen fixation corresponded to the nif gene cluster. Northern analysis revealed the presence of either a single 7.6-kb nif mRNA transcript or 10 smaller mRNA species containing portions of the large transcript. Polar effects of transposon insertions demonstrated that all of these mRNAs arose from a single promoter region, where transcription initiated 80 bp 5′ to nifH. Distinctive features of the nif gene cluster include the presence of the six primary nif genes in a single operon, the placement of the two glnB-like genes within the cluster, the apparent physical separation of the cluster from any other nif genes that might be in the genome, the fragmentation pattern of the mRNA, and the regulation of expression by a repression mechanism described previously. Our study and others with methanogenic archaea reporting multiple mRNAs arising from gene clusters with only a single putative promoter sequence suggest that mRNA processing following transcription may be a common occurrence in methanogens. PMID:9515920

  19. Mutant Forms of the Azotobacter vinelandii Transcriptional Activator NifA Resistant to Inhibition by the NifL Regulatory Protein

    OpenAIRE

    Reyes-Ramirez, Francisca; Little, Richard; Dixon, Ray

    2002-01-01

    The Azotobacter vinelandii σ54-dependent transcriptional activator protein NifA is regulated by the NifL protein in response to redox, carbon, and nitrogen status. Under conditions inappropriate for nitrogen fixation, NifL inhibits transcription activation by NifA through the formation of the NifL-NifA protein complex. NifL inhibits the ATPase activity of the central AAA+ domain of NifA required to drive open complex formation by σ54-RNA polymerase and may also inhibit the activator-polymeras...

  20. Low fuel convergence path to ignition on the NIF

    Science.gov (United States)

    Schmitt, M. J.; Molvig, Kim; Gianakon, T. A.; Woods, C. N.; Krasheninnikova, N. S.; Hsu, S. C.; Schmidt, D. W.; Dodd, E. S.; Zylstra, Alex; Scheiner, B.; McKenty, P.; Campbell, E. M.; Froula, D.; Betti, R.; Michel, T.

    2017-10-01

    A novel concept for achieving ignition on the NIF is proposed that obviates current issues plaguing single-shell high-convergence capsules. A large directly-driven Be shell is designed to robustly implode two nested internal shells by efficiently converting 1.7MJ of laser energy from a 6 ns, low intensity laser pulse, into a 1 ns dynamic pressure pulse to ignite and burn a central liquid DT core after a fuel convergence of only 9. The short, low intensity laser pulse mitigates LPI allowing more uniform laser drive of the target and eliminates hot e-, preheat and laser zooming issues. Preliminary rad-hydro simulations predict ignition initiation with 90% maximum inner shell velocity, before deceleration Rayleigh-Taylor growth can cause significant pusher shell mix into the compressed DT fuel. The gold inner pusher shell reduces pre-ignition radiation losses from the fuel allowing ignition to occur at 2.5keV. Further 2D simulations show that the short pulse design results in a spatially uniform kinetic drive that is tolerant to variations in laser cone power. A multi-pronged effort, in collaboration with LLE, is progressing to optimize this design for NIF's PDD laser configuration. Work performed under the auspices of the U.S. Dept. of Energy by the Los Alamos National Security, LLC, Los Alamos National Laboratory under contract DE-FG02-051ER54810.

  1. Testing and Quality Assurance of the Control System During NIF Commissioning

    International Nuclear Information System (INIS)

    Casavant, D.; Carey, R.; Cline, B.; Lagin, L.; Ludwigsen, P.; Reddi, U.; Van Arsdall, P.

    2003-01-01

    The strategy used to develop the National Ignition Facility Integrated Computer Control System (NIF ICCS) calls for incremental cycles of construction and formal test to deliver nearly one million lines of code. Software releases that implement specific functionality are approved for deployment when offline tests conducted in the ICCS Integration and Test Facility verify functional, performance and interface requirements using test procedures derived from system requirements. At this stage of the project the controls team has delivered approximately 3/4 of the planned software by performing dozens of development and test cycles within offline test facilities and followed by online tests to confirm integrated operation in the NIF. Test incidents are recorded and tracked from development to successful deployment by the verification team, with hardware and software changes approved by the appropriate change control board. Project metrics are generated by the Software Quality Assurance manager and monitored by ICCS management. Test results are summarized and reported to responsible individuals and Project managers under a work authorization and permit process that assesses risk and evaluates control system upgrade readiness. NIF is well into the first phases of its laser commissioning program to characterize and operate the first four laser beams and target systems. The integrated control system has successfully fired over 100 coordinated shots into beam diagnostics and an initial set of target diagnostics in the 10-m diameter target chamber. Extensive experience has been gained by integrating controls in prototype laboratories and in the NIF. This paper will discuss NIF's software QC and QA processes, capabilities of offline test facilities, and metrics collection

  2. Testing and Quality Assurance of the Control System During NIF Commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Casavant, D; Carey, R; Cline, B; Lagin, L; Ludwigsen, P; Reddi, U; Van Arsdall, P

    2003-10-13

    The strategy used to develop the National Ignition Facility Integrated Computer Control System (NIF ICCS) calls for incremental cycles of construction and formal test to deliver nearly one million lines of code. Software releases that implement specific functionality are approved for deployment when offline tests conducted in the ICCS Integration and Test Facility verify functional, performance and interface requirements using test procedures derived from system requirements. At this stage of the project the controls team has delivered approximately 3/4 of the planned software by performing dozens of development and test cycles within offline test facilities and followed by online tests to confirm integrated operation in the NIF. Test incidents are recorded and tracked from development to successful deployment by the verification team, with hardware and software changes approved by the appropriate change control board. Project metrics are generated by the Software Quality Assurance manager and monitored by ICCS management. Test results are summarized and reported to responsible individuals and Project managers under a work authorization and permit process that assesses risk and evaluates control system upgrade readiness. NIF is well into the first phases of its laser commissioning program to characterize and operate the first four laser beams and target systems. The integrated control system has successfully fired over 100 coordinated shots into beam diagnostics and an initial set of target diagnostics in the 10-m diameter target chamber. Extensive experience has been gained by integrating controls in prototype laboratories and in the NIF. This paper will discuss NIF's software QC and QA processes, capabilities of offline test facilities, and metrics collection.

  3. Concept of operations for channel characterization and simulation of coaxial transmission channels at the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Jr., Charles G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-23

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) executes experiments for inertial con nement fusion (ICF), world-class high energy density physics (HEDP), and critical national security missions. While the laser systems, target positioners, alignment systems, control systems, etc. enable the execution of such experiments, NIF’s utility would be greatly reduced without its suite of diagnostics. It would be e ectively “blind” to the incredible physics unleashed in its target chamber. Since NIF diagnostics are such an important part of its mission, the quality and reliability of the diagnostics, and of the data recorded from them, is crucial.

  4. Laser Science and Technology Program Annual Report-2002 NIF Programs Directorate

    International Nuclear Information System (INIS)

    Hackel, L; Chen, H L

    2003-01-01

    The Laser Science and Technology (LSandT) Program's mission is to develop advanced lasers, optics, materials technologies, and applications to solve problems and create new capabilities of importance to the nation and the Laboratory. A top, near-term priority is to provide technical support in the deployment and upgrade of the National Ignition Facility (NIF). Our other program activities synergistically develop technologies that are consistent with the goals of the NIF Directorate and develop state-of-the-art capabilities. The primary objectives of LSandT activities in 2002 have been fourfold--(a) to support deployment of hardware and to enhance laser and optics performance for NIF, (b) to develop high-energy petawatt laser science and technology for the Department of Energy (DOE), (c) to develop advanced solid-state laser systems and optical components for the Department of Defense (DoD), and (d) to invent, develop, and deliver improved concepts and hardware for other government agencies and industry. LSandT activities during 2002 focused on seven major areas: (1) NIF Project-LSandT led major advances in the deployment of NIF Final Optics Assembly (FOA) and the development of 30.1 optics processing and treatment technologies to enhance NIF's operations and performance capabilities. (2) Stockpile Stewardship Program (SSP)-LSandT personnel continued development of ultrashort-pulse lasers and high-power, large-aperture optics for applications in SSP, extreme-field science and national defense. To enhance the high-energy petawatt (HEPW) capability in NIF, LSandT continued development of advanced compressor-grating and front-end laser technologies utilizing optical-parametric chirped-pulse amplification (OPCPA). (3) High-energy-density physics and inertial fusion energy-LSandT continued development of kW- to MW-class, diode-pumped, solid-state laser (DPSSL). (4) Department of Defense (DoD)-LSandT continued development of a 100 kw-class solid-state heat-capacity laser

  5. NIF: IFE applications, waste management and environmental impacts

    International Nuclear Information System (INIS)

    Lazaro, M.A.; Kirchner, F.R.; Miley, G.H.; Petra, M.

    1996-01-01

    Although many energy sources have been suggested for the future, inertial confinement fusion (ICF) has been demonstrated as scientifically feasible and deserves support for continued development. The National Ignition Facility (NIF), proposed by US DOE, is a next step in that direction. NIF would use ICF technology to achieve ignition and energy gain that would allow the development and continued support of national security and other civilian applications including inertial fusion energy power plants. NIF would also guarantee US leadership in dense plasma research. Four sites are being considered for NIF: LLNL, Los Alamos, Sandia, and two NTS sites. An environmental evaluation was performed which considered all impacts. This paper provides the results of the waste management analyses conducted on the proposed NIF sites. Overall, the proposed construction and operation of NIF should qualify it as a low-hazard, non-nuclear radiological facility with minor onsite and negligible offsite environmental impacts

  6. Design calculations for NIF convergent ablator experiments

    Directory of Open Access Journals (Sweden)

    Olson R.E.

    2013-11-01

    Full Text Available The NIF convergent ablation tuning effort is underway. In the early experiments, we have discovered that the design code simulations over-predict the capsule implosion velocity and shock flash ρr, but under-predict the hohlraum x-ray flux measurements. The apparent inconsistency between the x-ray flux and radiography data implies that there are important unexplained aspects of the hohlraum and/or capsule behavior.

  7. Error Analysis of Fast Moving Target Geo-location in Wide Area Surveillance Ground Moving Target Indication Mode

    Directory of Open Access Journals (Sweden)

    Zheng Shi-chao

    2013-12-01

    Full Text Available As an important mode in airborne radar systems, Wide Area Surveillance Ground Moving Target Indication (WAS-GMTI mode has the ability of monitoring a large area in a short time, and then the detected moving targets can be located quickly. However, in real environment, many factors introduce considerable errors into the location of moving targets. In this paper, a fast location method based on the characteristics of the moving targets in WAS-GMTI mode is utilized. And in order to improve the location performance, those factors that introduce location errors are analyzed and moving targets are relocated. Finally, the analysis of those factors is proved to be reasonable by simulation and real data experiments.

  8. The expression of nifB gene from Herbaspirillum seropedicae is dependent upon the NifA and RpoN proteins.

    Science.gov (United States)

    Rego, Fabiane G M; Pedrosa, Fábio O; Chubatsu, Leda S; Yates, M Geoffrey; Wassem, Roseli; Steffens, Maria B R; Rigo, Liu U; Souza, Emanuel M

    2006-12-01

    The putative nifB promoter region of Herbaspirillum seropedicae contained two sequences homologous to NifA-binding site and a -24/-12 type promoter. A nifB::lacZ fusion was assayed in the backgrounds of both Escherichia coli and H. seropedicae. In E. coli, the expression of nifB::lacZ occurred only in the presence of functional rpoN and Klebsiella pneumoniae nifA genes. In addition, the integration host factor (IHF) stimulated the expression of the nifB::lacZ fusion in this background. In H. seropedicae, nifB expression occurred only in the absence of ammonium and under low levels of oxygen, and it was shown to be strictly dependent on NifA. DNA band shift experiments showed that purified K. pneumoniae RpoN and E. coli IHF proteins were capable of binding to the nifB promoter region, and in vivo dimethylsulfate footprinting showed that NifA binds to both NifA-binding sites. These results strongly suggest that the expression of the nifB promoter of H. seropedicae is dependent on the NifA and RpoN proteins and that the IHF protein stimulates NifA activation of nifB promoter.

  9. Progress towards the Conventionon Biological Diversity terrestrial2010 and marine 2012 targets forprotected area coverage

    DEFF Research Database (Denmark)

    Coad, Lauren; Burgess, Neil David; Fish, Lucy

    2010-01-01

    coverage targets. National protected areas data from the WDPA have been used to measure progress in protected areas coverage at global, regional and national scale. The mean protected area coverage per nation was 12.2% for terrestrial area, and only 5.1% for near-shore marine area. Variation in protected......Protected area coverage targets set by the Convention on Biological Diversity (CBD) for both terrestrial and marine environments provide a major incentive for governments to review and upgrade their protected area systems. Assessing progress towards these targets will form an important component...... of the work of the Xth CBD Conference of Parties meeting to be held in Japan in 2010. The World Database on Protected Areas (WDPA) is the largest assembly of data on the world's terrestrial and marine protected areas and, as such, represents a fundamental tool in tracking progress towards protected area...

  10. Current target industry analysis: Las Vegas Metropolitan Area

    International Nuclear Information System (INIS)

    Boyle, M.R.

    1988-06-01

    This is the second of three reports dealing with the Las Vegas MSA's economic development potential in support of an overall effort to prepare an environmental impact statement for the proposed underground nuclear waste storage facility at Yucca Mountain. The first report provides an assessment of the MSA current business climate for economic growth. This second report draws on that business climate assessment to evaluate the Las Vegas MSA's competitive posture in pursuing business investment in the ''primary'' sector of the economy -- businesses which sell their products or services outside the local marketplace and bring new money back into the area and businesses serving local customers who would otherwise import these products or services from suppliers outside the area. GSO has developed an analytic tool which attempts to model the decision process used by businesses in selecting locations for new or expanded business investment. This computer based model reflects variations in site selection decision making among industries and ownership and management types. The underlying premise of the GSO locational compatibility index (LCI) model is that locational decisions are based more on a process of elimination that on a process of selection. There are many factors, some essential and some desirable, which influence any site selection decision. Multivariate comparative analyses narrow the geographic field to a region, then a group of states, then a state, then a sub-state region, then a community and finally to a specific site. Sometimes these analyses are rational and quantitative. More often, they are at least partially random and intuitive. 2 tabs

  11. Functional organization of a single nif cluster in the mesophilic archaeon Methanosarcina mazei strain Gö1

    Directory of Open Access Journals (Sweden)

    Claudia Ehlers

    2002-01-01

    Full Text Available The mesophilic methanogenic archaeon Methanosarcina mazei strain Gö1 is able to utilize molecular nitrogen (N2 as its sole nitrogen source. We have identified and characterized a single nitrogen fixation (nif gene cluster in M. mazei Gö1 with an approximate length of 9 kbp. Sequence analysis revealed seven genes with sequence similarities to nifH, nifI1, nifI2, nifD, nifK, nifE and nifN, similar to other diazotrophic methanogens and certain bacteria such as Clostridium acetobutylicum, with the two glnB-like genes (nifI1 and nifI2 located between nifH and nifD. Phylogenetic analysis of deduced amino acid sequences for the nitrogenase structural genes of M. mazei Gö1 showed that they are most closely related to Methanosarcina barkeri nif2 genes, and also closely resemble those for the corresponding nif products of the gram-positive bacterium C. acetobutylicum. Northern blot analysis and reverse transcription PCR analysis demonstrated that the M. mazei nif genes constitute an operon transcribed only under nitrogen starvation as a single 8 kb transcript. Sequence analysis revealed a palindromic sequence at the transcriptional start site in front of the M. mazei nifH gene, which may have a function in transcriptional regulation of the nif operon.

  12. Polarimetry of uncoupled light on the NIF.

    Science.gov (United States)

    Turnbull, D; Moody, J D; Michel, P; Ralph, J E; Divol, L

    2014-11-01

    Polarimetry has been added to the full aperture backscatter diagnostic on the NIF. Wollaston prisms are used to sample a small region of a beam's backscatter, effectively separating it into two linear polarizations, one of which is parallel to the incident beam. A time-averaged measurement of each polarization is obtained by imaging the separated spots off of a scatter plate. Results have improved understanding of crossed beam energy transfer, glint, and sidescatter, and motivated plans to upgrade to a time-resolved polarimeter measuring the full Stokes vector.

  13. Polarimetry of uncoupled light on the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, D., E-mail: turnbull2@llnl.gov; Moody, J. D.; Michel, P.; Ralph, J. E.; Divol, L. [National Ignition Facility and Photon Science, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-11-15

    Polarimetry has been added to the full aperture backscatter diagnostic on the NIF. Wollaston prisms are used to sample a small region of a beam's backscatter, effectively separating it into two linear polarizations, one of which is parallel to the incident beam. A time-averaged measurement of each polarization is obtained by imaging the separated spots off of a scatter plate. Results have improved understanding of crossed beam energy transfer, glint, and sidescatter, and motivated plans to upgrade to a time-resolved polarimeter measuring the full Stokes vector.

  14. Breakthrough at NIF 'unlikely' in 2010

    Science.gov (United States)

    Harris, Margaret

    2010-05-01

    Hopes of reaching a milestone in fusion research by the end of 2010 have dimmed following a US government report that plays down the chances of an early breakthrough and sharply criticizes management of the 4bn National Ignition Facility (NIF). In the report, officials from the Government Accountability Office (GAO) state that ignition - fusion's "break-even" point - is "unlikely" to occur at the laser-fusion lab this year and that "significant scientific and technical challenges" could delay or even prevent the facility from achieving ignition by 2012.

  15. DIM and diagnostic placement for NIF experiments

    International Nuclear Information System (INIS)

    Kalantar, D.

    1999-01-01

    The input that has been provided on the NIF experiment setup sheets has allowed us to review the diagnostic and DIM placement as well as the baseline unconverted light management plan. We have done an iteration to identify common diagnostic lines of sight, and with additional requirements defined by specific experiments, we propose (1) a baseline plan for DIM placement requiring only five DIMs that may be moved between up to seven DIM ports, and (2) a modified baseline unconverted light management plan. We request additional input to identify primary vs. secondary diagnostics for each experiment definition

  16. NIF optical specifications - the importance of the RMS gradient specification

    International Nuclear Information System (INIS)

    Auerbach, J. M.; Cotton, C. T.; English, R. E.; Henesian, M. A.; Hunt, J. T.; Kelly, J. H.; Lawson, J. K.; Sacks, J. B.; Shoup, M. J.; Trenholme, W. H.

    1998-01-01

    The performance of the National Ignition Facility (NIF), especially in terms of laser focusability, will be determined by several key factors. One of these key factors is the optical specification for the thousands of large aperture optics that will comprise the 192 beamlines. We have previously reported on the importance of the specification of the power spectral density (PSD) on NIF performance. Recently, we have been studying the importance of long spatial wavelength (>33 mm) phase errors on focusability. We have concluded that the preferred metric for determining the impact of these long spatial wavelength phase errors is the rms phase gradient. In this paper, we outline the overall approach to NIF optical specifications, detail the impact of the rms phase gradient on NIF focusability, discuss its trade-off with the PSD in determining the spot size and review measurements of optics similar to those to be manufactured for NIF

  17. Investigation into the MgF2-NiF2, CaF2-NiF2, SrF2-NiF2 systems

    International Nuclear Information System (INIS)

    Ikrami, D.D.; Petrov, S.V.; Fedorov, P.P.; Ol'khovaya, L.A.; Luginina, A.A.; AN SSSR, Moscow. Inst. Fizicheskikh Problem; AN SSSR, Moscow. Inst. Kristallografii)

    1984-01-01

    Using the methods of differential thermal and X-ray phase analyses the systems MgF 2 -NiF 2 , CaF 2 -NiF 2 , SrF 2 -NiF 2 have been studied. In the system SrF 2 -NiF 2 the only orthorhombic compounds SrNiF 4 (a=14.43; b=3.93; c=5.66 (+-0.01 A)) is formed. SrNiF 4 density constitutes: dsub(X-ray)=4.60+-0.01 g/cm 3 , dsub(exp.)=4.60+-0.03 g/cm 3 . Refraction indices are as follows SrNiF 4 :Ng=1.500; Nsub(m)=1.497; Nsub(p)=1.479. SrNiF 4 magnetic ordering temperature Tsub(N) approximately 100 K

  18. First Results from the South Pole Bang Time (SPBT) Diagnostic on the NIF*

    Science.gov (United States)

    Edgell, D. H.; Glebov, V. Yu.; Magoon, J.; Sangster, T. C.; Shoup, M. J., III; Stoeckl, C.; Macphee, A.; Bradley, D. K.; Burns, S.; Celeste, J.; Eckart, M. J.; Jones, O. S.; Kilkenny, J. D.; Kimbrough, J. R.; MacKinnon, A. J.; Parker, J.; Thomas, T.

    2011-10-01

    The south pole bang time (SPBT) x-ray diagnostic has been successfully fielded on the NIF. SPBT consists of chemical-vapor-deposition diamond detectors, with different filtrations, located 3 m directly below target chamber center, viewing the implosion through the hohlraum laser entrance hole. The diamond detectors are sensitive to both x rays and neutrons. HOPG crystal mirror monochromators increase the x-ray signal to background ratio. SPBT is designed to measure the x-ray bang time with an accuracy of a few tens of picoseconds. SPBT x-ray and neutron results from NIF implosions are presented along with timing and error analysis. *This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

  19. Data Analysis of the Gated-LEH X-Ray Imaging Diagnostic at the NIF

    Science.gov (United States)

    Thibodeau, Matthew; Chen, Hui

    2017-10-01

    The Gated Laser Entrance Hole (G-LEH) x-ray imaging diagnostic in use at the NIF offers a desirable combination of spatial and temporal resolution. By looking inside of NIF hohlraums with time resolution, G-LEH measures target features including LEH size and capsule size. A framework is presented for automated and systematic analysis of G-LEH images that measures several physical parameters of interest and their evolution over time. The results from these analyses enable comparisons with hohlraum models and allow model validation of LEH closure velocity and the extent of capsule blow-off. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  20. The neutron imaging diagnostic at NIF (invited).

    Science.gov (United States)

    Merrill, F E; Bower, D; Buckles, R; Clark, D D; Danly, C R; Drury, O B; Dzenitis, J M; Fatherley, V E; Fittinghoff, D N; Gallegos, R; Grim, G P; Guler, N; Loomis, E N; Lutz, S; Malone, R M; Martinson, D D; Mares, D; Morley, D J; Morgan, G L; Oertel, J A; Tregillis, I L; Volegov, P L; Weiss, P B; Wilde, C H; Wilson, D C

    2012-10-01

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  1. The neutron imaging diagnostic at NIF (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Merrill, F. E.; Clark, D. D.; Danly, C. R.; Drury, O. B.; Fatherley, V. E.; Gallegos, R.; Grim, G. P.; Guler, N.; Loomis, E. N.; Martinson, D. D.; Mares, D.; Morley, D. J.; Morgan, G. L.; Oertel, J. A.; Tregillis, I. L.; Volegov, P. L.; Wilde, C. H.; Wilson, D. C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Bower, D.; Dzenitis, J. M. [Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2012-10-15

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  2. Managing NIF safety equipment in a high neutron and gamma radiation environment.

    Science.gov (United States)

    Datte, Philip; Eckart, Mark; Jackson, Mark; Khater, Hesham; Manuel, Stacie; Newton, Mark

    2013-06-01

    The National Ignition Facility (NIF) is a 192 laser beam facility that supports the Inertial Confinement Fusion program. During the ignition experimental campaign, the NIF is expected to perform shots with varying fusion yield producing 14 MeV neutrons up to 20 MJ or 7.1 × 10(18) neutrons per shot and a maximum annual yield of 1,200 MJ. Several infrastructure support systems will be exposed to varying high yield shots over the facility's 30-y life span. In response to this potential exposure, analysis and testing of several facility safety systems have been conducted. A detailed MCNP (Monte Carlo N-Particle Transport Code) model has been developed for the NIF facility, and it includes most of the major structures inside the Target Bay. The model has been used in the simulation of expected neutron and gamma fluences throughout the Target Bay. Radiation susceptible components were identified and tested to fluences greater than 10(13) (n cm(-2)) for 14 MeV neutrons and γ-ray equivalent. The testing includes component irradiation using a 60Co gamma source and accelerator-based irradiation using 4- and 14- MeV neutron sources. The subsystem implementation in the facility is based on the fluence estimates after shielding and survivability guidelines derived from the dose maps and component tests results. This paper reports on the evaluation and implementation of mitigations for several infrastructure safety support systems, including video, oxygen monitoring, pressure monitors, water sensing systems, and access control interfaces found at the NIF.

  3. Summary of the evidence file demonstrating completion of the NIF Project Completion Criteria

    Energy Technology Data Exchange (ETDEWEB)

    Haynam, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-12-04

    This document summarizes the results of performance verification tests on NIF that demonstrate it has met its performance-related Project Completion Criteria (PCC). It includes measurements made on NIF with the NIF diagnostics, the calibration of these diagnostics and the supporting analyses that verify the NIF performance criteria have been met.

  4. Functional NifD-K fusion protein in Azotobacter vinelandii is a homodimeric complex equivalent to the native heterotetrameric MoFe protein

    International Nuclear Information System (INIS)

    Lahiri, Surobhi; Pulakat, Lakshmi; Gavini, Nara

    2005-01-01

    The MoFe protein of the complex metalloenzyme nitrogenase folds as a heterotetramer containing two copies each of the homologous α and β subunits, encoded by the nifD and the nifK genes respectively. Recently, the functional expression of a fusion NifD-K protein of nitrogenase was demonstrated in Azotobacter vinelandii, strongly implying that the MoFe protein is flexible as it could accommodate major structural changes, yet remain functional [M.H. Suh, L. Pulakat, N. Gavini, J. Biol. Chem. 278 (2003) 5353-5360]. This finding led us to further explore the type of interaction between the fused MoFe protein units. We aimed to determine whether an interaction exists between the two fusion MoFe proteins to form a homodimer that is equivalent to native heterotetrameric MoFe protein. Using the Bacteriomatch Two-Hybrid System, translationally fused constructs of NifD-K (fusion) with the full-length λCI of the pBT bait vector and also NifD-K (fusion) with the N-terminal α-RNAP of the pTRG target vector were made. To compare the extent of interaction between the fused NifD-K proteins to that of the β-β interactions in the native MoFe protein, we proceeded to generate translationally fused constructs of NifK with the α-RNAP of the pTRG vector and λCI protein of the pBT vector. The strength of the interaction between the proteins in study was determined by measuring the β-galactosidase activity and extent of ampicillin resistance of the colonies expressing these proteins. This analysis demonstrated that direct protein-protein interaction exists between NifD-K fusion proteins, suggesting that they exist as homodimers. As the interaction takes place at the β-interfaces of the NifD-K fusion proteins, we propose that these homodimers of NifD-K fusion protein may function in a similar manner as that of the heterotetrameric native MoFe protein. The observation that the extent of protein-protein interaction between the β-subunits of the native MoFe protein in Bacterio

  5. Mutations in nif genes that cause Klebsiella pneumoniae to be derepressed for nitrogenase synthesis in the presence of ammonium.

    OpenAIRE

    MacNeil, D; Brill, W J

    1980-01-01

    Four Nif+ revertants from strains with polar insertions in nifL, were insensitive to ammonium and amino acid repression of nitrogenase synthesis. These strains have mutations located in or near the nifL region. The derepressed phenotype was dominant in a merodiploid containing a nif+ plasmid. These nif regulatory mutations also suppressed the Nif- phenotype of Gln- strains. Thus, regulation by fixed nitrogen (possible via glutamine synthetase) occurs on the nifLA operon but not on the other s...

  6. 100-N Area Decision Unit Target Analyte List Development for Soil

    Energy Technology Data Exchange (ETDEWEB)

    Ovink, R.

    2012-09-18

    This report documents the process used to identify source area target analytes in support of the 100-N Area remedial investigation/feasibility study (RI/FS) addendum to the Integrated 100 Area Remedial Investigation/Feasibility Study Work Plan (DOE/RL-2008-46, Rev. 0).

  7. Partial characterization of nif genes from the bacterium Azospirillum amazonense

    Directory of Open Access Journals (Sweden)

    D.P. Potrich

    2001-09-01

    Full Text Available Azospirillum amazonense revealed genomic organization patterns of the nitrogen fixation genes similar to those of the distantly related species A. brasilense. Our work suggests that A. brasilense nifHDK, nifENX, fixABC operons and nifA and glnB genes may be structurally homologous to the counterpart genes of A. amazonense. This is the first analysis revealing homology between A. brasilense nif genes and the A. amazonense genome. Sequence analysis of PCR amplification products revealed similarities between the amino acid sequences of the highly conserved nifD and glnB genes of A. amazonense and related genes of A. brasilense and other bacteria. However, the A. amazonense non-coding regions (the upstream activator sequence region and the region between the nifH and nifD genes differed from related regions of A. brasilense even in nitrogenase structural genes which are highly conserved among diazotrophic bacteria. The feasibility of the 16S ribosomal RNA gene-based PCR system for specific detection of A. amazonense was shown. Our results indicate that the PCR primers for 16S rDNA defined in this article are highly specific to A. amazonense and can distinguish this species from A. brasilense.

  8. National NIF Diagnostic Program Fiscal Year 2002 Second Quarter Report

    International Nuclear Information System (INIS)

    MacGowan, B

    2002-01-01

    Since October 2001 the development of the facility diagnostics for NIF has been funded by the NIF Director through the National NIF Diagnostic Program (NNDP). The current emphasis of the NNDP is on diagnostics for the early NIF quad scheduled to be available for experiment commissioning in FY03. During the past six months the NNDP has set in place processes for funding diagnostics, developing requirements for diagnostics, design reviews and monthly status reporting. Those processes are described in an interim management plan for diagnostics (National NIF Diagnostic Program Interim Plan, NIF-008 13 15, April 2002) and a draft Program Execution Plan (Program Execution Plan for the National NlF Diagnostic Program, NIF-0072083, October 2001) and documents cited therein. Work has been funded at Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Naval Research Laboratory (NRL), Sandia National Laboratories (SNL), Bechtel Nevada at Los Alamos and Santa Barbara. There are no major technical risks with the early diagnostics. The main concerns relate to integration of the diagnostics into the facility, all such issues are being worked. This report is organized to show the schedule and budget status and a summary of Change Control Board actions for the past six months. The following sections then provide short descriptions of the status of each diagnostic. Where design reviews or requirements documents are cited, the documents are available on the Diagnostics file server or on request

  9. Endophytic Herbaspirillum seropedicae expresses nif genes in gramineous plants.

    Science.gov (United States)

    Roncato-Maccari, Lauren D B; Ramos, Humberto J O; Pedrosa, Fabio O; Alquini, Yedo; Chubatsu, Leda S; Yates, Marshall G; Rigo, Liu U; Steffens, Maria Berenice R; Souza, Emanuel M

    2003-07-01

    Abstract The interactions between maize, sorghum, wheat and rice plants and Herbaspirillum seropedicae were examined microscopically following inoculation with the H. seropedicae LR15 strain, a Nif(+) (Pnif::gusA) mutant obtained by the insertion of a gusA-kanamycin cassette into the nifH gene of the H. seropedicae wild-type strain. The expression of the Pnif::gusA fusion was followed during the association of the diazotroph with the gramineous species. Histochemical analysis of seedlings of maize, sorghum, wheat and rice grown in vermiculite showed that strain LR15 colonized root surfaces and inner tissues. In early steps of the endophytic association, H. seropedicae colonized root exudation sites, such as axils of secondary roots and intercellular spaces of the root cortex; it then occupied the vascular tissue and there expressed nif genes. The expression of nif genes occurred in roots, stems and leaves as detected by the GUS reporter system. The expression of nif genes was also observed in bacterial colonies located in the external mucilaginous root material, 8 days after inoculation. Moreover, the colonization of plant tissue by H. seropedicae did not depend on the nitrogen-fixing ability, since similar numbers of cells were isolated from roots or shoots of the plants inoculated with Nif(+) or Nif(-) strains.

  10. National Ignition Facility Target Chamber

    International Nuclear Information System (INIS)

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-01-01

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was

  11. Qualitative values of radioactivity, area and volumetric: Application on phantoms (target and background)

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Rahman Al-Shakhrah, Issa [Department of Physics, University of Jordan, Queen Rania Street, Amman (Jordan)], E-mail: issashak@yahoo.com

    2009-04-15

    The visualization of a lesion depends on the contrast between the lesion and surrounding background (T/B; (target/background) ratio). For imaging in vivo not only is the radioactivity in the target organ important, but so too is the ratio of radioactivity in the target versus that in the background. Nearly all studies reported in the literature have dealt with the surface index, as a standard factor to study the relationship between the target (tissue or organ) and the background. It is necessary to know the ratio between the volumetric activity of lesions (targets) and normal tissues (background) instead of knowing the ratio between the area activity, the volume index being a more realistic factor than the area index as the targets (tissues or organs) are real volumes that have surfaces. The intention is that this work should aid in approaching a quantitative relationship and differentiation between different tissues (target/background or abnormal/normal tissues). For the background, square regions of interest (Rios) (11x11 pixels in size) were manually drawn by the observer at locations far from the border of the plastic cylinder (simulated organ), while an isocontour region with 50% threshold was drawn automatically over the cylinder. The total number of counts and pixels in each of these regions was calculated. The relationship between different phantom parameters, cylinder (target) depth, area activity ratio (background/target, A(B/T)) and real volumetric activity ratio (background/target, V(B/T)), was demonstrated. Variations in the area and volumetric activity ratio values with respect to the depth were deduced. To find a realistic value of the ratio, calibration charts have been constructed that relate the area and real volumetric ratios as a function of depth of the tissues and organs. Our experiments show that the cross-sectional area of the cylinder (applying a threshold 50% isocontour) has a weak dependence on the activity concentrations of the

  12. Qualitative values of radioactivity, area and volumetric: Application on phantoms (target and background)

    International Nuclear Information System (INIS)

    Abdel-Rahman Al-Shakhrah, Issa

    2009-01-01

    The visualization of a lesion depends on the contrast between the lesion and surrounding background (T/B; (target/background) ratio). For imaging in vivo not only is the radioactivity in the target organ important, but so too is the ratio of radioactivity in the target versus that in the background. Nearly all studies reported in the literature have dealt with the surface index, as a standard factor to study the relationship between the target (tissue or organ) and the background. It is necessary to know the ratio between the volumetric activity of lesions (targets) and normal tissues (background) instead of knowing the ratio between the area activity, the volume index being a more realistic factor than the area index as the targets (tissues or organs) are real volumes that have surfaces. The intention is that this work should aid in approaching a quantitative relationship and differentiation between different tissues (target/background or abnormal/normal tissues). For the background, square regions of interest (Rios) (11x11 pixels in size) were manually drawn by the observer at locations far from the border of the plastic cylinder (simulated organ), while an isocontour region with 50% threshold was drawn automatically over the cylinder. The total number of counts and pixels in each of these regions was calculated. The relationship between different phantom parameters, cylinder (target) depth, area activity ratio (background/target, A(B/T)) and real volumetric activity ratio (background/target, V(B/T)), was demonstrated. Variations in the area and volumetric activity ratio values with respect to the depth were deduced. To find a realistic value of the ratio, calibration charts have been constructed that relate the area and real volumetric ratios as a function of depth of the tissues and organs. Our experiments show that the cross-sectional area of the cylinder (applying a threshold 50% isocontour) has a weak dependence on the activity concentrations of the

  13. Empowerment Zones and Enterprise Districts - MDC_TargetUrbanAreaCorridor

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — A polygon feature class of Miami-Dade County, Targeted Urban Area Corridors. This coverage was created for the Office of Community & Economic Development (OCED)...

  14. A Platform for X-Ray Thomson Scattering Measurements of Radiation Hydrodynamics Experiments on the NIF

    Science.gov (United States)

    Lefevre, Heath; Ma, Kevin; Belancourt, Patrick; MacDonald, Michael; Doeppner, Tilo; Keiter, Paul; Kuranz, Carolyn

    2017-10-01

    A recent experiment on the National Ignition Facility (NIF) radiographed the evolution of the Rayleigh-Taylor (RT) instability under high and low drive cases. This experiment showed that under a high drive the growth rate of the RT instability is reduced relative to the low drive case. The high drive launches a radiative shock, increases the temperature of the post-shock region, and ablates the spikes, which reduces the RT growth rate. The plasma parameters must be measured to validate this claim. We present a target design for making X-Ray Thomson Scattering (XRTS) measurements on radiation hydrodynamics experiments on NIF to measure the electron temperature of the shocked region in the above cases. Specifically, we show that a previously fielded NIF radiation hydrodynamics platform can be modified to allow sufficient signal and temperature resolution for XRTS measurements. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956 and the National Science Foundation through the Basic Plasma Science and Engineering program.

  15. Decoding target distance and saccade amplitude from population activity in the macaque lateral intraparietal area (LIP

    Directory of Open Access Journals (Sweden)

    Frank Bremmer

    2016-08-01

    Full Text Available Primates perform saccadic eye movements in order to bring the image of an interesting target onto the fovea. Compared to stationary targets, saccades towards moving targets are computationally more demanding since the oculomotor system must use speed and direction information about the target as well as knowledge about its own processing latency to program an adequate, predictive saccade vector. In monkeys, different brain regions have been implicated in the control of voluntary saccades, among them the lateral intraparietal area (LIP. Here we asked, if activity in area LIP reflects the distance between fovea and saccade target, or the amplitude of an upcoming saccade, or both. We recorded single unit activity in area LIP of two macaque monkeys. First, we determined for each neuron its preferred saccade direction. Then, monkeys performed visually guided saccades along the preferred direction towards either stationary or moving targets in pseudo-randomized order. LIP population activity allowed to decode both, the distance between fovea and saccade target as well as the size of an upcoming saccade. Previous work has shown comparable results for saccade direction (Graf and Andersen, 2014a, b. Hence, LIP population activity allows to predict any two-dimensional saccade vector. Functional equivalents of macaque area LIP have been identified in humans. Accordingly, our results provide further support for the concept of activity from area LIP as neural basis for the control of an oculomotor brain-machine interface.

  16. Decoding Target Distance and Saccade Amplitude from Population Activity in the Macaque Lateral Intraparietal Area (LIP)

    Science.gov (United States)

    Bremmer, Frank; Kaminiarz, Andre; Klingenhoefer, Steffen; Churan, Jan

    2016-01-01

    Primates perform saccadic eye movements in order to bring the image of an interesting target onto the fovea. Compared to stationary targets, saccades toward moving targets are computationally more demanding since the oculomotor system must use speed and direction information about the target as well as knowledge about its own processing latency to program an adequate, predictive saccade vector. In monkeys, different brain regions have been implicated in the control of voluntary saccades, among them the lateral intraparietal area (LIP). Here we asked, if activity in area LIP reflects the distance between fovea and saccade target, or the amplitude of an upcoming saccade, or both. We recorded single unit activity in area LIP of two macaque monkeys. First, we determined for each neuron its preferred saccade direction. Then, monkeys performed visually guided saccades along the preferred direction toward either stationary or moving targets in pseudo-randomized order. LIP population activity allowed to decode both, the distance between fovea and saccade target as well as the size of an upcoming saccade. Previous work has shown comparable results for saccade direction (Graf and Andersen, 2014a,b). Hence, LIP population activity allows to predict any two-dimensional saccade vector. Functional equivalents of macaque area LIP have been identified in humans. Accordingly, our results provide further support for the concept of activity from area LIP as neural basis for the control of an oculomotor brain-machine interface. PMID:27630547

  17. Purification and binding analysis of the nitrogen fixation regulatory NifA protein from Azospirillum brasilense

    Directory of Open Access Journals (Sweden)

    L.M.P. Passaglia

    1998-11-01

    Full Text Available NifA protein activates transcription of nitrogen fixation operons by the alternative sigma54 holoenzyme form of RNA polymerase. This protein binds to a well-defined upstream activator sequence (UAS located at the -200/-100 position of nif promoters with the consensus motif TGT-N10-ACA. NifA of Azospirillum brasilense was purified in the form of a glutathione-S-transferase (GST-NifA fusion protein and proteolytic release of GST yielded inactive and partially soluble NifA. However, the purified NifA was able to induce the production of specific anti-A. brasilense NifA-antiserum that recognized NifA from A. brasilense but not from K. pneumoniae. Both GST-NifA and NifA expressed from the E. coli tac promoter are able to activate transcription from the nifHDK promoter but only in an A. brasilense background. In order to investigate the mechanism that regulates NifA binding capacity we have used E. coli total protein extracts expressing A. brasilense nifA in mobility shift assays. DNA fragments carrying the two overlapping, wild-type or mutated UAS motifs present in the nifH promoter region revealed a retarded band of related size. These data show that the binding activity present in the C-terminal domain of A. brasilense NifA protein is still functional even in the presence of oxygen.

  18. Performance of the NIF prototype beamlet

    International Nuclear Information System (INIS)

    Van Wonterghem, B.M.; Murray, J.R.; Speck, D.R.; Campbell, J.H.

    1994-01-01

    Beamlet is a full scale single beam prototype laser system, built to demonstrate the laser technology and performance of the 192 beam National Ignition Facility (NIF) fusion laser driver. Both laser systems apply multipass amplifier architectures. By passing the beam four times through the large aperture amplifier sections, the small signal gain during the first few passes is used efficiently to reduce expensive staged amplifier chains. The beamlet prototype laser integrates results of development programs for large aperture components: large aperture optical switch, polarizers, 2 x 2 multisegment amplifiers and new pulse generation and pre-amplification techniques. The authors report on performance test results of the recently completed 1 ω-laser section of Beamlet

  19. Omega experiments and preparation for moderate-gain direct-drive experiments on Nif

    International Nuclear Information System (INIS)

    Mr Crory, R.L.; Bahr, R.E.; Boehly, T.R.

    2000-01-01

    Direct-drive laser-fusion ignition experiments rely on detailed understanding and control of irradiation uniformity, Rayleigh-Taylor instability, and target fabrication. LLE is investigating various theoretical aspects of a direct-drive NIF ignition target based on an 'all-DT' design: a spherical target of ∼ 3.5 mm diameter, 1 to 2 μm if CH wall thickness, and a ∼ 350 μm DT-ice layer near the triple point of DT (μ19K). OMEGA experiments are designed to address the critical issues related to direct-drive laser fusion and to provide the necessary data to validate the predictive capability of LLE computer codes. The future cryogenic targets used on OMEGA are hydrodynamically equivalent to those planned for the NIF. The current experimental studies on OMEGA address all of the essential components of direct-drive laser fusion: irradiation uniformity and laser imprinting, Rayleigh-Taylor growth and saturation, compressed core performance and shell-fuel mixing, laser-plasma interactions and their effect on target performance, and cryogenic target fabrication and handling. (authors)

  20. Components of the CCR4-NOT complex function as nuclear hormone receptor coactivators via association with the NRC-interacting Factor NIF-1.

    Science.gov (United States)

    Garapaty, Shivani; Mahajan, Muktar A; Samuels, Herbert H

    2008-03-14

    CCR4-NOT is an evolutionarily conserved, multicomponent complex known to be involved in transcription as well as mRNA degradation. Various subunits (e.g. CNOT1 and CNOT7/CAF1) have been reported to be involved in influencing nuclear hormone receptor activities. Here, we show that CCR4/CNOT6 and RCD1/CNOT9, members of the CCR4-NOT complex, potentiate nuclear receptor activity. RCD1 interacts in vivo and in vitro with NIF-1 (NRC-interacting factor), a previously characterized nuclear receptor cotransducer that activates nuclear receptors via its interaction with NRC. As with NIF-1, RCD1 and CCR4 do not directly associate with nuclear receptors; however, they enhance ligand-dependent transcriptional activation by nuclear hormone receptors. CCR4 mediates its effect through the ligand binding domain of nuclear receptors and small interference RNA-mediated silencing of endogenous CCR4 results in a marked decrease in nuclear receptor activation. Furthermore, knockdown of CCR4 results in an attenuated stimulation of RARalpha target genes (e.g. Sox9 and HoxA1) as shown by quantitative PCR assays. The silencing of endogenous NIF-1 also resulted in a comparable decrease in the RAR-mediated induction of both Sox9 and HoxA1. Furthermore, CCR4 associates in vivo with NIF-1. In addition, the CCR4-enhanced transcriptional activation by nuclear receptors is dependent on NIF-1. The small interference RNA-mediated knockdown of NIF-1 blocks the ligand-dependent potentiating effect of CCR4. Our results suggest that CCR4 plays a role in the regulation of certain endogenous RARalpha target genes and that RCD1 and CCR4 might mediate their function through their interaction with NIF-1.

  1. NifH and NifD phylogenies: an evolutionary basis for understanding nitrogen fixation capabilities of methanotrophic bacteria.

    Science.gov (United States)

    Dedysh, Svetlana N; Ricke, Peter; Liesack, Werner

    2004-05-01

    The ability to utilize dinitrogen as a nitrogen source is an important phenotypic trait in most currently known methanotrophic bacteria (MB). This trait is especially important for acidophilic MB, which inhabit acidic oligotrophic environments, highly depleted in available nitrogen compounds. Phylogenetically, acidophilic MB are most closely related to heterotrophic dinitrogen-fixing bacteria of the genus BEIJERINCKIA: To further explore the phylogenetic linkage between these metabolically different organisms, the sequences of nifH and nifD gene fragments from acidophilic MB of the genera Methylocella and Methylocapsa, and from representatives of Beijerinckia, were determined. For reference, nifH and nifD sequences were also obtained from some type II MB of the alphaproteobacterial Methylosinus/Methylocystis group and from gammaproteobacterial type I MB. The trees constructed for the inferred amino acid sequences of nifH and nifD were highly congruent. The phylogenetic relationships among MB in the NifH and NifD trees also agreed well with the corresponding 16S rRNA-based phylogeny, except for two distinctive features. First, different methods used for phylogenetic analysis grouped the NifH and NifD sequences of strains of the gammaproteobacterial MB Methylococcus capsulatus within a clade mainly characterized by Alphaproteobacteria, including acidophilic MB and type II MB of the Methylosinus/Methylocystis group. From this and other genomic data from Methylococcus capsulatus Bath, it is proposed that an ancient event of lateral gene transfer was responsible for this aberrant branching. Second, the identity values of NifH and NifD sequences between Methylocapsa acidiphila B2 and representatives of Beijerinckia were clearly higher (98.5 and 96.6 %, respectively) than would be expected from their 16S rRNA-based relationships. Possibly, these two bacteria originated from a common acidophilic dinitrogen-fixing ancestor, and were subject to similar evolutionary pressure

  2. Urban-area extraction from polarimetric SAR image using combination of target decomposition and orientation angle

    Science.gov (United States)

    Zou, Bin; Lu, Da; Wu, Zhilu; Qiao, Zhijun G.

    2016-05-01

    The results of model-based target decomposition are the main features used to discriminate urban and non-urban area in polarimetric synthetic aperture radar (PolSAR) application. Traditional urban-area extraction methods based on modelbased target decomposition usually misclassified ground-trunk structure as urban-area or misclassified rotated urbanarea as forest. This paper introduces another feature named orientation angle to improve urban-area extraction scheme for the accurate mapping in urban by PolSAR image. The proposed method takes randomness of orientation angle into account for restriction of urban area first and, subsequently, implements rotation angle to improve results that oriented urban areas are recognized as double-bounce objects from volume scattering. ESAR L-band PolSAR data of the Oberpfaffenhofen Test Site Area was used to validate the proposed algorithm.

  3. The FLUKA study of the secondary particles fluence in the AD-Antiproton Decelerator target area

    CERN Document Server

    Calviani, M

    2014-01-01

    In this paper we present Monte Carlo FLUKA simulations [1, 2] carried out to investigate the secondary particles fluence emerging from the antiproton production target and their spatial distribution in the AD target area. The detailed quantitative analysis has been performed for different positions along the magnet dog-leg as well as after the main collimator. These results allow tuning the position of the new beam current transformers (BCT) in the target area, in order to have a precise pulse-by-pulse evaluation of the intensity of negative particles injected in the AD-ring before the deceleration phase.

  4. Molecular characterization of Azotobacter spp. nifH gene Isolated ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... Available online at http://www.academicjournals.org/AJB. ISSN 1684–5315 ... Molecular characterization of Azotobacter spp. nifH .... MATERIALS AND METHODS ..... rapidly expanding and is currently composed of over.

  5. NIFS contributions to 19th IAEA fusion energy conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-11-01

    NIFS has presented 21 papers at the 19th IAEA Fusion Energy Conference (Lyon, France, 14-19 October 2002). The contributed papers are collected in this report. The 21 papers are indexed individually. (J.P.N.)

  6. Science on high-energy lasers: From today to the NIF

    International Nuclear Information System (INIS)

    Lee, R.W.; Petrasso, R.; Falcone, R.W.

    1995-01-01

    This document presents both a concise definition of the current capabilities of high energy lasers and a description of capabilities of the NIF (National Ignition Facility). Five scientific areas are discussed (Astrophysics, Hydrodynamics, Material Properties, Plasma Physics, Radiation Sources, and Radiative Properties). In these five areas we project a picture of the future based on investigations that are being carried on today. Even with this very conservative approach we find that the development of new higher energy lasers will make many extremely exciting areas accessible to us

  7. The NIF DISCO Framework: facilitating automated integration of neuroscience content on the web.

    Science.gov (United States)

    Marenco, Luis; Wang, Rixin; Shepherd, Gordon M; Miller, Perry L

    2010-06-01

    This paper describes the capabilities of DISCO, an extensible approach that supports integrative Web-based information dissemination. DISCO is a component of the Neuroscience Information Framework (NIF), an NIH Neuroscience Blueprint initiative that facilitates integrated access to diverse neuroscience resources via the Internet. DISCO facilitates the automated maintenance of several distinct capabilities using a collection of files 1) that are maintained locally by the developers of participating neuroscience resources and 2) that are "harvested" on a regular basis by a central DISCO server. This approach allows central NIF capabilities to be updated as each resource's content changes over time. DISCO currently supports the following capabilities: 1) resource descriptions, 2) "LinkOut" to a resource's data items from NCBI Entrez resources such as PubMed, 3) Web-based interoperation with a resource, 4) sharing a resource's lexicon and ontology, 5) sharing a resource's database schema, and 6) participation by the resource in neuroscience-related RSS news dissemination. The developers of a resource are free to choose which DISCO capabilities their resource will participate in. Although DISCO is used by NIF to facilitate neuroscience data integration, its capabilities have general applicability to other areas of research.

  8. An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Robey, H F; Munro, D H; Spears, B K; Marinak, M M; Jones, O S; Patel, M V; Haan, S W; Salmonson, J D; Landen, O L [Lawrence Livermore National Laboratory, Livermore, CA (United States); Boehly, T R [Laboratory for Laser Energetics, Rochester, NY (United States); Nikroo, A [General Atomics, San Diego, CA (United States)], E-mail: robey1@llnl.gov

    2008-05-15

    Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of {<=} +/- 100ps. To meet these stringent requirements, dedicated tuning experiments are being planned to measure and adjust the shock timing on NIF. These tuning experiments will be performed in a modified hohlraum geometry, where a re-entrant Au cone is added to the standard NIF hohlraum to provide optical diagnostic (VISAR and SOP) access to the shocks as they break out of the ablator. This modified geometry is referred to as the 'keyhole' hohlraum and introduces a geometric difference between these tuning-experiments and the full ignition geometry. In order to assess the surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum.

  9. An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

    International Nuclear Information System (INIS)

    Robey, H F; Munro, D H; Spears, B K; Marinak, M M; Jones, O S; Patel, M V; Haan, S W; Salmonson, J D; Landen, O L; Boehly, T R; Nikroo, A

    2008-01-01

    Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of ≤ +/- 100ps. To meet these stringent requirements, dedicated tuning experiments are being planned to measure and adjust the shock timing on NIF. These tuning experiments will be performed in a modified hohlraum geometry, where a re-entrant Au cone is added to the standard NIF hohlraum to provide optical diagnostic (VISAR and SOP) access to the shocks as they break out of the ablator. This modified geometry is referred to as the 'keyhole' hohlraum and introduces a geometric difference between these tuning-experiments and the full ignition geometry. In order to assess the surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum

  10. NIF Projects Controls and Information Systems Software Quality Assurance Plan

    Energy Technology Data Exchange (ETDEWEB)

    Fishler, B

    2011-03-18

    Quality achievement for the National Ignition Facility (NIF) and the National Ignition Campaign (NIC) is the responsibility of the NIF Projects line organization as described in the NIF and Photon Science Directorate Quality Assurance Plan (NIF QA Plan). This Software Quality Assurance Plan (SQAP) is subordinate to the NIF QA Plan and establishes quality assurance (QA) activities for the software subsystems within Controls and Information Systems (CIS). This SQAP implements an activity level software quality assurance plan for NIF Projects as required by the LLNL Institutional Software Quality Assurance Program (ISQAP). Planned QA activities help achieve, assess, and maintain appropriate quality of software developed and/or acquired for control systems, shot data systems, laser performance modeling systems, business applications, industrial control and safety systems, and information technology systems. The objective of this SQAP is to ensure that appropriate controls are developed and implemented for management planning, work execution, and quality assessment of the CIS organization's software activities. The CIS line organization places special QA emphasis on rigorous configuration control, change management, testing, and issue tracking to help achieve its quality goals.

  11. NIF Projects Controls and Information Systems Software Quality Assurance Plan

    International Nuclear Information System (INIS)

    Fishler, B.

    2011-01-01

    Quality achievement for the National Ignition Facility (NIF) and the National Ignition Campaign (NIC) is the responsibility of the NIF Projects line organization as described in the NIF and Photon Science Directorate Quality Assurance Plan (NIF QA Plan). This Software Quality Assurance Plan (SQAP) is subordinate to the NIF QA Plan and establishes quality assurance (QA) activities for the software subsystems within Controls and Information Systems (CIS). This SQAP implements an activity level software quality assurance plan for NIF Projects as required by the LLNL Institutional Software Quality Assurance Program (ISQAP). Planned QA activities help achieve, assess, and maintain appropriate quality of software developed and/or acquired for control systems, shot data systems, laser performance modeling systems, business applications, industrial control and safety systems, and information technology systems. The objective of this SQAP is to ensure that appropriate controls are developed and implemented for management planning, work execution, and quality assessment of the CIS organization's software activities. The CIS line organization places special QA emphasis on rigorous configuration control, change management, testing, and issue tracking to help achieve its quality goals.

  12. Technical Targets - A Tool to Support Strategic Planning in the Subsurface Contaminants Focus Area

    International Nuclear Information System (INIS)

    Looney, B.B.

    2002-01-01

    The Subsurface Contaminants Focus Area (SCFA) is supported by a lead laboratory consisting of technical representatives from DOE laboratories across the country. This broadly representative scientific group has developed and implemented a process to define Technical Targets to assist the SCFA in strategic planning and in managing their environmental research and development portfolio. At an initial meeting in Golden Colorado, an initial set of Technical Targets was identified using a rapid consensus based technical triage process. Thirteen Technical Targets were identified and described. Vital scientific and technical objectives were generated for each target. The targets generally fall into one of the following five strategic investment categories: Enhancing Environmental Stewardship, Eliminating Contaminant Sources, Isolating Contaminants, Controlling Contaminant Plumes, Enabling DOEs CleanUp Efforts. The resulting targets and the detail they comprise on what is, and what is not, needed to meet Environmental Management needs provide a comprehensive technically-based framework to assist in prioritizing future work and in managing the SCFA program

  13. Modeling NIF experimental designs with adaptive mesh refinement and Lagrangian hydrodynamics

    Science.gov (United States)

    Koniges, A. E.; Anderson, R. W.; Wang, P.; Gunney, B. T. N.; Becker, R.; Eder, D. C.; MacGowan, B. J.; Schneider, M. B.

    2006-06-01

    Incorporation of adaptive mesh refinement (AMR) into Lagrangian hydrodynamics algorithms allows for the creation of a highly powerful simulation tool effective for complex target designs with three-dimensional structure. We are developing an advanced modeling tool that includes AMR and traditional arbitrary Lagrangian-Eulerian (ALE) techniques. Our goal is the accurate prediction of vaporization, disintegration and fragmentation in National Ignition Facility (NIF) experimental target elements. Although our focus is on minimizing the generation of shrapnel in target designs and protecting the optics, the general techniques are applicable to modern advanced targets that include three-dimensional effects such as those associated with capsule fill tubes. Several essential computations in ordinary radiation hydrodynamics need to be redesigned in order to allow for AMR to work well with ALE, including algorithms associated with radiation transport. Additionally, for our goal of predicting fragmentation, we include elastic/plastic flow into our computations. We discuss the integration of these effects into a new ALE-AMR simulation code. Applications of this newly developed modeling tool as well as traditional ALE simulations in two and three dimensions are applied to NIF early-light target designs.

  14. Modeling NIF Experimental Designs with Adaptive Mesh Refinement and Lagrangian Hydrodynamics

    International Nuclear Information System (INIS)

    Koniges, A E; Anderson, R W; Wang, P; Gunney, B N; Becker, R; Eder, D C; MacGowan, B J

    2005-01-01

    Incorporation of adaptive mesh refinement (AMR) into Lagrangian hydrodynamics algorithms allows for the creation of a highly powerful simulation tool effective for complex target designs with three-dimensional structure. We are developing an advanced modeling tool that includes AMR and traditional arbitrary Lagrangian-Eulerian (ALE) techniques. Our goal is the accurate prediction of vaporization, disintegration and fragmentation in National Ignition Facility (NIF) experimental target elements. Although our focus is on minimizing the generation of shrapnel in target designs and protecting the optics, the general techniques are applicable to modern advanced targets that include three-dimensional effects such as those associated with capsule fill tubes. Several essential computations in ordinary radiation hydrodynamics need to be redesigned in order to allow for AMR to work well with ALE, including algorithms associated with radiation transport. Additionally, for our goal of predicting fragmentation, we include elastic/plastic flow into our computations. We discuss the integration of these effects into a new ALE-AMR simulation code. Applications of this newly developed modeling tool as well as traditional ALE simulations in two and three dimensions are applied to NIF early-light target designs

  15. Modeling Nif experimental designs with adaptive mesh refinement and Lagrangian hydrodynamics

    International Nuclear Information System (INIS)

    Koniges, A.E.; Anderson, R.W.; Wang, P.; Gunney, B.T.N.; Becker, R.; Eder, D.C.; MacGowan, B.J.; Schneider, M.B.

    2006-01-01

    Incorporation of adaptive mesh refinement (AMR) into Lagrangian hydrodynamics algorithms allows for the creation of a highly powerful simulation tool effective for complex target designs with three-dimensional structure. We are developing an advanced modeling tool that includes AMR and traditional arbitrary Lagrangian-Eulerian (ALE) techniques. Our goal is the accurate prediction of vaporization, disintegration and fragmentation in National Ignition Facility (NIF) experimental target elements. Although our focus is on minimizing the generation of shrapnel in target designs and protecting the optics, the general techniques are applicable to modern advanced targets that include three-dimensional effects such as those associated with capsule fill tubes. Several essential computations in ordinary radiation hydrodynamics need to be redesigned in order to allow for AMR to work well with ALE, including algorithms associated with radiation transport. Additionally, for our goal of predicting fragmentation, we include elastic/plastic flow into our computations. We discuss the integration of these effects into a new ALE-AMR simulation code. Applications of this newly developed modeling tool as well as traditional ALE simulations in two and three dimensions are applied to NIF early-light target designs. (authors)

  16. Structural and Phylogenetic Analysis of Rhodobacter capsulatus NifF: Uncovering General Features of Nitrogen-fixation (nif-Flavodoxins

    Directory of Open Access Journals (Sweden)

    Inmaculada Pérez-Dorado

    2013-01-01

    Full Text Available Analysis of the crystal structure of NifF from Rhodobacter capsulatus and its homologues reported so far reflects the existence of unique structural features in nif flavodoxins: a leucine at the re face of the isoalloxazine, an eight-residue insertion at the C-terminus of the 50’s loop and a remarkable difference in the electrostatic potential surface with respect to non-nif flavodoxins. A phylogenetic study on 64 sequences from 52 bacterial species revealed four clusters, including different functional prototypes, correlating the previously defined as “short-chain” with the firmicutes flavodoxins and the “long-chain” with gram-negative species. The comparison of Rhodobacter NifF structure with other bacterial flavodoxin prototypes discloses the concurrence of specific features of these functional electron donors to nitrogenase.

  17. Structural and phylogenetic analysis of Rhodobacter capsulatus NifF: uncovering general features of nitrogen-fixation (nif)-flavodoxins.

    Science.gov (United States)

    Pérez-Dorado, Inmaculada; Bortolotti, Ana; Cortez, Néstor; Hermoso, Juan A

    2013-01-09

    Analysis of the crystal structure of NifF from Rhodobacter capsulatus and its homologues reported so far reflects the existence of unique structural features in nif flavodoxins: a leucine at the re face of the isoalloxazine, an eight-residue insertion at the C-terminus of the 50's loop and a remarkable difference in the electrostatic potential surface with respect to non-nif flavodoxins. A phylogenetic study on 64 sequences from 52 bacterial species revealed four clusters, including different functional prototypes, correlating the previously defined as "short-chain" with the firmicutes flavodoxins and the "long-chain" with gram-negative species. The comparison of Rhodobacter NifF structure with other bacterial flavodoxin prototypes discloses the concurrence of specific features of these functional electron donors to nitrogenase.

  18. First liquid-layer implosion experiments at the NIF

    Science.gov (United States)

    Zylstra, Alex

    2017-10-01

    Replacing the standard ice layer in an ignition design with a liquid layer allows fielding the target with a higher central vapor pressure, leading to reduced implosion convergence ratio (CR). At lower CR, the implosions are expected to be more robust to instabilities and asymmetries than standard ice-layer designs, and are also unique in that the hot spot can be primarily formed from material originating in the central fuel vapor. The first liquid-layer implosions on the National Ignition Facility (NIF) have been performed by wicking the liquid fuel into a supporting foam that lines the inside surface of the capsule. A series of shots has been conducted between CR of 12 and 20 using a HDC ablator driven by a 3-shock pulse in a near-vacuum Au hohlraum. At the lowest CR the implosion performance is well predicted by 2-D radiation-hydrodynamics calculations. However, as the CR is increased the nominal simulations do not capture the experimentally observed trends. Data-based models suggest that the hot spot formation is unexpectedly suppressed at higher convergence. The data could be explained by reduced hydrodynamic coupling efficiency, or an anomalously enhanced thermal conductivity in the mixed DT/foam material. We show that the latter hypothesis can explain observed trends in several experimental metrics, including the yield, ion temperature, and burn duration. This work was performed under the auspices of the U.S. DoE by LANL under contract DE-AC52-06NA52396.

  19. First Laser-Plasma Interaction and Hohlraum Experiments on NIF

    International Nuclear Information System (INIS)

    Dewald, E L; Glenzer, S H; Landen, O L; Suter, L J; Jones, O S; Schein, J; Froula, D; Divol, L; Campbell, K; Schneider, M S; McDonald, J W; Niemann, C; Mackinnon, A J

    2005-01-01

    Recently the first hohlraum experiments have been performed at the National Ignition Facility (NIF) in support of indirect drive Inertial Confinement Fusion (ICF) designs. The effects of laser beam smoothing by spectral dispersion (SSD) and polarization smoothing (PS) on the beam propagation in long scale gas-filled pipes has been studied at plasma scales as found in indirect drive gas filled ignition hohlraum designs. The long scale gas-filled target experiments have shown propagation over 7 mm of dense plasma without filamentation and beam break up when using full laser smoothing. Vacuum hohlraums have been irradiated with laser powers up to 6 TW, 1-9 ns pulse lengths and energies up to 17 kJ to activate several diagnostics, to study the hohlraum radiation temperature scaling with the laser power and hohlraum size, and to make contact with hohlraum experiments performed at the NOVA and Omega laser facilities. Subsequently, novel long laser pulse hohlraum experiments have tested models of hohlraum plasma filling and long pulse hohlraum radiation production. The validity of the plasma filling assessment in analytical models and in LASNEX calculations has been proven for the first time. The comparison of these results with modeling will be discussed

  20. The presence of five nifH-like sequences in Clostridium pasteurianum: sequence divergence and transcription properties.

    OpenAIRE

    Wang, S Z; Chen, J S; Johnson, J L

    1988-01-01

    The nifH gene encodes the iron protein (component II) of the nitrogenase complex. We have previously shown the presence in Clostridium pasteurianum of two nifH-like sequences in addition to the nifH1 gene which codes for a protein identical to the isolated iron protein. In the present study, we report that there are at least five nifH-like sequences in C. pasteurianum. DNA sequencing data indicate that the six nifH (nifH1) and nifH-like (nifH2, nifH3, nifH4, nifH5 and nifH6) sequences are not...

  1. The area centralis in the chicken retina contains efferent target amacrine cells

    Science.gov (United States)

    Weller, Cynthia; Lindstrom, Sarah H.; De Grip, Willem J.; Wilson, Martin

    2012-01-01

    The retinas of birds receive a substantial efferent, or centrifugal, input from a midbrain nucleus. The function of this input is presently unclear but previous work in the pigeon has shown that efferent input is excluded from the area centralis, suggesting that the functions of the area centralis and the efferent system are incompatible. Using an antibody specific to rods, we have identified the area centralis in another species, the chicken, and mapped the distribution of the unique amacrine cells that are the postsynaptic partners of efferent fibers. Efferent target amacrine cells are found within the chicken area centralis and their density is continuous across the border of the area centralis. In contrast to the pigeon retina then, we conclude that the chicken area centralis receives efferent input. We suggest that the difference between the 2 species is attributable to the presence of a fovea within the area centralis of the pigeon and its absence from that of the chicken. PMID:19296862

  2. Diversity and Functional Analysis of the FeMo-Cofactor Maturase NifB

    Directory of Open Access Journals (Sweden)

    Simon Arragain

    2017-11-01

    Full Text Available One of the main hurdles to engineer nitrogenase in a non-diazotrophic host is achieving NifB activity. NifB is an extremely unstable and oxygen sensitive protein that catalyzes a low-potential SAM-radical dependent reaction. The product of NifB activity is called NifB-co, a complex [8Fe-9S-C] cluster that serves as obligate intermediate in the biosyntheses of the active-site cofactors of all known nitrogenases. Here we study the diversity and phylogeny of naturally occurring NifB proteins, their protein architecture and the functions of the distinct NifB domains in order to understand what defines a catalytically active NifB. Focus is on NifB from the thermophile Chlorobium tepidum (two-domain architecture, the hyperthermophile Methanocaldococcus infernus (single-domain architecture and the mesophile Klebsiella oxytoca (two-domain architecture, showing in silico characterization of their nitrogen fixation (nif gene clusters, conserved NifB motifs, and functionality. C. tepidum and M. infernus NifB were able to complement an Azotobacter vinelandii (ΔnifB mutant restoring the Nif+ phenotype and thus demonstrating their functionality in vivo. In addition, purified C. tepidum NifB exhibited activity in the in vitro NifB-dependent nitrogenase reconstitution assay. Intriguingly, changing the two-domain K. oxytoca NifB to single-domain by removal of the C-terminal NifX-like extension resulted in higher in vivo nitrogenase activity, demonstrating that this domain is not required for nitrogen fixation in mesophiles.

  3. Identification of clinical target areas in the brainstem of prion‐infected mice

    Science.gov (United States)

    Mirabile, Ilaria; Jat, Parmjit S.; Brandner, Sebastian

    2015-01-01

    Aims While prion infection ultimately involves the entire brain, it has long been thought that the abrupt clinical onset and rapid neurological decline in laboratory rodents relates to involvement of specific critical neuroanatomical target areas. The severity and type of clinical signs, together with the rapid progression, suggest the brainstem as a candidate location for such critical areas. In this study we aimed to correlate prion pathology with clinical phenotype in order to identify clinical target areas. Method We conducted a comprehensive survey of brainstem pathology in mice infected with two distinct prion strains, which produce different patterns of pathology, in mice overexpressing prion protein (with accelerated clinical onset) and in mice in which neuronal expression was reduced by gene targeting (which greatly delays clinical onset). Results We identified specific brainstem areas that are affected by prion pathology during the progression of the disease. In the early phase of disease the locus coeruleus, the nucleus of the solitary tract, and the pre‐Bötzinger complex were affected by prion protein deposition. This was followed by involvement of the motor and autonomic centres of the brainstem. Conclusions Neurodegeneration in the locus coeruleus, the nucleus of the solitary tract and the pre‐Bötzinger complex predominated and corresponded to the manifestation of the clinical phenotype. Because of their fundamental role in controlling autonomic function and the overlap with clinical signs in sporadic Creutzfeldt–Jakob disease, we suggest that these nuclei represent key clinical target areas in prion diseases. PMID:25311251

  4. NIF laser bundle review. Final report

    International Nuclear Information System (INIS)

    Tietbohl, G.L.; Larson, D.W.; Erlandson, A.C.

    1995-01-01

    We performed additional bundle review effort subsequent to the completion of the preliminary report and are revising our original recommendations. We now recommend that the NIF baseline laser bundle size be changed to the 4x2 bundle configuration. There are several 4x2 bundle configurations that could be constructed at a cost similar to that of the baseline 4x12 (from $11M more to about $11M less than the baseline; unescalated, no contingency) and provide significant system improvements. We recommend that the building cost estimates (particularly for the in-line building options) be verified by an architect/engineer (A/E) firm knowledgeable about building design. If our cost estimates of the in-line building are accurate and therefore result in a change from the baseline U-shaped building layout, the acceptability of the in-line configuration must be reviewed from an operations viewpoint. We recommend that installation, operation, and maintenance of all laser components be reviewed to better determine the necessity of aisles, which add to the building cost significantly. The need for beam expansion must also be determined since it affects the type of bundle packing that can be used and increases the minimum laser bay width. The U-turn laser architecture (if proven viable) offers a reduction in building costs since this laser design is shorter than the baseline switched design and requires a shorter laser bay

  5. Ultrasonic Testing of NIF Amplifier FAU Top Plates

    International Nuclear Information System (INIS)

    Chinn, D.J.; Huber, R.D.; Haskins, J.J.; Rodriguez, J.A.; Souza, P.R.; Le, T.V.

    2002-01-01

    A key component in the National Ignition Facility (NIF) laser optic system is the amplifier frame assembly unit (FAU). The cast aluminum top plate that supports the FAU is required to withstand loads that would occur during an earthquake with a recurrence period of 1000 years. The stringent seismic requirements placed on the FAU top plate induced a study of the cast aluminum material used in the top plate. Ultrasonic testing was used to aid in characterizing the aluminum material used in the plates. This report documents the work performed using contact ultrasonic testing to characterize the FAU top plate material. The ultrasonic work reported here had 3 objectives: (1) inspect the plate material before cyclic testing conducted at the Pacific Earthquake Engineering Research Center (PEER); (2) determine the overall quality of individual plates; and (3) detect large defects in critical areas of individual plates. Section III, ''Pre-cyclic test inspection'', describes work performed in support of Objective 1. Section IV, ''Ultrasonic field measurements'', describes work performed in support of Objectives 2 and 3

  6. Swedish Hard Rock Laboratory first evaluation of preinvestigations 1986-87 and target area characterization

    International Nuclear Information System (INIS)

    Gustafson, G.; Stanfors, R.; Wikberg, P.

    1988-06-01

    SKB plans to site an underground research laboratory in the Simpevarp area. A regional survey started in 1986 and an extensive programme for geology, geohydrology and hydrochemistry was carried through. This report gives an evaluation of all available data gathered from the start of the project up to the drilling of core boreholes in some target areas in the autumn of 1987. A descriptive geological-tectonic model on a regional scale is presented that is intended to constitute a basis for the hydrogeological modelling work. Preliminary rock mass descriptions are also presented on a more detailed scale for some minor parts of the area. It is recommended that the island Aespoe is the principal target area for the continued work on the Swedish Hard Rock Laboratory. (orig.)

  7. Oxygen control of nif gene expression in Klebsiella pneumoniae depends on NifL reduction at the cytoplasmic membrane by electrons derived from the reduced quinone pool.

    Science.gov (United States)

    Grabbe, Roman; Schmitz, Ruth A

    2003-04-01

    In Klebsiella pneumoniae, the flavoprotein, NifL regulates NifA mediated transcriptional activation of the N2-fixation (nif) genes in response to molecular O2 and ammonium. We investigated the influence of membrane-bound oxidoreductases on nif-regulation by biochemical analysis of purified NifL and by monitoring NifA-mediated expression of nifH'-'lacZ reporter fusions in different mutant backgrounds. NifL-bound FAD-cofactor was reduced by NADH only in the presence of a redox-mediator or inside-out vesicles derived from anaerobically grown K. pneumoniae cells, indicating that in vivo NifL is reduced by electrons derived from membrane-bound oxidoreductases of the anaerobic respiratory chain. This mechanism is further supported by three lines of evidence: First, K. pneumoniae strains carrying null mutations of fdnG or nuoCD showed significantly reduced nif-induction under derepressing conditions, indicating that NifL inhibition of NifA was not relieved in the absence of formate dehydrogenase-N or NADH:ubiquinone oxidoreductase. The same effect was observed in a heterologous Escherichia coli system carrying a ndh null allele (coding for NADH dehydrogenaseII). Second, studying nif-induction in K. pneumoniae revealed that during anaerobic growth in glycerol, under nitrogen-limitation, the presence of the terminal electron acceptor nitrate resulted in a significant decrease of nif-induction. The final line of evidence is that reduced quinone derivatives, dimethylnaphthoquinol and menadiol, are able to transfer electrons to the FAD-moiety of purified NifL. On the basis of these data, we postulate that under anaerobic and nitrogen-limited conditions, NifL inhibition of NifA activity is relieved by reduction of the FAD-cofactor by electrons derived from the reduced quinone pool, generated by anaerobic respiration, that favours membrane association of NifL. We further hypothesize that the quinol/quinone ratio is important for providing the signal to NifL.

  8. Ground target geolocation based on digital elevation model for airborne wide-area reconnaissance system

    Science.gov (United States)

    Qiao, Chuan; Ding, Yalin; Xu, Yongsen; Xiu, Jihong

    2018-01-01

    To obtain the geographical position of the ground target accurately, a geolocation algorithm based on the digital elevation model (DEM) is developed for an airborne wide-area reconnaissance system. According to the platform position and attitude information measured by the airborne position and orientation system and the gimbal angles information from the encoder, the line-of-sight pointing vector in the Earth-centered Earth-fixed coordinate frame is solved by the homogeneous coordinate transformation. The target longitude and latitude can be solved with the elliptical Earth model and the global DEM. The influences of the systematic error and measurement error on ground target geolocation calculation accuracy are analyzed by the Monte Carlo method. The simulation results show that this algorithm can improve the geolocation accuracy of ground target in rough terrain area obviously. The geolocation accuracy of moving ground target can be improved by moving average filtering (MAF). The validity of the geolocation algorithm is verified by the flight test in which the plane flies at a geodetic height of 15,000 m and the outer gimbal angle is <47°. The geolocation root mean square error of the target trajectory is <45 and <7 m after MAF.

  9. Prediction of scaling physics laws for proton acceleration with extended parameter space of the NIF ARC

    Science.gov (United States)

    Bhutwala, Krish; Beg, Farhat; Mariscal, Derek; Wilks, Scott; Ma, Tammy

    2017-10-01

    The Advanced Radiographic Capability (ARC) laser at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is the world's most energetic short-pulse laser. It comprises four beamlets, each of substantial energy ( 1.5 kJ), extended short-pulse duration (10-30 ps), and large focal spot (>=50% of energy in 150 µm spot). This allows ARC to achieve proton and light ion acceleration via the Target Normal Sheath Acceleration (TNSA) mechanism, but it is yet unknown how proton beam characteristics scale with ARC-regime laser parameters. As theory has also not yet been validated for laser-generated protons at ARC-regime laser parameters, we attempt to formulate the scaling physics of proton beam characteristics as a function of laser energy, intensity, focal spot size, pulse length, target geometry, etc. through a review of relevant proton acceleration experiments from laser facilities across the world. These predicted scaling laws should then guide target design and future diagnostics for desired proton beam experiments on the NIF ARC. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and funded by the LLNL LDRD program under tracking code 17-ERD-039.

  10. Observations Of The LCROSS Impact With NIFS On The Gemini North Telescope

    Science.gov (United States)

    Roth, Katherine; Stephens, A. W.; Trujillo, C. A.; McDermid, R. M.; Woodward, C. E.; Walls, B. D.; Coulson, D. M.; Matulonis, A. C.; Ball, J. G.; Wooden, D. H.

    2010-01-01

    The Lunar CRater Observation and Sensing Satellite (LCROSS) Centaur rocket impacted a permanently shadowed crater near the south pole of the Moon at 11:31 UTC 2009 October 09. Gemini, one of several telescopes in a coordinated network observing the impact, conducted observations using NIFS to obtain 3D K-band imaging spectroscopy to detect water ice in the ejected plume of material. The spectral slope of the NIFS data can constrain the grain size and height distribution as the plume evolves, measuring the total mass and the water ice concentration in the plume. These observations provided an engineering challenge for Gemini, including the need to track non-sidereal with constantly changing track rates and guide on small bright moon craters, in order to keep the impact site within the NIFS field-of-view. High quality images taken by GMOS-N, NIRI and the acquisition camera during engineering periods at specific lunar libration and illumination were also used by the LCROSS ground based observing team to supplement slit positioning and offset plans for other ground based observatories. LCROSS mission support and engineering has resulted in improved telescope functionality for non-sidereal targets, including the ability to upload and import target ephemerides directly into the TCS, starting in semester 2010B. In this poster we present the engineering results and observing improvements which will facilitate enhanced user capabilities of the Gemini telescopes arising from the intensive LCROSS support challenge. Gemini Observatory is operated by AURA, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the NSF (United States), the STFC (United Kingdom), the NRC (Canada), CONICYT (Chile), the ARC (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). In part this research was supported by NASA through contracts to SWRI and NSF grant AST-0706980 to the U

  11. National Ignition Facility (NIF) Control Network Design and Analysis

    International Nuclear Information System (INIS)

    Bryant, R M; Carey, R W; Claybourn, R V; Pavel, G; Schaefer, W J

    2001-01-01

    The control network for the National Ignition Facility (NIF) is designed to meet the needs for common object request broker architecture (CORBA) inter-process communication, multicast video transport, device triggering, and general TCP/IP communication within the NIF facility. The network will interconnect approximately 650 systems, including the embedded controllers, front-end processors (FEPs), supervisory systems, and centralized servers involved in operation of the NIF. All systems are networked with Ethernet to serve the majority of communication needs, and asynchronous transfer mode (ATM) is used to transport multicast video and synchronization triggers. CORBA software infra-structure provides location-independent communication services over TCP/IP between the application processes in the 15 supervisory and 300 FEP systems. Video images sampled from 500 video cameras at a 10-Hz frame rate will be multicast using direct ATM Application Programming Interface (API) communication from video FEPs to any selected operator console. The Ethernet and ATM control networks are used to broadcast two types of device triggers for last-second functions in a large number of FEPs, thus eliminating the need for a separate infrastructure for these functions. Analysis, design, modeling, and testing of the NIF network has been performed to provide confidence that the network design will meet NIF control requirements

  12. NIF conventional facilities construction health and safety plan

    International Nuclear Information System (INIS)

    Benjamin, D W

    1998-01-01

    The purpose of this Plan is to outline the minimum health and safety requirements to which all participating Lawrence Livermore National Laboratory (LLNL) and non-LLNL employees (excluding National Ignition Facility [NIF] specific contractors and subcontractors covered under the construction subcontract packages (e.g., CSP-9)-see Construction Safety Program for the National Ignition Facility [CSP] Section I.B. ''NIF Construction Contractors and Subcontractors'' for specifics) shall adhere to for preventing job-related injuries and illnesses during Conventional Facilities construction activities at the NIF Project. For the purpose of this Plan, the term ''LLNL and non-LLNL employees'' includes LLNL employees, LLNL Plant Operations staff and their contractors, supplemental labor, contract labor, labor-only contractors, vendors, DOE representatives, personnel matrixed/assigned from other National Laboratories, participating guests, and others such as visitors, students, consultants etc., performing on-site work or services in support of the NIF Project. Based upon an activity level determination explained in Section 1.2.18, in this document, these organizations or individuals may be required by site management to prepare their own NIF site-specific safety plan. LLNL employees will normally not be expected to prepare a site-specific safety plan. This Plan also outlines job-specific exposures and construction site safety activities with which LLNL and non-LLNL employees shall comply

  13. Conceptual design of a high current ISOL target area at TRIUMF

    International Nuclear Information System (INIS)

    Beveridge, J.L.; Buchmann, L.; Clark, G.S.; Sprenger, H.; Thorson, I.; Vincent, J.; D'Auria, J.M.; Dombsky, M.

    1993-05-01

    Two similar conceptual designs for the handling of highly activated components at the target area of a high current radioactive beam facility have been investigated. The proposed designs are sufficiently flexible that practical detailed designs could be realized. Personnel exposure to radiation during the handling procedures is expected to be minimal. (author) 3 refs., 4 figs

  14. Methodology for estimation of potential for solar water heating in a target area

    International Nuclear Information System (INIS)

    Pillai, Indu R.; Banerjee, Rangan

    2007-01-01

    Proper estimation of potential of any renewable energy technology is essential for planning and promotion of the technology. The methods reported in literature for estimation of potential of solar water heating in a target area are aggregate in nature. A methodology for potential estimation (technical, economic and market potential) of solar water heating in a target area is proposed in this paper. This methodology links the micro-level factors and macro-level market effects affecting the diffusion or adoption of solar water heating systems. Different sectors with end uses of low temperature hot water are considered for potential estimation. Potential is estimated at each end use point by simulation using TRNSYS taking micro-level factors. The methodology is illustrated for a synthetic area in India with an area of 2 sq. km and population of 10,000. The end use sectors considered are residential, hospitals, nursing homes and hotels. The estimated technical potential and market potential are 1700 m 2 and 350 m 2 of collector area, respectively. The annual energy savings for the technical potential in the area is estimated as 110 kW h/capita and 0.55 million-kW h/sq. km. area, with an annual average peak saving of 1 MW. The annual savings is 650-kW h per m 2 of collector area and accounts for approximately 3% of the total electricity consumption of the target area. Some of the salient features of the model are the factors considered for potential estimation; estimation of electrical usage pattern for typical day, amount of electricity savings and savings during the peak load. The framework is general and enables accurate estimation of potential of solar water heating for a city, block. Energy planners and policy makers can use this framework for tracking and promotion of diffusion of solar water heating systems. (author)

  15. Physical and genetic map of the major nif gene cluster from Azotobacter vinelandii.

    OpenAIRE

    Jacobson, M R; Brigle, K E; Bennett, L T; Setterquist, R A; Wilson, M S; Cash, V L; Beynon, J; Newton, W E; Dean, D R

    1989-01-01

    Determination of a 28,793-base-pair DNA sequence of a region from the Azotobacter vinelandii genome that includes and flanks the nitrogenase structural gene region was completed. This information was used to revise the previously proposed organization of the major nif cluster. The major nif cluster from A. vinelandii encodes 15 nif-specific genes whose products bear significant structural identity to the corresponding nif-specific gene products from Klebsiella pneumoniae. These genes include ...

  16. Auxins upregulate nif and fix genes.

    Science.gov (United States)

    Bianco, Carmen; Defez, Roberto

    2010-10-01

    In a recent publication we analyzed the global effects triggered by IAA overproduction in S. meliloti RD64 under free-living conditions by comparing the gene expression pattern of wild type 1021 with that of RD64 and 1021 treated with IAA and other four chemically or functionally related molecules. Among the genes differentially expressed in RD64 and IAA-treated 1021 cells we found two genes of pho operon, phoT and phoC. Based on this finding we examined the mechanisms for mineral P solubilization in RD64 and the potential ability of this strain to improve Medicago growth under P-starved conditions. Here, we further analyze the expression profiles obtained in microarray analysis and evaluate the specificity and the extent of overlap between all treatments. Venn diagrams indicated that IAA- and 2,4-D-regulated genes were closely related. Furthermore, most differentially expressed genes from pSymA were induced in 1021 cells treated with 2,4-D, ICA, IND and Trp as compared to the untreated 1021 cells. RT-PCR analysis was employed to analyze the differential expression patterns of nitrogen fixation genes under free-living and symbiotic conditions. Under symbiotic condition, the relative expression levels of nif and fix genes were significantly induced in Mt- RD64 plants and in Mt-1021 plants treated with IAA and 2,4-D whereas they were unchanged or repressed in Mt-1021 plants treated with the other selected compounds when compared to the untreated Mt-1021 plants. © 2010 Landes Bioscience

  17. Research Performance Progress Report: Diverging Supernova Explosion Experiments on NIF

    Energy Technology Data Exchange (ETDEWEB)

    Plewa, Tomasz [Florida State Univ., Tallahassee, FL (United States)

    2016-10-25

    The aim of this project was to design a series of blast-wave driven Rayleigh-Taylor (RT) experiments on the National Ignition Facility (NIF). The experiments of this kind are relevant to mixing in core-collapse supernovae (ccSNe) and have the potential to address previously unanswered questions in high-energy density physics (HEDP) and astrophysics. The unmatched laser power of the NIF laser offers a unique chance to observe and study “new physics” like the mass extensions observed in HEDP RT experiments performed on the Omega laser [1], which might be linked to self-generated magnetic fields [2] and so far could not be reproduced by numerical simulations. Moreover, NIF is currently the only facility that offers the possibility to execute a diverging RT experiment, which would allow to observe processes such as inter-shell penetration via turbulent mixing and shock-proximity effects (distortion of the shock by RT spikes).

  18. Applied superconductivity and cryogenic research activities in NIFS

    International Nuclear Information System (INIS)

    Mito, T.; Sagara, A.; Imagawa, S.; Yamada, S.; Takahata, K.; Yanagi, N.; Chikaraishi, H.; Maekawa, R.; Iwamoto, A.; Hamaguchi, S.; Sato, M.; Noda, N.; Yamauchi, K.; Komori, A.; Motojima, O.

    2006-01-01

    Since the foundation of National Institute for Fusion Science (NIFS) in 1989, the primary mission of the applied superconductivity and cryogenic researches has been focused on the development of the large helical device (LHD): the largest fusion experimental apparatus exclusively utilizing superconducting technologies. The applied superconductivity and cryogenics group in NIFS was organized to be responsible for this activity. As a result of extensive research activities, the construction of LHD was completed in 1997. Since then, the LHD superconducting system has been demonstrating high availability of more than 97% during eight years operation and it keeps proving high reliability of large-scale superconducting systems. This paper describes the extensive activities of the applied superconductivity and cryogenic researches in NIFS during and after the development of LHD and the fundamental researches that aim at realizing a helical-type fusion reactor

  19. Capsule physics comparison of different ablators for NIF implosion designs

    Science.gov (United States)

    Clark, Daniel; Kritcher, Andrea; Yi, Austin; Zylstra, Alex; Haan, Steven; Ralph, Joseph; Weber, Christopher

    2017-10-01

    Indirect drive implosion experiments on the Naitonal Ignition Facility (NIF) have now tested three different ablator materials: glow discharge polymer (GDP) plastic, high density carbon (HDC), and beryllium. How do these different ablator choices compare in current and future implosion experiments on NIF? What are the relative advantages and disadvantages of each? This talk compares these different ablator options in capsule-only simulations of current NIF experiments and proposed future designs. The simulations compare the impact of the capsule fill tube, support tent, and interface surface roughness for each case, as well as all perturbations in combination. According to the simulations, each ablator is impacted by the various perturbation sources differently, and each material poses unique challenges in the pursuit of ignition. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  20. National Ignition Facility system design requirements NIF integrated computer controls SDR004

    International Nuclear Information System (INIS)

    Bliss, E.

    1996-01-01

    This System Design Requirement document establishes the performance, design, development, and test requirements for the NIF Integrated Computer Control System. The Integrated Computer Control System (ICCS) is covered in NIF WBS element 1.5. This document responds directly to the requirements detailed in the NIF Functional Requirements/Primary Criteria, and is supported by subsystem design requirements documents for each major ICCS Subsystem

  1. Targeted histology sampling from atypical small acinar proliferation area detected by repeat transrectal prostate biopsy

    Directory of Open Access Journals (Sweden)

    A. V. Karman

    2017-01-01

    Full Text Available Оbjective: to define the approach to the management of patients with the detected ASAP area.Materials and methods. In the time period from 2012 through 2015, 494 patients with previously negative biopsy and remaining suspicion of prostate cancer (PCa were examined. The patients underwent repeat 24-core multifocal prostate biopsy with taking additional tissue samples from suspicious areas detected by multiparametric magnetic resonance imaging and transrectal ultrasound. An isolated ASAP area was found in 127 (25. 7 % of the 494 examined men. All of them were offered to perform repeat target transrectal biopsy of this area. Targeted transrectal ultrasound guided biopsy of the ASAP area was performed in 56 (44.1 % of the 127 patients, 53 of them being included in the final analysis.Results. PCa was diagnosed in 14 (26.4 % of the 53 patients, their mean age being 64.4 ± 6.9 years. The average level of prostate-specific antigen (PSA in PCa patients was 6.8 ± 3.0 ng/ml, in those with benign lesions – 9.3 ± 6.5 ng/ml; the percentage ratio of free/total PSA with PCa was 16.2 ± 7,8 %, with benign lesions – 23.3 ± 7.7 %; PSA density in PCa patients was 0.14 ± 0.07 ng/ml/cm3, in those with benign lesions – 0.15 ± 0.12 ng/ml/cm3. Therefore, with ASAP area being detected in repeat prostate biopsy samples, it is advisable that targeted extended biopsy of this area be performed. 

  2. Directed mutagenesis affects recombination in Azospirillum brasilense nif genes

    Directory of Open Access Journals (Sweden)

    C.P. Nunes

    2000-12-01

    Full Text Available In order to improve the gene transfer/mutagenesis system for Azospirillum brasilense, gene-cartridge mutagenesis was used to replace the nifD gene with the Tn5 kanamycin resistance gene. The construct was transferred to A. brasilense by electrotransformation. Of the 12 colonies isolated using the suicide plasmid pSUP202 as vector, only four did not show vector integration into the chromosome. Nevertheless, all 12 colonies were deficient in acetylene reduction, indicating an Nif- phenotype. Four Nif- mutants were analyzed by Southern blot, using six different probes spanning the nif and Km r genes and the plasmid vector. Apparently, several recombination events occurred in the mutant genomes, probably caused mainly by gene disruption owing to the mutagenesis technique used: resistance gene-cartridge mutagenesis combined with electrotransformation.Com o objetivo de melhorar os sistemas de transferência gênica e mutagênese para Azospirillum brasilense, a técnica de mutagênese através do uso de um gene marcador ("gene-cartridge mutagenesis" foi utilizada para substituir a região genômica de A. brasilense correspondente ao gene nifD por um segmento de DNA do transposon Tn5 contendo o gene que confere resistência ao antibiótico canamicina. A construção foi transferida para a linhagem de A. brasilense por eletrotransformação. Doze colônias transformantes foram isoladas com o plasmídeo suicida pSUP202 servindo como vetor. Dessas, somente quatro não possuíam o vetor integrado no cromossomo da bactéria. Independentemente da integração ou não do vetor, as 12 colônias foram deficientes na redução do gás acetileno, evidenciando o fenótipo Nif -. Quatro mutantes Nif - foram analisados através da técnica de Southern blot, utilizando-se seis diferentes fragmentos contendo genes nif, de resistência à canamicina e do vetor como sondas. Os resultados sugerem a ocorrência de eventos recombinacionais variados no genoma dos mutantes. A

  3. Integrated modeling of cryogenic layered highfoot experiments at the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Kritcher, A. L.; Hinkel, D. E.; Callahan, D. A.; Hurricane, O. A.; Clark, D.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Döppner, T.; Barrios Garcia, M. A.; Haan, S.; Berzak Hopkins, L. F.; Jones, O.; Landen, O.; Ma, T.; Meezan, N.; Milovich, J. L.; Pak, A. E.; Park, H.-S.; Patel, P. K. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

    2016-05-15

    Integrated radiation hydrodynamic modeling in two dimensions, including the hohlraum and capsule, of layered cryogenic HighFoot Deuterium-Tritium (DT) implosions on the NIF successfully predicts important data trends. The model consists of a semi-empirical fit to low mode asymmetries and radiation drive multipliers to match shock trajectories, one dimensional inflight radiography, and time of peak neutron production. Application of the model across the HighFoot shot series, over a range of powers, laser energies, laser wavelengths, and target thicknesses predicts the neutron yield to within a factor of two for most shots. The Deuterium-Deuterium ion temperatures and the DT down scattered ratios, ratio of (10–12)/(13–15) MeV neutrons, roughly agree with data at peak fuel velocities <340 km/s and deviate at higher peak velocities, potentially due to flows and neutron scattering differences stemming from 3D or capsule support tent effects. These calculations show a significant amount alpha heating, 1–2.5× for shots where the experimental yield is within a factor of two, which has been achieved by increasing the fuel kinetic energy. This level of alpha heating is consistent with a dynamic hot spot model that is matched to experimental data and as determined from scaling of the yield with peak fuel velocity. These calculations also show that low mode asymmetries become more important as the fuel velocity is increased, and that improving these low mode asymmetries can result in an increase in the yield by a factor of several.

  4. Long-duration planar direct-drive hydrodynamics experiments on the NIF

    Science.gov (United States)

    Casner, A.; Mailliet, C.; Khan, S. F.; Martinez, D.; Izumi, N.; Kalantar, D.; Di Nicola, P.; Di Nicola, J. M.; Le Bel, E.; Igumenshchev, I.; Tikhonchuk, V. T.; Remington, B. A.; Masse, L.; Smalyuk, V. A.

    2018-01-01

    The advent of high-power lasers facilities such as the National Ignition Facility (NIF) and the laser megajoule provide unique platforms to study the physics of turbulent mixing flows in high energy density plasmas. We report here on the commissioning of a novel planar direct-drive platform on the NIF, which allows the acceleration of targets during 30 ns. Planar plastic samples were directly irradiated by 300-450 kJ of UV laser light (351 nm) and a very good planarity of the laser drive is demonstrated. No detrimental effect of imprint is observed in the case of these thick plastic targets (300 μm), which is beneficial for future academic experiments requesting similar irradiation conditions. The long-duration direct-drive (DD) platform is thereafter harnessed to study the ablative Rayleigh-Taylor instability (RTI) in DD. The growth of two-dimensional pre-imposed perturbations is quantified through time-resolved face-on x-ray radiography and used as a benchmark for radiative hydrocode simulations. The ablative RTI is then quantified in its highly nonlinear stage starting from intentionally large 3D imprinted broadband modulations. Two generations of bubble mergers is observed for the first time in DD, as a result of the unprecedented long laser acceleration.

  5. An assessment of the 3D geometric surrogacy of shock timing diagnostic techniques for tuning experiments on the NIF

    Science.gov (United States)

    Robey, H. F.; Munro, D. H.; Spears, B. K.; Marinak, M. M.; Jones, O. S.; Patel, M. V.; Haan, S. W.; Salmonson, J. D.; Landen, O. L.; Boehly, T. R.; Nikroo, A.

    2008-05-01

    Ignition capsule implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of four steps, which launch a corresponding series of shocks through the ablator and DT ice shell. The relative timing of these shocks is critical for maintaining the DT fuel on a low adiabat. The current NIF specification requires that the timing of all four shocks be tuned to an accuracy of surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The results from simulations of a quarter of the target geometry are presented. Comparisons of the hohlraum drive conditions and the resulting effect on the shock timing in the keyhole hohlraum are compared with the corresponding results for the standard ignition hohlraum.

  6. 33 CFR 334.1160 - San Pablo Bay, Calif.; target practice area, Mare Island Naval Shipyard, Vallejo.

    Science.gov (United States)

    2010-07-01

    ... practice area, Mare Island Naval Shipyard, Vallejo. 334.1160 Section 334.1160 Navigation and Navigable... REGULATIONS § 334.1160 San Pablo Bay, Calif.; target practice area, Mare Island Naval Shipyard, Vallejo. (a..., Mare Island Naval Shipyard, Vallejo, California, will conduct target practice in the area at intervals...

  7. Collaborative 3D Target Tracking in Distributed Smart Camera Networks for Wide-Area Surveillance

    Directory of Open Access Journals (Sweden)

    Xenofon Koutsoukos

    2013-05-01

    Full Text Available With the evolution and fusion of wireless sensor network and embedded camera technologies, distributed smart camera networks have emerged as a new class of systems for wide-area surveillance applications. Wireless networks, however, introduce a number of constraints to the system that need to be considered, notably the communication bandwidth constraints. Existing approaches for target tracking using a camera network typically utilize target handover mechanisms between cameras, or combine results from 2D trackers in each camera into 3D target estimation. Such approaches suffer from scale selection, target rotation, and occlusion, drawbacks typically associated with 2D tracking. In this paper, we present an approach for tracking multiple targets directly in 3D space using a network of smart cameras. The approach employs multi-view histograms to characterize targets in 3D space using color and texture as the visual features. The visual features from each camera along with the target models are used in a probabilistic tracker to estimate the target state. We introduce four variations of our base tracker that incur different computational and communication costs on each node and result in different tracking accuracy. We demonstrate the effectiveness of our proposed trackers by comparing their performance to a 3D tracker that fuses the results of independent 2D trackers. We also present performance analysis of the base tracker along Quality-of-Service (QoS and Quality-of-Information (QoI metrics, and study QoS vs. QoI trade-offs between the proposed tracker variations. Finally, we demonstrate our tracker in a real-life scenario using a camera network deployed in a building.

  8. Comparison of plastic, high-density carbon, and beryllium as NIF ablators

    Science.gov (United States)

    Kritcher, Andrea

    2017-10-01

    An effort is underway to compare the three principal ablators for National Ignition Facility (NIF) implosions: plastic (CH), High Density Carbon (HDC), and beryllium (Be). This presentation will summarize the comparison and discuss in more detail the issues pertaining to hohlraum performance and symmetry. Several aspects of the hohlraum design are affected by the ablator properties, as the ablator constrains the first shock and determines the overall pulse length. HDC targets can utilize shorter pulse lengths due to the thinner, higher density shell, and should be less susceptible to late time wall motion. However, HDC requires a larger picket energy to ensure adequate melt, leading to increased late time wall movement. Be is intermediate to CH and HDC in both these regards, and has more ablated material in the hohlraum. These tradeoffs as well as other design choices for currently fielded campaigns are assessed in this work. To assess consistently the radiation drive and symmetry, integrated postshot simulations of the hohlraum and capsule were done for each design using the same methodology. The simulation results are compared to experimental data. Using this post-shot model, we make a projection of the relative plausible performance that can be achieved, while maintaining adequate symmetry, using the full NIF laser, i.e. 1.8 MJ/500 TW Full NIF Equivalent (FNE). The hydrodynamic stability of the different ablators is also an important consideration and will be presented for the current platforms and projection to FNE. 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. Hotspots ampersand other hidden targets: Probability of detection, number, frequency and area

    International Nuclear Information System (INIS)

    Vita, C.L.

    1994-01-01

    Concepts and equations are presented for making probability-based estimates of the detection probability, and the number, frequency, and area of hidden targets, including hotspots, at a given site. Targets include hotspots, which are areas of extreme or particular contamination, and any object or feature that is hidden from direct visual observation--including buried objects and geologic or hydrologic details or anomalies. Being Bayesian, results are fundamentally consistent with observational methods. Results are tools for planning or interpreting exploration programs used in site investigation or characterization, remedial design, construction, or compliance monitoring, including site closure. Used skillfully and creatively, these tools can help streamline and expedite environmental restoration, reducing time and cost, making site exploration cost-effective, and providing acceptable risk at minimum cost. 14 refs., 4 figs

  10. Stereotactically Standard Areas: Applied Mathematics in the Service of Brain Targeting in Deep Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Ioannis N. Mavridis

    2017-12-01

    Full Text Available The concept of stereotactically standard areas (SSAs within human brain nuclei belongs to the knowledge of the modern field of stereotactic brain microanatomy. These are areas resisting the individual variability of the nuclear location in stereotactic space. This paper summarizes the current knowledge regarding SSAs. A mathematical formula of SSAs was recently invented, allowing for their robust, reproducible, and accurate application to laboratory studies and clinical practice. Thus, SSAs open new doors for the application of stereotactic microanatomy to highly accurate brain targeting, which is mainly useful for minimally invasive neurosurgical procedures, such as deep brain stimulation.

  11. Stereotactically Standard Areas: Applied Mathematics in the Service of Brain Targeting in Deep Brain Stimulation.

    Science.gov (United States)

    Mavridis, Ioannis N

    2017-12-11

    The concept of stereotactically standard areas (SSAs) within human brain nuclei belongs to the knowledge of the modern field of stereotactic brain microanatomy. These are areas resisting the individual variability of the nuclear location in stereotactic space. This paper summarizes the current knowledge regarding SSAs. A mathematical formula of SSAs was recently invented, allowing for their robust, reproducible, and accurate application to laboratory studies and clinical practice. Thus, SSAs open new doors for the application of stereotactic microanatomy to highly accurate brain targeting, which is mainly useful for minimally invasive neurosurgical procedures, such as deep brain stimulation.

  12. Target Surface Area Effects on Hot Electron Dynamics from High Intensity Laser-Plasma Interactions

    Science.gov (United States)

    2016-08-19

    Science, University ofMichigan, AnnArbor,MI 48109-2099, USA E-mail: czulick@umich.edu Keywords: laser- plasma ,mass-limited, fast electrons , sheath...New J. Phys. 18 (2016) 063020 doi:10.1088/1367-2630/18/6/063020 PAPER Target surface area effects on hot electron dynamics from high intensity laser... plasma interactions CZulick, ARaymond,AMcKelvey, VChvykov, AMaksimchuk, AGRThomas, LWillingale, VYanovsky andKKrushelnick Center forUltrafast Optical

  13. Beams configuration design in target area with successive quadratic programming method

    International Nuclear Information System (INIS)

    Shi Zhiquan; Tan Jichun; Wei Xiaofeng; Man Jongzai; Zhang Xiaomin; Yuan Jing; Yuan Xiaodong

    1998-01-01

    The author describes the application of successive quadratic programming method (SQP) to design laser beam configuration in target area. Based on the requirement of ICF experiment physics, a math model of indirect-driver beam geometry is given. A 3D wire-frame is plotted, in which support lines represent 60 laser entireties and 240 turning points of support lines' segments stand for the spatial positions of reflectors

  14. Iron depletion affects nitrogenase activity and expression of nifH and nifA genes in Herbaspirillum seropedicae.

    Science.gov (United States)

    Rosconi, Federico; Souza, Emanuel M; Pedrosa, Fabio O; Platero, Raúl A; González, Cecilia; González, Marcela; Batista, Silvia; Gill, Paul R; Fabiano, Elena R

    2006-05-01

    Herbaspirillum seropedicae Z67 is a nitrogen-fixing bacterium able to colonize the rhizosphere and the interior of several plants. As iron is a key element for nitrogen fixation, we examined the response of this microorganism to iron deficiency under nitrogen fixing conditions. We identified a H. seropedicae exbD gene that was induced in response to iron limitation and is involved in iron homeostasis. We found that an exbD mutant grown in iron-chelated medium is unable to fix nitrogen. Moreover, we provide evidence that expression of the nifH and nifA genes is iron dependent in a H. seropedicae genetic background.

  15. Role of conserved cysteine residues in Herbaspirillum seropedicae NifA activity.

    Science.gov (United States)

    Oliveira, Marco A S; Baura, Valter A; Aquino, Bruno; Huergo, Luciano F; Kadowaki, Marco A S; Chubatsu, Leda S; Souza, Emanuel M; Dixon, Ray; Pedrosa, Fábio O; Wassem, Roseli; Monteiro, Rose A

    2009-01-01

    Herbaspirillum seropedicae is an endophytic diazotrophic bacterium that associates with economically important crops. NifA protein, the transcriptional activator of nif genes in H. seropedicae, binds to nif promoters and, together with RNA polymerase-sigma(54) holoenzyme, catalyzes the formation of open complexes to allow transcription initiation. The activity of H. seropedicae NifA is controlled by ammonium and oxygen levels, but the mechanisms of such control are unknown. Oxygen sensitivity is attributed to a conserved motif of cysteine residues in NifA that spans the central AAA+ domain and the interdomain linker that connects the AAA+ domain to the C-terminal DNA binding domain. Here we mutagenized this conserved motif of cysteines and assayed the activity of mutant proteins in vivo. We also purified the mutant variants of NifA and tested their capacity to bind to the nifB promoter region. Chimeric proteins between H. seropedicae NifA, an oxygen-sensitive protein, and Azotobacter vinelandii NifA, an oxygen-tolerant protein, were constructed and showed that the oxygen response is conferred by the central AAA+ and C-terminal DNA binding domains of H. seropedicae NifA. We conclude that the conserved cysteine motif is essential for NifA activity, although single cysteine-to-serine mutants are still competent at binding DNA.

  16. The genome of Paenibacillus sabinae T27 provides insight into evolution, organization and functional elucidation of nif and nif-like genes

    OpenAIRE

    Li, Xinxin; Deng, Zhiping; Liu, Zhanzhi; Yan, Yongliang; Wang, Tianshu; Xie, Jianbo; Lin, Min; Cheng, Qi; Chen, Sanfeng

    2014-01-01

    Background Most biological nitrogen fixation is catalyzed by the molybdenum nitrogenase. This enzyme is a complex which contains the MoFe protein encoded by nifDK and the Fe protein encoded by nifH. In addition to nifHDK, nifHDK-like genes were found in some Archaea and Firmicutes, but their function is unclear. Results We sequenced the genome of Paenibacillus sabinae T27. A total of 4,793 open reading frames were predicted from its 5.27 Mb genome. The genome of P. sabinae T27 contains fiftee...

  17. VTVH-MCD study of the Delta nifB Delta nifZ MoFe protein from Azotobacter vinelandii.

    Science.gov (United States)

    Cotton, Marcia S; Rupnik, Kresimir; Broach, Robyn B; Hu, Yilin; Fay, Aaron W; Ribbe, Markus W; Hales, Brian J

    2009-04-08

    NifZ is a member of a series of proteins associated with the maturation of the nitrogenase MoFe protein. An MCD spectroscopic study was undertaken on the Delta nifB Delta nifZ MoFe protein generated in the absence of both NifZ and NifB (deletion of NifB generates an apo-MoFe protein lacking the FeMo cofactor). Results presented here show that, in the absence of NifZ, only one of the two P-clusters of the MoFe protein is matured to the ultimate [8Fe-7S] structure. The other P-cluster site in the protein contains a [4Fe-4S] cluster pair, representing a P-cluster precursor that is electronically identical to the analogous clusters observed in the Delta nifH MoFe protein. These results suggest that the MoFe protein is synthesized in a stepwise fashion where NifZ is specifically required for the formation of the second P-cluster.

  18. User Interface Framework for the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Fisher, J M; Bowers, G A; Carey, R W; Daveler, S A; Herndon Ford, K B; Ho, J C; Lagin, L J; Lambert, C J; Mauvais, J; Stout, E A; West, S L

    2007-01-01

    A user interface (UI) framework supports the development of user interfaces to operate the National Ignition Facility (NIF) using the Integrated Computer Control System (ICCS). [1] This framework simplifies UI development and ensures consistency for NIF operators. A comprehensive, layered collection of UIs in ICCS provides interaction with system-level processes, shot automation, and subsystem-specific devices. All user interfaces are written in Java, employing CORBA to interact with other ICCS components. ICCS developers use these frameworks to compose two major types of user interfaces: broadviews and control panels. Broadviews provide a visual representation of the NIF beamlines through interactive schematic drawings. Control panels provide status and control at a device level. The UI framework includes a suite of display components to standardize user interaction through data entry behaviors, common connection and threading mechanisms, and a common appearance. With these components, ICCS developers can more efficiently address usability issues in the facility when needed. The ICCS UI framework helps developers create consistent and easy-to-understand user interfaces for NIF operators

  19. Inkludering av ungdom med minoritetsbakgrunn i NIF-organisert idrett

    Directory of Open Access Journals (Sweden)

    Mari Kristin Sisjord

    2014-10-01

    Full Text Available Norges Idrettsforbund og Olympiske og Paralympiske Komité (NIF har en uttalt målsetting om en åpen og inkluderende idrett. Hvordan kommer dette til uttrykk i den praktiske virksomheten? Denne artikkelen, som bygger på data fra en undersøkelse om likestilling og mangfold i den organiserte idretten (NIF, retter søkelyset mot arbeid med inklusjon av ungdom med minoritetsbakgrunn på ulike organisasjonsnivå i NIF: særforbund, idrettskretser og idrettslag. Datamaterialet er kvalitative intervju med representanter fra ulike organisasjonsnivå. Resultatene viser at NIFs overordnede politikk i varierende grad nedfelles i særforbundenes virksomhet, i idrettskretsene og i idrettslagene. Av særforbundene skiller Fotballforbundet og Klatreforbundet seg ut som aktive pådrivere i arbeidet med inkludering. Mange idrettslag oppfattet slike spørsmål som lite aktuelle i sitt rekrutteringsområde. Representanter for lag som hadde erfaring med inkludering og rekruttering av minoritetsungdom, tilkjennega varierte erfaringer og synspunkter.

  20. Perspectives: Using Historical Documents To Think about NIF Issues.

    Science.gov (United States)

    National Archives and Records Service (GSA), Washington, DC.

    The purpose of using historical documents in the classroom is to generate and enhance discussion by providing a historical perspective for issues. Five documents are included in this packet and are to be used as a supplemental material for the National Issues Forum (NIF) topics. Issues raised include (1) an analysis of the documents and (2)…

  1. NIF ICCS Test Controller for Automated and Manual Testing

    International Nuclear Information System (INIS)

    Zielinski, J S

    2007-01-01

    The National Ignition Facility (NIF) Integrated Computer Control System (ICCS) is a large (1.5 MSLOC), hierarchical, distributed system that controls all aspects of the NIF laser [1]. The ICCS team delivers software updates to the NIF facility throughout the year to support shot operations and commissioning activities. In 2006, there were 48 releases of ICCS: 29 full releases, 19 patches. To ensure the quality of each delivery, thousands of manual and automated tests are performed using the ICCS Test Controller test infrastructure. The TestController system provides test inventory management, test planning, automated test execution and manual test logging, release testing summaries and test results search, all through a web browser interface. Automated tests include command line based frameworks server tests and Graphical User Interface (GUI) based Java tests. Manual tests are presented as a checklist-style web form to be completed by the tester. The results of all tests, automated and manual, are kept in a common repository that provides data to dynamic status reports. As part of the 3-stage ICCS release testing strategy, the TestController system helps plan, evaluate and track the readiness of each release to the NIF facility

  2. Using the Species-Area Relationship to Set Baseline Targets for Conservation

    Directory of Open Access Journals (Sweden)

    Philip Desmet

    2004-12-01

    Full Text Available This paper demonstrates how the power form of the Species-Area Relationship (SAR can be used to set conservation targets for land classes using biodiversity survey data. The log-transformation of the power model is a straight line; therefore, if one knows the average number of species recorded per survey site and can estimate the true species number present in the land class, using EstimateS software, it is possible to calculate the slope of the curve, or z-value. The z-value is the exponent in the power model and it can then be used to estimate the proportion of area required to represent a given proportion of species present in any land class. This application of the SAR is explored using phytosociological relevé data from South Africa's Succulent Karoo biome. We also provide suggestions for extrapolating the estimated z-values to other land classes within a bioregion that lack sufficient survey data, using the relationship between z-values and remotely determined landscape variables such as habitat diversity (topographic diversity and geographic location (latitude and longitude. The SAR predicts that for most Succulent Karoo vegetation types a conservation target of 10% of the land area would not be sufficient to conserve the majority of species. We also demonstrate that not all land classes are equal from a plant biodiversity perspective, so applying one target to all land classes in a region will lead to significant gaps and inefficiencies in any reserve network based on this universal target.

  3. Vertical displacement of the brain and the target area during open stereotaxic neurosurgery

    International Nuclear Information System (INIS)

    Wester, K.; Kraekenes, J.

    2001-01-01

    During stereotaxic thalamotomies, we observed that the brain surface was sinking. The study was carried out to investigate to what extent the target area also was displaced and how this would affect the accuracy of the stereotaxic procedure. In 12 thalamotomies, with the patients operated on in the sitting position, we found that the cortical surface sank 0-9 (mean 5) mm during the operation. The vertical co-ordinate of the thalamic target was consequently adjusted per-operatively, and the electrodes were advanced on additional distance of 1-5.5 (mean 3.5) mm in an attempt to compensate for the assumed sinking of the target. This per-operative adjustment was based on the surgeon's experience and the results of macro-stimulation studies. The exact location of the thalamotomy lesion, and thereby the accuracy of the adjustment, was evaluated on 3 months postoperative CT scans. These showed that the intended target was hit with a sufficient degree of accuracy in all the patients, although the vertical co-ordinate had been slightly over-adjusted, as the center of the lesion on the average was located 1 mm below the intended location. Thus, if the vertical position had not been adjusted, the lesion would on the average have been located 2.5 mm too high compared with the intended target. Patients undergoing thalamotomy and other stereotaxic procedures, where a high degree of accuracy is needed, should be operated on in the sitting position. At the thalamic level, the vertical displacement of the target should be adjusted for by additional advancement of the stereotaxic probe. On average, this compensatory adjustment should be about half the per-operative sinking of the cortical surface. (author)

  4. Transcriptional profiling of nitrogen fixation and the role of NifA in the diazotrophic endophyte Azoarcus sp. strain BH72.

    Directory of Open Access Journals (Sweden)

    Abhijit Sarkar

    Full Text Available BACKGROUND: The model endophyte Azoarcus sp. strain BH72 is known to contribute fixed nitrogen to its host Kallar grass and also expresses nitrogenase genes endophytically in rice seedlings. Availability of nitrogen is a signal regulating the transcription of nitrogenase genes. Therefore, we analysed global transcription in response to differences in the nitrogen source. METHODOLOGY/PRINCIPAL FINDINGS: A DNA microarray, comprising 70-mer oligonucleotides representing 3989 open reading frames of the genome of strain BH72, was used for transcriptome studies. Transcription profiles of cells grown microaerobically on N2 versus ammonium were compared. Expression of 7.2% of the genes was significantly up-regulated, and 5.8% down-regulated upon N2 fixation, respectively. A parallel genome-wide prediction of σ(54-type promoter elements mapped to the upstream region of 38 sequences of which 36 were modulated under the N2 response. In addition to modulation of genes related to N2 fixation, the expressions of gene clusters that might be related to plant-microbe interaction and of several transcription factors were significantly enhanced. While comparing under N2-fixation conditions the transcriptome of wild type with a nifLA(- insertion mutant, NifA being the essential transcriptional activator for nif genes, 24.5% of the genome was found to be affected in expression. A genome-wide prediction of 29 NifA binding sequences matched to 25 of the target genes whose expression was differential during microarray analysis, some of which were putatively negatively regulated by NifA. For selected genes, differential expression was corroborated by real time RT-PCR studies. CONCLUSION/SIGNIFICANCE: Our data suggest that life under conditions of nitrogen fixation is an important part of the lifestyle of strain BH72 in roots, as a wide range of genes far beyond the nif regulon is modulated. Moreover, the NifA regulon in strain BH72 appears to encompass a wider range of

  5. The effect of laser pulse shape variations on the adiabat of NIF capsule implosions

    Energy Technology Data Exchange (ETDEWEB)

    Robey, H. F.; MacGowan, B. J.; Landen, O. L.; LaFortune, K. N.; Widmayer, C.; Celliers, P. M.; Moody, J. D.; Ross, J. S.; Ralph, J.; LePape, S.; Berzak Hopkins, L. F.; Spears, B. K.; Haan, S. W.; Clark, D.; Lindl, J. D.; Edwards, M. J. [LLNL, Livermore, California 94550 (United States)

    2013-05-15

    Indirectly driven capsule implosions on the National Ignition Facility (NIF) [Moses et al., Phys. Plasmas 16, 041006 (2009)] are being performed with the goal of compressing a layer of cryogenic deuterium-tritium (DT) fuel to a sufficiently high areal density (ρR) to sustain the self-propagating burn wave that is required for fusion power gain greater than unity. These implosions are driven with a temporally shaped laser pulse that is carefully tailored to keep the DT fuel on a low adiabat (ratio of fuel pressure to the Fermi degenerate pressure). In this report, the impact of variations in the laser pulse shape (both intentionally and unintentionally imposed) on the in-flight implosion adiabat is examined by comparing the measured shot-to-shot variations in ρR from a large ensemble of DT-layered ignition target implosions on NIF spanning a two-year period. A strong sensitivity to variations in the early-time, low-power foot of the laser pulse is observed. It is shown that very small deviations (∼0.1% of the total pulse energy) in the first 2 ns of the laser pulse can decrease the measured ρR by 50%.

  6. Progress Toward Modeling Spectroscopic Signatures of Mix on Omega and NIF

    Science.gov (United States)

    Tregillis, I. L.; Schmitt, M. J.; Hsu, S. C.; Wysocki, F. J.; Cobble, J. A.; Murphy, T. J.

    2011-10-01

    Defect-induced mix processes may degrade the performance of ICF and ICF-like targets at Omega and NIF. An improved understanding of the relevant physics requires an experimental program built on a foundation of radiation-hydrodynamic simulations plus reliable synthetic diagnostic outputs. To that end, the Applications of Ignition (AoI) and Defect Implosion Experiment (DIME) efforts at LANL have focused on directly driven plastic capsules containing high-Z dopants and manufactured with an equatorial ``trench'' defect. One of the key diagnostic techniques for detecting and diagnosing the migration of dopant material into the hot core is Multi-Monochromatic X-ray Imaging (MMI). This talk will focus on recent efforts to model spectroscopic signatures of mix processes in AoI/DIME capsules via simulated MMI-type diagnostic instruments. It will also include data from recent Omega shots and calculations in support of Tier 1 experiments at NIF in FY2012. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

  7. Spectroscopic diagnostics of NIF ICF implosions using line ratios of Kr dopant in the ignition capsule

    Science.gov (United States)

    Dasgupta, Arati; Ouart, Nicholas; Giuiani, John; Clark, Robert; Schneider, Marilyn; Scott, Howard; Chen, Hui; Ma, Tammy

    2017-10-01

    X ray spectroscopy is used on the NIF to diagnose the plasma conditions in the ignition target in indirect drive ICF implosions. A platform is being developed at NIF where small traces of krypton are used as a dopant to the fuel gas for spectroscopic diagnostics using krypton line emissions. The fraction of krypton dopant was varied in the experiments and was selected so as not to perturb the implosion. Our goal is to use X-ray spectroscopy of dopant line ratios produced by the hot core that can provide a precise measurement of electron temperature. Simulations of the krypton spectra using a 1 in 104 atomic fraction of krypton in direct-drive exploding pusher with a range of electron temperatures and densities show discrepancies when different atomic models are used. We use our non-LTE atomic model with a detailed fine-structure level atomic structure and collisional-radiative rates to investigate the krypton spectra at the same conditions. Synthetic spectra are generated with a detailed multi-frequency radiation transport scheme from the emission regions of interest to analyze the experimental data with 0.02% Kr concentration and compare and contrast with the existing simulations at LLNL. Work supported by DOE/NNSA; Part of this work was also done under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  8. Neutronics and radiation field studies for the RIA fragmentation target area

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, Susana [Lawrence Livermore National Laboratory, P.O. Box 808, L-446, Livermore, CA 94550 (United States)]. E-mail: reyes20@llnl.gov; Boles, Jason L. [Lawrence Livermore National Laboratory, P.O. Box 808, L-446, Livermore, CA 94550 (United States); Ahle, Larry E. [Lawrence Livermore National Laboratory, P.O. Box 808, L-446, Livermore, CA 94550 (United States); Stein, Werner [Lawrence Livermore National Laboratory, P.O. Box 808, L-446, Livermore, CA 94550 (United States)

    2006-06-23

    Neutronics simulations and activation evaluations are currently in progress as part of the pre-conceptual research and development effort for the Rare Isotope Accelerator (RIA). The RIA project involves generating heavy element ion beams with powers up to 400 kw for use in a fragmentation target line to produce selected ion beams for physics research experiments. Designing a fragmentation beam dump for RIA is one of the most critical challenges for such a facility. Here, we present the results from neutronics and radiation field assessments for various beam dump concepts that can meet requirements for the RIA fragmentation line. Preliminary results from heavy ion transport including radiation damage evaluations for the RIA fragmentation beam dump are also presented. Initial neutronics and activation studies will be incorporated with other target area considerations to identify important challenges and explore possible solutions.

  9. Neutronics and radiation field studies for the RIA fragmentation target area

    Science.gov (United States)

    Reyes, Susana; Boles, Jason L.; Ahle, Larry E.; Stein, Werner

    2006-06-01

    Neutronics simulations and activation evaluations are currently in progress as part of the pre-conceptual research and development effort for the Rare Isotope Accelerator (RIA). The RIA project involves generating heavy element ion beams with powers up to 400 kW for use in a fragmentation target line to produce selected ion beams for physics research experiments. Designing a fragmentation beam dump for RIA is one of the most critical challenges for such a facility. Here, we present the results from neutronics and radiation field assessments for various beam dump concepts that can meet requirements for the RIA fragmentation line. Preliminary results from heavy ion transport including radiation damage evaluations for the RIA fragmentation beam dump are also presented. Initial neutronics and activation studies will be incorporated with other target area considerations to identify important challenges and explore possible solutions.

  10. 7 CFR 3402.4 - Food and agricultural sciences areas targeted for National Needs Graduate and Postdoctoral...

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Food and agricultural sciences areas targeted for..., AND EXTENSION SERVICE, DEPARTMENT OF AGRICULTURE FOOD AND AGRICULTURAL SCIENCES NATIONAL NEEDS... sciences areas targeted for National Needs Graduate and Postdoctoral Fellowship Grants Program support...

  11. Protected area connectivity: Shortfalls in global targets and country-level priorities.

    Science.gov (United States)

    Saura, Santiago; Bertzky, Bastian; Bastin, Lucy; Battistella, Luca; Mandrici, Andrea; Dubois, Grégoire

    2018-03-01

    Connectivity of protected areas (PAs) is crucial for meeting their conservation goals. We provide the first global evaluation of countries' progress towards Aichi Target 11 of the Convention on Biological Diversity that is to have at least 17% of the land covered by well-connected PA systems by 2020. We quantify how well the terrestrial PA systems of countries are designed to promote connectivity, using the Protected Connected (ProtConn) indicator. We refine ProtConn to focus on the part of PA connectivity that is in the power of a country to influence, i.e. not penalizing countries for PA isolation due to the sea and to foreign lands. We found that globally only 7.5% of the area of the countries is covered by protected connected lands, which is about half of the global PA coverage of 14.7%, and that only 30% of the countries currently meet the Aichi Target 11 connectivity element. These findings suggest the need for considerable efforts to improve PA connectivity globally. We further identify the main priorities for improving or sustaining PA connectivity in each country: general increase of PA coverage, targeted designation of PAs in strategic locations for connectivity, ensuring permeability of the unprotected landscapes between PAs, coordinated management of neighbouring PAs within the country, and/or transnational coordination with PAs in other countries. Our assessment provides a key contribution to evaluate progress towards global PA connectivity targets and to highlight important strengths and weaknesses of the design of PA systems for connectivity in the world's countries and regions.

  12. Final report for NIF chamber dynamics studies. Final report (May 1997), Subcontract No. B291847

    International Nuclear Information System (INIS)

    Peterson, P.F.; Jin, H.; Scott, J.M.

    1997-01-01

    The National Ignition Facility (NIF), a 1.8 MJ, 192 laser beam facility, will have anticipated fusion yields of up to 20 MJ from D-T pellets encased in a gold hohlraum target. The energy emitted from the target in the form of x rays, neutrons, target debris kinetic energy, and target shrapnel will be contained in a 5 m. radius spherical target chamber. Various diagnostics will be stationed around the target at varying distances from the target. During each shot, the target will emit x rays that will vaporize nearby target facing surfaces including those of the diagnostics, the target positioner, and other chamber structures. This ablated vapor will be transported throughout the chamber, and will eventually condense and deposit on surfaces in the chamber, including the final optics debris shields. The research at the University of California at Berkeley relates primarily to the NIF chamber dynamics. The key design issues are the ablation of the chamber structures, transport of the vapor through the chamber and the condensation or deposition processes of those vaporized materials. An understanding of these processes is essential in developing a concept for protecting the final optics debris shields from an excessive coating (> 10 Angstrom) of target debris and ablated material, thereby prolonging their lifetime between change- outs. At Berkeley, we have studied the physical issues of the ablation process and the effects of varying materials, the condensation process of the vaporized material, and design schemes that can lower the threat posed to the debris shields by these processes. In addition to the work described briefly above, we performed extensive analysis of the target-chamber thermal response to in- chamber CO 2 Cleaning and of work performed to model the behavior of silica vapor. The work completed this year has been published in several papers and a dissertation -6 This report provides a summary of the work completed this year, as well as copies of

  13. National Ignition Facility subsystem design requirements target positioning subsystem SSDR 1.8.2

    International Nuclear Information System (INIS)

    Pittenger, L.

    1996-01-01

    This Subsystem Design Requirement document is a development specification that establishes the performance, design, development and test requirements for the target positioner subsystem (WBS 1.8.2) of the NIF Target Experimental System (WBS 1.8)

  14. Changes in Extremely Hot Summers over the Global Land Area under Various Warming Targets.

    Science.gov (United States)

    Wang, Lei; Huang, Jianbin; Luo, Yong; Yao, Yao; Zhao, Zongci

    2015-01-01

    Summer temperature extremes over the global land area were investigated by comparing 26 models of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) with observations from the Goddard Institute for Space Studies (GISS) and the Climate Research Unit (CRU). Monthly data of the observations and models were averaged for each season, and statistics were calculated for individual models before averaging them to obtain ensemble means. The summers with temperature anomalies (relative to 1951-1980) exceeding 3σ (σ is based on the local internal variability) are defined as "extremely hot". The models well reproduced the statistical characteristics evolution, and partly captured the spatial distributions of historical summer temperature extremes. If the global mean temperature increases 2°C relative to the pre-industrial level, "extremely hot" summers are projected to occur over nearly 40% of the land area (multi-model ensemble mean projection). Summers that exceed 5σ warming are projected to occur over approximately 10% of the global land area, which were rarely observed during the reference period. Scenarios reaching warming levels of 3°C to 5°C were also analyzed. After exceeding the 5°C warming target, "extremely hot" summers are projected to occur throughout the entire global land area, and summers that exceed 5σ warming would become common over 70% of the land area. In addition, the areas affected by "extremely hot" summers are expected to rapidly expand by more than 25%/°C as the global mean temperature increases by up to 3°C before slowing to less than 16%/°C as the temperature continues to increase by more than 3°C. The area that experiences summers with warming of 5σ or more above the warming target of 2°C is likely to maintain rapid expansion of greater than 17%/°C. To reduce the impacts and damage from severely hot summers, the global mean temperature increase should remain low.

  15. Problems and Concerns Regarding Access Control System Construction in Radiation Facilities Based on the NIFS Experience

    International Nuclear Information System (INIS)

    Kawano, T.; Inoue, N.; Sakuma, Y.; Motojima, O.

    2001-01-01

    Full text: In 1998, access control system for the large helical device (LHD) experimental hall was constructed and put into operation at the National Institute for Fusion Science (NIFS) in Toki, Japan. Since then, the system has been continuously improved. It now controls access into the LHD controlled area through four entrances. The system has five turnstile gates and enables control of access at the four entrances. The system is always checking whether the shielding doors are open or closed at eight positions. The details pertaining to the construction of the system were reported at IRPA-10 held in Hiroshima, Japan, in 2000. Based on our construction experience of the NIFS access control system, we will discuss problems related to software and operational design of the system. We will also discuss some concerns regarding the use of the system in radiation facilities. The problems we will present concern, among other thing, individual registration, time control, turnstile control, interlock signal control, data aggregation and transactions, automatic and manual control, and emergency procedures. For example, in relation to the time control and turnstile control functions, we will discuss the gate-opening time interval for an access event, the timing of access data recording, date changing, turn bar control, double access, and access error handling. (author)

  16. 33 CFR 334.200 - Chesapeake Bay, Point Lookout to Cedar Point; aerial and surface firing range and target area, U...

    Science.gov (United States)

    2010-07-01

    ... degrees 09 minutes 26 seconds identified as Hannibal Target. (3) The regulations. Nonexplosive projectiles and bombs will be dropped at frequent intervals in the target areas. Hooper and Hannibal target areas...

  17. Neutron Radiation Shielding For The NIF Streaked X-Ray Detector (SXD) Diagnostic

    International Nuclear Information System (INIS)

    Song, P; Holder, J; Young, B; Kalantar, D; Eder, D; Kimbrough, J

    2006-01-01

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) is preparing for the National Ignition Campaign (NIC) scheduled in 2010. The NIC is comprised of several ''tuning'' physics subcampaigns leading up to a demonstration of Inertial Confinement Fusion (ICF) ignition. In some of these experiments, time-resolved x-ray imaging of the imploding capsule may be required to measure capsule trajectory (shock timing) or x-ray ''bang-time''. A capsule fueled with pure tritium (T) instead of a deutriun-tritium (DT) mixture is thought to offer useful physics surrogacy, with reduced yields of up to 5e14 neutrons. These measurements will require the use of the NIF streak x-ray detector (SXD). The resulting prompt neutron fluence at the planned SXD location (∼1.7 m from the target) would be ∼1.4e9/cm 2 . Previous measurements suggest the onset of significant background at a neutron fluence of ∼ 1e8/cm 2 . The radiation damage and operational upsets which starts at ∼1e8 rad-Si/sec must be factored into an integrated experimental campaign plan. Monte Carlo analyses were performed to predict the neutron and gamma/x-ray fluences and radiation doses for the proposed diagnostic configuration. A possible shielding configuration is proposed to mitigate radiation effects. The primary component of this shielding is an 80 cm thickness of Polyethylene (PE) between target chamber center (TCC) and the SXD diagnostic. Additionally, 6-8 cm of PE around the detector provide from the large number of neutrons that scatter off the inside of the target chamber. This proposed shielding configuration reduces the high-energy neutron fluence at the SXD by approximately a factor ∼50

  18. Neutron Radiation Shielding For The NIF Streaked X-Ray Detector (SXD) Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Song, P; Holder, J; Young, B; Kalantar, D; Eder, D; Kimbrough, J

    2006-11-02

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) is preparing for the National Ignition Campaign (NIC) scheduled in 2010. The NIC is comprised of several ''tuning'' physics subcampaigns leading up to a demonstration of Inertial Confinement Fusion (ICF) ignition. In some of these experiments, time-resolved x-ray imaging of the imploding capsule may be required to measure capsule trajectory (shock timing) or x-ray ''bang-time''. A capsule fueled with pure tritium (T) instead of a deutriun-tritium (DT) mixture is thought to offer useful physics surrogacy, with reduced yields of up to 5e14 neutrons. These measurements will require the use of the NIF streak x-ray detector (SXD). The resulting prompt neutron fluence at the planned SXD location ({approx}1.7 m from the target) would be {approx}1.4e9/cm{sup 2}. Previous measurements suggest the onset of significant background at a neutron fluence of {approx} 1e8/cm{sup 2}. The radiation damage and operational upsets which starts at {approx}1e8 rad-Si/sec must be factored into an integrated experimental campaign plan. Monte Carlo analyses were performed to predict the neutron and gamma/x-ray fluences and radiation doses for the proposed diagnostic configuration. A possible shielding configuration is proposed to mitigate radiation effects. The primary component of this shielding is an 80 cm thickness of Polyethylene (PE) between target chamber center (TCC) and the SXD diagnostic. Additionally, 6-8 cm of PE around the detector provide from the large number of neutrons that scatter off the inside of the target chamber. This proposed shielding configuration reduces the high-energy neutron fluence at the SXD by approximately a factor {approx}50.

  19. Expression, purification, and functional analysis of the C-terminal domain of Herbaspirillum seropedicae NifA protein.

    Science.gov (United States)

    Monteiro, Rose A; Souza, Emanuel M; Geoffrey Yates, M; Steffens, M Berenice R; Pedrosa, Fábio O; Chubatsu, Leda S

    2003-02-01

    The Herbaspirillum seropedicae NifA protein is responsible for nif gene expression. The C-terminal domain of the H. seropedicae NifA protein, fused to a His-Tag sequence (His-Tag-C-terminal), was over-expressed and purified by metal-affinity chromatography to yield a highly purified and active protein. Band-shift assays showed that the NifA His-Tag-C-terminal bound specifically to the H. seropedicae nifB promoter region in vitro. In vivo analysis showed that this protein inhibited the Central + C-terminal domains of NifA protein from activating the nifH promoter of K. pneumoniae in Escherichia coli, indicating that the protein must be bound to the NifA-binding site (UAS site) at the nifH promoter region to activate transcription. Copyright 2002 Elsevier Science (USA)

  20. Sequencing and functional analysis of the nifENXorf1orf2 gene cluster of Herbaspirillum seropedicae.

    Science.gov (United States)

    Klassen, G; Pedrosa, F O; Souza, E M; Yates, M G; Rigo, L U

    1999-12-01

    A 5.1-kb DNA fragment from the nifHDK region of H. seropedicae was isolated and sequenced. Sequence analysis showed the presence of nifENXorf1orf2 but nifTY were not present. No nif or consensus promoter was identified. Furthermore, orf1 expression occurred only under nitrogen-fixing conditions and no promoter activity was detected between nifK and nifE, suggesting that these genes are expressed from the upstream nifH promoter and are parts of a unique nif operon. Mutagenesis studies indicate that nifN was essential for nitrogenase activity whereas nifXorf1orf2 were not. High homology between the C-terminal region of the NifX and NifB proteins from H. seropedicae was observed. Since the NifX and NifY proteins are important for FeMo cofactor (FeMoco) synthesis, we propose that alternative proteins with similar activities exist in H. seropedicae.

  1. Alternative irradiation schemes for NIF and LMJ hohlraums

    Science.gov (United States)

    Bourgade, Jean-Luc; Bowen, Christopher; Gauthier, Pascal; Landen, Otto

    2018-02-01

    We explore two alternative irradiation schemes for the large (‘outer’) and small (‘inner’) angle beams that currently illuminate National Ignition Facility (NIF) and Laser Mégajoule cavities. In the first, while the outer laser beams enter through the usual end laser entrance holes (LEH), the inner beams enter through slots along the cavity axis wall, illuminating the back wall of the cavity. This avoids the current interaction of the inner laser beams with the gold wall bubbles generated by the outer beams, which leads to large time-dependent changes in drive symmetry. Another scheme potentially useful for NIF uses only the outer beams. The radiative losses through the slots or from the use of outer beams only are compensated by using a smaller cavity and LEH.

  2. Plasma Electrode Pockels Cells for the Beamlet and NIF lasers

    International Nuclear Information System (INIS)

    Rhodes, M.A.; Woods, B.; DeYoreo, J.; Atherton, J.

    1994-05-01

    We describe Plasma Electrode Pockels Cells (PEPC) for the Beamlet laser and the proposed National Ignition Facility (NIF) laser. These PEPCs, together with passive polarizers, function as large aperture (> 35 x 35 cm 2 ) optical switches enabling the design of high-energy (> 5 kJ), multipass laser amplifiers. In a PEPC, plasma discharges form on both sides of a thin (1 cm) electro-optic crystal (KDP). These plasma discharges produce highly conductive and transparent electrodes that facilitate rapid (< 100 ns) and uniform charging of the KDP up to the half-wave voltage (17 kV) and back to zero volts. We discuss the operating principles, design, and optical performance of the Beamlet PEPC and briefly discuss our plans to extend PEPC technology for the NIF

  3. Diversity and expression of nitrogenase genes (nifH) from ectomycorrhizas of Corsican pine (Pinus nigra).

    Science.gov (United States)

    Izumi, Hironari; Anderson, Ian C; Alexander, Ian J; Killham, Ken; Moore, Edward R B

    2006-12-01

    The diversity of bacterial nitrogenase genes (nifH) and their mRNA transcription in ectomycorrhizas of Corsican pine (Pinus nigra) were examined. DNA and RNA were extracted from surface-sterilized and non-sterilized Corsican pine roots colonized by the ectomycorrhizal (ECM) fungi, Suillus variegatus and Tomentellopsis submollis. DNA-derived nifH polymerase chain reaction (PCR) products were obtained from all samples, but only a few reverse transcription PCRs for nifH mRNA were successful, suggesting that nitrogenase genes were not always transcribed. Several different nifH sequences were detected and the bacteria actively transcribing nifH were different from those whose genes were detected through DNA-based PCR. Putative nitrogenase amino acid sequences revealed that more than half of the nifH products were derived from methylotrophic bacteria, such as Methylocella spp. The next most frequent sequence types were similar to those from Burkholderia.

  4. Inter-domain cross-talk controls the NifA protein activity of Herbaspirillum seropedicae.

    Science.gov (United States)

    Monteiro, R A; de Souza, E M; Wassem, R; Yates, M G; Pedrosa, F O; Chubatsu, L S

    2001-11-09

    Herbaspirillum seropedicae is an endophytic diazotroph, which colonizes sugar cane, wheat, rice and maize. The activity of NifA, a transcriptional activator of nif genes in H. seropedicae, is controlled by ammonium ions through a mechanism involving its N-terminal domain. Here we show that this domain interacts specifically in vitro with the N-truncated NifA protein, as revealed by protection against proteolysis, and this interaction caused an inhibitory effect on both the ATPase and DNA-binding activities of the N-truncated NifA protein. We suggest that the N-terminal domain inhibits NifA-dependent transcriptional activation by an inter-domain cross-talk between the catalytic domain of the NifA protein and its regulatory N-terminal domain in response to fixed nitrogen.

  5. Control of autogenous activation of Herbaspirillum seropedicae nifA promoter by the IHF protein.

    Science.gov (United States)

    Wassem, Roseli; Pedrosa, Fábio O; Yates, Marshall G; Rego, Fabiane G M; Chubatsu, Leda S; Rigo, Liu U; Souza, Emanuel M

    2002-07-02

    Analysis of the expression of the Herbaspirillum seropedicae nifA promoter in Escherichia coli and Herbaspirillum seropedicae, showed that nifA expression is primarily dependent on NtrC but also required NifA for maximal expression under nitrogen-fixing conditions. Deletion of the IHF (integration host factor)-binding site produced a promoter with two-fold higher activity than the native promoter in the H. seropedicae wild-type strain but not in a nifA strain, indicating that IHF controls NifA auto-activation. IHF is apparently required to prevent overexpression of the NifA protein via auto-activation under nitrogen-fixing conditions in H. seropedicae.

  6. Acute oral administration of low doses of methylphenidate targets calretinin neurons in the rat septal area.

    Directory of Open Access Journals (Sweden)

    Alvaro eGarcía-Aviles

    2015-03-01

    Full Text Available Methylphenidate (MPD is a commonly administered drug to treat children suffering from attention deficit hyperactivity disorder (ADHD. Alterations in septal driven hippocampal theta rhythm may underlie attention deficits observed in these patients. Amongst others, the septo-hippocampal connections have long been acknowledged to be important in preserving hippocampal function. Thus, we wanted to ascertain if methylphenidate administration, which improves attention in patients, could affect septal areas connecting with hippocampus. We used low and orally administered methylphenidate doses (1.3; 2.7 and 5mg/Kg to rats what mimics the dosage range in humans. In our model, we observed no effect when using 1.3mg/Kg methylphenidate; whereas 2.7 and 5 mg/Kg induced a significant increase in c-fos expression specifically in the medial septum, an area intimately connected to the hippocampus. We analyzed dopaminergic areas such as nucleus accumbens and striatum, and found that only 5mg/Kg induced c-fos levels increase. In these areas tyrosine hydroxylase correlated well with c-fos staining, whereas in the medial septum the sparse tyrosine hydroxylase fibres did not overlap with c-fos positive neurons. Double immunofluorescence of c-fos with neuronal markers in the septal area revealed that co-localization with choline acethyl transferase, parvalbumin, and calbindin with c-fos did not change with MPD treatment; whereas, calretinin and c-fos double labeled neurons increased after MPD administration. Altogether, these results suggest that low and acute doses of methylphenidate primary target specific populations of caltretinin medial septal neurons.

  7. Where to Go Next? Identifying Target Areas in the North Atlantic for Future Seafloor Mapping Initiatives

    Science.gov (United States)

    Woelfl, A. C.; Jencks, J.; Johnston, G.; Varner, J. D.; Devey, C. W.

    2017-12-01

    Human activities are rapidly expanding into the oceans, yet detailed bathymetric maps do not exist for most of the seafloor that would permit governments to formulate sensible usage rules. Changing this situation will require an enormous international mapping effort. To ensure that this effort is directed towards the regions most in need of mapping, we need to know which areas have already been mapped and which areas are potentially most interesting. Despite various mapping efforts in recent years, large parts of the Atlantic still lack detailed bathymetric information. To successfully plan for future mapping efforts to fill these gaps, knowledge of current data coverage is imperative to avoid duplication of effort. While certain datasets are publically available online (e.g. NOAA's NCEI, EMODnet, IHO-DCDB, LDEO's GMRT), many are not. However, with the limited information we do have at hand, the question remains, where should we map next? And what criteria should we take into account? In 2016, a study was taken on as part of the efforts of the International Atlantic Seabed Mapping Working Group (ASMIWG). The ASMIWG, established by the Tri-Partite Galway Statement Implementation Committee, was tasked to develop a cohesive seabed mapping strategy for the Atlantic Ocean. The aim of our study was to develop a reproducible process for identifying and evaluating potential target areas within the North Atlantic that represent suitable sites for future bathymetric surveys. The sites were selected by applying a GIS-based suitability analysis that included specific user group-based parameters of the marine environment. Furthermore, information regarding current data coverage were gathered to take into account in the selection process. The results reveal the suitability of sites within the North Atlantic based on the selected criteria. Three potential target sites should be seen as flexible suggestions for future mapping initiatives rather than a rigid, defined set of areas

  8. The National Ignition Facility (NIF) and High Energy Density Science Research at LLNL (Briefing Charts)

    Science.gov (United States)

    2013-06-21

    The National Ignition Facility ( NIF ) and High Energy Density Science Research at LLNL Presentation to: IEEE Pulsed Power and Plasma Science...Conference C. J. Keane Director, NIF User Office June 21, 2013 1491978-1-4673-5168-3/13/$31.00 ©2013 IEEE Report Documentation Page Form ApprovedOMB No...4. TITLE AND SUBTITLE The National Ignition Facility ( NIF ) and High Energy Density Science Research at LLNL 5a. CONTRACT NUMBER 5b. GRANT

  9. Song decrystallization in adult zebra finches does not require the song nucleus NIf.

    Science.gov (United States)

    Roy, Arani; Mooney, Richard

    2009-08-01

    In adult male zebra finches, transecting the vocal nerve causes previously stable (i.e., crystallized) song to slowly degrade, presumably because of the resulting distortion in auditory feedback. How and where distorted feedback interacts with song motor networks to induce this process of song decrystallization remains unknown. The song premotor nucleus HVC is a potential site where auditory feedback signals could interact with song motor commands. Although the forebrain nucleus interface of the nidopallium (NIf) appears to be the primary auditory input to HVC, NIf lesions made in adult zebra finches do not trigger song decrystallization. One possibility is that NIf lesions do not interfere with song maintenance, but do compromise the adult zebra finch's ability to express renewed vocal plasticity in response to feedback perturbations. To test this idea, we bilaterally lesioned NIf and then transected the vocal nerve in adult male zebra finches. We found that bilateral NIf lesions did not prevent nerve section-induced song decrystallization. To test the extent to which the NIf lesions disrupted auditory processing in the song system, we made in vivo extracellular recordings in HVC and a downstream anterior forebrain pathway (AFP) in NIf-lesioned birds. We found strong and selective auditory responses to the playback of the birds' own song persisted in HVC and the AFP following NIf lesions. These findings suggest that auditory inputs to the song system other than NIf, such as the caudal mesopallium, could act as a source of auditory feedback signals to the song motor network.

  10. The ecological representativeness of the global protected areas estate in 2009: progress towards the CBD 2010 target

    DEFF Research Database (Denmark)

    Coad, Lauren; Burgess, Neil David; Loucks, Colby

    The Convention on Biological Diversity has established a global target for the protection of 10% of each of the world's ecological regions by 2010. This report uses the WWF Terrestrial Ecoregions of the World and the 2009 version of the World Database of Protected Areas to analyse progress towards...... are still working to develop their protected area networks and it is likely that further ecoregions will reach the 10% protected area coverage target for terrestrial ecological regions by 2010. Although protection of the Global 200 priority ecoregions is higher than for the total set of ecoregions, with 72...... % reaching the 10% target, previous studies have suggested that areas of high biodiversity may require higher levels of protection and conservation planning. The approaching 2010 deadline provides a further opportunity to discuss and assess the effectiveness of the 10% target in affording adequate protection...

  11. Fungicides transport in runoff from vineyard plot and catchment: contribution of non-target areas.

    Science.gov (United States)

    Lefrancq, Marie; Payraudeau, Sylvain; García Verdú, Antonio Joaquín; Maillard, Elodie; Millet, Maurice; Imfeld, Gwenaël

    2014-04-01

    Surface runoff and erosion during the course of rainfall events are major processes of pesticides transport from agricultural land to aquatic ecosystem. These processes are generally evaluated either at the plot or the catchment scale. Here, we compared at both scales the transport and partitioning in runoff water of two widely used fungicides, i.e., kresoxim-methyl (KM) and cyazofamid (CY). The objective was to evaluate the relationship between fungicides runoff from the plot and from the vineyard catchment. The results show that seasonal exports for KM and CY at the catchment were larger than those obtained at the plot. This underlines that non-target areas within the catchment largely contribute to the overall load of runoff-associated fungicides. Estimations show that 85 and 62 % of the loads observed for KM and CY at the catchment outlet cannot be explained by the vineyard plots. However, the partitioning of KM and CY between three fractions, i.e., the suspended solids (>0.7 μm) and two dissolved fractions (i.e., between 0.22 and 0.7 µm and plot scales enable to evaluate the sources areas of pesticide off-site transport.

  12. Combining a thermal-imaging diagnostic with an existing imaging VISAR diagnostic at the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Robert M, Malone; John R, Celesteb; Peter M, Celliers; Brent C, Froggeta; Robert L, Guyton; Morris I, Kaufman; Tony L, Lee; Brian J, MacGowan; Edmund W, Ng; Imants P, Reinbachs; Ronald B, Robinson; Lynn G, Seppala; Tom W, Tunnell; Phillip W, Watts

    2005-01-01

    Optical diagnostics are currently being designed to analyze high-energy density physics experiments at the National Ignition Facility (NIF). Two independent line-imaging Velocity Interferometer System for Any Reflector (VISAR) interferometers have been fielded to measure shock velocities, breakout times, and emission of targets having sizes of 1-5 mm. An 8-inch-diameter, fused silica triplet lens collects light at f/3 inside the 30-foot-diameter NIF vacuum chamber. VISAR recordings use a 659.5-nm probe laser. By adding a specially coated beam splitter to the interferometer table, light at wavelengths from 540 to 645 nm is spilt into a thermal-imaging diagnostic. Because fused silica lenses are used in the first triplet relay, the intermediate image planes for different wavelengths separate by considerable distances. A corrector lens on the interferometer table reunites these separated wavelength planes to provide a good image. Thermal imaging collects light at f/5 from a 2-mm object placed at Target Chamber Center (TCC). Streak cameras perform VISAR and thermal-imaging recording. All optical lenses are on kinematic mounts so that pointing accuracy of the optical axis may be checked. Counter-propagating laser beams (orange and red) are used to align both diagnostics. The red alignment laser is selected to be at the 50 percent reflection point of the beam splitter. This alignment laser is introduced at the recording streak cameras for both diagnostics and passes through this special beam splitter on its way into the NIF vacuum chamber

  13. Uncertainty Detection for NIF Normal Pointing Images

    International Nuclear Information System (INIS)

    Awwal, A S; Law, C; Ferguson, S W

    2007-01-01

    The National Ignition Facility at the Lawrence Livermore National Laboratory when completed in 2009, will deliver 192-beams aligned precisely at the center of the target chamber producing extreme energy densities and pressures. Video images of laser beams along the beam path are used by automatic alignment algorithms to determine the position of the beams for alignment purposes. However, noise and other optical effects may affect the accuracy of the calculated beam location. Realistic estimation of the uncertainty is necessary to assure that the beam is monitored within the clear optical path. When the uncertainty is above a certain threshold the automated alignment operation is suspended and control of the beam is transferred to a human operator. This work describes our effort to quantify the uncertainty of measurement of the most common alignment beam

  14. Limited-area short-range ensemble predictions targeted for heavy rain in Europe

    Directory of Open Access Journals (Sweden)

    K. Sattler

    2005-01-01

    Full Text Available Inherent uncertainties in short-range quantitative precipitation forecasts (QPF from the high-resolution, limited-area numerical weather prediction model DMI-HIRLAM (LAM are addressed using two different approaches to creating a small ensemble of LAM simulations, with focus on prediction of extreme rainfall events over European river basins. The first ensemble type is designed to represent uncertainty in the atmospheric state of the initial condition and at the lateral LAM boundaries. The global ensemble prediction system (EPS from ECMWF serves as host model to the LAM and provides the state perturbations, from which a small set of significant members is selected. The significance is estimated on the basis of accumulated precipitation over a target area of interest, which contains the river basin(s under consideration. The selected members provide the initial and boundary data for the ensemble integration in the LAM. A second ensemble approach tries to address a portion of the model-inherent uncertainty responsible for errors in the forecasted precipitation field by utilising different parameterisation schemes for condensation and convection in the LAM. Three periods around historical heavy rain events that caused or contributed to disastrous river flooding in Europe are used to study the performance of the LAM ensemble designs. The three cases exhibit different dynamic and synoptic characteristics and provide an indication of the ensemble qualities in different weather situations. Precipitation analyses from the Deutsche Wetterdienst (DWD are used as the verifying reference and a comparison of daily rainfall amounts is referred to the respective river basins of the historical cases.

  15. Thermal analysis of the large close packed amplifiers in the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Brown, D.L.; Mannell, G.T.

    1995-05-01

    Flashlamp pumping of the large aperture multi-segment NIF amplifiers will result in large amounts of energy being deposited as heat in the amplifier components. The magnitude of the heating and the nonuniform distribution result in a delay time between shots due to wavefront distortion and steering error. A NEF requirement is that the thermal wavefront recovery must occur in less than six hours. The principal cause of long-term wavefront distortion is the thermal gradient produced in the slab as heat diffuses from the edge cladding into the pumped volume. Thermal equilibrium is established through conduction, convection, and exchange of thermal radiation. Radiative exchange between glass components, such as flashlamps, blast shields, and laser slabs is especially effective because of the large surface areas of these components and the high emissivity of the glass. Free convection within the amplifier enclosure is also important but is on the order of a 10 to 20% effect compared to radiation for the major surfaces. To evaluate the NIF design, the amplifier was modeled to calculate the thermal response of a single laser element. The amplifier is cooled by flowing room-temperature air or nitrogen through the flashlamp cassettes. Active cooling of the flashlamps and blast shields serves two purposes; the energy deposited in these components can be removed before it is transferred to the amplifier optical components, and the cooled blast shield provides a large area heat sink for removal of the residual heat from the laser slabs. Approximately 50 to 60% of the flashlamp energy is deposited in the flashlamps and blast shields. Thus, cooling the flashlamp cassette is a very effective method for removing a substantial fraction of the energy without disturbing the optical elements of the system. Preliminary thermal analysis indicates that active cooling with flow rates of 10 CFM per flashlamp is sufficient to meet the six hour thermal equilibrium requirement

  16. Diagnosing implosion performance at the National Ignition Facility (NIF) by means of neutron spectrometry

    International Nuclear Information System (INIS)

    Frenje, J.A.; Casey, D.T.; Johnson, M. Gatu; Bionta, R.; Bond, E.J.; Caggiano, J.A.; Cerjan, C.; Edwards, J.; Eckart, M.; Fittinghoff, D.N.; Friedrich, S.; Glenzer, S.; Haan, S.; Hatarik, R.; Hatchett, S.; Jones, O.S.; Glebov, V.Yu.; Knauer, J.P.; Grim, G.; Kilkenny, J.D.

    2013-01-01

    The neutron spectrum from a cryogenically layered deuterium–tritium (dt) implosion at the National Ignition Facility (NIF) provides essential information about the implosion performance. From the measured primary-neutron spectrum (13–15 MeV), yield (Y n ) and hot-spot ion temperature (T i ) are determined. From the scattered neutron yield (10–12 MeV) relative to Y n , the down-scatter ratio, and the fuel areal density (ρR) are determined. These implosion parameters have been diagnosed to an unprecedented accuracy with a suite of neutron-time-of-flight spectrometers and a magnetic recoil spectrometer implemented in various locations around the NIF target chamber. This provides good implosion coverage and excellent measurement complementarity required for reliable measurements of Y n , T i and ρR, in addition to ρR asymmetries. The data indicate that the implosion performance, characterized by the experimental ignition threshold factor, has improved almost two orders of magnitude since the first shot taken in September 2010. ρR values greater than 1 g cm −2 are readily achieved. Three-dimensional semi-analytical modelling and numerical simulations of the neutron-spectrometry data, as well as other data for the hot spot and main fuel, indicate that a maximum hot-spot pressure of ∼150 Gbar has been obtained, which is almost a factor of two from the conditions required for ignition according to simulations. Observed Y n are also 3–10 times lower than predicted. The conjecture is that the observed pressure and Y n deficits are partly explained by substantial low-mode ρR asymmetries, which may cause inefficient conversion of shell kinetic energy to hot-spot thermal energy at stagnation. (paper)

  17. FY17 NIF Performance Quad Campaign: laser performance results and conclusions

    Energy Technology Data Exchange (ETDEWEB)

    Di Nicola, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mennerat, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Widmayer, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-09

    The FY17 NIF Performance Quad Campaign exercised a single quad of NIF (Q45T) at elevated energy to assess the impact of recent improvements to the infrared (1ω) and ultraviolet (3ω) section of the laser on integrated performance.

  18. Orexin–Corticotropin-Releasing Factor Receptor Heteromers in the Ventral Tegmental Area as Targets for Cocaine

    Science.gov (United States)

    Navarro, Gemma; Quiroz, César; Moreno-Delgado, David; Sierakowiak, Adam; McDowell, Kimberly; Moreno, Estefanía; Rea, William; Cai, Ning-Sheng; Aguinaga, David; Howell, Lesley A.; Hausch, Felix; Cortés, Antonio; Mallol, Josefa; Casadó, Vicent; Lluís, Carme; Canela, Enric I.

    2015-01-01

    Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R–OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R–OX1R heteromer. Cocaine binding to the σ1R–CRF1R–OX1R complex promotes a long-term disruption of the orexin-A–CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking. PMID:25926444

  19. Orexin-corticotropin-releasing factor receptor heteromers in the ventral tegmental area as targets for cocaine.

    Science.gov (United States)

    Navarro, Gemma; Quiroz, César; Moreno-Delgado, David; Sierakowiak, Adam; McDowell, Kimberly; Moreno, Estefanía; Rea, William; Cai, Ning-Sheng; Aguinaga, David; Howell, Lesley A; Hausch, Felix; Cortés, Antonio; Mallol, Josefa; Casadó, Vicent; Lluís, Carme; Canela, Enric I; Ferré, Sergi; McCormick, Peter J

    2015-04-29

    Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R-OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R-OX1R heteromer. Cocaine binding to the σ1R-CRF1R-OX1R complex promotes a long-term disruption of the orexin-A-CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking. Copyright © 2015 the authors 0270-6474/15/356639-15$15.00/0.

  20. Defect-induced mix experiment for NIF

    Directory of Open Access Journals (Sweden)

    Schmitt M.J.

    2013-11-01

    Full Text Available The Defect Induced Mix Experiment (DIME-II will measure the implosion and mix characteristics of CH capsules filled with 5 atmospheres of DT by incorporating mid-Z dopant layers of Ge and Ga. This polar direct drive (PDD experiment also will demonstrate the filling of a CH capsule at target chamber center using a fill tube. Diagnostics for these experiments include areal x-ray backlighting to obtain early time images of the implosion trajectory and a multiple-monochromatic imager (MMI to collect spectrally-resolved images of the capsule dopant line emission near bangtime. The inclusion of two (or more thin dopant layers at separate depths within the capsule shell facilitates spatial correlation of mix between the layers and the hot gas core on a single shot. The dopant layers are typically 2 μm thick and contain dopant concentrations of 1.5%. Three dimensional Hydra simulations have been performed to assess the effects of PDD asymmetry on capsule performance.

  1. Towards understanding the nitrogen signal transduction for nif gene expression in Klebsiella pneumoniae.

    Science.gov (United States)

    Glöer, Jens; Thummer, Robert; Ullrich, Heike; Schmitz, Ruth A

    2008-12-01

    In the diazotroph Klebsiella pneumoniae, the nitrogen sensory protein GlnK mediates the cellular nitrogen status towards the NifL/NifA system that regulates transcription of the nitrogen fixation genes in response to ammonium and molecular oxygen. To identify amino acids of GlnK essential for this signal transduction by protein-protein interaction, we performed random point mutagenesis by PCR amplification under conditions of reduced Taq polymerase fidelity. Three thousand two hundred mutated glnK genes were screened to identify those that would no longer complement a K. pneumoniaeDeltaglnK strain for growth under nitrogen fixing conditions. Twenty-four candidates resulting in a Nif(-) phenotype were identified, carrying 1-11 amino acid changes in GlnK. Based on these findings, as well as structural data, several single mutations were introduced into glnK by site-directed mutagenesis, and the Nif phenotype and the respective effects on NifA-mediated nif gene induction was monitored in K. pneumoniae using a chromosomal nifK'-'lacZ fusion. Single amino acid changes resulting in significant nif gene inhibition under nitrogen limiting conditions were located within the highly conserved T-loop (A43G, A49T and N54D), the body of the protein (G87V and K79E) and in the C-terminal region (I100M, R103S, E106Q and D108G). Complex formation analyses between GlnK (wild-type or derivatives) and NifL or NifA in response to 2-oxoglutarate indicated that: (a) besides the T-loop, the C-terminal region of GlnK is essential for the interaction with NifL and NifA and (b) GlnK binds both proteins in the absence of 2-oxoglutarate, whereas, in the presence of 2-oxoglutarate, NifA is released but NifL remains bound to GlnK.

  2. Integrating Biodiversity and Ecosystem Services in the Post-2015 Development Agenda: Goal Structure, Target Areas and Means of Implementation

    Directory of Open Access Journals (Sweden)

    Paul L. Lucas

    2013-12-01

    Full Text Available The United Nations’ discussions on defining a new set of post-2015 development goals focus on poverty eradication and sustainable development. Biodiversity and ecosystem services are essential for poverty eradication, which is also one of the foundations of the Strategic Plan for Biodiversity of the Convention on Biological Diversity (CBD. Based on an assessment of current proposals of goals and targets, and a quantitative pathway analysis to meet long term biodiversity and food security goals, this paper discusses how biodiversity and ecosystem services can be integrated into a broad set of goals and targets, and concludes with relevant target areas and means of implementation for which specific targets need to be defined. Furthermore, it responds to the call of the CBD to consider the Strategic Plan for Biodiversity and the related Aichi biodiversity targets in the post-2015 development agenda. The paper’s analysis identifies three overlapping but also supplemental ways to integrate biodiversity and ecosystem services in the post-2015 agenda: integrated goals, goals addressing earth system functioning and goals addressing environmental limits. It further concludes seven target areas to be included under the goals to address biodiversity and ecosystem services in the context of food and agriculture: access to food, demand for agricultural products, sustainable intensification, ecosystem fragmentation, protected areas, essential ecosystem services and genetic diversity. The Strategic Plan for Biodiversity provides a good basis for integrating biodiversity and ecosystem services in the post-2015 development agenda. Many Aichi targets address the proposed target areas and the means of implementation discussed, while they need to be complemented with targets that specifically address human well-being, as well as institutions and governance.

  3. Technology strategy for enhanced recovery; Technology Target Areas; TTA3 - enhanced recovery

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    The Norwegian Continental Shelf (NCS) is facing new challenges in reserve replacement and improved recovery in order to maintain the overall oil production rate from the area. A new target for an increase in oil reserves of 800 million Sm3 of oil (5 billion barrels) by year 2015 has been set by NPD. This is an ambitious goal considering several of the large fields are on a steep decline, and most of the recent discoveries are relatively small. A significant part of these increased reserves will have to come from fields currently on production, from reservoir areas that have been partly or fully swept, and it is therefore evident that Enhanced Oil Recovery (EOR) methods have to play a key role in achieving this target. EOR methods can be divided into gas based EOR methods and water based EOR methods. Thermal methods are not considered applicable on the NCS due to the relatively light oils present, and the depth of the reservoirs. Gas Based EOR; Water Based EOR; CO{sub 2} injection; Surfactants; Air injection; Polymer; Nitrogen injection; Alkaline; Flue gas injection; Polymer gels; WAG; MEOR; FAWAG. The former OG21 strategy document gave high priority to Water Alternating Gas (WAG) methods and CO{sub 2} injection for enhanced recovery. A lot of research and development and evaluation projects on CO{sub 2} injection were launched and are on-going, most of these are being CO{sub 2} WAG studies. The main challenge now in order to realize CO{sub 2} injection on the NCS is on CO{sub 2} availability and transport. It is also believed that increasing gas prices will limit the availability of hydrocarbon gas for injection purposes in the future. There is, however, a clear need for developing alternative cost efficient EOR methods that can improve the sweep efficiency significantly. Since a majority of the fields on the NCS are being produced under water flooding (or WAG), methods that can improve the water flooding efficiency by chemical additives are of special interest and

  4. FABRICATION OF WINDOW SADDLES FOR NIF CRYOGENIC HOHLRAUMS

    International Nuclear Information System (INIS)

    GIRALDEZ, E; KAAE, J.L

    2003-09-01

    OAK-B135 A planar diagnostic viewing port attached to the cylindrical wall of the NIF cryogenic hohlraum requires a saddle-like transition piece. While the basic design of this window saddle is straightforward, its fabrication is not, given the scale and precision of the component. They solved the problem through the use of a two segment copper mandrel to electroform the gold window saddle. The segments were micro-machined using a combination of single-point diamond turning and single point diamond milling. These processes as well as the electroplating conditions, final machining and mandrel removal are described in this paper

  5. Status Update: Modeling Energy Balance in NIF Hohlraums

    Energy Technology Data Exchange (ETDEWEB)

    Jones, O. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-22

    We have developed a standardized methodology to model hohlraum drive in NIF experiments. We compare simulation results to experiments by 1) comparing hohlraum xray fluxes and 2) comparing capsule metrics, such as bang times. Long-pulse, high gas-fill hohlraums require a 20-28% reduction in simulated drive and inclusion of ~15% backscatter to match experiment through (1) and (2). Short-pulse, low fill or near-vacuum hohlraums require a 10% reduction in simulated drive to match experiment through (2); no reduction through (1). Ongoing work focuses on physical model modifications to improve these matches.

  6. The National Ignition Facility (NIF) and the issue of nonproliferation. Final study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-19

    NIF, the next step proposed by DOE in a progression of Inertial Confinement Fusion (ICF) facilities, is expected to reach the goal of ICF capsule ignition in the laboratory. This report is in response to a request of a Congressman that DOE resolve the question of whether NIF will aid or hinder U.S. nonproliferation efforts. Both technical and policy aspects are addressed, and public participation was part of the decision process. Since the technical proliferation concerns at NIF are manageable and can be made acceptable, and NIF can contribute positively to U.S. arms control and nonproliferation policy goals, it is concluded that NIF supports the nuclear nonproliferation objectives of the United States.

  7. IFE chamber technology testing program in NIF and chamber development test plan

    International Nuclear Information System (INIS)

    Abdou, M.A.

    1995-01-01

    Issues concerning chamber technology testing program in NIF involving: criteria for evaluation/prioritization of experiments, engineering scaling requirements for test article design and material selection and R and D plan prior to NIF testing were addressed in this paper. In order to maximize the benefits of testing program in NIF, the testing in NIF should provide the experimental data relevant to DEMO design choice or to DEMO design predictive capability by utilizing engineering scaling test article designs. Test plans were developed for 2 promising chamber design concepts. Early testing in non-fusion/non-ignition prior to testing in ignition facility serves a critical role in chamber R and D test plans in order to reduce the risks and costs of the more complex experiments in NIF

  8. The National Ignition Facility (NIF) and the issue of nonproliferation. Final study

    International Nuclear Information System (INIS)

    1995-01-01

    NIF, the next step proposed by DOE in a progression of Inertial Confinement Fusion (ICF) facilities, is expected to reach the goal of ICF capsule ignition in the laboratory. This report is in response to a request of a Congressman that DOE resolve the question of whether NIF will aid or hinder U.S. nonproliferation efforts. Both technical and policy aspects are addressed, and public participation was part of the decision process. Since the technical proliferation concerns at NIF are manageable and can be made acceptable, and NIF can contribute positively to U.S. arms control and nonproliferation policy goals, it is concluded that NIF supports the nuclear nonproliferation objectives of the United States

  9. Interaction of an IHF-like protein with the Rhizobium etli nifA promoter.

    Science.gov (United States)

    Benhassine, Traki; Fauvart, Maarten; Vanderleyden, Jos; Michiels, Jan

    2007-06-01

    The nifA gene fulfills an essential role in the regulation of nitrogen fixation genes in Rhizobium etli. Transcription analysis of the nifA gene, assessed using promoter deletions, indicated an oxygen-independent expression, threefold higher during symbiosis as compared with free-living conditions. Electrophoretic mobility shift assays using those nifA promoter deletion fragments, which were actively transcribed, demonstrated the specific interaction with R. etli cellular protein(s) resulting in the formation of two DNA-protein complexes. An interacting protein was purified by liquid chromatography on Heparin Sepharose and Mono S columns. The purified 12 kDa R. etli protein cross-reacted with antibodies directed against Escherichia coli integration host factor (IHF). Furthermore, purified E. coli IHF was able to specifically bind to the R. etli nifA promoter region. These results point to an as yet undisclosed function of IHF in the regulation of R. etli nifA expression.

  10. Application effect of TEM sounding survey on prospecting and target area selection of sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    He Jianguo; Liang Shanming; Zhao Cuiping

    2006-01-01

    Based on the results of transient electromagnetic (TEM) sounding survey during recent years regional geological reconnaissance with drilling (1:250000), the application effect of TEM sounding survey during regional reconnaissance is summarized in this paper. It is suggested that the data of TEM sounding are useful in judging hydrodynamic conditions of groundwater and determining favorable areas for uranium ore-formation; TEM sounding in large areas may be proper for prospecting in gobi-desert areas and be beneficial for regional reconnaissance and target area selection, and may reduce the target area and provide basis for further drilling program. It is of popularized significance in the prospecting for sandstone-type uranium deposits. (authors)

  11. Imaging of High-Energy X-Ray Emission from Cryogenic Thermonuclear Fuel Implosions on the NIF

    International Nuclear Information System (INIS)

    Ma, T.

    2012-01-01

    Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide spectrally resolved time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered targets. Using bremsstrahlung assumptions, the measured absolute x-ray brightness allows for the inference of electron temperature, electron density, hot spot mass, mix mass, and pressure. Current inertial confinement fusion (ICF) experiments conducted on the National Ignition Facility (NIF) seek to indirectly drive a spherical implosion, compressing and igniting a deuterium-tritium fuel. This DT fuel capsule is cryogenically prepared as a solid ice layer surrounded by a low-Z ablator material. Ignition will occur when the hot spot approaches sufficient temperature (∼3-4 keV) and ρR (∼0.3 g/cm 2 ) such that alpha deposition can further heat the hot spot and generate a self-sustaining burn wave. During the implosion, the fuel mass becomes hot enough to emit large amounts of x-ray radiation, the spectra and spatial variation of which contains key information that can be used to evaluate the implosion performance. The Ross filter diagnostic employs differential filtering to provide spectrally resolved, time-integrated, absolute x-ray self-emission images of the imploded core of cryogenic layered targets.

  12. Regulation of nif expression in Methanococcus maripaludis: roles of the euryarchaeal repressor NrpR, 2-oxoglutarate, and two operators.

    Science.gov (United States)

    Lie, Thomas J; Wood, Gwendolyn E; Leigh, John A

    2005-02-18

    The methanogenic archaean Methanococcus maripaludis can use ammonia, alanine, or dinitrogen as a nitrogen source for growth. The euryarchaeal nitrogen repressor NrpR controls the expression of the nif (nitrogen fixation) operon, resulting in full repression with ammonia, intermediate repression with alanine, and derepression with dinitrogen. NrpR binds to two tandem operators in the nif promoter region, nifOR(1) and nifOR(2). Here we have undertaken both in vivo and in vitro approaches to study the way in which NrpR, nifOR(1), nifOR(2), and the effector 2-oxoglutarate (2OG) combine to regulate nif expression, leading to a comprehensive understanding of this archaeal regulatory system. We show that NrpR binds as a dimer to nifOR(1) and cooperatively as two dimers to both operators. Cooperative binding occurs only with both operators present. nifOR(1) has stronger binding and by itself can mediate the repression of nif transcription during growth on ammonia, unlike the weakly binding nifOR(2). However, nifOR(2) in combination with nifOR(1) is critical for intermediate repression during growth on alanine. Accordingly, NrpR binds to both operators together with higher affinity than to nifOR(1) alone. NrpR responds directly to 2OG, which weakens its binding to the operators. Hence, 2OG is an intracellular indicator of nitrogen deficiency and acts as an inducer of nif transcription via NrpR. This model is upheld by the recent finding (J. A. Dodsworth and J. A. Leigh, submitted for publication) in our laboratory that 2OG levels in M. maripaludis vary with growth on different nitrogen sources.

  13. NIF special equipment construction health and safety plan

    Energy Technology Data Exchange (ETDEWEB)

    Sawicki, R.H.

    1997-07-28

    The purpose of this plan is to identify how the construction and deployment activities of the National Ignition Facility (NIF) Special Equipment (SE) will be safely executed. This plan includes an identification of (1) the safety-related responsibilities of the SE people and their interaction with other organizations involved; (2) safety related requirements, policies, and documentation; (3) a list of the potential hazards unique to SE systems and the mechanisms that will be implemented to control them to acceptable levels; (4) a summary of Environmental Safety and Health (ES&H) training requirements; and (5) requirements of contractor safety plans that will be developed and used by all SE contractors participating in site activities. This plan is a subsidiary document to the NIF Construction Safety Program (CSP) and is intended to compliment the requirements stated therein with additional details specific to the safety needs of the SE construction-related activities. If a conflict arises between these two documents, the CSP will supersede. It is important to note that this plan does not list all of the potential hazards and their controls because the design and safety analysis process is still ongoing. Additional safety issues win be addressed in the Final Safety Analysis Report, Operational Safety Procedures (OSPs), and other plans and procedures as described in Section 3.0 of this plan.

  14. Analysis of NIF experiments with the minimal energy implosion model

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, B., E-mail: bcheng@lanl.gov; Kwan, T. J. T.; Wang, Y. M.; Merrill, F. E.; Batha, S. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Cerjan, C. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-08-15

    We apply a recently developed analytical model of implosion and thermonuclear burn to fusion capsule experiments performed at the National Ignition Facility that used low-foot and high-foot laser pulse formats. Our theoretical predictions are consistent with the experimental data. Our studies, together with neutron image analysis, reveal that the adiabats of the cold fuel in both low-foot and high-foot experiments are similar. That is, the cold deuterium-tritium shells in those experiments are all in a high adiabat state at the time of peak implosion velocity. The major difference between low-foot and high-foot capsule experiments is the growth of the shock-induced instabilities developed at the material interfaces which lead to fuel mixing with ablator material. Furthermore, we have compared the NIF capsules performance with the ignition criteria and analyzed the alpha particle heating in the NIF experiments. Our analysis shows that alpha heating was appreciable only in the high-foot experiments.

  15. Quality Control, Testing, and Deployment Results in the NIF ICCS

    International Nuclear Information System (INIS)

    Woodruff, J P; Casavant, D; Cline, B D; Gorvad, M R

    2001-01-01

    The strategy used to develop the NIF Integrated Computer Control System (ICCS) calls for incremental cycles of construction and formal test to deliver a total of 1 million lines of code. Each incremental release takes four to six months to implement specific functionality and culminates when offline tests conducted in the ICCS Integration and Test Facility verify functional, performance, and interface requirements. Tests are then repeated on line to confirm integrated operation in dedicated laser laboratories or ultimately in the NIF. Test incidents along with other change requests are recorded and tracked to closure by the software change control board (SCCB). Annual independent audits advise management on software process improvements. Extensive experience has been gained by integrating controls in the prototype laser preamplifier laboratory. The control system installed in the preamplifier lab contains five of the ten planned supervisory subsystems and seven of sixteen planned front-end processors (FEPs). Beam alignment, timing, diagnosis and laser pulse amplification up to 20 joules was tested through an automated series of shots. Other laboratories have provided integrated testing of six additional FEPs. Process measurements including earned-value, product size, and defect densities provide software project controls and generate confidence that the control system will be successfully deployed

  16. Analysis of NIF experiments with the minimal energy implosion model

    International Nuclear Information System (INIS)

    Cheng, B.; Kwan, T. J. T.; Wang, Y. M.; Merrill, F. E.; Batha, S. H.; Cerjan, C. J.

    2015-01-01

    We apply a recently developed analytical model of implosion and thermonuclear burn to fusion capsule experiments performed at the National Ignition Facility that used low-foot and high-foot laser pulse formats. Our theoretical predictions are consistent with the experimental data. Our studies, together with neutron image analysis, reveal that the adiabats of the cold fuel in both low-foot and high-foot experiments are similar. That is, the cold deuterium-tritium shells in those experiments are all in a high adiabat state at the time of peak implosion velocity. The major difference between low-foot and high-foot capsule experiments is the growth of the shock-induced instabilities developed at the material interfaces which lead to fuel mixing with ablator material. Furthermore, we have compared the NIF capsules performance with the ignition criteria and analyzed the alpha particle heating in the NIF experiments. Our analysis shows that alpha heating was appreciable only in the high-foot experiments

  17. NIF special equipment construction health and safety plan

    International Nuclear Information System (INIS)

    Sawicki, R.H.

    1997-01-01

    The purpose of this plan is to identify how the construction and deployment activities of the National Ignition Facility (NIF) Special Equipment (SE) will be safely executed. This plan includes an identification of (1) the safety-related responsibilities of the SE people and their interaction with other organizations involved; (2) safety related requirements, policies, and documentation; (3) a list of the potential hazards unique to SE systems and the mechanisms that will be implemented to control them to acceptable levels; (4) a summary of Environmental Safety and Health (ES ampersand H) training requirements; and (5) requirements of contractor safety plans that will be developed and used by all SE contractors participating in site activities. This plan is a subsidiary document to the NIF Construction Safety Program (CSP) and is intended to compliment the requirements stated therein with additional details specific to the safety needs of the SE construction-related activities. If a conflict arises between these two documents, the CSP will supersede. It is important to note that this plan does not list all of the potential hazards and their controls because the design and safety analysis process is still ongoing. Additional safety issues win be addressed in the Final Safety Analysis Report, Operational Safety Procedures (OSPs), and other plans and procedures as described in Section 3.0 of this plan

  18. Technology strategy for subsea processing and transport; Technology Target Areas; TTA6 - Subsea processing and transportation

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    OG21 (www.OG21.org) Norway's official technology strategy for the petroleum sector issued a revised strategy document in November 2005 (new strategy planned in 2009). In this document 'Subsea processing and transport' was identified as one of the eight new technology target areas (TTAs). The overall OG21 strategy document is on an aggregated level, and therefore the Board of OG21 decided that a sub-strategy for each TTA was needed. This document proposes the sub-strategy for the technology target area 'Subsea processing and transport' which covers the technology and competence necessary to effectively transport well stream to a platform or to onshore facilities. This includes multiphase flow modelling, flow assurance challenges to avoid problems with hydrates, asphaltenes and wax, subsea or downhole fluid conditioning including bulk water removal, and optionally complete water removal, and sand handling. It also covers technologies to increase recovery by pressure boosting from subsea pumping and/or subsea compression. Finally it covers technologies to facilitate subsea processing such as control systems and power supply. The vision of the Subsea processing and transport TTA is: Norway is to be the leading international knowledge- and technology cluster in subsea processing and transport: Sustain increased recovery and accelerated production on the NCS by applying subsea processing and efficient transport solutions; Enable >500 km gas/condensate multiphase well stream transport; Enable >200 km oil-dominated multiphase well stream transport; Enable well stream transport of complex fluids; Enable subsea separation, boosting compression, and water injection; Enable deepwater developments; Enable environmentally friendly and energy efficient field development. Increase the export of subsea processing and transport technology: Optimize technology from the NCS for application worldwide; Develop new technology that can meet the challenges found in

  19. Nitrogenase activity of Herbaspirillum seropedicae grown under low iron levels requires the products of nifXorf1 genes.

    Science.gov (United States)

    Klassen, Giseli; de Oliveira Pedrosa, Fábio; de Souza, Emanuel M; Yates, M Geoffrey; Rigo, Liu Un

    2003-07-29

    Herbaspirillum seropedicae strains mutated in the nifX or orf1 genes showed 90% or 50% reduction in nitrogenase activity under low levels of iron or molybdenum respectively. Mutations in nifX or orf1 genes did not affect nif gene expression since a nifH::lacZ fusion was fully active in both mutants. nifX and the contiguous gene orf1 are essential for maximum nitrogen fixation under iron limitation and are probably involved in synthesis of nitrogenase iron or iron-molybdenum clusters.

  20. Achieving Aichi Biodiversity Target 11 to improve the performance of protected areas and conserve freshwater biodiversity

    Science.gov (United States)

    Diego Juffe-Bignoli; Ian Harrison; Stuart HM Butchart; Rebecca Flitcroft; Virgilio Hermoso; Harry Jonas; Anna Lukasiewicz; Michele Thieme; Eren Turak; Heather Bingham; James Dalton; William Darwall; Marine Deguignet; Nigel Dudley; Royal Gardner; Jonathan Higgins; Ritesh Kumar; Simon Linke; G Randy Milton; Jamie Pittock; Kevin G Smith; Arnout van Soesbergen

    2016-01-01

    1. The Strategic Plan for Biodiversity (2011–2020), adopted at the 10th meeting of the Conference of the Parties to the Convention on Biological Diversity, sets 20 Aichi Biodiversity Targets to be met by 2020 to address biodiversity loss and ensure its sustainable and equitable use. Aichi Biodiversity Target 11 describes what an improved conservation network would look...

  1. Studies on the roles of GlnK and GlnB in regulating Klebsiella pneumoniae NifL-dependent nitrogen control.

    NARCIS (Netherlands)

    Arcondeguy, T.; van Heeswijk, W.C.; Merrick, M.

    1999-01-01

    In Klebsiella pneumoniae, nitrogen fixation (nif) genes are regulated in response to fixed nitrogen and oxygen. The activity of the nif-specific transcriptional activator NifA is modulated by NifL, which mediates both oxygen and nitrogen control. The signal transduction protein GlnK is required to

  2. Sequencing and promoter analysis of the nifENXorf3orf5fdxAnifQ operon from Azospirillum brasilense Sp7

    Directory of Open Access Journals (Sweden)

    Potrich D.P.

    2001-01-01

    Full Text Available A 40-kb DNA region containing the major cluster of nif genes has been isolated from the Azospirillum brasilense Sp7 genome. In this region three nif operons have been identified: nifHDKorf1Y, nifENXorf3orf5fdxAnifQ and orf2nifUSVorf4. The operons containing nifENX and nifUSV genes are separated from the structural nifHDKorf1Y operon by about 5 kb and 10 kb, respectively. The present study shows the sequence analysis of the 6045-bp DNA region containing the nifENX genes. The deduced amino acid sequences from the open reading frames were compared to the nif gene products of other diazotrophic bacteria and indicate the presence of seven ORFs, all reading in the same direction as that of the nifHDKorf1Y operon. Consensus sigma54 and NifA-binding sites are present only in the promoter region upstream of the nifE gene. This promoter is activated by NifA protein and is approximately two-times less active than the nifH promoter, as indicated by the ß-galactosidase assays. This result suggests the differential expression of the nif genes and their respective products in Azospirillum.

  3. A comprehensive aligned nifH gene database: a multipurpose tool for studies of nitrogen-fixing bacteria.

    Science.gov (United States)

    Gaby, John Christian; Buckley, Daniel H

    2014-01-01

    We describe a nitrogenase gene sequence database that facilitates analysis of the evolution and ecology of nitrogen-fixing organisms. The database contains 32 954 aligned nitrogenase nifH sequences linked to phylogenetic trees and associated sequence metadata. The database includes 185 linked multigene entries including full-length nifH, nifD, nifK and 16S ribosomal RNA (rRNA) gene sequences. Evolutionary analyses enabled by the multigene entries support an ancient horizontal transfer of nitrogenase genes between Archaea and Bacteria and provide evidence that nifH has a different history of horizontal gene transfer from the nifDK enzyme core. Further analyses show that lineages in nitrogenase cluster I and cluster III have different rates of substitution within nifD, suggesting that nifD is under different selection pressure in these two lineages. Finally, we find that that the genetic divergence of nifH and 16S rRNA genes does not correlate well at sequence dissimilarity values used commonly to define microbial species, as stains having <3% sequence dissimilarity in their 16S rRNA genes can have up to 23% dissimilarity in nifH. The nifH database has a number of uses including phylogenetic and evolutionary analyses, the design and assessment of primers/probes and the evaluation of nitrogenase sequence diversity. Database URL: http://www.css.cornell.edu/faculty/buckley/nifh.htm.

  4. Kinetics of Nif gene expression in a nitrogen-fixing bacterium.

    Science.gov (United States)

    Poza-Carrión, César; Jiménez-Vicente, Emilio; Navarro-Rodríguez, Mónica; Echavarri-Erasun, Carlos; Rubio, Luis M

    2014-02-01

    Nitrogen fixation is a tightly regulated trait. Switching from N2 fixation-repressing conditions to the N2-fixing state is carefully controlled in diazotrophic bacteria mainly because of the high energy demand that it imposes. By using quantitative real-time PCR and quantitative immunoblotting, we show here how nitrogen fixation (nif) gene expression develops in Azotobacter vinelandii upon derepression. Transient expression of the transcriptional activator-encoding gene, nifA, was followed by subsequent, longer-duration waves of expression of the nitrogenase biosynthetic and structural genes. Importantly, expression timing, expression levels, and NifA dependence varied greatly among the nif operons. Moreover, the exact concentrations of Nif proteins and their changes over time were determined for the first time. Nif protein concentrations were exquisitely balanced, with FeMo cofactor biosynthetic proteins accumulating at levels 50- to 100-fold lower than those of the structural proteins. Mutants lacking nitrogenase structural genes or impaired in FeMo cofactor biosynthesis showed overenhanced responses to derepression that were proportional to the degree of nitrogenase activity impairment, consistent with the existence of at least two negative-feedback regulatory mechanisms. The first such mechanism responded to the levels of fixed nitrogen, whereas the second mechanism appeared to respond to the levels of the mature NifDK component. Altogether, these findings provide a framework to engineer N2 fixation in nondiazotrophs.

  5. Influence of the Target Vessel on the Location and Area of Maximum Skin Dose during Percutaneous Coronary Intervention

    International Nuclear Information System (INIS)

    Chida, K.; Fuda, K.; Kagaya, Y.; Saito, H.; Takai, Y.; Kohzuki, M.; Takahash i, S.; Yamada, S.; Zuguchi, M.

    2007-01-01

    Background: A number of cases involving radiation-associated patient skin injury attributable to percutaneous coronary intervention (PCI) have been reported. Knowledge of the location and area of the patient's maximum skin dose (MSD) in PCI is necessary to reduce the risk of skin injury. Purpose: To determine the location and area of the MSD in PCI, and separately analyze the effects of different target vessels. Material and Methods: 197 consecutive PCI procedures were studied, and the location and area of the MSD were calculated by a skin-dose mapping software program: Caregraph. The target vessels of the PCI procedures were divided into four groups based on the American Heart Association (AHA) classification. Results: The sites of the MSD for AHA no.1-3, AHA no.4, and AHA no.11-15 were located mainly on the right back skin, the lower right or center back skin, and the upper back skin areas, respectively, whereas the MSD sites for the AHA no. 5-10 PCI were widely spread. The MSD area for the AHA no. 4 PCI was larger than that for the AHA no. 11-15 PCI (P<0.0001). Conclusion: Although the radiation associated with PCI can be widely spread and variable, we observed a tendency regarding the location and area of the MSD when we separately analyzed the data for different target vessels. We recommend the use of a smaller radiation field size and the elimination of overlapping fields during PCI

  6. NifH- Harboring Bacterial Community Composition Across an Alaskan Permafrost Thaw Gradient

    Directory of Open Access Journals (Sweden)

    Christopher Ryan Penton

    2016-11-01

    Full Text Available Since nitrogen (N is often limiting in permafrost soils, we investigated the N2-fixing genetic potential and the inferred taxa harboring those genes by sequencing nifH gene fragments in samples taken along a permafrost thaw gradient in an Alaskan boreal soil. Samples from minimally, moderately and extensively thawed sites were taken to a depth of 79 cm to encompass zones above and below the depth of the water table. NifH reads were translated with frameshift correction and 112,476 sequences were clustered at 5% amino acid dissimilarity resulting in 1,631 OTUs. Sample depth in relation to water table depth was correlated to differences in the NifH sequence classes. NifH sequences most closely related to group I nifH-harboring Alpha- and Beta Proteobacteria were in higher abundance above water table depth while those related to group III nifH-harboring Delta and Gamma Proteobacteria were more abundant below. The most dominant below water table depth NifH sequences, comprising 1/3 of the total, were distantly related to Verrucomicrobia-Opitutaceae. Overall, these results suggest that permafrost thaw alters the class-level composition of N2-fixing communities in the thawed soil layers and that this distinction corresponds to the depth of the water table. These nifH data were also compared to nifH sequences obtained from a study at an Alaskan taiga site, and to those of other geographically distant, non-permafrost sites. The two Alaska sites were differentiated largely by changes in relative abundances of the same OTUs, whereas the non-Alaska sites were differentiated by the lack of many Alaskan OTUs, and the presence of unique halophilic, sulfate- and iron-reducing taxa in the Alaska sites.

  7. Enhanced oxygen consumption in Herbaspirillum seropedicae fnr mutants leads to increased NifA mediated transcriptional activation.

    Science.gov (United States)

    Batista, Marcelo Bueno; Wassem, Roseli; Pedrosa, Fábio de Oliveira; de Souza, Emanuel Maltempi; Dixon, Ray; Monteiro, Rose Adele

    2015-05-07

    Orthologous proteins of the Crp/Fnr family have been previously implicated in controlling expression and/or activity of the NifA transcriptional activator in some diazotrophs. This study aimed to address the role of three Fnr-like proteins from H. seropedicae SmR1 in controlling NifA activity and consequent NifA-mediated transcription activation. The activity of NifA-dependent transcriptional fusions (nifA::lacZ and nifB::lacZ) was analysed in a series of H. seropedicae fnr deletion mutant backgrounds. We found that combined deletions in both the fnr1 and fnr3 genes lead to higher expression of both the nifA and nifB genes and also an increased level of nifH transcripts. Expression profiles of nifB under different oxygen concentrations, together with oxygen consumption measurements suggest that the triple fnr mutant has higher respiratory activity when compared to the wild type, which we believe to be responsible for greater stability of the oxygen sensitive NifA protein. This conclusion was further substantiated by measuring the levels of NifA protein and its activity in fnr deletion strains in comparison with the wild-type. Fnr proteins are indirectly involved in controlling the activity of NifA in H. seropedicae, probably as a consequence of their influence on respiratory activity in relation to oxygen availability. Additionally we can suggest that there is some redundancy in the physiological function of the three Fnr paralogs in this organism, since altered respiration and effects on NifA activity are only observed in deletion strains lacking both fnr1 and fnr3.

  8. Shock timing measurements and analysis in deuterium-tritium-ice layered capsule implosions on NIF

    Energy Technology Data Exchange (ETDEWEB)

    Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R.; Ross, J. S.; LePape, S.; Ralph, J. E.; Dewald, E. L.; Berzak Hopkins, L.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Landen, O. L.; Edwards, M. J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Hohenberger, M.; Boehly, T. R. [Laboratory for Laser Energetics, Rochester, New York 14623 (United States); Nikroo, A. [General Atomics, San Diego, California 92196 (United States)

    2014-02-15

    Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion implosions [Boehly et al., Phys. Rev. Lett. 106, 195005 (2011); Robey et al., Phys. Rev. Lett. 108, 215004 (2012)] were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs. DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique. Comparison of the data with simulation shows good agreement for the timing of the first three shocks, but reveals a considerable discrepancy in the timing of the 4th shock in DT ice layered implosions. Electron preheat is examined as a potential cause of the observed discrepancy in the 4th shock timing.

  9. Shock timing measurements and analysis in deuterium-tritium-ice layered capsule implosions on NIF

    Science.gov (United States)

    Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R.; Ross, J. S.; LePape, S.; Ralph, J. E.; Hohenberger, M.; Dewald, E. L.; Berzak Hopkins, L.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Boehly, T. R.; Nikroo, A.; Landen, O. L.; Edwards, M. J.

    2014-02-01

    Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion implosions [Boehly et al., Phys. Rev. Lett. 106, 195005 (2011); Robey et al., Phys. Rev. Lett. 108, 215004 (2012)] were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs. DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique. Comparison of the data with simulation shows good agreement for the timing of the first three shocks, but reveals a considerable discrepancy in the timing of the 4th shock in DT ice layered implosions. Electron preheat is examined as a potential cause of the observed discrepancy in the 4th shock timing.

  10. Shock timing measurements and analysis in deuterium-tritium-ice layered capsule implosions on NIF

    International Nuclear Information System (INIS)

    Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R.; Ross, J. S.; LePape, S.; Ralph, J. E.; Dewald, E. L.; Berzak Hopkins, L.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Landen, O. L.; Edwards, M. J.; Hohenberger, M.; Boehly, T. R.; Nikroo, A.

    2014-01-01

    Recent advances in shock timing experiments and analysis techniques now enable shock measurements to be performed in cryogenic deuterium-tritium (DT) ice layered capsule implosions on the National Ignition Facility (NIF). Previous measurements of shock timing in inertial confinement fusion implosions [Boehly et al., Phys. Rev. Lett. 106, 195005 (2011); Robey et al., Phys. Rev. Lett. 108, 215004 (2012)] were performed in surrogate targets, where the solid DT ice shell and central DT gas were replaced with a continuous liquid deuterium (D2) fill. These previous experiments pose two surrogacy issues: a material surrogacy due to the difference of species (D2 vs. DT) and densities of the materials used and a geometric surrogacy due to presence of an additional interface (ice/gas) previously absent in the liquid-filled targets. This report presents experimental data and a new analysis method for validating the assumptions underlying this surrogate technique. Comparison of the data with simulation shows good agreement for the timing of the first three shocks, but reveals a considerable discrepancy in the timing of the 4th shock in DT ice layered implosions. Electron preheat is examined as a potential cause of the observed discrepancy in the 4th shock timing

  11. The MIT HEDP Accelerator Facility for Diagnostic Development for OMEGA, Z, and the NIF

    Science.gov (United States)

    Sio, H.; Gatu Johnson, M.; Birkel, A.; Doeg, E.; Frankel, R.; Kabadi, N. V.; Lahmann, B.; Manzin, M.; Simpson, R. A.; Parker, C. E.; Sutcliffe, G. D.; Wink, C.; Frenje, J. A.; Li, C. K.; Seguin, F. H.; Petrasso, R. D.; Leeper, R.; Hahn, K.; Ruiz, C. L.; Sangster, T. C.; Hilsabeck, T.

    2017-10-01

    The MIT HEDP Accelerator Facility utilizes a 135-keV, linear electrostatic ion accelerator; DT and DD neutron sources; and two x-ray sources for development and characterization of nuclear diagnostics for OMEGA, Z, and the NIF. The accelerator generates DD and D3He fusion products through the acceleration of D+ ions onto a 3He-doped Erbium-Deuteride target. Accurately characterized fusion product rates of around 106 s- 1 are routinely achieved. The DT and DD neutron sources generate up to 6×108 and 1×107 neutrons/s, respectively. One x-ray generator is a thick-target W source with a peak energy of 225 keV and a maximum dose rate of 12 Gy/min; the other uses Cu, Mo, or Ti elemental tubes to generate x-rays with a maximum energy of 40 keV. Diagnostics developed and calibrated at this facility include CR-39-based charged-particle spectrometers, neutron detectors, and the particle Time-Of-Flight (pTOF) and Magnetic PTOF CVD-diamond-based bang time detectors. The accelerator is also a valuable hands-on tool for graduate and undergraduate education at MIT. This work was supported in part by the U.S. DoE, SNL, LLE and LLNL.

  12. Optimal use of EEG recordings to target active brain areas with transcranial electrical stimulation.

    Science.gov (United States)

    Dmochowski, Jacek P; Koessler, Laurent; Norcia, Anthony M; Bikson, Marom; Parra, Lucas C

    2017-08-15

    To demonstrate causal relationships between brain and behavior, investigators would like to guide brain stimulation using measurements of neural activity. Particularly promising in this context are electroencephalography (EEG) and transcranial electrical stimulation (TES), as they are linked by a reciprocity principle which, despite being known for decades, has not led to a formalism for relating EEG recordings to optimal stimulation parameters. Here we derive a closed-form expression for the TES configuration that optimally stimulates (i.e., targets) the sources of recorded EEG, without making assumptions about source location or distribution. We also derive a duality between TES targeting and EEG source localization, and demonstrate that in cases where source localization fails, so does the proposed targeting. Numerical simulations with multiple head models confirm these theoretical predictions and quantify the achieved stimulation in terms of focality and intensity. We show that constraining the stimulation currents automatically selects optimal montages that involve only a few (4-7) electrodes, with only incremental loss in performance when targeting focal activations. The proposed technique allows brain scientists and clinicians to rationally target the sources of observed EEG and thus overcomes a major obstacle to the realization of individualized or closed-loop brain stimulation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Atomic and Molecular Data Activities at NIFS in 2009 - 2011

    International Nuclear Information System (INIS)

    Murakami, I.

    2011-01-01

    We open and maintain the NIFS atomic and molecular numerical databases. Numbers of data records increase to 476,048 in total (as of Aug. 23, 2011) and mainly new data are added for AMDIS (electron impact ionization, excitation, and recombination cross sections and rate coefficients) and CHART (charge transfer of atom - ion collisions cross sections) during last two years. A collaboration group has started for research on atomic and molecular processes in plasma using the Large Helical Device and we measure visible and extreme ultraviolet spectra of W and rare earth elements. We also organize a collaboration group with atomic physicists from Japanese universities for research on W to study atomic data, spectra and collisional-radiative models for W ions. (author)

  14. Comparisons of NIF convergent ablation simulations with radiograph data.

    Science.gov (United States)

    Olson, R E; Hicks, D G; Meezan, N B; Koch, J A; Landen, O L

    2012-10-01

    A technique for comparing simulation results directly with radiograph data from backlit capsule implosion experiments will be discussed. Forward Abel transforms are applied to the kappa*rho profiles of the simulation. These provide the transmission ratio (optical depth) profiles of the simulation. Gaussian and top hat blurs are applied to the simulated transmission ratio profiles in order to account for the motion blurring and imaging slit resolution of the experimental measurement. Comparisons between the simulated transmission ratios and the radiograph data lineouts are iterated until a reasonable backlighter profile is obtained. This backlighter profile is combined with the blurred, simulated transmission ratios to obtain simulated intensity profiles that can be directly compared with the radiograph data. Examples will be shown from recent convergent ablation (backlit implosion) experiments at the NIF.

  15. Proceedings of the twelfth target fabrication specialists` meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-01

    Research in fabrication for inertial confinement fusion (ICF) comprises at least three broad categories: targets for high energy density physics on existing drivers, ignition capsule fabrication, and cryogenic fuel layer formation. The latter two are being pursued primarily for the National Ignition Facility (NIF). Scientists from over 14 laboratories, universities, and businesses contributed over 100 papers on all aspects of ICF target fabrication. The NIF is well along in construction and photos of poured concrete and exposed steel added to the technical excitement. It was clear from the meeting that there has been significant progress toward the fabrication of an ignition target for NIF and that new techniques are resulting in higher quality targets for high energy density research.

  16. Hydrodynamic instabilities in beryllium targets for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Yi, S. A., E-mail: austinyi@lanl.gov; Simakov, A. N.; Wilson, D. C.; Olson, R. E.; Kline, J. L.; Batha, S. H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, D. S.; Hammel, B. A.; Milovich, J. L.; Salmonson, J. D.; Kozioziemski, B. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

    2014-09-15

    Beryllium ablators offer higher ablation velocity, rate, and pressure than their carbon-based counterparts, with the potential to increase the probability of achieving ignition at the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. We present here a detailed hydrodynamic stability analysis of low (NIF Revision 6.1) and high adiabat NIF beryllium target designs. Our targets are optimized to fully utilize the advantages of beryllium in order to suppress the growth of hydrodynamic instabilities. This results in an implosion that resists breakup of the capsule, and simultaneously minimizes the amount of ablator material mixed into the fuel. We quantify the improvement in stability of beryllium targets relative to plastic ones, and show that a low adiabat beryllium capsule can be at least as stable at the ablation front as a high adiabat plastic target.

  17. Proceedings of the twelfth target fabrication specialists' meeting

    International Nuclear Information System (INIS)

    1999-01-01

    Research in fabrication for inertial confinement fusion (ICF) comprises at least three broad categories: targets for high energy density physics on existing drivers, ignition capsule fabrication, and cryogenic fuel layer formation. The latter two are being pursued primarily for the National Ignition Facility (NIF). Scientists from over 14 laboratories, universities, and businesses contributed over 100 papers on all aspects of ICF target fabrication. The NIF is well along in construction and photos of poured concrete and exposed steel added to the technical excitement. It was clear from the meeting that there has been significant progress toward the fabrication of an ignition target for NIF and that new techniques are resulting in higher quality targets for high energy density research

  18. On the design of the NIF Continuum Spectrometer

    Science.gov (United States)

    Thorn, D. B.; MacPhee, A.; Ayers, J.; Galbraith, J.; Hardy, C. M.; Izumi, N.; Bradley, D. K.; Pickworth, L. A.; Bachmann, B.; Kozioziemski, B.; Landen, O.; Clark, D.; Schneider, M. B.; Hill, K. W.; Bitter, M.; Nagel, S.; Bell, P. M.; Person, S.; Khater, H. Y.; Smith, C.; Kilkenny, J.

    2017-08-01

    In inertial confinement fusion (ICF) experiments on the National Ignition Facility (NIF), measurements of average ion temperature using DT neutron time of flight broadening and of DD neutrons do not show the same apparent temperature. Some of this may be due to time and space dependent temperature profiles in the imploding capsule which are not taken into account in the analysis. As such, we are attempting to measure the electron temperature by recording the free-free electron-ion scattering-spectrum from the tail of the Maxwellian temperature distribution. This will be accomplished with the new NIF Continuum Spectrometer (ConSpec) which spans the x-ray range of 20 keV to 30 keV (where any opacity corrections from the remaining mass of the ablator shell are negligible) and will be sensitive to temperatures between ˜ 3 keV and 6 keV. The optical design of the ConSpec is designed to be adaptable to an x-ray streak camera to record time resolved free-free electron continuum spectra for direct measurement of the dT/dt evolution across the burn width of a DT plasma. The spectrometer is a conically bent Bragg crystal in a focusing geometry that allows for the dispersion plane to be perpendicular to the spectrometer axis. Additionally, to address the spatial temperature dependence, both time integrated and time resolved pinhole and penumbral imaging will be provided along the same polar angle. The optical and mechanical design of the instrument is presented along with estimates for the dispersion, solid angle, photometric sensitivity, and performance.

  19. A plasma amplifier to combine multiple beams at NIF

    Science.gov (United States)

    Kirkwood, R. K.; Turnbull, D. P.; Chapman, T.; Wilks, S. C.; Rosen, M. D.; London, R. A.; Pickworth, L. A.; Colaitis, A.; Dunlop, W. H.; Poole, P.; Moody, J. D.; Strozzi, D. J.; Michel, P. A.; Divol, L.; Landen, O. L.; MacGowan, B. J.; Van Wonterghem, B. M.; Fournier, K. B.; Blue, B. E.

    2018-05-01

    Combining laser beams in a plasma is enabled by seeded stimulated Brillouin scattering which allows cross-beam energy transfer (CBET) to occur and re-distributes the energy between beams that cross with different incident angles and small differences in wavelength [Kirkwood et al. Phys. Plasmas 4, 1800 (1997)]. Indirect-drive implosions at the National Ignition Facility (NIF) [Haynam et al. Appl. Opt. 46, 3276-3303 (2007)] have controlled drive symmetry by using plasma amplifiers to transfer energy between beams [Kirkwood et al., Plasma Phys. Controlled Fusion 55, 103001 (2013); Lindl et al., Phys. Plasmas 21, 020501 (2014); and Hurricane et al. Nature 506, 343-348 (2014)]. In this work, we show that the existing models are well enough validated by experiments to allow a design of a plasma beam combiner that, once optimized, is expected to produce a pulse of light in a single beam with the energy greatly enhanced over existing sources. The scheme combines up to 61 NIF beams with 120 kJ of available energy into a single f/20 beam with a 1 ns pulse duration and a 351 nm wavelength by both resonant and off-resonance CBET. Initial experiments are also described that have already succeeded in producing a 4 kJ, 1 ns pulse in a single beam by combination of up to eight incident pump beams containing <1.1 kJ/beam, which are maintained near resonance for CBET in a plasma that is formed by 60 pre-heating beams [Kirkwood et al., Nat. Phys. 14, 80 (2018)].

  20. Phosphorus losses from agricultural areas in river basins; effects and uncertainties of targeted mitigation measures

    NARCIS (Netherlands)

    Kronvang, B.; Bechmann, M.; Lundekvam, H.; Behrendt, H.; Rubaek, G.H.; Schoumans, O.F.; Syversen, N.; Andersen, H.E.; Hoffmann, C.C.

    2005-01-01

    In this paper we show the quantitative and relative importance of phosphorus (P) losses from agricultural areas within European river basins and demonstrate the importance of P pathways, linking agricultural source areas to surface water at different scales. Agricultural P losses are increasingly

  1. Rural Diversity and heterogeneity in less-favoured areas: the quest for policy targeting

    NARCIS (Netherlands)

    Ruben, R.; Pender, J.

    2004-01-01

    Wide diversity among farmers and fields is a prime characteristic of livelihoods and production systems in less-favoured areas. One-size-fits-all policies can therefore not provide adequate solutions to poverty and degradation problems. Sustainable rural development strategies in these areas need to

  2. Large area isotopic silicon targets for astrophysical reaction rate studies in Si-26

    NARCIS (Netherlands)

    Greene, JP; Berg, GPA

    2005-01-01

    For measurements of stellar reaction rates of proton rich nuclei involving resonance levels just above threshold, targets of Si-28 were used in studies of the Si-21(He-4, He-6)Si-26 reaction using the Research Center for Nuclear Physics (RCNP) Ring Cyclotron at Osaka University. Resonance structure

  3. NIF: Impacts of chemical accidents and comparison of chemical/radiological accident approaches

    International Nuclear Information System (INIS)

    Lazaro, M.A.; Policastro, A.J.; Rhodes, M.

    1996-01-01

    The US Department of Energy (DOE) proposes to construct and operate the National Ignition Facility (NIF). The goals of the NIF are to (1) achieve fusion ignition in the laboratory for the first time by using inertial confinement fusion (ICF) technology based on an advanced-design neodymium glass solid-state laser, and (2) conduct high-energy-density experiments in support of national security and civilian applications. The primary focus of this paper is worker-public health and safety issues associated with postulated chemical accidents during the operation of NIF. The key findings from the accident analysis will be presented. Although NIF chemical accidents will be emphasized, the important differences between chemical and radiological accident analysis approaches and the metrics for reporting results will be highlighted. These differences are common EIS facility and transportation accident assessments

  4. Molecular phylogeny, population genetics, and evolution of heterocystous cyanobacteria using nifH gene sequences

    Czech Academy of Sciences Publication Activity Database

    Singh, P.; Singh, S. S.; Elster, Josef; Mishra, A. K.

    2013-01-01

    Roč. 250, č. 3 (2013), s. 751-764 ISSN 0033-183X Institutional support: RVO:67985939 Keywords : evolution * heterocystous cyanobacteria * nifH gene Subject RIV: EH - Ecology, Behaviour Impact factor: 3.171, year: 2013

  5. Gamma Knife irradiation method based on dosimetric controls to target small areas in rat brains

    International Nuclear Information System (INIS)

    Constanzo, Julie; Paquette, Benoit; Charest, Gabriel; Masson-Côté, Laurence; Guillot, Mathieu

    2015-01-01

    Purpose: Targeted and whole-brain irradiation in humans can result in significant side effects causing decreased patient quality of life. To adequately investigate structural and functional alterations after stereotactic radiosurgery, preclinical studies are needed. The purpose of this work is to establish a robust standardized method of targeted irradiation on small regions of the rat brain. Methods: Euthanized male Fischer rats were imaged in a stereotactic bed, by computed tomography (CT), to estimate positioning variations relative to the bregma skull reference point. Using a rat brain atlas and the stereotactic bregma coordinates obtained from CT images, different regions of the brain were delimited and a treatment plan was generated. A single isocenter treatment plan delivering ≥100 Gy in 100% of the target volume was produced by Leksell GammaPlan using the 4 mm diameter collimator of sectors 4, 5, 7, and 8 of the Gamma Knife unit. Impact of positioning deviations of the rat brain on dose deposition was simulated by GammaPlan and validated with dosimetric measurements. Results: The authors’ results showed that 90% of the target volume received 100 ± 8 Gy and the maximum of deposited dose was 125 ± 0.7 Gy, which corresponds to an excellent relative standard deviation of 0.6%. This dose deposition calculated with GammaPlan was validated with dosimetric films resulting in a dose-profile agreement within 5%, both in X- and Z-axes. Conclusions: The authors’ results demonstrate the feasibility of standardizing the irradiation procedure of a small volume in the rat brain using a Gamma Knife

  6. Effect of point mutations on Herbaspirillum seropedicae NifA activity

    International Nuclear Information System (INIS)

    Aquino, B.; Stefanello, A.A.; Oliveira, M.A.S.; Pedrosa, F.O.; Souza, E.M.; Monteiro, R.A.; Chubatsu, L.S.

    2015-01-01

    NifA is the transcriptional activator of the nif genes in Proteobacteria. It is usually regulated by nitrogen and oxygen, allowing biological nitrogen fixation to occur under appropriate conditions. NifA proteins have a typical three-domain structure, including a regulatory N-terminal GAF domain, which is involved in control by fixed nitrogen and not strictly required for activity, a catalytic AAA+ central domain, which catalyzes open complex formation, and a C-terminal domain involved in DNA-binding. In Herbaspirillum seropedicae, a β-proteobacterium capable of colonizing Graminae of agricultural importance, NifA regulation by ammonium involves its N-terminal GAF domain and the signal transduction protein GlnK. When the GAF domain is removed, the protein can still activate nif genes transcription; however, ammonium regulation is lost. In this work, we generated eight constructs resulting in point mutations in H. seropedicae NifA and analyzed their effect on nifH transcription in Escherichia coli and H. seropedicae. Mutations K22V, T160E, M161V, L172R, and A215D resulted in inactive proteins. Mutations Q216I and S220I produced partially active proteins with activity control similar to wild-type NifA. However, mutation G25E, located in the GAF domain, resulted in an active protein that did not require GlnK for activity and was partially sensitive to ammonium. This suggested that G25E may affect the negative interaction between the N-terminal GAF domain and the catalytic central domain under high ammonium concentrations, thus rendering the protein constitutively active, or that G25E could lead to a conformational change comparable with that when GlnK interacts with the GAF domain

  7. Effect of point mutations on Herbaspirillum seropedicae NifA activity

    Directory of Open Access Journals (Sweden)

    B. Aquino

    2015-08-01

    Full Text Available NifA is the transcriptional activator of the nif genes in Proteobacteria. It is usually regulated by nitrogen and oxygen, allowing biological nitrogen fixation to occur under appropriate conditions. NifA proteins have a typical three-domain structure, including a regulatory N-terminal GAF domain, which is involved in control by fixed nitrogen and not strictly required for activity, a catalytic AAA+ central domain, which catalyzes open complex formation, and a C-terminal domain involved in DNA-binding. In Herbaspirillum seropedicae, a β-proteobacterium capable of colonizing Graminae of agricultural importance, NifA regulation by ammonium involves its N-terminal GAF domain and the signal transduction protein GlnK. When the GAF domain is removed, the protein can still activate nif genes transcription; however, ammonium regulation is lost. In this work, we generated eight constructs resulting in point mutations in H. seropedicae NifA and analyzed their effect on nifH transcription in Escherichia coli and H. seropedicae. Mutations K22V, T160E, M161V, L172R, and A215D resulted in inactive proteins. Mutations Q216I and S220I produced partially active proteins with activity control similar to wild-type NifA. However, mutation G25E, located in the GAF domain, resulted in an active protein that did not require GlnK for activity and was partially sensitive to ammonium. This suggested that G25E may affect the negative interaction between the N-terminal GAF domain and the catalytic central domain under high ammonium concentrations, thus rendering the protein constitutively active, or that G25E could lead to a conformational change comparable with that when GlnK interacts with the GAF domain.

  8. Antagonism of CD11b with neutrophil inhibitory factor (NIF inhibits vascular lesions in diabetic retinopathy.

    Directory of Open Access Journals (Sweden)

    Alexander A Veenstra

    Full Text Available Leukocytes and proteins that govern leukocyte adhesion to endothelial cells play a causal role in retinal abnormalities characteristic of the early stages of diabetic retinopathy, including diabetes-induced degeneration of retinal capillaries. Leukocyte integrin αmβ2 (CD11b/CD18, MAC1, a protein mediating adhesion, has been shown to mediate damage to endothelial cells by activated leukocytes in vitro. We hypothesized that Neutrophil Inhibitory Factor (NIF, a selective antagonist of integrin αmβ2, would inhibit the diabetes-induced degeneration of retinal capillaries by inhibiting the excessive interaction between leukocytes and retinal endothelial cells in diabetes. Wild type animals and transgenic animals expressing NIF were made diabetic with streptozotocin and assessed for diabetes-induced retinal vascular abnormalities and leukocyte activation. To assess if the leukocyte blocking therapy compromised the immune system, animals were challenged with bacteria. Retinal superoxide production, leukostasis and leukocyte superoxide production were increased in wild type mice diabetic for 10 weeks, as was the ability of leukocytes isolated from diabetic animals to kill retinal endothelial cells in vitro. Retinal capillary degeneration was significantly increased in wild type mice diabetic 40 weeks. In contrast, mice expressing NIF did not develop any of these abnormalities, with the exception that non-diabetic and diabetic mice expressing NIF generated greater amounts of superoxide than did similar mice not expressing NIF. Importantly, NIF did not significantly impair the ability of mice to clear an opportunistic bacterial challenge, suggesting that NIF did not compromise immune surveillance. We conclude that antagonism of CD11b (integrin αmβ2 by NIF is sufficient to inhibit early stages of diabetic retinopathy, while not compromising the basic immune response.

  9. Effect of point mutations on Herbaspirillum seropedicae NifA activity

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, B.; Stefanello, A.A.; Oliveira, M.A.S.; Pedrosa, F.O.; Souza, E.M.; Monteiro, R.A.; Chubatsu, L.S. [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR (Brazil)

    2015-07-10

    NifA is the transcriptional activator of the nif genes in Proteobacteria. It is usually regulated by nitrogen and oxygen, allowing biological nitrogen fixation to occur under appropriate conditions. NifA proteins have a typical three-domain structure, including a regulatory N-terminal GAF domain, which is involved in control by fixed nitrogen and not strictly required for activity, a catalytic AAA+ central domain, which catalyzes open complex formation, and a C-terminal domain involved in DNA-binding. In Herbaspirillum seropedicae, a β-proteobacterium capable of colonizing Graminae of agricultural importance, NifA regulation by ammonium involves its N-terminal GAF domain and the signal transduction protein GlnK. When the GAF domain is removed, the protein can still activate nif genes transcription; however, ammonium regulation is lost. In this work, we generated eight constructs resulting in point mutations in H. seropedicae NifA and analyzed their effect on nifH transcription in Escherichia coli and H. seropedicae. Mutations K22V, T160E, M161V, L172R, and A215D resulted in inactive proteins. Mutations Q216I and S220I produced partially active proteins with activity control similar to wild-type NifA. However, mutation G25E, located in the GAF domain, resulted in an active protein that did not require GlnK for activity and was partially sensitive to ammonium. This suggested that G25E may affect the negative interaction between the N-terminal GAF domain and the catalytic central domain under high ammonium concentrations, thus rendering the protein constitutively active, or that G25E could lead to a conformational change comparable with that when GlnK interacts with the GAF domain.

  10. Antagonism of CD11b with neutrophil inhibitory factor (NIF) inhibits vascular lesions in diabetic retinopathy.

    Science.gov (United States)

    Veenstra, Alexander A; Tang, Jie; Kern, Timothy S

    2013-01-01

    Leukocytes and proteins that govern leukocyte adhesion to endothelial cells play a causal role in retinal abnormalities characteristic of the early stages of diabetic retinopathy, including diabetes-induced degeneration of retinal capillaries. Leukocyte integrin αmβ2 (CD11b/CD18, MAC1), a protein mediating adhesion, has been shown to mediate damage to endothelial cells by activated leukocytes in vitro. We hypothesized that Neutrophil Inhibitory Factor (NIF), a selective antagonist of integrin αmβ2, would inhibit the diabetes-induced degeneration of retinal capillaries by inhibiting the excessive interaction between leukocytes and retinal endothelial cells in diabetes. Wild type animals and transgenic animals expressing NIF were made diabetic with streptozotocin and assessed for diabetes-induced retinal vascular abnormalities and leukocyte activation. To assess if the leukocyte blocking therapy compromised the immune system, animals were challenged with bacteria. Retinal superoxide production, leukostasis and leukocyte superoxide production were increased in wild type mice diabetic for 10 weeks, as was the ability of leukocytes isolated from diabetic animals to kill retinal endothelial cells in vitro. Retinal capillary degeneration was significantly increased in wild type mice diabetic 40 weeks. In contrast, mice expressing NIF did not develop any of these abnormalities, with the exception that non-diabetic and diabetic mice expressing NIF generated greater amounts of superoxide than did similar mice not expressing NIF. Importantly, NIF did not significantly impair the ability of mice to clear an opportunistic bacterial challenge, suggesting that NIF did not compromise immune surveillance. We conclude that antagonism of CD11b (integrin αmβ2) by NIF is sufficient to inhibit early stages of diabetic retinopathy, while not compromising the basic immune response.

  11. Control of Herbaspirillum seropedicae NifA Activity by Ammonium Ions and Oxygen

    Science.gov (United States)

    Souza, E. M.; Pedrosa, F. O.; Drummond, M.; Rigo, L. U.; Yates, M. G.

    1999-01-01

    The activity of a truncated form of Herbaspirillum seropedicae NifA in different genetic backgrounds showed that its regulatory domain is involved in nitrogen control but not in O2 sensitivity or Fe dependence. The model for nitrogen control involving PII could thus apply to the proteobacteria at large. NifA may have a role in controlling ADP-ribosylation of nitrogenase in Azospirillum brasilense. PMID:9882688

  12. Effect of point mutations on Herbaspirillum seropedicae NifA activity.

    Science.gov (United States)

    Aquino, B; Stefanello, A A; Oliveira, M A S; Pedrosa, F O; Souza, E M; Monteiro, R A; Chubatsu, L S

    2015-08-01

    NifA is the transcriptional activator of the nif genes in Proteobacteria. It is usually regulated by nitrogen and oxygen, allowing biological nitrogen fixation to occur under appropriate conditions. NifA proteins have a typical three-domain structure, including a regulatory N-terminal GAF domain, which is involved in control by fixed nitrogen and not strictly required for activity, a catalytic AAA+ central domain, which catalyzes open complex formation, and a C-terminal domain involved in DNA-binding. In Herbaspirillum seropedicae, a β-proteobacterium capable of colonizing Graminae of agricultural importance, NifA regulation by ammonium involves its N-terminal GAF domain and the signal transduction protein GlnK. When the GAF domain is removed, the protein can still activate nif genes transcription; however, ammonium regulation is lost. In this work, we generated eight constructs resulting in point mutations in H. seropedicae NifA and analyzed their effect on nifH transcription in Escherichia coli and H. seropedicae. Mutations K22V, T160E, M161V, L172R, and A215D resulted in inactive proteins. Mutations Q216I and S220I produced partially active proteins with activity control similar to wild-type NifA. However, mutation G25E, located in the GAF domain, resulted in an active protein that did not require GlnK for activity and was partially sensitive to ammonium. This suggested that G25E may affect the negative interaction between the N-terminal GAF domain and the catalytic central domain under high ammonium concentrations, thus rendering the protein constitutively active, or that G25E could lead to a conformational change comparable with that when GlnK interacts with the GAF domain.

  13. Widespread expression of BDNF but not NT3 by target areas of basal forebrain cholinergic neurons

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, H.S.; Hains, J.M.; Laramee, G.R.; Rosenthal, A.; Winslow, J.W. (Genentech, San Francisco, CA (USA))

    1990-10-12

    Brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) are homologs of the well-known neurotrophic factor nerve growth factor. The three members of this family display distinct patterns of target specificity. To examine the distribution in brain of messenger RNA for these molecules, in situ hybridization was performed. Cells hybridizing intensely to antisense BDNF probe were located throughout the major targets of the rat basal forebrain cholinergic system, that is, the hippocampus, amygdala, and neocortex. Strongly hybridizing cells were also observed in structures associated with the olfactory system. The distribution of NT3 mRNA in forebrain was much more limited. Within the hippocampus, labeled cells were restricted to CA2, the most medial portion of CA1, and the dentate gyrus. In human hippocampus, cells expressing BDNF and mRNA are distributed in a fashion similar to that observed in the rat. These findings point to both basal forebrain cholinergic cells and olfactory pathways as potential central targets for BDNF.

  14. Widespread expression of BDNF but not NT3 by target areas of basal forebrain cholinergic neurons

    International Nuclear Information System (INIS)

    Phillips, H.S.; Hains, J.M.; Laramee, G.R.; Rosenthal, A.; Winslow, J.W.

    1990-01-01

    Brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) are homologs of the well-known neurotrophic factor nerve growth factor. The three members of this family display distinct patterns of target specificity. To examine the distribution in brain of messenger RNA for these molecules, in situ hybridization was performed. Cells hybridizing intensely to antisense BDNF probe were located throughout the major targets of the rat basal forebrain cholinergic system, that is, the hippocampus, amygdala, and neocortex. Strongly hybridizing cells were also observed in structures associated with the olfactory system. The distribution of NT3 mRNA in forebrain was much more limited. Within the hippocampus, labeled cells were restricted to CA2, the most medial portion of CA1, and the dentate gyrus. In human hippocampus, cells expressing BDNF and mRNA are distributed in a fashion similar to that observed in the rat. These findings point to both basal forebrain cholinergic cells and olfactory pathways as potential central targets for BDNF

  15. Flicker sensitivity as a function of target area with and without temporal noise.

    Science.gov (United States)

    Rovamo, J; Donner, K; Näsänen, R; Raninen, A

    2000-01-01

    Flicker sensitivities (1-30 Hz) in foveal, photopic vision were measured as functions of stimulus area with and without strong external white temporal noise. Stimuli were circular, sinusoidally flickering sharp-edged spots of variable diameters (0.25-4 degrees ) but constant duration (2 s), surrounded by a uniform equiluminant field. The data was described with a model comprising (i) low-pass filtering in the retina (R), with a modulation transfer function (MTF) of a form derived from responses of cones; (ii) normalisation of the temporal luminance distribution by the average luminance; (iii) high-pass filtering by postreceptoral neural pathways (P), with an MTF proportional to temporal frequency; (iv) addition of internal white neural noise (N(i)); (v) integration over a spatial window; and (vi) detection by a suboptimal temporal matched filter of efficiency eta. In strong external noise, flicker sensitivity was independent of spot area. Without external noise, sensitivity increased with the square root of stimulus area (Piper's law) up to a critical area (A(c)), where it reaches a maximum level (S(max)). Both A(c) and eta were monotonic functions of temporal frequency (f), such that log A(c) increased and log eta decreased linearly with log f. Remarkably, the increase in spatial integration area and the decrease in efficiency were just balanced, so A(c)(f)eta(f) was invariant against f. Thus the bandpass characteristics of S(max)(f) directly reflected the composite effect of the distal filters R(f) and P(f). The temporal equivalent (N(it)) of internal neural noise (N(i)) decreased in inverse proportion to spot area up to A(c) and then stayed constant indicating that spatially homogeneous signals and noise are integrated over the same area.

  16. Land substitution effects of biofuel side products and implications on the land area requirement for EU 2020 biofuel targets

    International Nuclear Information System (INIS)

    Ozdemir, Enver Doruk; Haerdtlein, Marlies; Eltrop, Ludger

    2009-01-01

    The provision of biofuels today is based on energy crops rather than residual biomass, which results in the requirement of agricultural land area. The side products may serve as animal feed and thus prevent cultivation of other feedstock and the use of corresponding land area. These effects of biofuel provision have to be taken into account for a comprising assessment of land area requirement for biofuel provision. Between 18.5 and 21.1 Mio. hectares (ha) of land area is needed to meet the EU 2020 biofuel target depending on the biofuel portfolio when substitution effects are neglected. The utilization of the bioethanol side products distiller's dried grain and solubles (DDGS) and pressed beet slices may save up to 0.7 Mio. ha of maize cultivation area in the EU. The substitution effect due to the utilization of biodiesel side products (oil cakes of rape, palm and soy) as animal feed may account for up to 7.1 Mio. ha of soy cultivation area in Brazil. The results show that the substitution of land area due to use of side products might ease the pressures on land area requirement considerably and should therefore not be neglected in assessing the impacts of biofuel provision worldwide.

  17. Abundance and genetic diversity of nifH gene sequences in anthropogenically affected Brazilian mangrove sediments.

    Science.gov (United States)

    Dias, Armando Cavalcante Franco; Pereira e Silva, Michele de Cassia; Cotta, Simone Raposo; Dini-Andreote, Francisco; Soares, Fábio Lino; Salles, Joana Falcão; Azevedo, João Lúcio; van Elsas, Jan Dirk; Andreote, Fernando Dini

    2012-11-01

    Although mangroves represent ecosystems of global importance, the genetic diversity and abundance of functional genes that are key to their functioning scarcely have been explored. Here, we present a survey based on the nifH gene across transects of sediments of two mangrove systems located along the coast line of São Paulo state (Brazil) which differed by degree of disturbance, i.e., an oil-spill-affected and an unaffected mangrove. The diazotrophic communities were assessed by denaturing gradient gel electrophoresis (DGGE), quantitative PCR (qPCR), and clone libraries. The nifH gene abundance was similar across the two mangrove sediment systems, as evidenced by qPCR. However, the nifH-based PCR-DGGE profiles revealed clear differences between the mangroves. Moreover, shifts in the nifH gene diversities were noted along the land-sea transect within the previously oiled mangrove. The nifH gene diversity depicted the presence of nitrogen-fixing bacteria affiliated with a wide range of taxa, encompassing members of the Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and also a group of anaerobic sulfate-reducing bacteria. We also detected a unique mangrove-specific cluster of sequences denoted Mgv-nifH. Our results indicate that nitrogen-fixing bacterial guilds can be partially endemic to mangroves, and these communities are modulated by oil contamination, which has important implications for conservation strategies.

  18. Abundance and Genetic Diversity of nifH Gene Sequences in Anthropogenically Affected Brazilian Mangrove Sediments

    Science.gov (United States)

    Dias, Armando Cavalcante Franco; Pereira e Silva, Michele de Cassia; Cotta, Simone Raposo; Dini-Andreote, Francisco; Soares, Fábio Lino; Salles, Joana Falcão; Azevedo, João Lúcio; van Elsas, Jan Dirk

    2012-01-01

    Although mangroves represent ecosystems of global importance, the genetic diversity and abundance of functional genes that are key to their functioning scarcely have been explored. Here, we present a survey based on the nifH gene across transects of sediments of two mangrove systems located along the coast line of São Paulo state (Brazil) which differed by degree of disturbance, i.e., an oil-spill-affected and an unaffected mangrove. The diazotrophic communities were assessed by denaturing gradient gel electrophoresis (DGGE), quantitative PCR (qPCR), and clone libraries. The nifH gene abundance was similar across the two mangrove sediment systems, as evidenced by qPCR. However, the nifH-based PCR-DGGE profiles revealed clear differences between the mangroves. Moreover, shifts in the nifH gene diversities were noted along the land-sea transect within the previously oiled mangrove. The nifH gene diversity depicted the presence of nitrogen-fixing bacteria affiliated with a wide range of taxa, encompassing members of the Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and also a group of anaerobic sulfate-reducing bacteria. We also detected a unique mangrove-specific cluster of sequences denoted Mgv-nifH. Our results indicate that nitrogen-fixing bacterial guilds can be partially endemic to mangroves, and these communities are modulated by oil contamination, which has important implications for conservation strategies. PMID:22941088

  19. Truck-mounted Area-wide Application of Pyriproxyfen Targeting Aedes aegypti and Aedes albopictus in Northeast Florida

    Science.gov (United States)

    2014-12-01

    TRUCK-MOUNTED AREA-WIDE APPLICATION OF PYRIPROXYFEN TARGETING AEDES AEGYPTI AND AEDES ALBOPICTUS IN NORTHEAST FLORIDA1 CARL W. DOUD,2,3 ANTHONY M...truck-mounted ultra-low volume applications of pyriproxyfen against Aedes aegypti larvae in artificial water containers and wild adult Ae. albopictus...larval control, Aedes aegypti, Aedes albopictus INTRODUCTION Aedes albopictus (Skuse) (Asian tiger mosquito) and Ae. aegypti (L.) (yellow fever

  20. Monitoring Ground Deformation of Subway Area during the Construction Based on the Method of Multi-Temporal Coherent Targets Analysis

    Science.gov (United States)

    Zhang, L.; Wu, J.; Zhao, J.; Yuan, M.

    2018-04-01

    Multi-temporal coherent targets analysis is a high-precision and high-spatial-resolution monitoring method for urban surface deformation based on Differential Synthetic Aperture Radar (DInSAR), and has been successfully applied to measure land subsidence, landslide and strain accumulation caused by fault movement and so on. In this paper, the multi-temporal coherent targets analysis is used to study the settlement of subway area during the period of subway construction. The eastern extension of Shanghai Metro Line. 2 is taking as an example to study the subway settlement during the construction period. The eastern extension of Shanghai Metro Line. 2 starts from Longyang Road and ends at Pudong airport. Its length is 29.9 kilometers from east to west and it is a key transportation line to the Pudong Airport. 17 PalSAR images during 2007 and 2010 are applied to analyze and invert the settlement of the buildings nearby the subway based on the multi-temporal coherent targets analysis. But there are three significant deformation areas nearby the Line 2 between 2007 and 2010, with maximum subsidence rate up to 30 mm/y in LOS. The settlement near the Longyang Road station and Chuansha Town are both caused by newly construction and city expansion. The deformation of the coastal dikes suffer from heavy settlement and the rate is up to -30 mm/y. In general, the area close to the subway line is relatively stable during the construction period.

  1. Modeling Laser-Plasma Interaction over a Suite of NIF Experiments

    Science.gov (United States)

    Strozzi, D. J.; Berger, R. L.; Jones, O. S.; Chapman, T.; Woods, D. T.; MacLaren, S. A.; Michel, P.; Divol, L.

    2017-10-01

    We systematically study laser-plasma interaction (LPI) on NIF indirect-drive experiments, namely backscatter and cross-beam energy transfer. LLNL's best practice radiation-hydrodynamic simulation methodology in the Lasnex simulation code is employed without ad-hoc tuning to match experimental data. This entails converged numerical resolution, an improved DCA model for coronal (ne 1 keV) gold opacity, electron heat flux strongly limited to 0.03neTe3 / 2 me- 1 / 2 , and the inline CBET model. The rad-hydro plasma conditions are used for LPI analysis, namely linear instability gains, and the paraxial-envelope code pF3D. Simulated scattered-light spectra are also compared to measurements. We initially focus on shots with low backscatter, so its self-consistent treatment should not be important. These shots have low hohlraum fill density and short laser pulses, and the only significant backscatter is outer-beams Brillouin. Our long-term goals are to understand reflectivity trends to guide target design and develop LPI mitigation strategies. Work performed under auspices of US DoE by LLNL under Contract DE-AC52-07NA27344.

  2. A Computational Study of Re-emission Balls Proposed for the NIF Ignition Symmetry Campaign

    Science.gov (United States)

    Meeker, D. J.; Amendt, P.; Dewald, E.; Edwards, M. J.; Milovich, J.; Suter, L.

    2006-10-01

    Re-emission balls are high-Z spheres used as surrogates for ICF ignition capsules to detect and correct early-time asymmetries of radiation flux at the target. Emission from these balls mimics the incoming flux due to their high albedo, providing a useful symmetry diagnostic. Experiments on Nova by LANL [1] and LLNL used bismuth (Bi) as the surrogate, selected for its high albedo and insensitivity to the fluorescence of the gold hohlraum wall. We are studying the applicability of these capsules to the NIF symmetry campaign as a potential tuning mechanism to achieve the accuracies required for symmetric implosions. We will describe 2-D simulations that predict the emission of the Bi ball as a function of time, frequency, and spatial distribution, as well as quantifying surrogacy of re- emission balls. Using several tuning examples, we will show the resolution expected from this diagnostic. Suggestions for extending this technique to longer times will be discussed as well as describing 3-D effects from diagnostic viewing ports and an opposing hole to eliminate competing wall emission. [1] Delamater, Phys. Rev. E 53, 5240 (1996), Magelssen, Phys. Rev. E 57, 4663 (1998)

  3. Expression of the nifA gene of Herbaspirillum seropedicae: role of the NtrC and NifA binding sites and of the -24/-12 promoter element.

    Science.gov (United States)

    Souza, E M; Pedrosa, F O; Rigo, L U; Machado, H B; Yates, M G

    2000-06-01

    The nifA promoter of Herbaspirillum seropedicae contains potential NtrC, NifA and IHF binding sites together with a -12/-24 sigma(N)-dependent promoter. This region has now been investigated by deletion mutagenesis for the effect of NtrC and NifA on the expression of a nifA::lacZ fusion. A 5' end to the RNA was identified at position 641, 12 bp downstream from the -12/-24 promoter. Footprinting experiments showed that the G residues at positions -26 and -9 are hypermethylated, and that the region from -10 to +10 is partially melted under nitrogen-fixing conditions, confirming that this is the active nifA promoter. In H. seropedicae nifA expression from the sigma(N)-dependent promoter is repressed by fixed nitrogen but not by oxygen and is probably activated by the NtrC protein. NifA protein is apparently not essential for nifA expression but it can still bind the NifA upstream activating sequence.

  4. Characterizing high energy spectra of NIF ignition Hohlraums using a differentially filtered high energy multipinhole x-ray imager.

    Science.gov (United States)

    Park, Hye-Sook; Dewald, E D; Glenzer, S; Kalantar, D H; Kilkenny, J D; MacGowan, B J; Maddox, B R; Milovich, J L; Prasad, R R; Remington, B A; Robey, H F; Thomas, C A

    2010-10-01

    Understanding hot electron distributions generated inside Hohlraums is important to the national ignition campaign for controlling implosion symmetry and sources of preheat. While direct imaging of hot electrons is difficult, their spatial distribution and spectrum can be deduced by detecting high energy x-rays generated as they interact with target materials. We used an array of 18 pinholes with four independent filter combinations to image entire Hohlraums with a magnification of 0.87× during the Hohlraum energetics campaign on NIF. Comparing our results with Hohlraum simulations indicates that the characteristic 10-40 keV hot electrons are mainly generated from backscattered laser-plasma interactions rather than from Hohlraum hydrodynamics.

  5. Closure Report for Corrective Action Unit 408: Bomblet Target Area Tonopah Test Range (TTR), Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss

    2010-09-01

    This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 408: Bomblet Target Area (TTR), Tonopah Test Range, Nevada. This CR complies with the requirements of the Federal Facility Agreement and Consent Order that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. Corrective Action Unit 408 is located at the Tonopah Test Range, Nevada, and consists of Corrective Action Site (CAS) TA-55-002-TAB2, Bomblet Target Areas. This CAS includes the following seven target areas: • Mid Target • Flightline Bomblet Location • Strategic Air Command (SAC) Target Location 1 • SAC Target Location 2 • South Antelope Lake • Tomahawk Location 1 • Tomahawk Location 2 The purpose of this CR is to provide documentation supporting the completed corrective actions and data confirming that the closure objectives for the CAS within CAU 408 were met. To achieve this, the following actions were performed: • Review the current site conditions, including the concentration and extent of contamination. • Implement any corrective actions necessary to protect human health and the environment. • Properly dispose of corrective action and investigation wastes. • Document Notice of Completion and closure of CAU 408 issued by the Nevada Division of Environmental Protection. From July 2009 through August 2010, closure activities were performed as set forth in the Streamlined Approach for Environmental Restoration Plan for CAU 408: Bomblet Target Area, Tonopah Test Range (TTR), Nevada. The purposes of the activities as defined during the data quality objectives process were as follows: • Identify and remove munitions of explosive concern (MEC) associated with DOE activities. • Investigate potential disposal pit locations. • Remove depleted uranium-contaminated fragments and soil. • Determine whether contaminants of concern (COCs) are

  6. Exploration and reservoir characterization; Technology Target Areas; TTA2 - Exploration and reservoir characterisation

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    In future, research within exploration and reservoir characterization will play an even more important role for Norway since resources are decreasing and new challenges like deep sea, harsh environment and last but not least environmental issues have to be considered. There are two major fields which have to be addressed within exploration and reservoir characterization: First, replacement of reserves by new discoveries and ultimate field recoveries in mature basins at the Norwegian Continental shelf, e.g. at the Halten Terrace has to be addressed. A wealth of data exists in the more mature areas. Interdisciplinary integration is a key feature of reservoir characterization, where available data and specialist knowledge need to be combined into a consistent reservoir description. A systematic approach for handling both uncertainties in data sources and uncertainties in basic models is needed. Fast simulation techniques are necessary to generate models spanning the event space, covering both underground based and model-based uncertainties. Second, exploration in frontier areas like the Barents Sea region and the deeper Voering Basin has to be addressed. The scarcity of wells in these frontier areas leads to uncertainties in the geological understanding. Basin- and depositional modelling are essential for predicting where source rocks and reservoir rocks are deposited, and if, when and which hydrocarbons are generated and trapped. Predictive models and improved process understanding is therefore crucial to meet these issues. Especially the challenges related to the salt deposits e.g. sub-salt/sub-basalt reservoir definitions in the Nordkapp Basin demands up-front research and technology developments. TTA2 stresses the need to focus on the development of new talents. We also see a strong need to push cooperation as far as possible in the present competitive environment. Projects that may require a substantial financial commitment have been identified. The following

  7. Research on Methods of High Coherent Target Extraction in Urban Area Based on Psinsar Technology

    Science.gov (United States)

    Li, N.; Wu, J.

    2018-04-01

    PSInSAR technology has been widely applied in ground deformation monitoring. Accurate identification of Persistent Scatterers (PS) is key to the success of PSInSAR data processing. In this paper, the theoretic models and specific algorithms of PS point extraction methods are summarized and the characteristics and applicable conditions of each method, such as Coherence Coefficient Threshold method, Amplitude Threshold method, Dispersion of Amplitude method, Dispersion of Intensity method, are analyzed. Based on the merits and demerits of different methods, an improved method for PS point extraction in urban area is proposed, that uses simultaneously backscattering characteristic, amplitude and phase stability to find PS point in all pixels. Shanghai city is chosen as an example area for checking the improvements of the new method. The results show that the PS points extracted by the new method have high quality, high stability and meet the strong scattering characteristics. Based on these high quality PS points, the deformation rate along the line-of-sight (LOS) in the central urban area of Shanghai is obtained by using 35 COSMO-SkyMed X-band SAR images acquired from 2008 to 2010 and it varies from -14.6 mm/year to 4.9 mm/year. There is a large sedimentation funnel in the cross boundary of Hongkou and Yangpu district with a maximum sedimentation rate of more than 14 mm per year. The obtained ground subsidence rates are also compared with the result of spirit leveling and show good consistent. Our new method for PS point extraction is more reasonable, and can improve the accuracy of the obtained deformation results.

  8. Implication of the displacement of the T1 primary target in the west area at the CERN SPS

    CERN Document Server

    Gatignon, L

    1999-01-01

    As soon as the transfer line T12 for proton injection into the LHC must be installed, the T1 primary target has to be at least partly dismantled, as its shielding would block the passage of the beam. Even though the installation of T12 is only foreseen for later, in view of sharing of workload related to the SLI project, it is preferred to move the primary production target T1 for the West Area to its new position already in the shutdown 1999/2000. The new position of the target requires major modifications of support structures in TCC6, of the transfer line towards T1 and of a more than 500 metres long section of the H3 secondary beam in the West Area, all to be completed in the 1999/2000 shutdown. To allow the work to be finished in time, part of it (including some civil engineering in TT4) is already done in the 1998/99 shutdown. In this memo the necessary modifications are described, cost estimates are given and a planning is provided.

  9. Technology strategy for gas technologies; Technology Target Areas; TTA8 Gas Technology

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    TTA8 - Gas technologies points out the various routes Norway can follow to capitalise on the vast resources of natural gas that will be produced in the years to come by developing a strong technology and competence platform. A broad view is taken for the value creation having as basis the continued gas export from NCS to Europe, but also a strong focus on development of gas resources in other parts of the world. The latter can also be seen as part of international positioning for upstream resources and does also include involvements in projects, and export of technology and products. The TTA has structured the analysis into 3 main areas: Gas transport and processing (pipeline, LNG, other); Gas conversion to fuels, chemicals and materials; CO{sub 2} management. In this report, for each of these areas, scenarios based on a gap analysis are presented. One of the key goals has been to identify pacing and emerging technologies for the next 20 years. Based on this, technologies have been mapped according to importance for future competitiveness and technology ambitions. This also includes primary funding responsibilities (public and/or industry). The road map below reflects the key issues in the proposed strategy. The base level of the figure explains areas that will have to be pursued to maintain Norway's role as a key gas and gas technology provider. The second layer represents near term options and possibilities with a reasonable risk profile that could further enhance the Norwegian position given the resources and drive to further develop this industry. As the top layer we have selected some of our 'dreams', what we may achieve if a progressive approach is followed with a strongly innovation based policy. It is acknowledged by the TTA that Norway cannot be a leading technology player in all aspects of the gas value chain. For some technologies we should be an active player and developer, whilst for other technologies we should become a competent buyer and user. This

  10. Technology strategy for gas technologies; Technology Target Areas; TTA8 Gas Technology

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    TTA8 - Gas technologies points out the various routes Norway can follow to capitalise on the vast resources of natural gas that will be produced in the years to come by developing a strong technology and competence platform. A broad view is taken for the value creation having as basis the continued gas export from NCS to Europe, but also a strong focus on development of gas resources in other parts of the world. The latter can also be seen as part of international positioning for upstream resources and does also include involvements in projects, and export of technology and products. The TTA has structured the analysis into 3 main areas: Gas transport and processing (pipeline, LNG, other); Gas conversion to fuels, chemicals and materials; CO{sub 2} management. In this report, for each of these areas, scenarios based on a gap analysis are presented. One of the key goals has been to identify pacing and emerging technologies for the next 20 years. Based on this, technologies have been mapped according to importance for future competitiveness and technology ambitions. This also includes primary funding responsibilities (public and/or industry). The road map below reflects the key issues in the proposed strategy. The base level of the figure explains areas that will have to be pursued to maintain Norway's role as a key gas and gas technology provider. The second layer represents near term options and possibilities with a reasonable risk profile that could further enhance the Norwegian position given the resources and drive to further develop this industry. As the top layer we have selected some of our 'dreams', what we may achieve if a progressive approach is followed with a strongly innovation based policy. It is acknowledged by the TTA that Norway cannot be a leading technology player in all aspects of the gas value chain. For some technologies we should be an active player and developer, whilst for other technologies we should become a competent buyer

  11. Tertiary particle production and target optimization of the H2 beam line in the SPS North Area

    CERN Document Server

    AUTHOR|(CDS)2079540; Tellander, Felix; CERN. Geneva. ATS Department

    2016-01-01

    In this note, the tertiary particle yield from secondary targets of different materials placed at the ‘filter’ position of the H2 beam line of SPS North Area are presented. The production is studied for secondary beams of different momenta in the range of 50-250 GeV/c. More specifically, we studied six different targets: two copper cylinders with a radius of 40 mm and lengths of 100 and 300 mm, one solid tungsten cylinder with a radius of 40 mm and a length of 150 mm and three polyethylene cylinders with radius of 40 mm and lengths of 550, 700 and 1000 mm. Eight different momenta of the secondary beam (50, 60, 70, 100, 120, 150, 200 and 250 GeV/c) as well as two different physics lists (QGSP_BIC and FTFP_BERT) have been extensively studied. The purpose of this study is (a) to optimize (using the appropriate filter target) the particle production from the secondary targets as demanded by the experiments (b) investigate the proton production (with respect to the pion production) in the produced tertiary bea...

  12. Hot spot mix in ICF implosions on the NIF

    Science.gov (United States)

    Ma, Tammy

    2016-10-01

    In the quest to achieve ignition through the inertial confinement fusion scheme, one of the critical challenges is to drive a symmetric implosion at high velocity without hydrodynamic instabilities becoming detrimental. These instabilities, primarily at the ablation front and the fuel-ablator interface, can cause mix of the higher-Z shell into the hot spot, resulting in increased radiation loss and thus reduced temperature and neutron yield. To quantify the level of mix, we developed a model that infers the level of hot spot contamination using the ratio of the enhanced x-ray production relative to the neutron yield. Applying this methodology to the full ensemble of indirect-drive National Ignition Facility (NIF) cryogenically layered DT implosions provides insight on the sensitivity of performance to the level of ablator-hot spot mix. In particular, the improvement seen with the High Foot design can be primarily attributed to a reduction in ablation-front instability mix that enabled the implosions to be pushed to higher velocity and performance. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, Lawrence Livermore National Security, LLC.

  13. Wetted Foam Liquid DT Layer ICF Experiments at the NIF

    Science.gov (United States)

    Olson, R. E.; Leeper, R. J.; Peterson, R. R.; Yi, S. A.; Zylstra, A. B.; Kline, J. L.; Bradley, P. A.; Yin, L.; Wilson, D. C.; Haines, B. M.; Batha, S. H.

    2016-10-01

    A key physics issue in indirect-drive ICF relates to the understanding of the limitations on hot spot convergence ratio (CR), principally set by the hohlraum drive symmetry, the capsule mounting hardware (the ``tent''), and the capsule fill tube. An additional key physics issue relates to the complex process by which a hot spot must be dynamically formed from the inner ice surface in a DT ice-layer implosion. These physics issues have helped to motivate the development of a new liquid DT layer wetted foam platform at the NIF that provides an ability to form the hot spot from DT vapor and experimentally study and understand hot spot formation at a variety of CR's in the range of 12hot spot and the low adiabat cold fuel during the stagnation process and can allow for a fundamentally different (and potentially more robust) process of hot spot formation. This new experimental platform is currently being used in a series of experiments to discover a range of CR's at which DT layered implosions will have understandable performance - providing a sound basis from which to determine the requirements for ICF ignition. This work was performed under the auspices of the U. S. DOE by LANL under contract DE-AC52-06NA25396.

  14. A trial to combine heterogeneous computer systems in NIFS

    International Nuclear Information System (INIS)

    Emoto, M.; Watanabe, K.; Ohdachi, S.; Matsunami, S.; Yamaguchi, S.; Sudo, S.; Okumura, H.

    2000-01-01

    Several computer systems in NIFS (the National Institute for Fusion Science) are involved in the operation of the LHD (Large Helical Device) for plasma experiments. Because these systems are independent of each other, it is burdensome to the programmers and the researchers to use several of them for one project. Currently, the programmers must write low-level data access routines for each system, then the researchers, after having learned these routines, can install the applications to retrieve the data on each system. In order to improve this situation, we have been developing a new system. This system employs two technologies, the signed applet and HORB, to combine the independent systems. These technologies were chosen for the following reasons: (1) The signed applet is an applet free from the general restrictions of applets, and can connect to any server and save the retrieved data to client machines; and (2) HORB is the Java-based ORB (Object Request Broker), the use of which makes it easy to build a Java-based, distributed environment. When the system is completed, it will allow users to obtain data from the above independent systems by means of ordinary Web browsers, without having to install additional applications

  15. The Ignition Physics Campaign on NIF: Status and Progress

    International Nuclear Information System (INIS)

    Edwards, M. J.

    2016-01-01

    We have made significant progress in ICF implosion performance on NIF since the 2011 IFSA. Employing a 3-shock, high adiabat CH (“High-Foot”) design, total neutron yields have increased 10-fold to 6.3 x10 15 (a yield of ∼ 17 kJ, which is greater than the energy invested in the DT fuel ∼ 12kJ). At that level, the yield from alpha self-heating is essentially equivalent to the compression yield, indicating that we are close to the alpha self-heating regime. Low adiabat, 4-shock High Density Carbon (HDC) capsules have been imploded in conventional gas-filled hohlraums, and employing a 6 ns, 2-shock pulse, HDC capsules were imploded in near-vacuum hohlraums with overall coupling ∼ 98%. Both the 4- and 2-shock HDC capsules had very low mix and high yield over simulated performance. Rugby holraums have demonstrated uniform x-ray drive with minimal Cross Beam Energy Transfer (CBET), and we have made good progress in measuring and modelling growth of ablation front hydro instabilities. (paper)

  16. Results from neutron imaging of ICF experiments at NIF

    Science.gov (United States)

    Merrill, F. E.; Danly, C. R.; Fittinghoff, D. N.; Grim, G. P.; Guler, N.; Volegov, P. L.; Wilde, C. H.

    2016-03-01

    In 2011 a neutron imaging diagnostic was commissioned at the National Ignition Facility (NIF). This new system has been used to collect neutron images to measure the size and shape of the burning DT plasma and the surrounding fuel assembly. The imaging technique uses a pinhole neutron aperture placed between the neutron source and a neutron detector. The detection system measures the two-dimensional distribution of neutrons passing through the pinhole. This diagnostic collects two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically one image measures the distribution of the 14 MeV neutrons, and the other image measures the distribution of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core. Images have been collected for the majority of the experiments performed as part of the ignition campaign. Results from this data have been used to estimate a burn-averaged fuel assembly as well as providing performance metrics to gauge progress towards ignition. This data set and our interpretation are presented.

  17. Progress towards monochromatic imaging of mix at the NIF

    Science.gov (United States)

    Kyrala, G. A.; Murphy, T. J.; Bradley, P. A.; Krashenninnikova, N. S.; Tregillis, I. L.; Obrey, K.; Shah, R. C.; Hakel, P.; Kline, J. L.; Grim, G. P.; Schmitt, M. J.; Kanzleiter, R. J.; Regan, S. P.; Barrios, M. A.

    2013-10-01

    Mix of non-hydrogenic (Z >1) material into the hydrogenic (D and T) ICF capsule fuel degrades implosion performance. The amount of degradation depends on the degree and the spatial distribution of mix. Experiments are underway at NIF to quantify the mix of shell material into fuel using directly driven capsules. CH or CD shells with various dopants, implanted at different depths in the shell are being used to change the amount of dopant mix. Spatially and spectrally resolved emission from the ionized dopants will be used to generate spatially and temporally dependent density and temperature maps of the ionized dopants that are mixed and heated in the core plasma. This information will be used to validate different mix models. This talk will describe the search for the appropriate dopant that gave a radiation spectrum that could be used to record images with the MMI diagnostic. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

  18. Exploring the universe through Discovery Science on NIF

    Science.gov (United States)

    Remington, Bruce

    2017-10-01

    New regimes of science are being experimentally studied at high energy density facilities around the world, spanning drive energies from microjoules to megajoules, and time scales from femtoseconds to microseconds. The ability to shock and ramp compress samples to very high pressures and densities allows new states of matter relevant to planetary and stellar interiors to be studied. Shock driven hydrodynamic instabilities evolving into turbulent flows relevant to the dynamics of exploding stars (such as supernovae), accreting compact objects (such as white dwarfs, neutron stars, and black holes), and planetary formation dynamics (relevant to the exoplanets) are being probed. The dynamics of magnetized plasmas relevant to astrophysics, both in collisional and collisionless systems, are starting to be studied. High temperature, high velocity interacting flows are being probed for evidence of astrophysical collisionless shock formation, the turbulent magnetic dynamo effect, magnetic reconnection, and particle acceleration. And new results from thermonuclear reactions in hot dense plasmas relevant to stellar and big bang nucleosynthesis are starting to emerge. A selection of examples of frontier research through NIF Discovery Science in the coming decade will be presented. This work was performed under the auspices of U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

  19. Ultra High Mode Mix in NIF NIC Implosions

    Science.gov (United States)

    Scott, Robbie; Garbett, Warren

    2017-10-01

    This work re-examines a sub-set of the low adiabat implosions from the National Ignition Campaign in an effort to better understand potential phenomenological sources of `excess' mix observed experimentally. An extensive effort has been made to match both shock-timing and backlit radiography (Con-A) implosion data in an effort to reproduce the experimental conditions as accurately as possible. Notably a 30% reduction in ablation pressure at peak drive is required to match the experimental data. The reduced ablation pressure required to match the experimental data allows the ablator to decompress, in turn causing the DT ice-ablator interface to go Rayleigh-Taylor unstable early in the implosion acceleration phase. Post-processing the runs with various mix models indicates high-mode mix from the DT ice-ablator interface may penetrate deep into the hotspot. This work offers a potential explanation of why these low-adiabat implosions exhibited significantly higher levels of mix than expected from high-fidelity multi-dimensional simulations. Through this new understanding, a possible route forward for low-adiabat implosions on NIF is suggested.

  20. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 408: Bomblet Target Area, Tonopah Test Range, Nevada

    International Nuclear Information System (INIS)

    NSTec Environmental Management

    2006-01-01

    This Streamlined Approach for Environmental Restoration Plan provides the details for the closure of Corrective Action Unit (CAU) 408, Bomblet Target Area. CAU 408 is located at the Tonopah Test Range and is currently listed in Appendix III of the Federal Facility Agreement and Consent Order of 1996. One Corrective Action Site (CAS) is included in CAU 408: (lg b ullet) CAS TA-55-002-TAB2, Bomblet Target Areas Based on historical documentation, personnel interviews, process knowledge, site visits, aerial photography, multispectral data, preliminary geophysical surveys, and the results of data quality objectives process (Section 3.0), clean closure will be implemented for CAU 408. CAU 408 closure activities will consist of identification and clearance of bomblet target areas, identification and removal of depleted uranium (DU) fragments on South Antelope Lake, and collection of verification samples. Any soil containing contaminants at concentrations above the action levels will be excavated and transported to an appropriate disposal facility. Based on existing information, contaminants of potential concern at CAU 408 include explosives. In addition, at South Antelope Lake, bomblets containing DU were tested. None of these contaminants is expected to be present in the soil at concentrations above the action levels; however, this will be determined by radiological surveys and verification sample results. The corrective action investigation and closure activities have been planned to include data collection and hold points throughout the process. Hold points are designed to allow decision makers to review the existing data and decide which of the available options are most suitable. Hold points include the review of radiological, geophysical, and analytical data and field observations

  1. Measurements and simulations of the BLM response to a radiation field inside the CERF target area

    CERN Document Server

    Lebbos, E; Dehning, B; Effinger, E; Ferrari, A; Kramer, D; Nordt, A; Roeed, K; Roesler, S; Sapinski, M; Vlachoudis, V

    2010-01-01

    The CERN-EU high-energy reference field (CERF) facility is installed in one of the secondary beam lines (H6) of the Super Proton Synchrotron (SPS), in the North Experimental Area at CERN. This facility is used as a reference for testing, inter-comparing and calibrating passive and active instruments. In May 2009, the SPS provided a mixed hadron beam (protons, pions and kaons) during a few days, in order to perform several measurements with different devices such as the Radiation Protection Monitor used for residual dose rates due to Induced Radioactivity in the LHC (PMI), the Secondary Emission Monitor used for high beam losses (SEM), the Radiation Monitor for electronics (RadMon), and the Beam Loss Monitor for the LHC (BLM). This report focuses on the measurements of the BLM response during this year’s operation at CERF. The measurements evaluate the sensitivity of the BLM signal to the particle energy spectrum, with special attention to the contribution coming from thermal neutrons. For this purpose, meas...

  2. Conservation targets in marine protected area management suffer from shifting baseline syndrome: A case study on the Dogger Bank.

    Science.gov (United States)

    Plumeridge, Annabel A; Roberts, Callum M

    2017-03-15

    The Dogger Bank is a subtidal hill in the North Sea that is a candidate Special Area of Conservation under the EU Habitats Directive in UK waters. Historical records indicate that the Bank has been subject to human exploitation from before the 16th century but conservation objectives have been developed using recent survey data. This has the potential to significantly underestimate the alteration this ecosystem has experienced, making the Dogger Bank an example of shifting baseline syndrome in protected area management. We compile quantitative and qualitative descriptions from historical records of change in catch rates, fishing effort, price and fish size to show that there have been prolonged declines in abundance of fish on the Bank since the early 19th century. Use of present day data to inform conservation has led to unambitious recovery targets. Historical data, we argue, are an essential input to conservation decision making. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Normalized impact factor (NIF): an adjusted method for calculating the citation rate of biomedical journals.

    Science.gov (United States)

    Owlia, P; Vasei, M; Goliaei, B; Nassiri, I

    2011-04-01

    The interests in journal impact factor (JIF) in scientific communities have grown over the last decades. The JIFs are used to evaluate journals quality and the papers published therein. JIF is a discipline specific measure and the comparison between the JIF dedicated to different disciplines is inadequate, unless a normalization process is performed. In this study, normalized impact factor (NIF) was introduced as a relatively simple method enabling the JIFs to be used when evaluating the quality of journals and research works in different disciplines. The NIF index was established based on the multiplication of JIF by a constant factor. The constants were calculated for all 54 disciplines of biomedical field during 2005, 2006, 2007, 2008 and 2009 years. Also, ranking of 393 journals in different biomedical disciplines according to the NIF and JIF were compared to illustrate how the NIF index can be used for the evaluation of publications in different disciplines. The findings prove that the use of the NIF enhances the equality in assessing the quality of research works produced by researchers who work in different disciplines. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. FANTM: The First Article NIF Test Module for the Laser Power Conditioning System

    International Nuclear Information System (INIS)

    Hammon, Jud; Harjes, Henry C.; Moore, William B.S.; Smith, David L.; Wilson, J. Michael

    1999-01-01

    Designing and developing the 1.7 to 2. 1-MJ Power Conditioning System (PCS) that powers the flashlamps for the National Ignition Facility (NIF), currently being constructed at Lawrence Livermore National Labs (LLNL), is one of several responsibilities assumed by Sandia National Labs (SNL) in support of the NIF Project. The test facility that has evolved over the last three years to satisfy the project requirements is called FANTM. It was built at SNL and has operated for about 17,000 shots to demonstrate component performance expectations over the lifetime of NIF. A few modules similar to the one shown in Fig. 1 will be used initially in the amplifier test phase of the project. The final till NIF system will require 192 of them (48 in each of four capacitor bays). This paper briefly summarizes the final design of the FANTM facility and compares its performance with the predictions of circuit simulations for both normal operation and fault-mode response. Applying both the measured and modeled power pulse waveforms as input to a physics-based, semi-empirical amplifier gain code indicates that the 20-capacitor PCS can satisfy the NIF requirement for an average gain coefficient of 5.00 %/cm and can exceed 5.20%/cm with 24 capacitors

  5. National Ignition Facility subsystem design requirements laser and target area building (LTAB) SSDR 1.2.2.1

    International Nuclear Information System (INIS)

    Kempel, P.; Hands, J.

    1996-01-01

    This Subsystem Design Requirements (SSDR) document establishes the performance, design, and verification requirements for the conventional building systems and subsystems of the Laser and Target Area Building (LTAB), including those that house and support the operation of high-energy laser equipment and the operational flow of personnel and materials throughout the facility. This SSDR addresses the following subsystems associated with the LTAB: Building structural systems for the Target Bay, Switchyards, Diagnostic Building, Decontamination Area, Laser Bays, Capacitor Bays and Operations Support Area, and the necessary space associated with building-support equipment; Architectural building features associated with housing the space and with the operational cleanliness of the functional operation of the facilities; Heating, Ventilating, and Air Conditioning (HVAC) systems for maintaining a clean and thermally stable ambient environment within the facilities; Plumbing systems that provide potable water and sanitary facilities for the occupants, plus stormwater drainage for transporting rainwater; Fire Protection systems that guard against fire damage to the facilities and their contents; Material handling systems for transporting personnel and heavy materials within the building areas; Mechanical process piping systems for liquids and gases that provide cooling and other service to experimental laser equipment and components; Electrical power and grounding systems that provide service and standby power to building and experimental equipment, including lighting distribution and communications systems for the facilities; Instrumentation and control systems that ensure the safe operation of conventional facilities systems, such as those listed above. Detailed requirements for building subsystems that are not addressed in this document (such as specific sizes, locations, or capacities) are included in detail-level NIP Project Interface Control Documents (ICDS)

  6. The regional metallogenesis and optimum selection of prospecting target for superlarge uranium deposit in metallogenic area of erguna

    International Nuclear Information System (INIS)

    Luo Yi; Wang Zhengbang; Hou Huiqun; Zhou Dean; Qi Fucheng; Xiao Xiangping

    1995-06-01

    The study area, an activation zone of the median Massif in Xingmeng geosynclinal area, geologically underwent the multiple tectono-magmatic reworking of granitizations during Shinagan, Caledonia and Hercynian periods and of continental rift volcanism in the Mesozoic-Cenozoic era. It is an important potential area for uranium metallogenesis in volcanic basin in North China. The study identifies that four stages of uranium preconcentration and three phases of hydrothermal superimposed-reworking uranium metallogenesis occurred along with the regional geological elevation process. Studies on the U-Pb isotope and induced fission track of various kinds of basement rocks from the area indicate that the basement composed of crustal source remelting type Caledonian and Hercynian granites is favourable for uranium metallogenesis in volcanic basin, and that the late Jurassic intermediate-acid volcano-rock directly act as the source of uranium and that Cretaceous-Tertiary extension-rift basalt magmatic activation supply an important hydrothermal reworking condition for the uranium metallogenesis in volcanic basin. Based on comparative study on the metallogenetic conditions of typical large-scale volcanic uranium deposits at home and abroad, nine prospecting criteria are summarized, the polygenetic mixing hydrothermal uranium metallogenetic model for penetrable volcano-collapse basin is presented, and the main prospecting targets of uranium deposits are pointed out. (2 figs.)

  7. Mesoscale Assessment of CO2 Storage Potential and Geological Suitability for Target Area Selection in the Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Yujie Diao

    2017-01-01

    Full Text Available In China, south of the Yangtze River, there are a large number of carbon sources, while the Sichuan Basin is the largest sedimentary basin; it makes sense to select the targets for CO2 geological storage (CGUS early demonstration. For CO2 enhanced oil and gas, coal bed methane recovery (CO2-EOR, EGR, and ECBM, or storage in these depleted fields, the existing oil, gas fields, or coal seams could be the target areas in the mesoscale. This paper proposed a methodology of GIS superimposed multisource information assessment of geological suitability for CO2 enhanced water recovery (CO2-EWR or only storage in deep saline aquifers. The potential per unit area of deep saline aquifers CO2 storage in Central Sichuan is generally greater than 50 × 104 t/km2 at P50 probability level, with Xujiahe group being the main reservoir. CO2 storage potential of depleted gas fields is 53.73 × 108 t, while it is 33.85 × 108 t by using CO2-EGR technology. This paper recommended that early implementation of CGUS could be carried out in the deep saline aquifers and depleted gas fields in the Sichuan Basin, especially that of the latter because of excellent traps, rich geological data, and well-run infrastructures.

  8. Tritium and ignition target management at the National Ignition Facility.

    Science.gov (United States)

    Draggoo, Vaughn

    2013-06-01

    Isotopic mixtures of hydrogen constitute the basic fuel for fusion targets of the National Ignition Facility (NIF). A typical NIF fusion target shot requires approximately 0.5 mmoles of hydrogen gas and as much as 750 GBq (20 Ci) of 3H. Isotopic mix ratios are specified according to the experimental shot/test plan and the associated test objectives. The hydrogen isotopic concentrations, absolute amounts, gas purity, configuration of the target, and the physical configuration of the NIF facility are all parameters and conditions that must be managed to ensure the quality and safety of operations. An essential and key step in the preparation of an ignition target is the formation of a ~60 μm thick hydrogen "ice" layer on the inner surface of the target capsule. The Cryogenic Target Positioning System (Cryo-Tarpos) provides gas handling, cyro-cooling, x-ray imaging systems, and related instrumentation to control the volumes and temperatures of the multiphase (solid, liquid, and gas) hydrogen as the gas is condensed to liquid, admitted to the capsule, and frozen as a single spherical crystal of hydrogen in the capsule. The hydrogen fuel gas is prepared in discrete 1.7 cc aliquots in the LLNL Tritium Facility for each ignition shot. Post-shot hydrogen gas is recovered in the NIF Tritium Processing System (TPS). Gas handling systems, instrumentation and analytic equipment, material accounting information systems, and the shot planning systems must work together to ensure that operational and safety requirements are met.

  9. Crystallization and preliminary crystallographic data of the PAS domain of the NifL protein from Azotobacter vinelandii.

    NARCIS (Netherlands)

    Hefti, M.H.; Hendle, J.; Enroth, C.; Vervoort, J.J.M.; Tucker, P.A.

    2001-01-01

    The Azotobacter vinelandii NifL protein is a redox-sensing flavoprotein which inhibits the activity of the nitrogen-specific transcriptional activator NifA. The N-terminal PAS domain has been overexpressed in Escherichia coli and crystallized by the hanging-drop vapour-diffusion method. The crystal

  10. Measuring the absolute DT neutron yield using the Magnetic Recoil Spectrometer at OMEGA and the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Mackinnon, A; Casey, D; Frenje, J A; Johnson, M G; Seguin, F H; Li, C K; Petrasso, R D; Glebov, V Y; Katz, J; Knauer, J; Meyerhofer, D; Sangster, T; Bionta, R; Bleuel, D; Hachett, S P; Hartouni, E; Lepape, S; Mckernan, M; Moran, M; Yeamans, C

    2012-05-03

    A Magnetic Recoil Spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

  11. AN UPDATE ON THE STATUS OF THE NIF POWER CONDITIONING SYSTEM

    International Nuclear Information System (INIS)

    Arnold, P A; Hulsey, S; Ullery, G T; Petersen, D E; Pendleton, D L; Ollis, C W; Newton, M A; Harwell, T; Cordoza, D; Hadovski, L

    2007-01-01

    The National Ignition Facility (NIF) Power Conditioning System provides the pulsed excitation required to drive flashlamps in the laser's optical amplifiers. Modular in design, each of the 192 Main Energy Storage Modules (MESMs) stores up to 2.2 MJ of electrical energy in its capacitor bank before delivering the energy to 20 pairs of flashlamps in a 400 (micro)s pulse (10% power points). The peak current of each MESM discharge is 0.5 MA. Production, installation, commissioning and operation of the NIF Power Conditioning continue to progress rapidly, with the goals of completing accelerated production and commissioning by early 2008, while maintaining an aggressive operation schedule. To date, more than 97% of the required modules have been assembled, shipped and installed in the facility, representing more that 380 MJ of stored energy available for driving NIF flashlamps. The MESMs have displayed outstanding reliability during daily, multiple-shift operations

  12. Interaction of GlnK with the GAF domain of Herbaspirillum seropedicae NifA mediates NH₄⁺-regulation.

    Science.gov (United States)

    Oliveira, Marco A S; Aquino, Bruno; Bonatto, Ana Claudia; Huergo, Luciano F; Chubatsu, Leda S; Pedrosa, Fábio O; Souza, Emanuel M; Dixon, Ray; Monteiro, Rose A

    2012-04-01

    Nitrogen fixation in Herbaspirillum seropedicae is transcriptionally regulated by NifA, a σ(54) transcriptional activator with three structural domains: an N-terminal GAF domain, a catalytic AAA+ domain and a C-terminal DNA-binding domain. NifA is only active in H. seropedicae when cultures are grown in the absence of fixed nitrogen and at low oxygen tensions. There is evidence that the inactivation of NifA in response to fixed nitrogen is mediated by the regulatory GAF domain. However, the mechanism of NifA repression by the GAF domain, as well as the transduction of nitrogen status to NifA, is not understood. In order to study the regulation of NifA activity by fixed nitrogen independently of oxygen regulation, we constructed a chimeric protein containing the GAF domain of H. seropedicae NifA fused to the AAA+ and C-terminal domains of Azotobacter vinelandii NifA. This chimeric protein (NifAQ1) lacks the cysteine motif found in oxygen sensitive NifA proteins and is not oxygen responsive in vivo. Our results demonstrate that NifAQ1 responds to fixed nitrogen and requires GlnK protein for activity, a behavior similar to H. seropedicae NifA. In addition, protein footprinting analysis indicates that this response probably involves a protein-protein contact between the GAF domain and the GlnK protein. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  13. The NIF: An international high energy density science and inertial fusion user facility

    Directory of Open Access Journals (Sweden)

    Moses E.I.

    2013-11-01

    Full Text Available The National Ignition Facility (NIF, a 1.8-MJ/500-TW Nd:Glass laser facility designed to study inertial confinement fusion (ICF and high-energy-density science (HEDS, is operational at Lawrence Livermore National Laboratory (LLNL. A primary goal of NIF is to create the conditions necessary to demonstrate laboratory-scale thermonuclear ignition and burn. NIF experiments in support of indirect-drive ignition began late in FY2009 as part of the National Ignition Campaign (NIC, an international effort to achieve fusion ignition in the laboratory. To date, all of the capabilities to conduct implosion experiments are in place with the goal of demonstrating ignition and developing a predictable fusion experimental platform in 2012. The results from experiments completed are encouraging for the near-term achievement of ignition. Capsule implosion experiments at energies up to 1.6 MJ have demonstrated laser energetics, radiation temperatures, and symmetry control that scale to ignition conditions. Of particular importance is the demonstration of peak hohlraum temperatures near 300 eV with overall backscatter less than 15%. Important national security and basic science experiments have also been conducted on NIF. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of laser-driven Inertial Fusion Energy (IFE. This paper will describe the results achieved so far on the path toward ignition, the beginning of fundamental science experiments and the plans to transition NIF to an international user facility providing access to HEDS and fusion energy researchers around the world.

  14. The NIF: An international high energy density science and inertial fusion user facility

    Science.gov (United States)

    Moses, E. I.; Storm, E.

    2013-11-01

    The National Ignition Facility (NIF), a 1.8-MJ/500-TW Nd:Glass laser facility designed to study inertial confinement fusion (ICF) and high-energy-density science (HEDS), is operational at Lawrence Livermore National Laboratory (LLNL). A primary goal of NIF is to create the conditions necessary to demonstrate laboratory-scale thermonuclear ignition and burn. NIF experiments in support of indirect-drive ignition began late in FY2009 as part of the National Ignition Campaign (NIC), an international effort to achieve fusion ignition in the laboratory. To date, all of the capabilities to conduct implosion experiments are in place with the goal of demonstrating ignition and developing a predictable fusion experimental platform in 2012. The results from experiments completed are encouraging for the near-term achievement of ignition. Capsule implosion experiments at energies up to 1.6 MJ have demonstrated laser energetics, radiation temperatures, and symmetry control that scale to ignition conditions. Of particular importance is the demonstration of peak hohlraum temperatures near 300 eV with overall backscatter less than 15%. Important national security and basic science experiments have also been conducted on NIF. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of laser-driven Inertial Fusion Energy (IFE). This paper will describe the results achieved so far on the path toward ignition, the beginning of fundamental science experiments and the plans to transition NIF to an international user facility providing access to HEDS and fusion energy researchers around the world.

  15. Geothermal Energy Potential in Low Enthalpy Areas as a Future Energy Resource: Identifying Feasible Targets, Quebec, Canada, Study Case

    Directory of Open Access Journals (Sweden)

    Jacek Majorowicz

    2015-07-01

    Full Text Available Heat flow of the sedimentary succession of the Eastern Canada Sedimentary Basins varies from 40 mW/m2 close to the exposed shield in the north to high 60–70 mW/m2 in the southwest–northeast St. Lawrence corridor. As high fluid flow rates are required for a successful geothermal application, the most important targets are deep existing permeable aquifers rather than hard rock, which would need to be fracked. Unfortunately, the ten most populated Québec urban centers are in the areas where the Grenville (Canadian Shield is exposed or at shallow depths with sedimentary cover where temperatures are 30 °C or less. The city of Drummondville will be the exception, as the basement deepens sharply southwest, and higher temperatures reaching >120 °C are expected in the deep Cambrian sedimentary aquifers near a 4–5-km depth. Deep under the area where such sediments could be occurring under Appalachian nappes, temperatures significantly higher than 140 °C are predicted. In parts of the deep basin, temperatures as high as 80 °C–120 °C exist at depths of 3–4 km, mainly southeast of the major geological boundary: the Logan line. There is a large amount of heat resource at such depths to be considered in this area for district heating.

  16. Testing a new NIF neutron time-of-flight detector with a bibenzyl scintillator on OMEGA.

    Science.gov (United States)

    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.

  17. Charged-particle spectroscopy for diagnosing shock ρR and strength in NIF implosions.

    Science.gov (United States)

    Zylstra, A B; Frenje, J A; Séguin, F H; Rosenberg, M J; Rinderknecht, H G; Johnson, M Gatu; Casey, D T; Sinenian, N; Manuel, M J-E; Waugh, C J; Sio, H W; Li, C K; Petrasso, R D; Friedrich, S; Knittel, K; Bionta, R; McKernan, M; Callahan, D; Collins, G W; Dewald, E; Döppner, T; Edwards, M J; Glenzer, S; Hicks, D G; Landen, O L; London, R; Mackinnon, A; Meezan, N; Prasad, R R; Ralph, J; Richardson, M; Rygg, J R; Sepke, S; Weber, S; Zacharias, R; Moses, E; Kilkenny, J; Nikroo, A; Sangster, T C; Glebov, V; Stoeckl, C; Olson, R; Leeper, R J; Kline, J; Kyrala, G; Wilson, D

    2012-10-01

    The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign diagnostic. The WRF measures the spectrum of protons from D-(3)He reactions in tuning-campaign implosions containing D and (3)He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total ρR through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.

  18. Spectroscopic and functional characterization of iron-bound forms of Azotobacter vinelandii (Nif)IscA.

    Science.gov (United States)

    Mapolelo, Daphne T; Zhang, Bo; Naik, Sunil G; Huynh, Boi Hanh; Johnson, Michael K

    2012-10-16

    The ability of Azotobacter vinelandii(Nif)IscA to bind Fe has been investigated to assess the role of Fe-bound forms in NIF-specific Fe-S cluster biogenesis. (Nif)IscA is shown to bind one Fe(III) or one Fe(II) per homodimer and the spectroscopic and redox properties of both the Fe(III)- and Fe(II)-bound forms have been characterized using the UV-visible absorption, circular dichroism, and variable-temperature magnetic circular dichroism, electron paramagnetic resonance, Mössbauer and resonance Raman spectroscopies. The results reveal a rhombic intermediate-spin (S = 3/2) Fe(III) center (E/D = 0.33, D = 3.5 ± 1.5 cm(-1)) that is most likely 5-coordinate with two or three cysteinate ligands and a rhombic high spin (S = 2) Fe(II) center (E/D = 0.28, D = 7.6 cm(-1)) with properties similar to reduced rubredoxins or rubredoxin variants with three cysteinate and one or two oxygenic ligands. Iron-bound (Nif)IscA undergoes reversible redox cycling between the Fe(III)/Fe(II) forms with a midpoint potential of +36 ± 15 mV at pH 7.8 (versus NHE). l-Cysteine is effective in mediating release of free Fe(II) from both the Fe(II)- and Fe(III)-bound forms of (Nif)IscA. Fe(III)-bound (Nif)IscA was also shown to be a competent iron source for in vitro NifS-mediated [2Fe-2S] cluster assembly on the N-terminal domain of NifU, but the reaction occurs via cysteine-mediated release of free Fe(II) rather than direct iron transfer. The proposed roles of A-type proteins in storing Fe under aerobic growth conditions and serving as iron donors for cluster assembly on U-type scaffold proteins or maturation of biological [4Fe-4S] centers are discussed in light of these results.

  19. Expression and characterization of an N-truncated form of the NifA protein of Azospirillum brasilense

    Directory of Open Access Journals (Sweden)

    C.Y. Nishikawa

    2012-02-01

    Full Text Available Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ54 co-factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL. A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study, we have expressed, purified and characterized an N-truncated form of A. brasilense NifA. The protein expression was carried out in Escherichia coli and the N-truncated NifA protein was purified by chromatography using an affinity metal-chelating resin followed by a heparin-bound resin. Protein homogeneity was determined by densitometric analysis. The N-truncated protein activated in vivo nifH::lacZ transcription regardless of fixed nitrogen concentration (absence or presence of 20 mM NH4Cl but only under low oxygen levels. On the other hand, the aerobically purified N-truncated NifA protein bound to the nifB promoter, as demonstrated by an electrophoretic mobility shift assay, implying that DNA-binding activity is not strictly controlled by oxygen levels. Our data show that, while the N-truncated NifA is inactive in vivo under aerobic conditions, it still retains DNA-binding activity, suggesting that the oxidized form of NifA bound to DNA is not competent to activate transcription.

  20. Expression and characterization of an N-truncated form of the NifA protein of Azospirillum brasilense

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, C.Y.; Araújo, L.M.; Kadowaki, M.A.S.; Monteiro, R.A.; Steffens, M.B.R.; Pedrosa, F.O.; Souza, E.M.; Chubatsu, L.S. [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR (Brazil)

    2012-01-27

    Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes) in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ{sup 54} factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL). A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study, we have expressed, purified and characterized an N-truncated form of A. brasilense NifA. The protein expression was carried out in Escherichia coli and the N-truncated NifA protein was purified by chromatography using an affinity metal-chelating resin followed by a heparin-bound resin. Protein homogeneity was determined by densitometric analysis. The N-truncated protein activated in vivo nifH::lacZ transcription regardless of fixed nitrogen concentration (absence or presence of 20 mM NH{sub 4}Cl) but only under low oxygen levels. On the other hand, the aerobically purified N-truncated NifA protein bound to the nifB promoter, as demonstrated by an electrophoretic mobility shift assay, implying that DNA-binding activity is not strictly controlled by oxygen levels. Our data show that, while the N-truncated NifA is inactive in vivo under aerobic conditions, it still retains DNA-binding activity, suggesting that the oxidized form of NifA bound to DNA is not competent to activate transcription.

  1. Expression and characterization of an N-truncated form of the NifA protein of Azospirillum brasilense.

    Science.gov (United States)

    Nishikawa, C Y; Araújo, L M; Kadowaki, M A S; Monteiro, R A; Steffens, M B R; Pedrosa, F O; Souza, E M; Chubatsu, L S

    2012-02-01

    Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes) in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ(54) co-factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL). A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study, we have expressed, purified and characterized an N-truncated form of A. brasilense NifA. The protein expression was carried out in Escherichia coli and the N-truncated NifA protein was purified by chromatography using an affinity metal-chelating resin followed by a heparin-bound resin. Protein homogeneity was determined by densitometric analysis. The N-truncated protein activated in vivo nifH::lacZ transcription regardless of fixed nitrogen concentration (absence or presence of 20 mM NH(4)Cl) but only under low oxygen levels. On the other hand, the aerobically purified N-truncated NifA protein bound to the nifB promoter, as demonstrated by an electrophoretic mobility shift assay, implying that DNA-binding activity is not strictly controlled by oxygen levels. Our data show that, while the N-truncated NifA is inactive in vivo under aerobic conditions, it still retains DNA-binding activity, suggesting that the oxidized form of NifA bound to DNA is not competent to activate transcription.

  2. Expression and characterization of an N-truncated form of the NifA protein of Azospirillum brasilense

    International Nuclear Information System (INIS)

    Nishikawa, C.Y.; Araújo, L.M.; Kadowaki, M.A.S.; Monteiro, R.A.; Steffens, M.B.R.; Pedrosa, F.O.; Souza, E.M.; Chubatsu, L.S.

    2012-01-01

    Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes) in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ 54 factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL). A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study, we have expressed, purified and characterized an N-truncated form of A. brasilense NifA. The protein expression was carried out in Escherichia coli and the N-truncated NifA protein was purified by chromatography using an affinity metal-chelating resin followed by a heparin-bound resin. Protein homogeneity was determined by densitometric analysis. The N-truncated protein activated in vivo nifH::lacZ transcription regardless of fixed nitrogen concentration (absence or presence of 20 mM NH 4 Cl) but only under low oxygen levels. On the other hand, the aerobically purified N-truncated NifA protein bound to the nifB promoter, as demonstrated by an electrophoretic mobility shift assay, implying that DNA-binding activity is not strictly controlled by oxygen levels. Our data show that, while the N-truncated NifA is inactive in vivo under aerobic conditions, it still retains DNA-binding activity, suggesting that the oxidized form of NifA bound to DNA is not competent to activate transcription

  3. NSP2 Target Areas

    Data.gov (United States)

    Department of Housing and Urban Development — The American Recovery and Reinvestment Act (ARRA) provided a second round of funds in 2009. NSP2 provides grants to states, local governments, nonprofits and a...

  4. NSP3 Target Areas

    Data.gov (United States)

    Department of Housing and Urban Development — NSP3 funds authorized under the Dodd–Frank Wall Street Reform and Consumer Protection Act (Dodd-Frank Act) of 2010 provides a third round of neighborhood...

  5. NSP1 Target Areas

    Data.gov (United States)

    Department of Housing and Urban Development — The Housing and Economic Recovery Act (HERA) of 2008 provided a first round of formula funding to States and units of general local government, and is referred to as...

  6. The potential impact of case-area targeted interventions in response to cholera outbreaks: A modeling study.

    Science.gov (United States)

    Finger, Flavio; Bertuzzo, Enrico; Luquero, Francisco J; Naibei, Nathan; Touré, Brahima; Allan, Maya; Porten, Klaudia; Lessler, Justin; Rinaldo, Andrea; Azman, Andrew S

    2018-02-01

    Cholera prevention and control interventions targeted to neighbors of cholera cases (case-area targeted interventions [CATIs]), including improved water, sanitation, and hygiene, oral cholera vaccine (OCV), and prophylactic antibiotics, may be able to efficiently avert cholera cases and deaths while saving scarce resources during epidemics. Efforts to quickly target interventions to neighbors of cases have been made in recent outbreaks, but little empirical evidence related to the effectiveness, efficiency, or ideal design of this approach exists. Here, we aim to provide practical guidance on how CATIs might be used by exploring key determinants of intervention impact, including the mix of interventions, "ring" size, and timing, in simulated cholera epidemics fit to data from an urban cholera epidemic in Africa. We developed a micro-simulation model and calibrated it to both the epidemic curve and the small-scale spatiotemporal clustering pattern of case households from a large 2011 cholera outbreak in N'Djamena, Chad (4,352 reported cases over 232 days), and explored the potential impact of CATIs in simulated epidemics. CATIs were implemented with realistic logistical delays after cases presented for care using different combinations of prophylactic antibiotics, OCV, and/or point-of-use water treatment (POUWT) starting at different points during the epidemics and targeting rings of various radii around incident case households. Our findings suggest that CATIs shorten the duration of epidemics and are more resource-efficient than mass campaigns. OCV was predicted to be the most effective single intervention, followed by POUWT and antibiotics. CATIs with OCV started early in an epidemic focusing on a 100-m radius around case households were estimated to shorten epidemics by 68% (IQR 62% to 72%), with an 81% (IQR 69% to 87%) reduction in cases compared to uncontrolled epidemics. These same targeted interventions with OCV led to a 44-fold (IQR 27 to 78) reduction in

  7. Integrated watershed- and farm-scale modeling framework for targeting critical source areas while maintaining farm economic viability.

    Science.gov (United States)

    Ghebremichael, Lula T; Veith, Tamie L; Hamlett, James M

    2013-01-15

    Quantitative risk assessments of pollution and data related to the effectiveness of mitigating best management practices (BMPs) are important aspects of nonpoint source pollution control efforts, particularly those driven by specific water quality objectives and by measurable improvement goals, such as the total maximum daily load (TMDL) requirements. Targeting critical source areas (CSAs) that generate disproportionately high pollutant loads within a watershed is a crucial step in successfully controlling nonpoint source pollution. The importance of watershed simulation models in assisting with the quantitative assessments of CSAs of pollution (relative to their magnitudes and extents) and of the effectiveness of associated BMPs has been well recognized. However, due to the distinct disconnect between the hydrological scale in which these models conduct their evaluation and the farm scale at which feasible BMPs are actually selected and implemented, and due to the difficulty and uncertainty involved in transferring watershed model data to farm fields, there are limited practical applications of these tools in the current nonpoint source pollution control efforts by conservation specialists for delineating CSAs and planning targeting measures. There are also limited approaches developed that can assess impacts of CSA-targeted BMPs on farm productivity and profitability together with the assessment of water quality improvements expected from applying these measures. This study developed a modeling framework that integrates farm economics and environmental aspects (such as identification and mitigation of CSAs) through joint use of watershed- and farm-scale models in a closed feedback loop. The integration of models in a closed feedback loop provides a way for environmental changes to be evaluated with regard to the impact on the practical aspects of farm management and economics, adjusted or reformulated as necessary, and revaluated with respect to effectiveness of

  8. Laser-Driven Hydrodynamic Experiments in the Turbulent Plasma Regime: from OMEGA to NIF

    International Nuclear Information System (INIS)

    Robey, H F; Miles, A R; Hansen, J F; Blue, B E; Drake, R P

    2003-01-01

    There is a great deal of interest in studying the evolution of hydrodynamic phenomena in high energy density plasmas that have transitioned beyond the initial phases of instability into an Ely developed turbulent state. Motivation for this study arises both in fusion plasmas as well as in numerous astrophysical applications where the understanding of turbulent mixing is essential. Double-shell ignition targets, for example, are subject to large growth of short wavelength perturbations on both surfaces of the high-Z inner shell. These perturbations, initiated by Richtmyer-Meshkov and Rayleigh-Taylor instabilities, can transition to a turbulent state and will lead to deleterious mixing of the cooler shell material with the hot burning fuel. In astrophysical plasmas, due to the extremely large scale, turbulent hydrodynamic mixing is also of wide-spread interest. The radial mixing that occurs in the explosion phase of core-collapse supernovae is an example that has received much attention in recent years and yet remains only poorly understood. In all of these cases, numerical simulation of the flow field is very difficult due to the large Reynolds number and corresponding wide range of spatial scales characterizing the plasma. Laboratory experiments on high energy density facilities that can access this regime are therefore of great interest. Experiments exploring the transition to turbulence that are currently being conducted on the Omega laser will be described. We will also discuss experiments being planned for the initial commissioning phases of the NIF as well as the enhanced experimental parameter space that will become available, as additional quads are made operational

  9. Mutational analysis of GlnB residues critical for NifA activation in Azospirillum brasilense.

    Science.gov (United States)

    Inaba, Juliana; Thornton, Jeremy; Huergo, Luciano Fernandes; Monteiro, Rose Adele; Klassen, Giseli; Pedrosa, Fábio de Oliveira; Merrick, Mike; de Souza, Emanuel Maltempi

    2015-02-01

    PII proteins are signal transduction that sense cellular nitrogen status and relay this signals to other targets. Azospirillum brasilense is a nitrogen fixing bacterium, which associates with grasses and cereals promoting beneficial effects on plant growth and crop yields. A. brasilense contains two PII encoding genes, named glnB and glnZ. In this paper, glnB was mutagenised in order to identify amino acid residues involved in GlnB signaling. Two variants were obtained by random mutagenesis, GlnBL13P and GlnBV100A and a site directed mutant, GlnBY51F, was obtained. Their ability to complement nitrogenase activity of glnB mutant strains of A. brasilense were determined. The variant proteins were also overexpressed in Escherichia coli, purified and characterized biochemically. None of the GlnB variant forms was able to restore nitrogenase activity in glnB mutant strains of A. brasilense LFH3 and 7628. The purified GlnBY51F and GlnBL13P proteins could not be uridylylated by GlnD, whereas GlnBV100A was uridylylated but at only 20% of the rate for wild type GlnB. Biochemical and computational analyses suggest that residue Leu13, located in the α helix 1 of GlnB, is important to maintain GlnB trimeric structure and function. The substitution V100A led to a lower affinity for ATP binding. Together the results suggest that NifA activation requires uridylylated GlnB bound to ATP. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Polyimide capsules may hold high pressure DT fuel without cryogenic support for the National Ignition Facility indirect-drive targets

    International Nuclear Information System (INIS)

    Sanchez, J.J.; Letts, S.A.

    1997-01-01

    New target designs for the Omega upgrade laser and ignition targets in the National Ignition Facility (NIF) require thick (80 - 100 microm) cryogenic fuel layers. The Omega upgrade target will require cryogenic handling after initial fill because of the high fill pressures and the thin capsule walls. For the NIF indirectly driven targets, a larger capsule size and new materials offer hope that they can be built, filled and stored in a manner similar to the targets used in the Nova facility without requiring cryogenic handling

  11. Prospecting direction and favourable target areas for exploration of large and super-large uranium deposits in China

    International Nuclear Information System (INIS)

    Liu Xingzhong

    1993-01-01

    A host of large uranium deposits have been successively discovered abroad by means of geological exploration, metallogenetic model studies and the application of new geophysical and geochemical methods since 1970's. Thorough undertaking geological research relevant to prospecting for super large uranium deposits have attracted great attention of the worldwide geological circle. The important task for the vast numbers of uranium geological workers is to make an afford to discover more numerous large and super large uranium deposits in China. The author comprehensively analyses the regional geological setting and geological metallogenetic conditions for the super large uranium deposits in the world. Comparative studies have been undertaken and the prospecting direction and favourable target areas for the exploration of super large uranium deposits in China have been proposed

  12. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 408: Bomblet Target Area Tonopah Test Range (TTR), Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss

    2010-03-01

    This Streamlined Approach for Environmental Restoration Plan addresses the actions needed to achieve closure of Corrective Action Unit (CAU) 408, Bomblet Target Area (TTR). Corrective Action Unit 408 is located at the Tonopah Test Range and is currently listed in Appendix III of the Federal Facility Agreement and Consent Order. Corrective Action Unit 408 comprises Corrective Action Site TA-55-002-TAB2, Bomblet Target Areas. Clean closure of CAU 408 will be accomplished by removal of munitions and explosives of concern within seven target areas and potential disposal pits. The target areas were used to perform submunitions related tests for the U.S. Department of Energy (DOE). The scope of CAU 408 is limited to submunitions released from DOE activities. However, it is recognized that the presence of other types of unexploded ordnance and munitions may be present within the target areas due to the activities of other government organizations. The CAU 408 closure activities consist of: • Clearing bomblet target areas within the study area. • Identifying and remediating disposal pits. • Collecting verification samples. • Performing radiological screening of soil. • Removing soil containing contaminants at concentrations above the action levels. Based on existing information, contaminants of potential concern at CAU 408 include unexploded submunitions, explosives, Resource Conservation Recovery Act metals, and depleted uranium. Contaminants are not expected to be present in the soil at concentrations above the action levels; however, this will be determined by radiological surveys and verification sample results.

  13. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 408: Bomblet Target Area Tonopah Test Range (TTR), Nevada, Revision 1

    International Nuclear Information System (INIS)

    Krauss, Mark

    2010-01-01

    This Streamlined Approach for Environmental Restoration Plan addresses the actions needed to achieve closure of Corrective Action Unit (CAU) 408, Bomblet Target Area (TTR). Corrective Action Unit 408 is located at the Tonopah Test Range and is currently listed in Appendix III of the Federal Facility Agreement and Consent Order. Corrective Action Unit 408 comprises Corrective Action Site TA-55-002-TAB2, Bomblet Target Areas. Clean closure of CAU 408 will be accomplished by removal of munitions and explosives of concern within seven target areas and potential disposal pits. The target areas were used to perform submunitions related tests for the U.S. Department of Energy (DOE). The scope of CAU 408 is limited to submunitions released from DOE activities. However, it is recognized that the presence of other types of unexploded ordnance and munitions may be present within the target areas due to the activities of other government organizations. The CAU 408 closure activities consist of: (1) Clearing bomblet target areas within the study area. (2) Identifying and remediating disposal pits. (3) Collecting verification samples. (4) Performing radiological screening of soil. (5) Removing soil containing contaminants at concentrations above the action levels. Based on existing information, contaminants of potential concern at CAU 408 include unexploded submunitions, explosives, Resource Conservation Recovery Act metals, and depleted uranium. Contaminants are not expected to be present in the soil at concentrations above the action levels; however, this will be determined by radiological surveys and verification sample results.

  14. A retrospective population-based cohort study identifying target areas for prevention of acute lower respiratory infections in children

    Directory of Open Access Journals (Sweden)

    Richmond Peter

    2010-12-01

    Full Text Available Abstract Background Acute lower respiratory infections (ALRI are a major cause of hospitalisation in young children. Many factors can lead to increased risk of ALRI in children and predispose a child to hospitalisation, but population attributable fractions for different risk factors and how these fractions differ between Indigenous and non-Indigenous children is unknown. This study investigates population attributable fractions of known infant and maternal risk factors for ALRI to inform prevention strategies that target high-risk groups or particular risk factors. Methods A retrospective population-based data linkage study of 245,249 singleton births in Western Australia. Population attributable fractions of known maternal and infant risk factors for hospitalisation with ALRI between 1996 and 2005 were calculated using multiple logistic regression. Results The overall ALRI hospitalisation rate was 16.1/1,000 person-years for non-Aboriginal children and 93.0/1,000 for Aboriginal children. Male gender, being born in autumn, gestational age Conclusions The population attributable fractions estimated in this study should help in guiding public health interventions to prevent ALRI. A key risk factor for all children is maternal smoking during pregnancy, and multiple previous pregnancies and autumnal births are important high-risk groups. Specific key target areas are reducing elective caesareans in non-Aboriginal women and reducing teenage pregnancies and improving access to services and living conditions for the Aboriginal population.

  15. Design of a deuterium and tritium-ablator shock ignition target for the National Ignition Facility

    International Nuclear Information System (INIS)

    Terry, Matthew R.; Perkins, L. John; Sepke, Scott M.

    2012-01-01

    Shock ignition presents a viable path to ignition and high gain on the National Ignition Facility (NIF). In this paper, we describe the development of the 1D design of 0.5 MJ class, all-deuterium and tritium (fuel and ablator) shock ignition target that should be reasonably robust to Rayleigh-Taylor fluid instabilities, mistiming, and hot electron preheat. The target assumes “day one” NIF hardware and produces a yield of 31 MJ with reasonable allowances for laser backscatter, absorption efficiency, and polar drive power variation. The energetics of polar drive laser absorption require a beam configuration with half of the NIF quads dedicated to launching the ignitor shock, while the remaining quads drive the target compression. Hydrodynamic scaling of the target suggests that gains of 75 and yields 70 MJ may be possible.

  16. Summary of Blast Shield and Material Testing for Development of Solid Debris Collection at the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Shaughnessy, D.A.; Gostic, J.M.; Moody, K.J.; Grant, P.M.; Lewis, L.A.; Hutcheon, I.D.

    2011-01-01

    The ability to collect solid debris from the target chamber following a NIF shot has application for both capsule diagnostics, particularly for fuel-ablator mix, and measuring cross sections relevant to the Stockpile Stewardship program and nuclear astrophysics. Simulations have shown that doping the capsule with up to 10 15 atoms of an impurity not otherwise found in the capsule does not affect its performance. The dopant is an element that will undergo nuclear activations during the NIF implosion, forming radioactive species that can be collected and measured after extraction from the target chamber. For diagnostics, deuteron or alpha induced reactions can be used to probe the fuel-ablator mix. For measuring neutron cross sections, the dopant should be something that is sensitive to the 14 MeV neutrons produced through the fusion of deuterium and tritium. Developing the collector is a challenge due to the extreme environment of the NIF chamber. The collector surface is exposed to a large photon flux from x-rays and unconverted laser light before it is exposed to a debris wind that is formed from vaporized material from the target chamber center. The photons will ablate the collector surface to some extent, possibly impeding the debris from reaching the collector and sticking. In addition, the collector itself must be mechanically strong enough to withstand the large amount of energy it will be exposed to, and it should be something that will be easy to count and chemically process. In order to select the best material for the collector, a variety of different metals have been tested in the NIF chamber. They were exposed to high-energy laser shots in order to evaluate their postshot surface characterization, morphology, degree of melt, and their ability to retain debris from the chamber center. The first set of samples consisted of 1 mm thick pieces of aluminum that had been fielded in the chamber as blast shields protecting the neutron activation diagnostic. Ten

  17. Nitrogen Fixation Aligns with nifH Abundance and Expression in Two Coral Trophic Functional Groups

    KAUST Repository

    Pogoreutz, Claudia

    2017-06-28

    Microbial nitrogen fixation (diazotrophy) is a functional trait widely associated with tropical reef-building (scleractinian) corals. While the integral role of nitrogen fixation in coral nutrient dynamics is recognized, its ecological significance across different coral functional groups remains yet to be evaluated. Here we set out to compare molecular and physiological patterns of diazotrophy (i.e., nifH gene abundance and expression as well as nitrogen fixation rates) in two coral families with contrasting trophic strategies: highly heterotrophic, free-living members of the family Fungiidae (Pleuractis granulosa, Ctenactis echinata), and mostly autotrophic coral holobionts with low heterotrophic capacity (Pocilloporidae: Pocillopora verrucosa, Stylophora pistillata). The Fungiidae exhibited low diazotroph abundance (based on nifH gene copy numbers) and activity (based on nifH gene expression and the absence of detectable nitrogen fixation rates). In contrast, the mostly autotrophic Pocilloporidae exhibited nifH gene copy numbers and gene expression two orders of magnitude higher than in the Fungiidae, which coincided with detectable nitrogen fixation activity. Based on these data, we suggest that nitrogen fixation compensates for the low heterotrophic nitrogen uptake in autotrophic corals. Consequently, the ecological importance of diazotrophy in coral holobionts may be determined by the trophic functional group of the host.

  18. Abundance and genetic diversity of nifH gene sequences in anthropogenically affected Brazilian mangrove sediments

    NARCIS (Netherlands)

    Franco Dias, Armando Cavalcante; Pereira e Silva, Michele de Cassia; Cotta, Simone Raposo; Dini Andreote, Francisco; Soares, Fabio Lino; Salles, Joana Falcao; Azevedo, Joao Lucio; van Elsas, Jan Dirk; Andreote, Fernando Dini

    Although mangroves represent ecosystems of global importance, the genetic diversity and abundance of functional genes that are key to their functioning scarcely have been explored. Here, we present a survey based on the nifH gene across transects of sediments of two mangrove systems located along

  19. Nitrogen Fixation Aligns with nifH Abundance and Expression in Two Coral Trophic Functional Groups

    KAUST Repository

    Pogoreutz, Claudia; Radecker, Nils; Cardenas, Anny; Gä rdes, Astrid; Wild, Christian; Voolstra, Christian R.

    2017-01-01

    Microbial nitrogen fixation (diazotrophy) is a functional trait widely associated with tropical reef-building (scleractinian) corals. While the integral role of nitrogen fixation in coral nutrient dynamics is recognized, its ecological significance across different coral functional groups remains yet to be evaluated. Here we set out to compare molecular and physiological patterns of diazotrophy (i.e., nifH gene abundance and expression as well as nitrogen fixation rates) in two coral families with contrasting trophic strategies: highly heterotrophic, free-living members of the family Fungiidae (Pleuractis granulosa, Ctenactis echinata), and mostly autotrophic coral holobionts with low heterotrophic capacity (Pocilloporidae: Pocillopora verrucosa, Stylophora pistillata). The Fungiidae exhibited low diazotroph abundance (based on nifH gene copy numbers) and activity (based on nifH gene expression and the absence of detectable nitrogen fixation rates). In contrast, the mostly autotrophic Pocilloporidae exhibited nifH gene copy numbers and gene expression two orders of magnitude higher than in the Fungiidae, which coincided with detectable nitrogen fixation activity. Based on these data, we suggest that nitrogen fixation compensates for the low heterotrophic nitrogen uptake in autotrophic corals. Consequently, the ecological importance of diazotrophy in coral holobionts may be determined by the trophic functional group of the host.

  20. Precision Cleaning and Protection of Coated Optical Components for NIF Small Optics

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, Jim [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-19

    The purpose of this procedure shall be to define the precision cleaning of finished, coated, small optical components for NIF at Lawrence Livermore National Laboratories. The term “small optical components” includes coated optics that are set into simple mounts, as well as coated, un-mounted optics.

  1. Differential accumulation of nif structural gene mRNA in Azotobacter vinelandii.

    Science.gov (United States)

    Hamilton, Trinity L; Jacobson, Marty; Ludwig, Marcus; Boyd, Eric S; Bryant, Donald A; Dean, Dennis R; Peters, John W

    2011-09-01

    Northern analysis was employed to investigate mRNA produced by mutant strains of Azotobacter vinelandii with defined deletions in the nif structural genes and in the intergenic noncoding regions. The results indicate that intergenic RNA secondary structures effect the differential accumulation of transcripts, supporting the high Fe protein-to-MoFe protein ratio required for optimal diazotrophic growth.

  2. Money and Politics: Who Owns Democracy? NIF Report on the Issues, 2001.

    Science.gov (United States)

    National Issues Forums, Dayton, OH.

    National Issues Forums (NIF) bring together citizens to deliberate and make choices about challenging social and political issues of the day. These forums have addressed issues such as the economy, education, health care, foreign affairs, and crime. This report is an analysis of what happened in a forum on "Money and Politics" that took…

  3. In silico characterization and transcriptomic analysis of nif family genes from Anabaena sp. PCC7120.

    Science.gov (United States)

    Singh, Shilpi; Shrivastava, Alok Kumar

    2017-10-01

    In silico approaches in conjunction with morphology, nitrogenase activity, and qRT-PCR explore the impact of selected abiotic stressor such as arsenic, salt, cadmium, copper, and butachlor on nitrogen fixing (nif family) genes of diazotrophic cyanobacterium Anabaena sp. PCC7120. A total of 19 nif genes are present within the Anabaena genome that is involved in the process of nitrogen fixation. Docking studies revealed the interaction between these nif gene-encoded proteins and the selected abiotic stressors which were further validated through decreased heterocyst frequency, fragmentation of filaments, and downregulation of nitrogenase activity under these stresses indicating towards their toxic impact on nitrogen fixation potential of filamentous cyanobacterium Anabaena sp. PCC7120. Another appealing finding of this study is even though having similar binding energy and similar interacting residues between arsenic/salt and copper/cadmium to nif-encoded proteins, arsenic and cadmium are more toxic than salt and copper for nitrogenase activity of Anabaena which is crucial for growth and yield of rice paddy and soil reclamation.

  4. NifI inhibits nitrogenase by competing with Fe protein for binding to the MoFe protein

    International Nuclear Information System (INIS)

    Dodsworth, Jeremy A.; Leigh, John A.

    2007-01-01

    Reduction of substrate by nitrogenase requires direct electron transfer from the Fe protein to the MoFe protein. Inhibition of nitrogenase activity in Methanococcus maripaludis occurs when the regulatory protein NifI 1,2 binds the MoFe protein. This inhibition is relieved by 2-oxoglutarate. Here we present evidence that NifI 1,2 binding prevents association of the two nitrogenase components. Increasing amounts of Fe protein competed with NifI 1,2 , decreasing its inhibitory effect. NifI 1,2 prevented the co-purification of MoFe protein with a mutant form of the Fe protein that forms a stable complex with the MoFe protein, and NifI 1,2 was unable to bind to an AlF 4 - -stabilized Fe protein:MoFe protein complex. NifI 1,2 inhibited ATP- and MoFe protein-dependent oxidation of the Fe protein, and 2OG relieved this inhibition. These results support a model where NifI 1,2 competes with the Fe protein for binding to MoFe protein and prevents electron transfer

  5. Technology strategy for cost-effective drilling and intervention; Technology Target Areas; TTA4 - Cost effective drilling and intervention

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    The main goals of the OG21 initiative are to (1) develop new technology and knowledge to increase the value creation of Norwegian oil and gas resources and (2) enhance the export of Norwegian oil and gas technology. The OG21 Cost-effective Drilling and Intervention (CEDI) Technology Target Area (TTA) has identified some key strategic drilling and well intervention needs to help meet the goals of OG21. These key strategic drilling and well intervention needs are based on a review of present and anticipated future offshore-Norway drilling and well intervention conditions and the Norwegian drilling and well intervention industry. A gap analysis has been performed to assess the extent to which current drilling and well intervention research and development and other activities will meet the key strategic needs. Based on the identified strategic drilling and well intervention needs and the current industry res each and development and other activities, the most important technology areas for meeting the OG21 goals are: environment-friendly and low-cost exploration wells; low-cost methods for well intervention/sidetracks; faster and extended-reach drilling; deep water drilling, completion and intervention; offshore automated drilling; subsea and sub-ice drilling; drilling through basalt and tight carbonates; drilling and completion in salt formation. More specific goals for each area: reduce cost of exploration wells by 50%; reduce cost for well intervention/sidetracks by 50%; increase drilling efficiency by 40%; reduce drilling cost in deep water by 40 %; enable offshore automated drilling before 2012; enable automated drilling from seabed in 2020. Particular focus should be placed on developing new technology for low-cost exploration wells to stem the downward trends in the number of exploration wells drilled and the volume of discovered resources. The CEDI TTA has the following additional recommendations: The perceived gaps in addressing the key strategic drilling and

  6. Upgrade of the MIT Linear Electrostatic Ion Accelerator (LEIA) for nuclear diagnostics development for Omega, Z and the NIF.

    Science.gov (United States)

    Sinenian, N; Manuel, M J-E; Zylstra, A B; Rosenberg, M; Waugh, C J; Rinderknecht, H G; Casey, D T; Sio, H; Ruszczynski, J K; Zhou, L; Gatu Johnson, M; Frenje, J A; Séguin, F H; Li, C K; Petrasso, R D; Ruiz, C L; Leeper, R J

    2012-04-01

    The MIT Linear Electrostatic Ion Accelerator (LEIA) generates DD and D(3)He fusion products for the development of nuclear diagnostics for Omega, Z, and the National Ignition Facility (NIF). Significant improvements to the system in recent years are presented. Fusion reaction rates, as high as 10(7) s(-1) and 10(6) s(-1) for DD and D(3)He, respectively, are now well regulated with a new ion source and electronic gas control system. Charged fusion products are more accurately characterized, which allows for better calibration of existing nuclear diagnostics. In addition, in situ measurements of the on-target beam profile, made with a CCD camera, are used to determine the metrology of the fusion-product source for particle-counting applications. Finally, neutron diagnostics development has been facilitated by detailed Monte Carlo N-Particle Transport (MCNP) modeling of neutrons in the accelerator target chamber, which is used to correct for scattering within the system. These recent improvements have resulted in a versatile platform, which continues to support the existing nuclear diagnostics while simultaneously facilitating the development of new diagnostics in aid of the National Ignition Campaign at the National Ignition Facility. © 2012 American Institute of Physics

  7. Electroplating Gold-Silver Alloys for Spherical Capsules for NIF Double-Shell Targets

    Energy Technology Data Exchange (ETDEWEB)

    Bhandarkar, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Horwood, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bunn, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stadermann, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-08-17

    For Inertial Confinement Fusion (ICF) implosions, a design based on gradients of high and mid Z materials could potentially be more robust than single element capsule systems. To that end, gold and silver alloys were electroplated on 2.0 mm diameter surrogate brass spheres using a new flow–based pulsed plating method specifically designed to minimize surface roughness without reducing plating rates. The coatings were analyzed by scanning electron microscope (SEM) and white light interferometry for surface topography, and by energy dispersive x-ray spectroscopy (EDX) to determine near-surface gold and silver compositions. The alloy range attainable was 15 to 85 weight percent gold using 1:1 and 1:3 silver to gold ratio plating baths at applied potentials of -0.7 volts to -1.8 volts. This range was bounded by the open circuit potential of the system and hydrogen evolution, and in theory could be extended by using ionic liquids or aprotic solutions. Preliminary gradient trials proved constant composition alloy data could be translated to smooth gradient plating, albeit at higher gold compositions.

  8. Behavior-Dependent Activity and Synaptic Organization of Septo-hippocampal GABAergic Neurons Selectively Targeting the Hippocampal CA3 Area.

    Science.gov (United States)

    Joshi, Abhilasha; Salib, Minas; Viney, Tim James; Dupret, David; Somogyi, Peter

    2017-12-20

    Rhythmic medial septal (MS) GABAergic input coordinates cortical theta oscillations. However, the rules of innervation of cortical cells and regions by diverse septal neurons are unknown. We report a specialized population of septal GABAergic neurons, the Teevra cells, selectively innervating the hippocampal CA3 area bypassing CA1, CA2, and the dentate gyrus. Parvalbumin-immunopositive Teevra cells show the highest rhythmicity among MS neurons and fire with short burst duration (median, 38 ms) preferentially at the trough of both CA1 theta and slow irregular oscillations, coincident with highest hippocampal excitability. Teevra cells synaptically target GABAergic axo-axonic and some CCK interneurons in restricted septo-temporal CA3 segments. The rhythmicity of their firing decreases from septal to temporal termination of individual axons. We hypothesize that Teevra neurons coordinate oscillatory activity across the septo-temporal axis, phasing the firing of specific CA3 interneurons, thereby contributing to the selection of pyramidal cell assemblies at the theta trough via disinhibition. VIDEO ABSTRACT. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Amylin and GLP-1 target different populations of area postrema neurons that are both modulated by nutrient stimuli.

    Science.gov (United States)

    Züger, Daniela; Forster, Karoline; Lutz, Thomas A; Riediger, Thomas

    2013-03-15

    The area postrema mediates the hypophagic effect of the pancreatic hormone amylin and is also sensitive to glucagon-like peptide 1 (GLP-1). Protein seems to modulate amylin responsiveness because amylin seems to produce a stronger hypophagic effect and a stronger c-Fos expression when protein is absent from the diet. Accordingly, amylin induces a stronger c-Fos expression in the AP when injected in fasted compared to ad libitum fed rats. Here we tested the hypothesis that diet-derived protein attenuates the amylin dependent suppression of feeding and AP activation using isocaloric diets that differed in their protein content. Moreover, we investigated whether peripheral amino acid injection attenuates amylin-induced c-Fos expression in fasted rats. Since recent evidence suggests that GLP-1 may also reduce eating via the AP we tested whether 24 h fasting also increases neuronal AP responsiveness to GLP-1 similar to the fasting-induced increase in amylin responsiveness. Finally, we used the calcitonin receptor (CTR) as an immunohistochemical marker for amylin-receptive AP neurons to investigate whether amylin's target neurons differ from GLP-1 responsive AP neurons. We also dissociated amylin responsive cells from neurons implicated in other AP-mediated functions such as aversion or blood pressure regulation. For this purpose, we conducted c-Fos/CTR double staining after LiCl or angiotensin II treatment, respectively. Amylin (5 μg/kg s.c.) was more effective to reduce the intake of a 1% vs. an 8% or 18% protein diet and to induce c-Fos expression in the AP in rats receiving 1% vs. 18% protein diet. Increased protein intake was associated with increased blood amino acid levels. Peripheral injection of amino acids (1 g/kg i.p.) attenuated the amylin-induced AP activation in 24 h fasted rats. Similar to amylin, GLP-1 (100 μg/kg i.p.) elicited a significant c-Fos response only in fasted but not in ad libitum fed rats. However, in contrast to a high co-localization of

  10. Los Alamos contribution to target diagnostics on the National Ignition Facility

    International Nuclear Information System (INIS)

    Mack, J.M.; Baker, D.A.; Caldwell, S.E.

    1994-01-01

    The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ''phase I diagnostics.'' Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given

  11. Los Alamos contribution to target diagnostics on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Mack, J.M.; Baker, D.A.; Caldwell, S.E. [and others

    1994-07-01

    The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ``phase I diagnostics.`` Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given.

  12. The NifA-RpoN regulon of Mesorhizobium loti strain R7A and its symbiotic activation by a novel LacI/GalR-family regulator.

    Directory of Open Access Journals (Sweden)

    John T Sullivan

    Full Text Available Mesorhizobium loti is the microsymbiont of Lotus species, including the model legume L. japonicus. M. loti differs from other rhizobia in that it contains two copies of the key nitrogen fixation regulatory gene nifA, nifA1 and nifA2, both of which are located on the symbiosis island ICEMlSym(R7A. M. loti R7A also contains two rpoN genes, rpoN1 located on the chromosome outside of ICEMlSym(R7A and rpoN2 that is located on ICEMlSym(R7A. The aims of the current work were to establish how nifA expression was activated in M. loti and to characterise the NifA-RpoN regulon. The nifA2 and rpoN2 genes were essential for nitrogen fixation whereas nifA1 and rpoN1 were dispensable. Expression of nifA2 was activated, possibly in response to an inositol derivative, by a novel regulator of the LacI/GalR family encoded by the fixV gene located upstream of nifA2. Other than the well-characterized nif/fix genes, most NifA2-regulated genes were not required for nitrogen fixation although they were strongly expressed in nodules. The NifA-regulated nifZ and fixU genes, along with nifQ which was not NifA-regulated, were required in M. loti for a fully effective symbiosis although they are not present in some other rhizobia. The NifA-regulated gene msi158 that encodes a porin was also required for a fully effective symbiosis. Several metabolic genes that lacked NifA-regulated promoters were strongly expressed in nodules in a NifA2-dependent manner but again mutants did not have an overt symbiotic phenotype. In summary, many genes encoded on ICEMlSym(R7A were strongly expressed in nodules but not free-living rhizobia, but were not essential for symbiotic nitrogen fixation. It seems likely that some of these genes have functional homologues elsewhere in the genome and that bacteroid metabolism may be sufficiently plastic to adapt to loss of certain enzymatic functions.

  13. Fnr is involved in oxygen control of Herbaspirillum seropedicae N-truncated NifA protein activity in Escherichia coli.

    Science.gov (United States)

    Monteiro, Rose A; de Souza, Emanuel M; Yates, M Geoffrey; Pedrosa, Fabio O; Chubatsu, Leda S

    2003-03-01

    Herbaspirillum seropedicae is an endophytic diazotroph belonging to the beta-subclass of the class Proteobacteria, which colonizes many members of the Gramineae. The activity of the NifA protein, a transcriptional activator of nif genes in H. seropedicae, is controlled by ammonium ions through its N-terminal domain and by oxygen through mechanisms that are not well understood. Here we report that the NifA protein of H. seropedicae is inactive and more susceptible to degradation in an fnr Escherichia coli background. Both effects correlate with oxygen exposure and iron deprivation. Our results suggest that the oxygen sensitivity and iron requirement for H. seropedicae NifA activity involve the Fnr protein.

  14. Molybdenum x-ray absorption studies of the mutant Kp nifV of nitrogenase MO-FE protein

    International Nuclear Information System (INIS)

    Eidsness, M.K.; Smith, B.E.; Flood, A.C.; Garner, C.D.; Cramer, S.P.

    1985-01-01

    The nifV mutant nitrogenase enzyme of Klebsiella pheumoniae exhibits altered substrate reducing activity. This nitrogenase mutant cannot fix N 2 in vivo but can reduce C 2 H 2 to C 2 H 4 . The nifV mutant enzyme differs further from the wild-type enzyme by CO inhibition of its H 2 evolution activity, up to 80%. The NifV - phenotype (NifV - Kp1) has been shown to be associated with the iron-molybdenum cofactor (FeMoco) in the Mo Fe protein which is generally accepted as the site for substrate reduction. An X-Ray absorption study of the Mo site in this mutant may reveal a difference in its FeMoco structure. The authors report here a comparison of Mo X-Ray absorption data from the nitrogenase enzymes of the wild-type and NifV - strains in three different forms: (1) as isolated, (2) dye-oxidized, and (3) fixing enzyme systems. Mo edge structure of NifV - Kp1 and wild-type enzymes are nearly identical. Small shifts to higher energies are observed in the oxidized and fixing states. Mo EXAFS of NifV - Kp1 and wild-type in the ''as isolated'' state appear indistinguishable. Curve fitting results best describe the molybdenum in FeMoco as bound by 4-5 S atoms at 2.36 A ,3 Fe atoms at 2.69 A, and 0-2 O(N) atoms at 2.19 A. The spectral similarity of these results concerning the nifV mutant FeMoco structure is discussed

  15. Larval abundances of rockfishes that were historically targeted by fishing increased over 16 years in association with a large marine protected area.

    Science.gov (United States)

    Thompson, Andrew R; Chen, Dustin C; Guo, Lian W; Hyde, John R; Watson, William

    2017-09-01

    Marine protected areas (MPAs) can facilitate recovery of diminished stocks by protecting reproductive adults. To effectively augment fisheries, however, reproductive output must increase within the bounds of MPAs so that larvae can be exported to surrounding areas and seed the region. In response to dramatic declines of rockfishes ( Sebastes spp.) in southern California by the late 1990s two large MPAs, the Cowcod Conservation Areas (CCAs), were established in 2001. To evaluate whether the CCAs affected rockfish productivity we evaluated the dynamics of 8 species that were, and 7 that were not, historically targeted by fishing. Abundances of 6/8 targeted and 4/7 non-targeted species increased regionally from 1998 to 2013. These upturns were probably affected by environmental conditions in addition to changes in fishing pressure as the presence of most species correlated negatively with temperature, and temperature was lower than the historic average in 11/15 years. Seventy-five per cent of the targeted, but none of the non-targeted species increased at a greater rate inside than outside the CCAs while controlling for environmental factors. Results indicate that management actions, coupled with favourable environmental conditions, facilitated the resurgence of multiple rockfish species that were targeted by intense fishing effort for decades.

  16. Functional participation of a nifH-arsA2 chimeric fusion gene in arsenic reduction by Escherichia coli

    International Nuclear Information System (INIS)

    Lahiri, Surobhi; Pulakat, Lakshmi; Gavini, Nara

    2008-01-01

    The NifH (dimer) and ArsA proteins are structural homologs and share common motifs like nucleotide-binding domains, signal transduction domains and also possible similar metal center ligands. Given the similarity between two proteins, we investigated if the NifH protein from Azotobacter vinelandii could functionally substitute for the ArsA1 half of the ArsA protein of Escherichia coli. The chimeric NifH-ArsA2 protein was expressed and detected in the E. coli strain by Western blotting. Growth comparisons of E. coli strains containing plasmids encoding for complete ArsA, partial ArsA (ArsA2) or chimeric ArsA (NifH-ArsA2) in media with increasing sodium arsenite concentrations (0-5 mM) showed that the chimeric NifH-ArsA2 could substitute for the ArsA. This functional complementation demonstrated the strong conservation of essential domains that have been maintained in NifH and ArsA even after their divergence to perform varied functions

  17. Organization of nif gene cluster in Frankia sp. EuIK1 strain, a symbiont of Elaeagnus umbellata.

    Science.gov (United States)

    Oh, Chang Jae; Kim, Ho Bang; Kim, Jitae; Kim, Won Jin; Lee, Hyoungseok; An, Chung Sun

    2012-01-01

    The nucleotide sequence of a 20.5-kb genomic region harboring nif genes was determined and analyzed. The fragment was obtained from Frankia sp. EuIK1 strain, an indigenous symbiont of Elaeagnus umbellata. A total of 20 ORFs including 12 nif genes were identified and subjected to comparative analysis with the genome sequences of 3 Frankia strains representing diverse host plant specificities. The nucleotide and deduced amino acid sequences showed highest levels of identity with orthologous genes from an Elaeagnus-infecting strain. The gene organization patterns around the nif gene clusters were well conserved among all 4 Frankia strains. However, characteristic features appeared in the location of the nifV gene for each Frankia strain, depending on the type of host plant. Sequence analysis was performed to determine the transcription units and suggested that there could be an independent operon starting from the nifW gene in the EuIK strain. Considering the organization patterns and their total extensions on the genome, we propose that the nif gene clusters remained stable despite genetic variations occurring in the Frankia genomes.

  18. Technology strategy for integrated operations and real time reservoir management; Technology Target Areas; TTA5 - Integrated operations and RTRM

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    In Norway Integrated Operations (IO) is a concept which in the first phase (G1) has been used to describe how to integrate processes and people onshore and offshore using ICT solutions and facilities that improve onshore's ability to support offshore operationally. The second generation (G2) Integrated Operations aims to help operators utilize vendors' core competencies and services more efficiently. Utilizing digital services and vendor products, operators will be able to update reservoir models, drilling targets and well trajectories as wells are drilled, manage well completions remotely, optimize production from reservoir to export lines, and implement condition-based maintenance concepts. The total impact on production, recovery rates, costs and safety will be profound. When the international petroleum business moves to the Arctic region the setting is very different from what is the case on the Norwegian Continental Shelf (NCS) and new challenges will arise. The Norwegian Ministry of Environment has recently issued an Integrated Management Plan for the Barents Sea where one focus is on 'Monitoring of the Marine Environment in the North'. The Government aims to establish a new and more coordinated system for monitoring the marine ecosystems in the north. A representative group consisting of the major Operators, the Service Industry, Academia and the Authorities have developed the enclosed strategy for the OG21 Integrated Operations and Real Time Reservoir Management (IO and RTRM) Technology Target Area (TTA). Major technology and work process research and development gaps have been identified in several areas: Bandwidth down-hole to surface; Sensor development including Nano-technology; Cross discipline use of Visualisation, Simulation and model development particularly in Drilling and Reservoir management areas; Software development in terms of data handling, model updating and calculation speed; Enabling reliable and robust communications particularly for

  19. Technology strategy for integrated operations and real time reservoir management; Technology Target Areas; TTA5 - Integrated operations and RTRM

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    In Norway Integrated Operations (IO) is a concept which in the first phase (G1) has been used to describe how to integrate processes and people onshore and offshore using ICT solutions and facilities that improve onshore's ability to support offshore operationally. The second generation (G2) Integrated Operations aims to help operators utilize vendors' core competencies and services more efficiently. Utilizing digital services and vendor products, operators will be able to update reservoir models, drilling targets and well trajectories as wells are drilled, manage well completions remotely, optimize production from reservoir to export lines, and implement condition-based maintenance concepts. The total impact on production, recovery rates, costs and safety will be profound. When the international petroleum business moves to the Arctic region the setting is very different from what is the case on the Norwegian Continental Shelf (NCS) and new challenges will arise. The Norwegian Ministry of Environment has recently issued an Integrated Management Plan for the Barents Sea where one focus is on 'Monitoring of the Marine Environment in the North'. The Government aims to establish a new and more coordinated system for monitoring the marine ecosystems in the north. A representative group consisting of the major Operators, the Service Industry, Academia and the Authorities have developed the enclosed strategy for the OG21 Integrated Operations and Real Time Reservoir Management (IO and RTRM) Technology Target Area (TTA). Major technology and work process research and development gaps have been identified in several areas: Bandwidth down-hole to surface; Sensor development including Nano-technology; Cross discipline use of Visualisation, Simulation and model development particularly in Drilling and Reservoir management areas; Software development in terms of data handling, model updating and calculation speed; Enabling reliable and robust communications

  20. National Ignition Facility Cryogenic Target Systems Interim Management Plan

    International Nuclear Information System (INIS)

    Warner, B

    2002-01-01

    Restricted availability of funding has had an adverse impact, unforeseen at the time of the original decision to projectize the National Ignition Facility (NIF) Cryogenic Target Handling Systems (NCTS) Program, on the planning and initiation of these efforts. The purpose of this document is to provide an interim project management plan describing the organizational structure and management processes currently in place for NCTS. Preparation of a Program Execution Plan (PEP) for NCTS has been initiated, and a current draft is provided as Attachment 1 to this document. The National Ignition Facility is a multi-megajoule laser facility being constructed at Lawrence Livermore National Laboratory (LLNL) by the National Nuclear Security Administration (NNSA) in the Department of Energy (DOE). Its primary mission is to support the Stockpile Stewardship Program (SSP) by performing experiments studying weapons physics, including fusion ignition. NIF also supports the missions of weapons effects, inertial fusion energy, and basic science in high-energy-density physics. NIF will be operated by LLNL under contract to the University of California (UC) as a national user facility. NIF is a low-hazard, radiological facility, and its operation will meet all applicable federal, state, and local Environmental Safety and Health (ES and H) requirements. The NCTS Interim Management Plan provides a summary of primary design criteria and functional requirements, current organizational structure, tracking and reporting procedures, and current planning estimates of project scope, cost, and schedule. The NIF Director controls the NIF Cryogenic Target Systems Interim Management Plan. Overall scope content and execution schedules for the High Energy Density Physics Campaign (SSP Campaign 10) are currently undergoing rebaselining and will be brought into alignment with resources expected to be available throughout the NNSA Future Years National Security Plan (FYNSP). The revised schedule for

  1. Identification of the target areas to be resected in patients with non-bullous emphysema by using gas and perfusion SPECT images

    International Nuclear Information System (INIS)

    Sugi, Kazuro; Ueda, Kazuhiro; Fujita, Nobuhiro; Nawata, Kouichi; Kaneda, Yoshikazu; Nawata, Sumihiko; Esato, Kensuke

    1997-01-01

    Significant improvement of pulmonary function after the volume reduction surgery has been reported in patients with bullous emphysema. However, there has been no successful report in patients with non-bullous emphysema. The reason of failure in patients with non-bullous emphysema should lie mainly on the difficulty to identify the target areas to be resected. We describe how to identify the target areas in the patients with non-bullous emphysema by using gas and perfusion single-photon emission computed tomography (SPECT). Twelve patients with non-bullous emphysema were studied by 133 Xe gas and 99m Tc MAA SPECT, which revealed that abnormal retention and low perfusion areas were located in the apex of the upper lobe and the basal segment of the lower lobe. The resections were performed thoracoscopically focused on the target areas by hockey-stick shape resection in the upper lobe and spiral shape resection in the lower lobe without deformity formation of the residual lung. Slight but significant improvement in the pulmonary functions was observed after the surgery in patients with non-bullous emphysema. The Xe gas and Tc MAA SPECT were useful procedures to identify the target areas to be resected in patients with non-bullous emphysema. (author)

  2. Gain measurements on a prototype NIF/LMJ amplifier pump cavity

    International Nuclear Information System (INIS)

    Rotter, M.D.; McCracken, R.; Erlandson, A.; Guenet, M.

    1996-12-01

    We are currently developing large-aperture amplifiers for the National Ignition Facility (NIF) and Laser Megajoules (LMJ) lasers. These multisegment amplifiers are of the flashlamp-pumped, Nd:Glass qW and are designed to propagate a nominally 36 cm square beam. The apertures within a particular amplifier bundle are arranged in a four-high by two-wide configuration and utilize two side lamp arrays and a central flashlamp array for pumping. The configuration is very similar to that used in the Beamlet laser, a single-beam prototype for the NIF/LMJ lasers, which has four apertures arranged in a two- high by two-wide configuration

  3. Sensitivity of Inferred Electron Temperature from X-ray Emission of NIF Cryogenic DT Implosions

    Energy Technology Data Exchange (ETDEWEB)

    Klem, Michael [Univ. of Dallas, Irving, TX (United States)

    2015-05-01

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory seeks to achieve thermonuclear ignition through inertial confinement fusion. The accurate assessment of the performance of each implosion experiment is a crucial step. Here we report on work to derive a reliable electron temperature for the cryogenic deuteriumtritium implosions completed on the NIF using the xray signal from the Ross filter diagnostic. These Xrays are dominated by bremsstrahlung emission. By fitting the xray signal measured through each of the individual Ross filters, the source bremsstrahlung spectrum can be inferred, and an electron temperature of the implosion hot spot inferred. Currently, each filter is weighted equally in this analysis. We present work quantifying the errors with such a technique and the results from investigating the contribution of each filter to the overall accuracy of the temperature inference. Using this research, we also compare the inferred electron temperature against other measured implosion quantities to develop a more complete understanding of the hotspot physics.

  4. Precision Neutron Time-of-Flight Detectors Provide Insight into NIF Implosion Dynamics

    Science.gov (United States)

    Schlossberg, David; Eckart, M. J.; Grim, G. P.; Hartouni, E. P.; Hatarik, R.; Moore, A. S.; Waltz, C. S.

    2017-10-01

    During inertial confinement fusion, higher-order moments of neutron time-of-flight (nToF) spectra can provide essential information for optimizing implosions. The nToF diagnostic suite at the National Ignition Facility (NIF) was recently upgraded to include novel, quartz Cherenkov detectors. These detectors exploit the rapid Cherenkov radiation process, in contrast with conventional scintillator decay times, to provide high temporal-precision measurements that support higher-order moment analyses. Preliminary measurements have been made on the NIF during several implosions and initial results are presented here. Measured line-of-sight asymmetries, for example in ion temperatures, will be discussed. Finally, advanced detector optimization is shown to advance accessible physics, with possibilities for energy discrimination, gamma source identification, and further reduction in quartz response times. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  5. Neutron peak velocity measurements at the National Ignition Facility (NIF) using novel quartz detectors

    Science.gov (United States)

    Grim, Gary; Eckart, Mark; Hartouni, Edward; Hatarik, Robert; Moore, Alastair; Root, Jaben; Sayre, Daniel; Schlossberg, David; Waltz, Cory

    2017-10-01

    In mid-2017 the NIF implemented quartz based neutron time-of-flight (nToF) detectors which have a faster and narrower impulse response function (IRF) relative to traditional scintillator detectors. In this presentation we report on comparisons between fusion neutron first moments as measured by quartz and scintillator based detectors using DT layered implosions at the NIF. We report on the change in precision presaged by the quartz converter and quantify the change in both in shot, line-of-site velocity variability. as well as, shot-to-shot variation. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. LLNL-ABS-734511-DRAFT.

  6. The MIT HEDP Accelerator Facility for education and advanced diagnostics development for OMEGA, Z and the NIF

    Science.gov (United States)

    Petrasso, R.; Gatu Johnson, M.; Armstrong, E.; Han, H. W.; Kabadi, N.; Lahmann, B.; Orozco, D.; Rojas Herrera, J.; Sio, H.; Sutcliffe, G.; Frenje, J.; Li, C. K.; Séguin, F. H.; Leeper, R.; Ruiz, C. L.; Sangster, T. C.

    2015-11-01

    The MIT HEDP Accelerator Facility utilizes a 135-keV linear electrostatic ion accelerator, a D-T neutron source and two x-ray sources for development and characterization of nuclear diagnostics for OMEGA, Z, and the NIF. The ion accelerator generates D-D and D-3He fusion products through acceleration of D ions onto a 3He-doped Erbium-Deuteride target. Fusion reaction rates around 106 s-1 are routinely achieved, and fluence and energy of the fusion products have been accurately characterized. The D-T neutron source generates up to 6 × 108 neutrons/s. The two x-ray generators produce spectra with peak energies of 35 keV and 225 keV and maximum dose rates of 0.5 Gy/min and 12 Gy/min, respectively. Diagnostics developed and calibrated at this facility include CR-39 based charged-particle spectrometers, neutron detectors, and the particle Time-Of-Flight (pTOF) and Magnetic PTOF CVD-diamond-based bang time detectors. The accelerator is also a vital tool in the education of graduate and undergraduate students at MIT. This work was supported in part by SNL, DOE, LLE and LLNL.

  7. NIF-Scale Hohlraum Asymmetry Studies Using Point-Projection Radiograph of Thin Shells

    International Nuclear Information System (INIS)

    Pollaine, S.; Bradley, D.; Landen, O.; Wallace, R.; Jones, O.

    2000-01-01

    Our current OMEGA experimental campaign is developing the thin shell diagnostic for use on NIF with the needed accuracy. The thin shell diagnostic has the advantage of linearity over alternative measurement techniques, so that low-order modes will not corrupt the measurement of high-order modes. Although our random measurement errors are adequate, we need to monitor beam balance and ensure that the thin shells have a uniform thickness

  8. An aerial radiological survey of the Tonopah Test Range including Clean Slate 1,2,3, Roller Coaster, decontamination area, Cactus Springs Ranch target areas. Central Nevada

    International Nuclear Information System (INIS)

    Proctor, A.E.; Hendricks, T.J.

    1995-08-01

    An aerial radiological survey was conducted of major sections of the Tonopah Test Range (TTR) in central Nevada from August through October 1993. The survey consisted of aerial measurements of both natural and man-made gamma radiation emanating from the terrestrial surface. The initial purpose of the survey was to locate depleted uranium (detecting 238 U) from projectiles which had impacted on the TTR. The examination of areas near Cactus Springs Ranch (located near the western boundary of the TTR) and an animal burial area near the Double Track site were secondary objectives. When more widespread than expected 241 Am contamination was found around the Clean Slates sites, the survey was expanded to cover the area surrounding the Clean Slates and also the Double Track site. Results are reported as radiation isopleths superimposed on aerial photographs of the area

  9. AXIS: An instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Tommasini, R.; Carpenter, A. C.; Palmer, N. E.; Zacharias, R.; Felker, B.; Holder, J. P.; Allen, F. V.; Bell, P. M.; Bradley, D.; Montesanti, R.; Landen, O. L. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

    2014-11-15

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  10. ORGANIZATION OF THE nif GENES OF THE NONHETEROCYSTOUS CYANOBACTERIUM TRICHODESMIUM SP. IMS101.

    Science.gov (United States)

    Dominic, Benny; Zani, Sabino; Chen, Yi-Bu; Mellon, Mark T; Zehr, Jonathan P

    2000-08-26

    An approximately 16-kb fragment of the Trichodesmium sp. IMS101 (a nonheterocystous filamentous cyanobacterium) "conventional"nif gene cluster was cloned and sequenced. The gene organization of the Trichodesmium and Anabaena variabilis vegetative (nif 2) nitrogenase gene clusters spanning the region from nif B to nif W are similar except for the absence of two open reading frames (ORF3 and ORF1) in Trichodesmium. The Trichodesmium nif EN genes encode a fused Nif EN polypeptide that does not appear to be processed into individual Nif E and Nif N polypeptides. Fused nif EN genes were previously found in the A. variabilis nif 2 genes, but we have found that fused nif EN genes are widespread in the nonheterocystous cyanobacteria. Although the gene organization of the nonheterocystous filamentous Trichodesmium nif gene cluster is very similar to that of the A. variabilis vegetative nif 2 gene cluster, phylogenetic analysis of nif sequences do not support close relatedness of Trichodesmium and A. variabilis vegetative (nif 2) nitrogenase genes.

  11. AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

    Science.gov (United States)

    Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

    2014-11-01

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  12. An exploration of Lasnex designs to support the MShock campaign at NIF

    Energy Technology Data Exchange (ETDEWEB)

    DeVolder, Barbara Gloria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-11

    In support of planned MShock experiments at NIF, Lasnex is being used to explore possible laser sources and halfraum designs that launch two shocks into an ablator - shock tube configuration. Two design features were investigated: (1) launching a two-component laser source consisting of an early pre-pulse separated in time from a later main pulse, to create two shocks, and (2) adding a liner on the inner surface of the gold wall of the halfraum, to delay or prevent gold stagnation on-axis and to preserve the effectiveness of the second laser pulse. The clearest indication of two shocks propagating in the shock tube occurred when the pre-pulse mimicked a direct drive, achieved by re-pointing the inner beam cones, and when a liner was used to ensure that the free-electron number density was below the critical density for NIF. Additional simulations (presented in the Appendix) that used the two-component laser source but focused on specific choices in laser-pulse design space, as proposed by Kirk Flippo for use in the first MShock experiments at NIF, also demonstrated the presence of two shocks.

  13. Analysis of phylogeny and codon usage bias and relationship of GC content, amino acid composition with expression of the structural nif genes.

    Science.gov (United States)

    Mondal, Sunil Kanti; Kundu, Sudip; Das, Rabindranath; Roy, Sujit

    2016-08-01

    Bacteria and archaea have evolved with the ability to fix atmospheric dinitrogen in the form of ammonia, catalyzed by the nitrogenase enzyme complex which comprises three structural genes nifK, nifD and nifH. The nifK and nifD encodes for the beta and alpha subunits, respectively, of component 1, while nifH encodes for component 2 of nitrogenase. Phylogeny based on nifDHK have indicated that Cyanobacteria is closer to Proteobacteria alpha and gamma but not supported by the tree based on 16SrRNA. The evolutionary ancestor for the different trees was also different. The GC1 and GC2% analysis showed more consistency than GC3% which appeared to below for Firmicutes, Cyanobacteria and Euarchaeota while highest in Proteobacteria beta and clearly showed the proportional effect on the codon usage with a few exceptions. Few genes from Firmicutes, Euryarchaeota, Proteobacteria alpha and delta were found under mutational pressure. These nif genes with low and high GC3% from different classes of organisms showed similar expected number of codons. Distribution of the genes and codons, based on codon usage demonstrated opposite pattern for different orientation of mirror plane when compared with each other. Overall our results provide a comprehensive analysis on the evolutionary relationship of the three structural nif genes, nifK, nifD and nifH, respectively, in the context of codon usage bias, GC content relationship and amino acid composition of the encoded proteins and exploration of crucial statistical method for the analysis of positive data with non-constant variance to identify the shape factors of codon adaptation index.

  14. Regulation of nif gene expression and the energetics of N2 fixation over the diel cycle in a hot spring microbial mat

    DEFF Research Database (Denmark)

    Steunou, Anne-Soisig; Jensen, Sheila I; Brecht, Eric

    2008-01-01

    Nitrogen fixation, a prokaryotic, O(2)-inhibited process that reduces N(2) gas to biomass, is of paramount importance in biogeochemical cycling of nitrogen. We analyzed the levels of nif transcripts of Synechococcus ecotypes, NifH subunit and nitrogenase activity over the diel cycle...... in the microbial mat of an alkaline hot spring in Yellowstone National Park. The results showed a rise in nif transcripts in the evening, with a subsequent decline over the course of the night. In contrast, immunological data demonstrated that the level of the NifH polypeptide remained stable during the night...

  15. Impact of target area selection in 125 Iodine seed brachytherapy on locoregional recurrence in patients with non-small cell lung cancer.

    Science.gov (United States)

    Yan, Wei-Liang; Lv, Jin-Shuang; Guan, Zhi-Yu; Wang, Li-Yang; Yang, Jing-Kui; Liang, Ji-Xiang

    2017-05-01

    Computed tomography (CT)-guided percutaneous implantation of 125 Iodine radioactive seeds requires the precise arrangement of seeds by tumor shape. We tested whether selecting target areas, including subclinical areas around tumors, can influence locoregional recurrence in patients with non-small cell lung cancer (NSCLC). We divided 82 patients with NSCLC into two groups. Target areas in group 1 (n = 40) were defined along tumor margins based on lung-window CT. Target areas in group 2 (n = 42) were extended by 0.5 cm in all dimensions outside tumor margins. Preoperative plans for both groups were based on a treatment plan system, which guided 125 I seed implantation. Six months later, patients underwent chest CT to evaluate treatment efficacy (per Response Evaluation Criteria in Solid Tumors version 1). We compared locoregional recurrences between the groups after a year of follow-up. We then used the treatment plan system to extend target areas for group 1 patients by 0.5 cm (defined as group 3 data) and compared these hypothetical group 3 planned seeds with the actual seed numbers used in group 1 patients. All patients successfully underwent implantation; none died during the follow-up period. Recurrence was significantly lower in group 2 than in group 1 ( P  area for 125 I seeds can decrease recurrence risk by eradicating cancerous lymph-duct blockades within the extended areas. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  16. Estimasi kebutuhan spektrum untuk memenuhi target rencana pita lebar Indonesia di wilayah perkotaan [The estimation of spectrum requirements to meet the target of Indonesia broadband plan in urban area

    Directory of Open Access Journals (Sweden)

    Kasmad Ariansyah

    2015-12-01

    Full Text Available Pemerintah Indonesia telah mengesahkan Rencana Pita Lebar Indonesia menjelang akhir tahun 2014. Dokumen tersebut berisi panduan dan arah pembangunan pita lebar nasional dan berisi berisi target-target pencapaian berkelanjutan antara tahun 2014-2019. Terkait target capaian pita lebar nirkabel, ketersediaan dan kecukupan spektrum frekuensi merupakan salah satu hal yang sangat penting.  Studi ini dilakukan untuk mengestimasi kebutuhan spektrum frekuensi dalam rangka memenuhi target capaian Rencana Pita Lebar Indonesia khususnya layanan pita lebar nirkabel di wilayah perkotaan. DKI Jakarta dipilih sebagai sampel wilayah perkotaan. Analisis dilakukan dengan menghitung luas cakupan BTS, mengestimasi jumlah potensi pengguna, mengestimasi kebutuhan spektrum dan membandingkannya dengan spektrum yang sudah dialokasikan untuk mendapatkan jumlah kekurangan spektrum. 3G dan 4G diasumsikan sebagai teknologi yang digunakan untuk memenuhi sasaran pita lebar bergerak. Hasil analisis menunjukkan pada rentang tahun 2016-2019 akan terjadi kekurangan spektrum di wilayah perkotaan sebesar 2x234,5 MHz sampai dengan 2x240,5MHz (untuk mode FDD atau sebesar 313 MHz sampai dengan 321 MHz (untuk mode TDD. Spektrum frekuensi merupakan sumber daya yang reusable, dengan mengasumsikan kebutuhan spektrum di perdesaan lebih rendah dibanding kebutuhan di perkotaan, maka estimasi ini dapat pula digunakan untuk menggambarkan kebutuhan spektrum di Indonesia secara keseluruhan.*****Indonesian government has issued Indonesia Broadband Plan (IBP at the end of 2014. IBP provides guidance and direction for the development of national broadband and contains targets in the period of 2014 to 2019. Relating to wireless broadband target, the availability and the adequacy of spectrum is very important. This study was conducted to estimate the spectrum requirements to meet the Indonesia broadband plan target especially the target of mobile broadband in urban area. DKI Jakarta was taken as

  17. Occurrence and Environmental Effects of Boscalid and Other Fungicides in Three Targeted Use Areas in the United States

    Science.gov (United States)

    Reilly, T. J.; Smalling, K. L.; Wilson, E. R.

    2011-12-01

    Fungicides are typically used to control the outbreak of persistent, historically significant plant diseases like late blight (caused by Phytophthora infestans and responsible for the Irish Potato famine of 1846) and newer plant diseases like Asian Soy Rust, both of which are potentially devastating if not controlled. Of the more than 67,000 pesticide products currently registered for use in the United States, over 3,600 are used to combat fungal diseases. Although they are widely used, relatively little is known about the fate and potential secondary effects of fungicides in the aquatic environment. Even less is known about the fate and environmental occurrence of recently registered fungicides including boscalid, which was first registered for use in the US in 2003. Unlike most other pesticides, multiple fungicides are typically applied as a prophylactic crop protectant upwards of ten times per season (depending upon conditions and crop type), but at lower application rates than herbicides or insecticides. This difference in usage increases the likelihood of chronic exposure of aquatic ecosystems to low concentrations of fungicides. Using a newly developed analytical method, the U.S. Geological Survey measured 33 fungicides in surface water and shallow groundwater in three geographic areas of intense fungicide use across the US. Sampling sites were selected near or within farms using prophylactic fungicides at rates and types typical of the crop type and their geographic location. At least one fungicide was detected in 75% of the surface waters (n=60) and 58% of the groundwater (n=12) samples. Twelve fungicides were detected in surface- and groundwater including boscalid (72%), azoxystrobin (51%), pyraclostrobin (40%), chlorothalonil (38%) and pyrimethanil (28%). Boscalid was the most frequently detected pesticide and has not been previously documented in the aquatic environment. In this study, an average of 44% of the pesticide concentration in a water sample

  18. Hohlraum designs for high velocity implosions on NIF

    Directory of Open Access Journals (Sweden)

    Meezan Nathan B.

    2013-11-01

    Full Text Available In this paper, we compare experimental shock and capsule trajectories to design calculations using the radiation-hydrodynamics code hydra. The measured trajectories from surrogate ignition targets are consistent with reducing the x-ray flux on the capsule by about 85%. A new method of extracting the radiation temperature from x-ray data shows that about half of the apparent 15% flux deficit in the data with respect to the simulations can be explained by hydra overestimating the x-ray flux on the capsule.

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

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, F.; Kemp, G. E.; Barrios, M. A.; Pino, J.; Scott, H.; Ayers, S.; Chen, H.; Emig, J.; Colvin, J. D.; Fournier, K. B., E-mail: fournier2@llnl.gov [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, California 94551 (United States); Regan, S. P.; Bedzyk, M.; Shoup, M. J.; Agliata, A.; Yaakobi, B.; Marshall, F. J.; Hamilton, R. A. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Jaquez, J.; Farrell, M.; Nikroo, A. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

    2014-11-15

    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.

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

    Science.gov (United States)

    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.

  1. Spectroscopic and functional characterization of iron-sulfur cluster-bound forms of Azotobacter vinelandii (Nif)IscA.

    Science.gov (United States)

    Mapolelo, Daphne T; Zhang, Bo; Naik, Sunil G; Huynh, Boi Hanh; Johnson, Michael K

    2012-10-16

    The mechanism of [4Fe-4S] cluster assembly on A-type Fe-S cluster assembly proteins, in general, and the specific role of (Nif)IscA in the maturation of nitrogen fixation proteins are currently unknown. To address these questions, in vitro spectroscopic studies (UV-visible absorption/CD, resonance Raman and Mössbauer) have been used to investigate the mechanism of [4Fe-4S] cluster assembly on Azotobacter vinelandii(Nif)IscA, and the ability of (Nif)IscA to accept clusters from NifU and to donate clusters to the apo form of the nitrogenase Fe-protein. The results show that (Nif)IscA can rapidly and reversibly cycle between forms containing one [2Fe-2S](2+) and one [4Fe-4S](2+) cluster per homodimer via DTT-induced two-electron reductive coupling of two [2Fe-2S](2+) clusters and O(2)-induced [4Fe-4S](2+) oxidative cleavage. This unique type of cluster interconversion in response to cellular redox status and oxygen levels is likely to be important for the specific role of A-type proteins in the maturation of [4Fe-4S] cluster-containing proteins under aerobic growth or oxidative stress conditions. Only the [4Fe-4S](2+)-(Nif)IscA was competent for rapid activation of apo-nitrogenase Fe protein under anaerobic conditions. Apo-(Nif)IscA was shown to accept clusters from [4Fe-4S] cluster-bound NifU via rapid intact cluster transfer, indicating a potential role as a cluster carrier for delivery of clusters assembled on NifU. Overall the results support the proposal that A-type proteins can function as carrier proteins for clusters assembled on U-type proteins and suggest that they are likely to supply [2Fe-2S] clusters rather than [4Fe-4S] for the maturation of [4Fe-4S] cluster-containing proteins under aerobic or oxidative stress growth conditions.

  2. Proposed equation of state experimental program at NOVA/NIF

    International Nuclear Information System (INIS)

    Holmes, N.C.; Cauble, R.; Celliers, P.; Collins, G.; DaSilva, L.; Hammel, B.; Stewart, R.; Strand, O.; Sullivan, A.

    1996-03-01

    The high pressure equations of state of materials must be accurately known for confident design, simulation, and interpretation of ICF target experiments and for weapons. Here, the authors sketch out a program to perform precise and accurate equation of state (EOS) experiments using large, high-power lasers. The program is divided into three phases: (1) a driver qualification program which will determine the necessary drive and target design parameters; (2) characterization of low and high-Z standard materials; (3) accurate impedance-match experiments to determine equations of state of materials of interest relative to the qualified standards. Novel methods are proposed for the first phase which are an order of magnitude more sensitive than those applied previously. They identify and describe the choices for standards and the samples slated for initial studies. In all cases, their goal is to obtain data that is of sufficiently high quality to serve for design purposes and to validate theories of material response at high pressures of the order of 1--10 TPa. This is particularly important right now, for materials such as CH plastics and hydrogen (DT). In addition, they will suggest a program for EOS measurements for P > 10 TPa, the region of maximum theoretical EOS uncertainty for many materials

  3. Development and implementation of a geographical area categorisation method with targeted performance indicators for nationwide EMS in Finland.

    Science.gov (United States)

    Pappinen, Jukka; Laukkanen-Nevala, Päivi; Mäntyselkä, Pekka; Kurola, Jouni

    2018-05-15

    In Finland, hospital districts (HD) are required by law to determine the level and availability of Emergency Medical Services (EMS) for each 1-km 2 sized area (cell) within their administrative area. The cells are currently categorised into five risk categories based on the predicted number of missions. Methodological defects and insufficient instructions have led to incomparability between EMS services. The aim of this study was to describe a new, nationwide method for categorising the cells, analyse EMS response time data and describe possible differences in mission profiles between the new risk category areas. National databases of EMS missions, population and buildings were combined with an existing nationwide 1-km 2 hexagon-shaped cell grid. The cells were categorised into four groups, based on the Finnish Environment Institute's (FEI) national definition of urban and rural areas, population and historical EMS mission density within each cell. The EMS mission profiles of the cell categories were compared using risk ratios with confidence intervals in 12 mission groups. In total, 87.3% of the population lives and 87.5% of missions took place in core or other urban areas, which covered only 4.7% of the HDs' surface area. Trauma mission incidence per 1000 inhabitants was higher in core urban areas (42.2) than in other urban (24.2) or dispersed settlement areas (24.6). The results were similar for non-trauma missions (134.8, 93.2 and 92.2, respectively). Each cell category had a characteristic mission profile. High-energy trauma missions and cardiac problems were more common in rural and uninhabited cells, while violence, intoxication and non-specific problems dominated in urban areas. The proposed area categories and grid-based data collection appear to be a useful method for evaluating EMS demand and availability in different parts of the country for statistical purposes. Due to a similar rural/urban area definition, the method might also be usable for

  4. Polar tent for reduced perturbation of NIF ignition capsules

    Science.gov (United States)

    Hammel, B. A.; Pickworth, L.; Stadermann, M.; Field, J.; Robey, H.; Scott, H. A.; Smalyuk, V.

    2016-10-01

    In simulations, a tent that contacts the capsule near the poles and departs tangential to the capsule surface greatly reduces the capsule perturbation, and the resulting mass injected into the hot-spot, compared to current capsule support methods. Target fabrication appears feasible with a layered tent (43-nm polyimide + 8-nm C) for increased stiffness. We are planning quantitative measurements of the resulting shell- ρR perturbation near peak implosion velocity (PV) using enhanced self-emission backlighting, achieved by adding 1% Ar to the capsule fill in Symcaps (4He + H). Layered DT implosions are also planned for an integrated test of capsule performance. We will describe the design and simulation predictions. Prepared by LLNL under Contract DE-AC52-07NA27344.

  5. Possible version of the compression degradation of the thermonuclear indirect-irradiation targets at the national ignition facility and a reason for the failure of ignition

    Energy Technology Data Exchange (ETDEWEB)

    Rozanov, V. B., E-mail: rozanov@sci.lebedev.ru; Vergunova, G. A., E-mail: verg@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

    2017-01-15

    The main parameters of compression of a target and tendencies at change in the irradiation conditions are determined by analyzing the published results of experiments at the megajoule National Ignition Facility (NIF) on the compression of capsules in indirect-irradiation targets by means of the one-dimensional RADIAN program in the spherical geometry. A possible version of the “failure of ignition” of an indirect-irradiation target under the NIF conditions is attributed to radiation transfer. The application of onedimensional model to analyze the National Ignition Campaign (NIC) experiments allows identifying conditions corresponding to the future ignition regime and distinguishing them from conditions under which ignition does not occur.

  6. Evaulation of B4C as an ablator material for NIF capsules. Revision 1

    International Nuclear Information System (INIS)

    Burnham, A.K.; Alford, C.S.; Makowiecki, D.M.; Dittrich, T.R.; Wallace, R.J.; Honea, E.C.; King, C.M.; Steinman, D.

    1997-01-01

    Boron carbide (B 4 C) is examined as a potential fuel container and ablator for implosion capsules on the National Ignition Facility (NIF). A capsule of pure B 4 C encasing a layer of solid DT implodes stably and ignites with anticipated NIF x-ray drives, producing 18 MJ of energy. Thin films of B 4 C were found to be resistant to oxidation and modestly transmitting in the infrared (IR), possibly enabling IR fuel characterization and enhancement for thin permeation barriers but not for full-thickness capsules. Polystyrene mandrels 0.5 mm in diameter were successfully coated with 0.15-2.0 micrometers of B 4 C. Thickness estimated from optical density agreed well with those measured by scanning electron microscopy (SEM). The B 4 C microstructure was columnar but finer than for Be made at the same conditions. B 4 C is a very strong material, with a fiber tensile strength capable of holding NIF fill pressures at room temperature, but it is also very brittle, and microscopic flaws or grain structure may limit the noncryogenic fill pressure. Argon (Ar) permeation rates were measured for a few capsules that had been further coated with 5 micrometers of plasma polymer. The B 4 C coatings tended to crack under tensile load. Some shells filled more slowly than they leaked, suggesting that the cracks open and close under opposite pressure loading. As observed earlier for Ti coatings, 0.15-micrometer layers of B 4 C had better gas retention properties than 2-micrometer layers, possibly because of fewer cracks. Permeation and fill strength issues for capsules with a full ablator thickness of B 4 C are unresolved. 21 refs., 6 figs

  7. Measuring the absolute deuterium-tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF.

    Science.gov (United States)

    Casey, D T; Frenje, J A; Gatu Johnson, M; Séguin, F H; Li, C K; Petrasso, R D; Glebov, V Yu; Katz, J; Knauer, J P; Meyerhofer, D D; Sangster, T C; Bionta, R M; Bleuel, D L; Döppner, T; Glenzer, S; Hartouni, E; Hatchett, S P; Le Pape, S; Ma, T; MacKinnon, A; McKernan, M A; Moran, M; Moses, E; Park, H-S; Ralph, J; Remington, B A; Smalyuk, V; Yeamans, C B; Kline, J; Kyrala, G; Chandler, G A; Leeper, R J; Ruiz, C L; Cooper, G W; Nelson, A J; Fletcher, K; Kilkenny, J; Farrell, M; Jasion, D; Paguio, R

    2012-10-01

    A magnetic recoil spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

  8. Design process for NIF laser alignment and beam diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Grey, A., LLNL

    1998-06-09

    In a controller for an adaptive optic system designed to correct phase aberrations in a high power laser, the wavefront sensor is a discrete Hartmann-Shack design. It uses an army of lenslets (like a fly` s eye) to focus the laser into 77 spots on a CCD camera. Average local tilt of the wavefront across each lenslet changes the position of its focal spot. The system requires 0.1 pixel accuracy in determining the focal spot location. We determine a small area around each spot` s previous location. Within this area, we calculate the centroid of the light intensity in x and y. This calculation fails if the spot regions overlap. Especially during initial acquisition of a highly distorted beam, distinguishing overlapping spots is difficult. However, low resolution analysis of the overlapping spots allows the system to estimate their positions. With this estimate, it can use the deformable mirror to correct the beam enough so we can detect the spots using conventional image processing.

  9. Research on ore-controlling factors and prospecting targets in Shihongtan uranium deposit area, turpan-hami basin

    International Nuclear Information System (INIS)

    Fu Chengming

    2005-01-01

    Based on analyzing the controlling role of geologic structure, host formation and hydrodynamic environments on interlayer oxidation zone and uranium mineralization, the author suggests that the Aiding structural slope, block-faulting structure, and subsidiary faults and folds are indications of uranium mineralization emplacement, sand bodies of braided stream facies provide favorable space for the development of interlayer oxidation zone and uranium mineralization, and variation sites of interlayer artesian water and geochemical environments are important places for the precipitation of ore material. Based on the above-mentioned a prediction of favorable metallogenic targets is made. (author)

  10. Metallogenic geologic prerequisites of sandstone-type uranium deposits and target area selection. Taking Erlian and Ordos basins as examples

    International Nuclear Information System (INIS)

    Chen Fazheng

    2002-01-01

    Sandstone-type uranium deposit is the main target of recent uranium prospecting and exploration. According to the metallogenic characteristics, sandstone-type uranium deposits are divided into three groups: paleo-channel type, interlayer oxidation zone type and phreatic interlayer oxidation type. The author makes an analysis on the geologic prerequisites of the three types of uranium deposits, the similarities and difference, and preliminarily summarizes genetic models of different types of uranium deposits. Finally, taking Erlian and Ordos basins as examples, the author makes an evaluation and a strategic analysis on the uranium metallogenic prospect of the above two basins

  11. Full aperture backscatter diagnostic for the NIF laser facility (abstract)

    International Nuclear Information System (INIS)

    Sewall, Noel; Lewis, Izzy; Kirkwood, Robert; Moody, John; Celeste, John

    2001-01-01

    The current schemes for achieving ignition on the National Ignition Facility require efficient coupling of energy from 192 laser beams to the deuterium--tritium fuel capsule. Each laser beam must propagate through a long scalelength plasma region before being converted to x rays (indirect drive) or being absorbed on the capsule (direct drive). Laser-plasma instabilities such as stimulated Brillouin and stimulated Raman scattering (SBS and SRS) will scatter a fraction of the incident laser energy out of the target leading to an overall reduction in the coupling efficiency. It is important to measure the character of this scattered light in order to understand it and to develop methods for reducing it to acceptable levels. We are designing a system called the full aperature backscatter diagnostic with the capability to measure the time-dependent amplitude and spectral content of the light which is backscattered through the incident beam focusing optic. The backscattered light will be collected over about 85% of the full beam aperture and separated into the SBS wavelength band (348--354 nm) and the SRS wavelength band (400--700 nm). Spectrometers coupled to streak cameras will provide time-resolved spectra for both scattered light components. The scattered light amplitude will be measured with fast and slow diodes. The entire system will be routinely calibrated. Analysis of the data will provide important information for reducing scattered power, achieving power balance, and finally achieving ignition

  12. Developments in numerical simulation of IFE target and chamber physics

    International Nuclear Information System (INIS)

    Velarde, G.; Minguez, E.; Alonso, E.; Gil, J.M.; Malerba, L.; Marian, J.; Martel, P.; Martinez-Val, J.M.; Munoz, R.; Ogando, F.; Perlado, J.M.; Piera, M.; Reyes, S.; Rubiano, J.G.; Sanz, J.; Sauvan, P.; Velarde, M.; Velarde, P.

    2000-01-01

    The work presented outlines the global frame given at the Institute of Nuclear Fusion (DENIM) for having an integral perspective of the different research areas with the development of Inertial Fusion for energy generation. The coupling of a new radiation transport (RT) solver with an existing multi-material fluid dynamics code using Adaptive Mesh Refinement (ARM) is presented in Section 2, including improvements and additional information about the solver precision. In Section 3, new developments in the atomic physics codes under target conditions, to determine populations, opacity data and emissivities have been performed. Exotic and innovative ideas about Inertial Fusion Energy (IFE), as catalytic fuels and Z-pinches have been explored, and they are explained in Section 4. Numerical simulations demonstrate important reductions in the tritium inventory. Section 5 is devoted to safety and environment of the IFE. Uncertainties analysis in activation calculations have been included in the ACAB activation code, and also calculations on pulse activation in IFE reactors and on the activation of target debris in NIF are presented. A comparison of the accidental releases of tritium from some IFE reactors computed using MACCS2 code is explained. Finally, Section 6 contains the research on the basic mechanisms of neutron damage in SiC (low-activation material) and FeCu alloy using the DENIM/LLNL molecular dynamics code MDCASK. (authors)

  13. NIFS joint research meeting on plasma facing components, PSI, and heat/particle control

    International Nuclear Information System (INIS)

    Yamashina, T.

    1997-10-01

    The LHD collaboration has been started in 1996. Particle and heat control is one of the categories for the collaboration, and a few programs have been nominated in these two years. A joint research meeting on PFC, PSI, heat and particle meeting was held at NIFS on June 27, 1997, in which present status of these programs were reported. This is a collection of the notes and view graphs presented in this meeting. Brief reviews and research plan of each program are included in relation to divertor erosion and sputtering, impurity generation, hydrogen recycling, edge plasma structure, edge transport and its control, heat removal, particle exhaust, wall conditioning etc. (author)

  14. Beam control and diagnostic functions in the NIF transport spatial filter

    International Nuclear Information System (INIS)

    Holdener, F.R.; Ables, E.; Bliss, E.S.

    1996-10-01

    Beam control and diagnostic systems are required to align the National Ignition Facility (NIF) laser prior to a shot as well as to provide diagnostics on 192 beam lines at shot time. A design that allows each beam's large spatial filter lenses to also serve as objective lenses for beam control and diagnostic sensor packages helps to accomplish the task at a reasonable cost. However, this approach also causes a high concentration of small optics near the pinhole plane of the transport spatial filter (TSF) at the output of each beam. This paper describes the optomechanical design in and near the central vacuum vessel of the TSF

  15. Damage sources for the NIF Grating Debris Shield (GDS) and methods for their mitigation

    Science.gov (United States)

    Carr, C. W.; Bude, J.; Miller, P. E.; Parham, T.; Whitman, P.; Monticelli, M.; Raman, R.; Cross, D.; Welday, B.; Ravizza, F.; Suratwala, T.; Davis, J.; Fischer, M.; Hawley, R.; Lee, H.; Matthews, M.; Norton, M.; Nostrand, M.; Vanblarcom, D.; Sommer, S.

    2017-11-01

    The primary sources of damage on the National Ignition Facility (NIF) Grating Debris Shield (GDS) are attributed to two independent types of laser-induced particulates. The first comes from the eruptions of bulk damage in a disposable debris shield downstream of the GDS. The second particle source comes from stray light focusing on absorbing glass armor at higher than expected fluences. We show that the composition of the particles is secondary to the energetics of their delivery, such that particles from either source are essentially benign if they arrive at the GDS with low temperatures and velocities.

  16. User friendly tools to target vulnerable areas at watershed scale: evaluation of the soil vulnerability and conductivity claypan indices

    Science.gov (United States)

    One finding of the Conservation Effects Assessment Program (CEAP) watershed studies was that Best Management practices (BMPs) were not always installed where most needed: in many watersheds, only a fraction of BMPs were implemented in the most vulnerable areas. While complex computer simulation mode...

  17. RESULTS FROM RECENT SCIENCE AND TECHNOLOGY INVESTIGATIONS TARGETING CHROMIUM IN THE 100D AREA HANFORD SITE WASHINGTON USA

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN SW; THOMPSON KM; TONKIN MJ

    2009-12-03

    Sodium dichromate was used in Hanford's 100D Area during the reactor operations period of 1950 to 1964 to retard corrosion in the reactor cooling systems. Some of the sodium dichromate was released to the environment by spills and/or leaks from pipelines used to deliver the chemical to water treatment plants in the area. As a result, hexavalent chromium [Cr(VI)] has migrated through the vadose zone to the groundwater and contaminated nearly 1 km{sup 2} of groundwater to above the drinking water standard of 48 {micro}g/L. Three technology tests have recently been completed in this area to characterize the source area of the plumes and evaluate alternative methods to remove Cr(VI) from groundwater. These are (1) refine the source area of the southern plume; (2) test electrocoagulation as an alternative groundwater treatment technology; and (3) test the ability to repair a permeable reactive barrier by injecting micron or nanometer-size zero-valent iron (ZVI). The projects were funded by the US Department of Energy as part of a program to interject new technologies and accelerate active cleanup. Groundwater monitoring over the past 10 years has shown that Cr(VI) concentrations in the southern plume have not significantly diminished, strongly indicating a continuing source. Eleven groundwater wells were installed in 2007 and 2008 near a suspected source area and monitored for Cr(VI) and groundwater levels. Interpretation of these data has led to refinement of the source area location to an area of less than 1 hectare (ha, 2.5 acres). Vadose zone soil samples collected during drilling did not discover significant concentrations of Cr(VI), indicating the source is localized, with a narrow wetted path from the surface to the water table. Electrocoagulation was evaluated through a pilot-scale treatability test. Over 8 million liters of groundwater were treated to Cr(VI) concentrations of {le}20 {micro}g/L. The test determined that this technology has the potential to

  18. Results From Recent Science And Technology Investigations Targeting Chromium In The 100D Area, Hanford Site, Washington, USA

    International Nuclear Information System (INIS)

    Petersen, S.W.; Thompson, K.M.; Tonkin, M.J.

    2009-01-01

    Sodium dichromate was used in Hanford's 100D Area during the reactor operations period of 1950 to 1964 to retard corrosion in the reactor cooling systems. Some of the sodium dichromate was released to the environment by spills and/or leaks from pipelines used to deliver the chemical to water treatment plants in the area. As a result, hexavalent chromium (Cr(VI)) has migrated through the vadose zone to the groundwater and contaminated nearly 1 km 2 of groundwater to above the drinking water standard of 48 (micro)g/L. Three technology tests have recently been completed in this area to characterize the source area of the plumes and evaluate alternative methods to remove Cr(VI) from groundwater. These are (1) refine the source area of the southern plume; (2) test electrocoagulation as an alternative groundwater treatment technology; and (3) test the ability to repair a permeable reactive barrier by injecting micron or nanometer-size zero-valent iron (ZVI). The projects were funded by the US Department of Energy as part of a program to interject new technologies and accelerate active cleanup. Groundwater monitoring over the past 10 years has shown that Cr(VI) concentrations in the southern plume have not significantly diminished, strongly indicating a continuing source. Eleven groundwater wells were installed in 2007 and 2008 near a suspected source area and monitored for Cr(VI) and groundwater levels. Interpretation of these data has led to refinement of the source area location to an area of less than 1 hectare (ha, 2.5 acres). Vadose zone soil samples collected during drilling did not discover significant concentrations of Cr(VI), indicating the source is localized, with a narrow wetted path from the surface to the water table. Electrocoagulation was evaluated through a pilot-scale treatability test. Over 8 million liters of groundwater were treated to Cr(VI) concentrations of (le)20 (micro)g/L. The test determined that this technology has the potential to treat Cr

  19. Occurrence and persistence of fungicides in bed sediments and suspended solids from three targeted use areas in the United States.

    Science.gov (United States)

    Smalling, Kelly L; Reilly, Timothy J; Sandstrom, Mark W; Kuivila, Kathryn M

    2013-03-01

    To document the environmental occurrence and persistence of fungicides, a robust and sensitive analytical method was used to measure 34 fungicides and an additional 57 current-use pesticides in bed sediments and suspended solids collected from areas of intense fungicide use within three geographic areas across the United States. Sampling sites were selected near or within agricultural research farms using prophylactic fungicides at rates and types typical of their geographic location. At least two fungicides were detected in 55% of the bed and 83% of the suspended solid samples and were detected in conjunction with herbicides and insecticides. Six fungicides were detected in all samples including pyraclostrobin (75%), boscalid (53%), chlorothalonil (41%) and zoxamide (22%). Pyraclostrobin, a strobilurin fungicide, used frequently in the United States on a variety of crops, was detected more frequently than p,p'-DDE, the primary degradate of p,p'-DDT, which is typically one of the most frequently occurring pesticides in sediments collected within highly agricultural areas. Maximum fungicide concentrations in bed sediments and suspended solids were 198 and 56.7 μg/kg dry weight, respectively. There is limited information on the occurrence, fate, and persistence of many fungicides in sediment and the environmental impacts are largely unknown. The results of this study indicate the importance of documenting the persistence of fungicides in the environment and the need for a better understanding of off-site transport mechanisms, particularly in areas where crops are grown that require frequent treatments to prevent fungal diseases. Published by Elsevier B.V.

  20. Distinct GABAergic targets of feedforward and feedback connections between lower and higher areas of rat visual cortex.

    Science.gov (United States)

    Gonchar, Yuri; Burkhalter, Andreas

    2003-11-26

    Processing of visual information is performed in different cortical areas that are interconnected by feedforward (FF) and feedback (FB) pathways. Although FF and FB inputs are excitatory, their influences on pyramidal neurons also depend on the outputs of GABAergic neurons, which receive FF and FB inputs. Rat visual cortex contains at least three different families of GABAergic neurons that express parvalbumin (PV), calretinin (CR), and somatostatin (SOM) (Gonchar and Burkhalter, 1997). To examine whether pathway-specific inhibition (Shao and Burkhalter, 1996) is attributable to distinct connections with GABAergic neurons, we traced FF and FB inputs to PV, CR, and SOM neurons in layers 1-2/3 of area 17 and the secondary lateromedial area in rat visual cortex. We found that in layer 2/3 maximally 2% of FF and FB inputs go to CR and SOM neurons. This contrasts with 12-13% of FF and FB inputs onto layer 2/3 PV neurons. Unlike inputs to layer 2/3, connections to layer 1, which contains CR but lacks SOM and PV somata, are pathway-specific: 21% of FB inputs go to CR neurons, whereas FF inputs to layer 1 and its CR neurons are absent. These findings suggest that FF and FB influences on layer 2/3 pyramidal neurons mainly involve disynaptic connections via PV neurons that control the spike outputs to axons and proximal dendrites. Unlike FF input, FB input in addition makes a disynaptic link via CR neurons, which may influence the excitability of distal pyramidal cell dendrites in layer 1.

  1. Optimized beryllium target design for indirectly driven inertial confinement fusion experiments on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Simakov, Andrei N., E-mail: simakov@lanl.gov; Wilson, Douglas C.; Yi, Sunghwan A.; Kline, John L.; Batha, Steven H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, Daniel S.; Milovich, Jose L.; Salmonson, Jay D. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

    2014-02-15

    For indirect drive inertial confinement fusion, Beryllium (Be) ablators offer a number of important advantages as compared with other ablator materials, e.g., plastic and high density carbon. In particular, the low opacity and relatively high density of Be lead to higher rocket efficiencies giving a higher fuel implosion velocity for a given X-ray drive; and to higher ablation velocities providing more ablative stabilization and reducing the effect of hydrodynamic instabilities on the implosion performance. Be ablator advantages provide a larger target design optimization space and can significantly improve the National Ignition Facility (NIF) [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] ignition margin. Herein, we summarize the Be advantages, briefly review NIF Be target history, and present a modern, optimized, low adiabat, Revision 6 NIF Be target design. This design takes advantage of knowledge gained from recent NIF experiments, including more realistic levels of laser-plasma energy backscatter, degraded hohlraum-capsule coupling, and the presence of cross-beam energy transfer.

  2. Simulated impact of self-generated magnetic fields in the hot-spot of NIF implosions

    Science.gov (United States)

    Partha, M. A.; Haan, S. W.; Koning, J.; Marinak, M. M.; Weber, C. R.; Clark, D. S.

    2016-10-01

    Deviations from sphericity in an imploded hot-spot result in magnetic fields generated by the Biermann battery effect. The magnetic field can reduce thermal conductivity, affect α transport, change instability growth, and cause magnetic pressure. Previous estimates of these effects have indicated that they are not of great consequence, but have suggested that they could plausibly affect NIF observables such as yield and ion temperature by 5-25%. Using the MHD capability in the Hydra code, we evaluated the impact of these processes in a post-shot model for a typical NIF implosion. Various implosion asymmetries were implemented, with the goal of surveying plausible implosion configurations to find the geometry in which the MHD effects were the most significant. Magnetic fields are estimated to approach 104 Tesla, and to affect conductivity locally by more than 50%, but global impact on observables is small in most cases. Work performed under the auspices of the U.S. D.O.E. by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  3. IGNITOR, ITER and NIF in the Context of the World Effort on Fusion Burning Plasmas

    Science.gov (United States)

    Azizov, E.; Coppi, B.; Velikhov, E.

    2012-03-01

    As of last summer, the ITER program has been recognized as being directed at providing an ``International Platform for Fusion Technology.'' Then, the two experimental programs that have the explicit goal to approach ignition conditions with D-T plasmas are NIF and IGNITOR. NIF, the National Ignition Facility, is based on the inertial confinement principle using a laser system capable of delivering 1.6 MJ and is being operated in Livermore. IGNITOR will be operated by the Kurchatov Institute within the research center of Troitzk presently owned by Rosatom and involves a high level collaboration between Italy and Russia. For this, Ignitor has been defined as a Flagship Project by Italy and the construction of its core has been funded. The Ignitor design is based on the experimental results obtained by the high field line of experiments carried out at MIT, within the Alcator Program, and in Italy within the Frascati Torus Program. A wide set of experiments in Japan, on high density plasmas, in the US, Russia and Europe have produced plasma physics results and technology developments that have guided the evolution of the Ignitor design. The main theoretical plasma physics issues to be dealt with in connection with this program are discussed.

  4. Comparison of plastic, high density carbon, and beryllium as indirect drive NIF ablators

    Science.gov (United States)

    Kritcher, A. L.; Clark, D.; Haan, S.; Yi, S. A.; Zylstra, A. B.; Callahan, D. A.; Hinkel, D. E.; Berzak Hopkins, L. F.; Hurricane, O. A.; Landen, O. L.; MacLaren, S. A.; Meezan, N. B.; Patel, P. K.; Ralph, J.; Thomas, C. A.; Town, R.; Edwards, M. J.

    2018-05-01

    Detailed radiation hydrodynamic simulations calibrated to experimental data have been used to compare the relative strengths and weaknesses of three candidate indirect drive ablator materials now tested at the NIF: plastic, high density carbon or diamond, and beryllium. We apply a common simulation methodology to several currently fielded ablator platforms to benchmark the model and extrapolate designs to the full NIF envelope to compare on a more equal footing. This paper focuses on modeling of the hohlraum energetics which accurately reproduced measured changes in symmetry when changes to the hohlraum environment were made within a given platform. Calculations suggest that all three ablator materials can achieve a symmetric implosion at a capsule outer radius of ˜1100 μm, a laser energy of 1.8 MJ, and a DT ice mass of 185 μg. However, there is more uncertainty in the symmetry predictions for the plastic and beryllium designs. Scaled diamond designs had the most calculated margin for achieving symmetry and the highest fuel absorbed energy at the same scale compared to plastic or beryllium. A comparison of the relative hydrodynamic stability was made using ultra-high resolution capsule simulations and the two dimensional radiation fluxes described in this work [Clark et al., Phys. Plasmas 25, 032703 (2018)]. These simulations, which include low and high mode perturbations, suggest that diamond is currently the most promising for achieving higher yields in the near future followed by plastic, and more data are required to understand beryllium.

  5. Modulation of telomere binding proteins: a future area of research for skin protection and anti-aging target.

    Science.gov (United States)

    Imbert, Isabelle; Botto, Jean-Marie; Farra, Claude D; Domloge, Nouha

    2012-06-01

    Telomere shortening is considered as one of the main characteristics of cellular aging by limiting cellular division. Besides the fundamental advances through the discoveries of telomere and telomerase, which were recognized by a Nobel Prize, telomere protection remains an essential area of research. Recently, it was evidenced that studying the cross-talks between the proteins associated with telomere should provide a better understanding of the mechanistic basis for telomere-associated aging phenotypes. In this review, we discuss the current knowledge on telomere shortening, telomerase activity, and the essential role of telomere binding proteins in telomere stabilization and telomere-end protection. This review highlights the capacity of telomere binding proteins to limit cellular senescence and to maintain skin tissue homeostasis, which is of key importance to reduce accelerated tissue aging. Future studies addressing telomere protection and limitation of DNA damage response in human skin should include investigations on telomere binding proteins. As little is known about the expression of telomere binding proteins in human skin and modulation of their expression with aging, it remains an interesting field of skin research and a key area for future skin protection and anti-aging developments. © 2012 Wiley Periodicals, Inc.

  6. Spatial organization of the cytoskeleton enhances cargo delivery to specific target areas on the plasma membrane of spherical cells

    Science.gov (United States)

    Hafner, Anne E.; Rieger, Heiko

    2016-12-01

    Intracellular transport is vital for the proper functioning and survival of a cell. Cargo (proteins, vesicles, organelles, etc) is transferred from its place of creation to its target locations via molecular motor assisted transport along cytoskeletal filaments. The transport efficiency is strongly affected by the spatial organization of the cytoskeleton, which constitutes an inhomogeneous, complex network. In cells with a centrosome microtubules grow radially from the central microtubule organizing center towards the cell periphery whereas actin filaments form a dense meshwork, the actin cortex, underneath the cell membrane with a broad range of orientations. The emerging ballistic motion along filaments is frequently interrupted due to constricting intersection nodes or cycles of detachment and reattachment processes in the crowded cytoplasm. In order to investigate the efficiency of search strategies established by the cell’s specific spatial organization of the cytoskeleton we formulate a random velocity model with intermittent arrest states. With extensive computer simulations we analyze the dependence of the mean first passage times for narrow escape problems on the structural characteristics of the cytoskeleton, the motor properties and the fraction of time spent in each state. We find that an inhomogeneous architecture with a small width of the actin cortex constitutes an efficient intracellular search strategy.

  7. Spatial organization of the cytoskeleton enhances cargo delivery to specific target areas on the plasma membrane of spherical cells.

    Science.gov (United States)

    Hafner, Anne E; Rieger, Heiko

    2016-11-15

    Intracellular transport is vital for the proper functioning and survival of a cell. Cargo (proteins, vesicles, organelles, etc) is transferred from its place of creation to its target locations via molecular motor assisted transport along cytoskeletal filaments. The transport efficiency is strongly affected by the spatial organization of the cytoskeleton, which constitutes an inhomogeneous, complex network. In cells with a centrosome microtubules grow radially from the central microtubule organizing center towards the cell periphery whereas actin filaments form a dense meshwork, the actin cortex, underneath the cell membrane with a broad range of orientations. The emerging ballistic motion along filaments is frequently interrupted due to constricting intersection nodes or cycles of detachment and reattachment processes in the crowded cytoplasm. In order to investigate the efficiency of search strategies established by the cell's specific spatial organization of the cytoskeleton we formulate a random velocity model with intermittent arrest states. With extensive computer simulations we analyze the dependence of the mean first passage times for narrow escape problems on the structural characteristics of the cytoskeleton, the motor properties and the fraction of time spent in each state. We find that an inhomogeneous architecture with a small width of the actin cortex constitutes an efficient intracellular search strategy.

  8. Fabrication and testing of gas filled targets for large scale plasma experiments on Nova

    International Nuclear Information System (INIS)

    Stone, G.F.; Spragge, M.; Wallace, R.J.; Rivers, C.J.

    1995-01-01

    An experimental campaign on the Nova laser was started in July 1993 to study one st of target conditions for the point design of the National Ignition Facility (NIF). The targets were specified to investigate the current NIF target conditions--a plasma of ∼3 keV electron temperature and an electron density of ∼1.0 E + 21 cm -3 . A gas cell target design was chosen to confine as gas of ∼0.01 cm 3 in volume at ∼ 1 atmosphere. This paper will describe the major steps and processes necessary in the fabrication, testing and delivery of these targets for shots on the Nova Laser at LLNL

  9. Ultra-stable, diode-pumped Nd-doped glass regenerative amplifier for the National Ignition Facility (NIF)

    International Nuclear Information System (INIS)

    Crane, J.K.; Martinez, M.; Beach, R.J.; Mitchell, S.; Pratt, G.; Christensen, J.J.

    1995-12-01

    We describe a diode laser-pumped Nd:glass regenerative amplifier that amplifies temporally shaped pulses with low distortion, high pulse-to- pulse stability, and high gain. This laser amplifier is a prototype subsystem for the National Ignition Facility (NIF) laser system. 2 refs., 1 fig

  10. Area-under-the-curve monitoring of cyclosporine therapy: Performance of different assay methods and their target concentrations

    International Nuclear Information System (INIS)

    Grevel, J.; Napoli, K.L.; Gibbons, S.; Kahan, B.D.

    1990-01-01

    The measurement of areas under the concentration-time curve (AUC) was recently introduced as an alternative to trough level monitoring of cyclosporine therapy. The AUC is divided by the oral dosing interval to calculate an average concentration. All measurements are performed at clinical steady state. The initial evaluation of AUC monitoring showed advantages over trough level monitoring with concentrations of cyclosporine measured in serum by the polyclonal radioimmunoassay of Sandoz. This assay technique is no longer available and the following assays were performed in parallel during up to 173 AUC determinations in 51 consecutive renal transplant patients: polyclonal fluorescence polarization immunoassay of Abbott in serum, specific and nonspecific monoclonal radioimmunoassays using 3 H and 125 I tracers in serum and whole blood, and high performance liquid chromatography in whole blood. Both trough levels and average concentrations at steady state measured by those different techniques were significantly correlated with the oral dose. The best correlation (r2 = 0.54) was shown by average concentrations measured in whole blood by the specific monoclonal radioimmunoassay of Sandoz ( 3 H tracer). This monitoring technique was also associated with the smallest absolute error between repeated observations in the same patient while the oral dose rate remained the same or was changed. Both allegedly specific monoclonal radioimmunoassays (with 3 H and 125 I tracer) measured significantly higher concentrations than the liquid chromatography

  11. Evidence for high-temperature in situ nifH transcription in an alkaline hot spring of Lower Geyser Basin, Yellowstone National Park.

    Science.gov (United States)

    Loiacono, Sara T; Meyer-Dombard, D'Arcy R; Havig, Jeff R; Poret-Peterson, Amisha T; Hartnett, Hilairy E; Shock, Everett L

    2012-05-01

    Genes encoding nitrogenase (nifH) were amplified from sediment and photosynthetic mat samples collected in the outflow channel of Mound Spring, an alkaline thermal feature in Yellowstone National Park. Results indicate the genetic capacity for nitrogen fixation over the entire range of temperatures sampled (57.2°C to 80.2°C). Amplification of environmental nifH transcripts revealed in situ expression of nifH genes at temperatures up to 72.7°C. However, we were unable to amplify transcripts of nifH at the higher-temperature locations (> 72.7°C). These results indicate that microbes at the highest temperature sites contain the genetic capacity to fix nitrogen, yet either do not express nifH or do so only transiently. Field measurements of nitrate and ammonium show fixed nitrogen limitation as temperature decreases along the outflow channel, suggesting nifH expression in response to the downstream decrease in bioavailable nitrogen. Nitrogen stable isotope values of Mound Spring sediment communities further support geochemical and genetic data. DNA and cDNA nifH amplicons form several unique phylogenetic clades, some of which appear to represent novel nifH sequences in both photosynthetic and chemosynthetic microbial communities. This is the first report of in situ nifH expression in strictly chemosynthetic zones of terrestrial (non-marine) hydrothermal systems, and sets a new upper temperature limit (72.7°C) for nitrogen fixation in alkaline, terrestrial hydrothermal environments. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  12. p35 regulates the CRM1-dependent nucleocytoplasmic shuttling of nuclear hormone receptor coregulator-interacting factor 1 (NIF-1.

    Directory of Open Access Journals (Sweden)

    Xiao-Su Zhao

    Full Text Available Cyclin-dependent kinase 5 (Cdk5 is a proline-directed serine/threonine kinase, which plays critical roles in a wide spectrum of neuronal functions including neuronal survival, neurite outgrowth, and synapse development and plasticity. Cdk5 activity is controlled by its specific activators: p35 or p39. While knockout studies reveal that Cdk5/p35 is critical for neuronal migration during early brain development, functions of Cdk5/p35 have been unraveled through the identification of the interacting proteins of p35, most of which are Cdk5/p35 substrates. However, it remains unclear whether p35 can regulate neuronal functions independent of Cdk5 activity. Here, we report that a nuclear protein, nuclear hormone receptor coregulator (NRC-interacting factor 1 (NIF-1, is a new interacting partner of p35. Interestingly, p35 regulates the functions of NIF-1 independent of Cdk5 activity. NIF-1 was initially discovered as a transcriptional regulator that enhances the transcriptional activity of nuclear hormone receptors. Our results show that p35 interacts with NIF-1 and regulates its nucleocytoplasmic trafficking via the nuclear export pathway. Furthermore, we identified a nuclear export signal on p35; mutation of this site or blockade of the CRM1/exportin-dependent nuclear export pathway resulted in the nuclear accumulation of p35. Intriguingly, blocking the nuclear export of p35 attenuated the nuclear accumulation of NIF-1. These findings reveal a new p35-dependent mechanism in transcriptional regulation that involves the nucleocytoplasmic shuttling of transcription regulators.

  13. p35 regulates the CRM1-dependent nucleocytoplasmic shuttling of nuclear hormone receptor coregulator-interacting factor 1 (NIF-1).

    Science.gov (United States)

    Zhao, Xiao-Su; Fu, Wing-Yu; Chien, Winnie W Y; Li, Zhen; Fu, Amy K Y; Ip, Nancy Y

    2014-01-01

    Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase, which plays critical roles in a wide spectrum of neuronal functions including neuronal survival, neurite outgrowth, and synapse development and plasticity. Cdk5 activity is controlled by its specific activators: p35 or p39. While knockout studies reveal that Cdk5/p35 is critical for neuronal migration during early brain development, functions of Cdk5/p35 have been unraveled through the identification of the interacting proteins of p35, most of which are Cdk5/p35 substrates. However, it remains unclear whether p35 can regulate neuronal functions independent of Cdk5 activity. Here, we report that a nuclear protein, nuclear hormone receptor coregulator (NRC)-interacting factor 1 (NIF-1), is a new interacting partner of p35. Interestingly, p35 regulates the functions of NIF-1 independent of Cdk5 activity. NIF-1 was initially discovered as a transcriptional regulator that enhances the transcriptional activity of nuclear hormone receptors. Our results show that p35 interacts with NIF-1 and regulates its nucleocytoplasmic trafficking via the nuclear export pathway. Furthermore, we identified a nuclear export signal on p35; mutation of this site or blockade of the CRM1/exportin-dependent nuclear export pathway resulted in the nuclear accumulation of p35. Intriguingly, blocking the nuclear export of p35 attenuated the nuclear accumulation of NIF-1. These findings reveal a new p35-dependent mechanism in transcriptional regulation that involves the nucleocytoplasmic shuttling of transcription regulators.

  14. Recent results from the first polar direct drive plastic capsule implosions on NIF

    Science.gov (United States)

    Schmitt, Mark J.

    2012-10-01

    Polar direct drive (PDD) offers a simplified platform for conducting strongly driven implosions on NIF to investigate mix, hydro-burn and ignition-relevant physics. Its successful use necessitates a firm understanding and predictive capability of its implosion characteristics including hydro performance, symmetry and yield. To assess this capability, the first two PDD implosions of deuterium filled CH capsules were recently conducted at NIF. The P2 Legendre mode symmetry seen in these implosions agreed with pre-shot predictions even though the 700kJ drive energy produced intensities that far exceeded thresholds for both Raman and Brillouin stimulated scattering. These shots were also the first to employ image backlighting driven by two laser quads. Preliminary results indicate that the yield from the uncoated 2.25 mm diameter, 42 μm thick, CH shells was reduced by about a factor of two owing to as-shot laser drive asymmetries. Similarly, a small (sim50 μm) centroid offset between the upper and lower shell hemispheres seen in the first shot appears to be indicative of the laser quad energies. Overall, the implosion trajectories agreed with pre-shot predictions of bangtime. The second shot incorporated an 80 ?m wide,10 ?m deep depression encircling the equator of the capsule. This engineered feature was imposed to test our capability to predict the effect of high-mode features on yield and mix. A predicted yield reduction factor of 3 was not observed.[4pt] In collaboration with P. A. Bradley, J. A. Cobble, P. Hakel, S. C. Hsu, N. S. Krasheninnikova, G. A. Kyrala, G. R. Magelssen, T. J. Murphy, K. A. Obrey, R. C. Shah, I. L. Tregillis and F. J. Wysocki of Los Alamos National Laboratory; M. Marinak, R. Wallace, T. Parham, M. Cowan, S. Glenn, R. Benedetti and the NIF Operations Team of Lawrence Livermore National Laboratory; R. S. Craxton and P. W. McKenty of the Univ. Rochester; P. Fitzsimmons and A. Nikroo of General Atomics; H. Rinderknecht, M. Rosenberg, and M. G

  15. Enhanced hydrogen storage properties of MgH2 co-catalyzed with K2NiF6 and CNTs.

    Science.gov (United States)

    Sulaiman, N N; Ismail, M

    2016-12-06

    The composite of MgH 2 /K 2 NiF 6 /carbon nanotubes (CNTs) is prepared by ball milling, and its hydrogenation properties are studied for the first time. MgH 2 co-catalyzed with K 2 NiF 6 and CNTs exhibited an improvement in the onset dehydrogenation temperature and isothermal de/rehydrogenation kinetics compared with the MgH 2 -K 2 NiF 6 composite. The onset dehydrogenation temperature of MgH 2 doped with 10 wt% K 2 NiF 6 and 5 wt% CNTs is 245 °C, which demonstrated a reduction of 25 °C compared with the MgH 2 + 10 wt% K 2 NiF 6 composite. In terms of rehydrogenation kinetics, MgH 2 doped with 10 wt% K 2 NiF 6 and 5 wt% CNTs samples absorbed 3.4 wt% of hydrogen in 1 min at 320 °C, whereas the MgH 2 + 10 wt% K 2 NiF 6 sample absorbed 2.6 wt% of hydrogen under the same conditions. For dehydrogenation kinetics at 320 °C, the MgH 2 + 10 wt% K 2 NiF 6 + 5 wt% CNTs sample released 3.3 wt% hydrogen after 5 min of dehydrogenation. By contrast, MgH 2 doped with 10 wt% K 2 NiF 6 released 3.0 wt% hydrogen in the same time period. The apparent activation energy, E a , for the dehydrogenation of MgH 2 doped with 10 wt% K 2 NiF 6 reduced from 100.0 kJ mol -1 to 70.0 kJ mol -1 after MgH 2 was co-doped with 10 wt% K 2 NiF 6 and 5 wt% CNTs. Based on the experimental results, the hydrogen storage properties of the MgH 2 /K 2 NiF 6 /CNTs composite is enhanced because of the catalytic effects of the active species of KF, KH and Mg 2 Ni that are formed in situ during dehydrogenation, as well as the unique structure of CNTs.

  16. Radiation effects on active camera electronics in the target chamber at the National Ignition Facility

    Science.gov (United States)

    Dayton, M.; Datte, P.; Carpenter, A.; Eckart, M.; Manuel, A.; Khater, H.; Hargrove, D.; Bell, P.

    2017-08-01

    The National Ignition Facility's (NIF) harsh radiation environment can cause electronics to malfunction during high-yield DT shots. Until now there has been little experience fielding electronic-based cameras in the target chamber under these conditions; hence, the performance of electronic components in NIF's radiation environment was unknown. It is possible to purchase radiation tolerant devices, however, they are usually qualified for radiation environments different to NIF, such as space flight or nuclear reactors. This paper presents the results from a series of online experiments that used two different prototype camera systems built from non-radiation hardened components and one commercially available camera that permanently failed at relatively low total integrated dose. The custom design built in Livermore endured a 5 × 1015 neutron shot without upset, while the other custom design upset at 2 × 1014 neutrons. These results agreed with offline testing done with a flash x-ray source and a 14 MeV neutron source, which suggested a methodology for developing and qualifying electronic systems for NIF. Further work will likely lead to the use of embedded electronic systems in the target chamber during high-yield shots.

  17. Modulation of aryl hydrocarbon receptor target genes in circulating lymphocytes from dairy cows bred in a dioxin-like PCB contaminated area

    International Nuclear Information System (INIS)

    Girolami, Flavia; Spalenza, Veronica; Carletti, Monica; Sacchi, Paola; Rasero, Roberto; Nebbia, Carlo

    2013-01-01

    Animal productions (i.e. fish, eggs, milk and dairy products) represent the major source of exposure to dioxins, furans, and dioxin-like (DL) polychlorobiphenyls for humans. The negative effects of these highly toxic and persistent pollutants are mediated by the activation of the aryl hydrocarbon receptor (AHR) that elicits the transcriptional induction of several genes, including those involved in xenobiotic metabolism. Previously we demonstrated the presence and functioning of the AHR signaling pathway in primary cultures of bovine blood lymphocytes. The aim of the present study was to investigate by real time PCR the expression and the inducibility of selected target genes (i.e. AHR, AHR nuclear translocator (ARNT), AHR repressor, CYP1A1 and CYP1B1) in uncultured cells from dairy cows naturally exposed to DL-compounds. The study was carried out on two groups of animals bred in a highly polluted area and characterized by a different degree of contamination, as assessed by bulk milk TEQ values, and a control group reared in an industry free area. Bovine lymphocytes expressed only AHR, ARNT and CYP1B1 genes to a detectable level; moreover, only CYP1B1 expression appeared to be correlated to TEQ values, being higher in the most contaminated group, and decreasing along with animal decontamination. Finally, lymphocytes from exposed cows displayed a lower inducibility of both CYP1A1 and CYP1B1 after the in vitro treatment with a specific AHR ligand. In conclusion, our results indicate that DL-compound contaminated cows may display significant changes in AHR-target gene expression of circulating lymphocytes. - Highlights: ► The expression of AHR-target genes in blood bovine lymphocytes was evaluated. ► The lymphocyte CYP1B1 expression appears to be related to bulk milk TEQ values. ► Blood lymphocytes from dairy cows might represent a matrix for dioxin biomonitoring

  18. Modulation of aryl hydrocarbon receptor target genes in circulating lymphocytes from dairy cows bred in a dioxin-like PCB contaminated area

    Energy Technology Data Exchange (ETDEWEB)

    Girolami, Flavia [Department of Animal Pathology, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco (Italy); Spalenza, Veronica [Department of Animal Production, Epidemiology and Ecology, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco (Italy); Carletti, Monica [Department of Animal Pathology, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco (Italy); Sacchi, Paola [Department of Animal Production, Epidemiology and Ecology, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco (Italy); Rasero, Roberto [Department of Animal Production, Epidemiology and Ecology, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco (Italy); Nebbia, Carlo [Department of Animal Pathology, University of Turin, Via Leonardo da Vinci 44, 10095 Grugliasco (Italy)

    2013-04-15

    Animal productions (i.e. fish, eggs, milk and dairy products) represent the major source of exposure to dioxins, furans, and dioxin-like (DL) polychlorobiphenyls for humans. The negative effects of these highly toxic and persistent pollutants are mediated by the activation of the aryl hydrocarbon receptor (AHR) that elicits the transcriptional induction of several genes, including those involved in xenobiotic metabolism. Previously we demonstrated the presence and functioning of the AHR signaling pathway in primary cultures of bovine blood lymphocytes. The aim of the present study was to investigate by real time PCR the expression and the inducibility of selected target genes (i.e. AHR, AHR nuclear translocator (ARNT), AHR repressor, CYP1A1 and CYP1B1) in uncultured cells from dairy cows naturally exposed to DL-compounds. The study was carried out on two groups of animals bred in a highly polluted area and characterized by a different degree of contamination, as assessed by bulk milk TEQ values, and a control group reared in an industry free area. Bovine lymphocytes expressed only AHR, ARNT and CYP1B1 genes to a detectable level; moreover, only CYP1B1 expression appeared to be correlated to TEQ values, being higher in the most contaminated group, and decreasing along with animal decontamination. Finally, lymphocytes from exposed cows displayed a lower inducibility of both CYP1A1 and CYP1B1 after the in vitro treatment with a specific AHR ligand. In conclusion, our results indicate that DL-compound contaminated cows may display significant changes in AHR-target gene expression of circulating lymphocytes. - Highlights: ► The expression of AHR-target genes in blood bovine lymphocytes was evaluated. ► The lymphocyte CYP1B1 expression appears to be related to bulk milk TEQ values. ► Blood lymphocytes from dairy cows might represent a matrix for dioxin biomonitoring.

  19. Acoustic Longitudinal Field NIF Optic Feature Detection Map Using Time-Reversal & MUSIC

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, S K

    2006-02-09

    We developed an ultrasonic longitudinal field time-reversal and MUltiple SIgnal Classification (MUSIC) based detection algorithm for identifying and mapping flaws in fused silica NIF optics. The algorithm requires a fully multistatic data set, that is one with multiple, independently operated, spatially diverse transducers, each transmitter of which, in succession, launches a pulse into the optic and the scattered signal measured and recorded at every receiver. We have successfully localized engineered ''defects'' larger than 1 mm in an optic. We confirmed detection and localization of 3 mm and 5 mm features in experimental data, and a 0.5 mm in simulated data with sufficiently high signal-to-noise ratio. We present the theory, experimental results, and simulated results.

  20. Simulations and experiments of the growth of the “tent” perturbation in NIF ignition implosions

    Science.gov (United States)

    Hammel, B. A.; Tommasini, R.; Clark, D. S.; Field, J.; Stadermann, M.; Weber, C.

    2016-05-01

    NIF capsules are supported in the hohlraum by two thin (∼15-110 nm) Formvar films (“tent”). Highly resolved HYDRA simulations indicate that a large (∼40% peak-average) areal density (ρR) perturbation develops on the capsule during acceleration as a consequence of this support geometry. This perturbation results in a jet of dense DT and, in some cases, CH that penetrates and cools the hot spot, significantly degrading the neutron yield (∼10-20% of 1D yield). We examine “low-foot” and “high-foot” pulse shapes, tent thicknesses, and geometries. Simulations indicate that thinner tents result in a smaller pR perturbation, however, the departure angle of the tent from the capsule surface is important, with steeper angles resulting in larger perturbations.

  1. The Magnetic Recoil Spectrometer for time-resolved neutron measurements (MRSt) at the NIF

    Science.gov (United States)

    Parker, C. E.; Frenje, J. A.; Wink, C. W.; Gatu Johnson, M.; Lahmann, B.; Li, C. K.; Seguin, F. H.; Petrasso, R. D.; Hilsabeck, T. J.; Kilkenny, J. D.; Bionta, R.; Casey, D. T.; Khater, H. Y.; Forrest, C. J.; Glebov, V. Yu.; Sorce, C.; Hares, J. D.; Siegmund, O. H. W.

    2017-10-01

    The next-generation Magnetic Recoil Spectrometer, called MRSt, will provide time-resolved measurements of the DT-neutron spectrum. These measurements will provide critical information about the time evolution of the fuel assembly, hot-spot formation, and nuclear burn in Inertial Confinement Fusion (ICF) implosions at the National Ignition Facility (NIF). The neutron spectrum in the energy range 12-16 MeV will be measured with high accuracy ( 5%), unprecedented energy resolution ( 100 keV) and, for the first time ever, time resolution ( 20 ps). An overview of the physics motivation, conceptual design for meeting these performance requirements, and the status of the offline tests for critical components will be presented. This work was supported in part by the U.S. DOE, LLNL, and LLE.

  2. Response Time Measurements of the NIF DANTE XRD-31 X-Ray Diodes (Pre-print)

    International Nuclear Information System (INIS)

    Pellinen, Don; Griffin, Michael

    2009-01-01

    The XRD-31 is a fast, windowless X-ray vacuum