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Sample records for nif optics assembly

  1. Management Prestart Review Phase 1 for the NIF Optics Assembly Building (OAB)

    International Nuclear Information System (INIS)

    Dragoo, V

    2000-01-01

    A Management Prestart Review (MPR) for the National Ignition Facility (NIF) Optics Assembly Building (OAB) was conducted from June, 2000, through October, 2000. This review was performed to determine readiness of the facility and management to transfer the facility from the construction to the commissioning and operations phase. This review process provides assurance that the appropriate line management is in place to effect the turnover. Completion and acceptance of this report constitutes a turnover of facility and equipment operational responsibility from the Beampath Infrastructure System Construction organization to the Assembly Installation and Refurbishment Operations (assembly equipment installation/activation and mechanical cleaning operations) and the Beampath Infrastructure System (BIS) Commissioning and Operations Organizations (conventional facility operations). The OAB MPR provides to the NIF Project Manager an independent, systematic assessment of: (1) Readiness of line management for the turnover to take place, (2) Completeness of the equipment and facility installation of the OAB, (3) Readiness of personnel to operate within the facility, and (4) Implementation and efficacy of key management control processes and procedures. The MPR process assures that the technical, cost, and schedule risk associated with the installation/activation of OAB special equipment, mechanical cleaning, and conventional facility operations within the OAB are evaluated and are acceptable. Specifically, the scope of the review addresses technical and operational attributes of the equipment and facility systems that have been determined to have significant project risk. This report implements the LLNL requirement that MPRs shall be conducted before all new facilities are brought into operation, Lawrence Livermore National Laboratory (LLNL) ES and H Manual (M-010), Section 2.2.5, Pre-Start Reviews. The MPR process is an essential part of the ISM work authorization and

  2. 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.

  3. 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

  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. 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

  6. Penetrating radiation impact on NIF final optic components

    International Nuclear Information System (INIS)

    Marshall, C.D.; Speth, J.A.; DeLoach, L.D.; Payne, S.A.

    1996-01-01

    Goal of the National Ignition Facility (NIF) is to achieve thermonuclear ignition in a laboratory environment in inertial confinement fusion (ICF). This will enable NIF to service the DOE stockpile stewardship management program, inertial fusion energy goals, and advance scientific frontiers. All of these applications will make use of the extreme conditions that the facility will create in the target chamber. In the case of a prospected 20 MJ yield scenario, NIF will produce 10 19 neutrons with DT fusion 14 MeV energy per neutron. There will also be high-energy x rays as well as solid, liquid, and gaseous target debris produced either directly or indirectly by the inertial confinement fusion process. A critical design issue is the protection of the final optical components as well as sophisticated target diagnostics in such a harsh environment

  7. 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.

  8. Optical Space Telescope Assembly

    Data.gov (United States)

    National Aeronautics and Space Administration — The Optical Space Telescope Assembly (OSTA) task is to demonstrate the technology readiness of assembling large space telescopes on orbit in 2015. This task is an...

  9. 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.

  10. Upgrades to the VISAR-streaked optical pyrometer (SOP) system on NIF

    Science.gov (United States)

    Manuel, A. M.; Millot, M.; Seppala, L. G.; Frieders, G.; Zeid, Z.; Christensen, K.; Celliers, P. M.

    2015-08-01

    The Velocity Interferometer System for Any Reflector (VISAR) is a critical diagnostic in Inertial Confinement Fusion and High Energy Density research as it has the ability to track shock fronts or interfaces moving 0.1-100 km/s with great accuracy. At the National Ignition Facility (NIF), the VISAR has recently been used successfully for implosion tuning and equation of state measurements. However, the initial design of the companion Streaked Optical Pyrometer (SOP) to measure spectral radiance - hence shock temperature - suffers from large background levels and poor spatial resolution. We report on an upgrade to improve the spatial resolution in the 560-640nm band by using custom lenses and replacing the Dove prism with a K-mirror and implementing a gating-circuit for the streak camera to reduce background signal. We envision that upgraded SOP will provide high quality data collection matching NIF VISAR's standards.

  11. Ultraviolet Light Generation and Transport in the Final Optics Assembly of the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Wegner, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hackel, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Feit, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Parham, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kozlowski, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whitman, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-02-12

    The design of the National Ignition Facility (NIF) includes a Final Optics Assembly (FOA) subsystem for ultraviolet (UV) light generation and transport for each of the 192 beamlines. Analytical and experimental work has been done to help understand and predict the performance of FOA.

  12. 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.

  13. Monolithic fiber optic sensor assembly

    Science.gov (United States)

    Sanders, Scott

    2015-02-10

    A remote sensor element for spectrographic measurements employs a monolithic assembly of one or two fiber optics to two optical elements separated by a supporting structure to allow the flow of gases or particulates therebetween. In a preferred embodiment, the sensor element components are fused ceramic to resist high temperatures and failure from large temperature changes.

  14. Optics assembly for high power laser tools

    Science.gov (United States)

    Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.

    2016-06-07

    There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

  15. Study of the integrity of pressurized LEH window assemblies at cryogenic temperatures for NIF targets

    Energy Technology Data Exchange (ETDEWEB)

    Hamza, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-08-05

    The National Ignition Facility (NIF) is a directorate of LLNL, a DOE Lab, and is home to the world’s largest laser. This laser shoots its 192 beams at a target about the size of a pencil eraser. Within the target are two main chambers; and depending on the type of shot, those chambers need to be pressurized to a certain point at a very low temperature (18 Kelvin). The component used for keeping the hohlraum at its designated pressure is a Laser Entrance Hole (LEH) window, made from a thin (0.5um) polyimide film and an aluminum washer attached with a miniscule amount of polymeric adhesive. One issue that has been known to happen is the chambers will leak, at very low rates (5.0E-7 mBar-liter/s and under). At higher pressures significantly larger leak rates have been observed.There are three proposed mechanisms by which the LEH windows are leaking. The first is that there is a small pinhole somewhere in the freestanding film. This is the most unlikely because before any film is shipped from Luxel, it must pass a 50-75 torr room temperature pressure test. The second is a tear in the film at the edge of the washer. This type of damage suggests that the film is under additional stress at this edge portion and/or the edge of the washer itself is what is doing the damage. Lastly, it has been hypothesized that there are small channels under the window that do not get completely filled by the glue and, if they connect to the edge of the freestanding portion of the film, then the pressure can escape through them. These channels were the mechanism being most directly tested over the course of the experiments.

  16. Design calculations for a xenon plasma x-ray shield to protect the NIF optical Thomson scattering diagnostic.

    Science.gov (United States)

    Swadling, G F; Ross, J S; Datte, P; Moody, J; Divol, L; Jones, O; Landen, O

    2016-11-01

    An Optical Thomson Scattering (OTS) diagnostic is currently being developed for the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. This diagnostic is designed to make measurements of the hohlraum plasma parameters, such as the electron temperature and the density, during inertial confinement fusion (ICF) experiments. NIF ICF experiments present a very challenging environment for optical measurements; by their very nature, hohlraums produce intense soft x-ray emission, which can cause "blanking" (radiation induced opacity) of the radiation facing optical components. The soft x-ray fluence at the surface of the OTS blast shield, 60 cm from the hohlraum, is estimated to be ∼8 J cm -2 . This is significantly above the expected threshold for the onset of "blanking" effects. A novel xenon plasma x-ray shield is proposed to protect the blast shield from x-rays and mitigate "blanking." Estimates suggest that an areal density of 10 19 cm -2 Xe atoms will be sufficient to absorb 99.5% of the soft x-ray flux. Two potential designs for this shield are presented.

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

    Energy Technology Data Exchange (ETDEWEB)

    Malone, Robert; Celeste, John; Celliers, Peter; Frogget, Brent; Robert Guyton,,; Kaufman, Morris; Lee, Tony; MacGowan, Brian; Ng, Edmend; Reinbachs, Imants; Robinson, Ronald; Tunnell, Thomas; Watts, Phillip

    2007-08-01

    The National Ignition Facility (NIF) requires optical diagnostics for measuring shock velocities in shock physics experiments. The nature of the NIF facility requires the alignment of complex three-dimensional optical systems of very long distances. Access to the alignment mechanisms can be limited, and any alignment system must be operator friendly. 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 21 m. 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. Movable aperture cards, placed before and after lens groups, show the spread of alignment spots created by the orange and red alignment lasers. Optical elements include 1-in. to 15-in. diameter mirrors, lenses with up to 10.5-in. 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.

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

    Science.gov (United States)

    Malone, Robert M.; Celeste, John R.; Celliers, Peter M.; Frogget, Brent C.; Guyton, Robert L.; Kaufman, Morris I.; Lee, Tony L.; MacGowan, Brian J.; Ng, Edmund W.; Reinbachs, Imants P.; Robinson, Ronald B.; Tunnell, Thomas W.; Watts, Phillip W.

    2007-09-01

    The National Ignition Facility (NIF) requires optical diagnostics for measuring shock velocities in shock physics experiments. The nature of the NIF facility requires the alignment of complex three-dimensional optical systems of very long distances. Access to the alignment mechanisms can be limited, and any alignment system must be operator-friendly. The Velocity Interferometer System for Any Reflector (VISAR) measures shock velocities and shock breakout times of 1- to 5-mm targets at a location remote to the NIF target chamber. A third imaging system measures self-emission of the targets. These three optical systems using the same vacuum chamber port each have a total track of 21 m. All optical lenses are on kinematic mounts or sliding rails, enabling pointing accuracy of the optical axis to be systematically checked. Counter-propagating laser beams (orange and red) align these diagnostics to a listing of tolerances. Floating apertures, placed before and after lens groups, display misalignment by showing the spread of alignment spots created by the orange and red alignment lasers. Optical elements include 1-in. to 15-in. diameter mirrors, lenses with up to 10.5-in. diameters, beam splitters, 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 is achieved before each shot.

  19. Photovoltaic concentrator assembly with optically active cover

    Science.gov (United States)

    Plesniak, Adam P

    2014-01-21

    A photovoltaic concentrator assembly that includes a housing that defines an internal volume and includes a rim, wherein the rim defines an opening into the internal volume, a photovoltaic cell positioned in the internal volume, and an optical element that includes an optically active body and a flange extending outward from the body, wherein the flange is sealingly engaged with the rim of the housing to enclose the internal volume.

  20. Fiber optical assembly for fluorescence spectrometry

    Science.gov (United States)

    Carpenter, II, Robert W.; Rubenstein, Richard; Piltch, Martin; Gray, Perry

    2010-12-07

    A system for analyzing a sample for the presence of an analyte in a sample. The system includes a sample holder for containing the sample; an excitation source, such as a laser, and at least one linear array radially disposed about the sample holder. Radiation from the excitation source is directed to the sample, and the radiation induces fluorescent light in the sample. Each linear array includes a plurality of fused silica optical fibers that receive the fluorescent light and transmits a fluorescent light signal from the first end to an optical end port of the linear array. An end port assembly having a photo-detector is optically coupled to the optical end port. The photo-detector detects the fluorescent light signal and converts the fluorescent light signal into an electrical signal.

  1. Optical matrix for nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Romero G, M.; Gonzaga O, A.

    1996-01-01

    In order to detect the presence of fuel rods, it was selected a reflection optical transducer, which provides a measurable electrical signal when the beam at a certain distance is interrupted then there is a reflection causing a excitation to the sensor that provides a change of state at the output of transducer. This step is coupled through an operational amplifier which drives the opto coupler circuit isolating this step of the interface and a personal computer. This work presents the description of components, designs, signal coupler and opto isolater circuit, interface circuit and tutorial assemble program. (Author)

  2. Optical Assembly and Characterization System for Nano-Photonics Research

    Science.gov (United States)

    2016-03-01

    Integrated device characterization for both in-plane and surface-normal photonic devices. This assembly and characterization system will significantly...Unlimited Final Report: Optical Assembly and Characterization System for Nano- Photonics Research The views, opinions and/or findings contained in this...reviewed journals: Final Report: Optical Assembly and Characterization System for Nano- Photonics Research Report Title With this equipment funding support

  3. Cone penetrometer fiber optic raman spectroscopy probe assembly

    Science.gov (United States)

    Kyle, Kevin R.; Brown, Steven B.

    2000-01-01

    A chemically and mechanically robust optical Raman spectroscopy probe assembly that can be incorporated in a cone penetrometer (CPT) for subsurface deployment. This assembly consists of an optical Raman probe and a penetrometer compatible optical probe housing. The probe is intended for in-situ chemical analysis of chemical constituents in the surrounding environment. The probe is optically linked via fiber optics to the light source and the detection system at the surface. A built-in broadband light source provides a strobe method for direct measurement of sample optical density. A mechanically stable sapphire window is sealed directly into the side-wall of the housing using a metallic, chemically resistant, hermetic seal design. This window permits transmission of the interrogation light beam and the resultant signal. The spectroscopy probe assembly is capable of accepting Raman, Laser induced Fluorescence, reflectance, and other optical probes with collimated output for CPT deployment.

  4. National Ignition Facility subsystem design requirements optics assembly building (OAB) SSDR 1.2.2.3

    International Nuclear Information System (INIS)

    Kempel, P.; Hands, J.

    1996-01-01

    This Subsystem Design Requirement (SSDR) document establishes the performance, design, and verification requirements 'for the conventional building systems and subsystems of the Optics Assembly Building (OAB). These building system requirements are associated with housing and supporting the operational flow of personnel and materials throughout the OAB for preparing and repairing optical and mechanical components used in the National Ignition Facility (NIF) Laser and Target Building (LTAB). This SSDR addresses the following subsystems associated with the OAB: * Structural systems for the building spaces and operational-support equipment and building- support equipment. * Architectural building features associated with housing the space, operational cleanliness, and functional operation of the facility. * Heating, Ventilating, and Air Conditioning (HVAC) systems for maintaining a clean and thermally stable ambient environment within the facility. * Plumbing systems that provide potable water and sanitary facilities for the occupants and stormwater drainage for transporting rainwater. * Fire Protection systems that guard against fire damage to the facility and its contents. * Material handling equipment for transferring optical assemblies and other materials within building areas and to the LTAB. * Mechanical process piping systems for liquids and gases that provide cooling, cleaning, and other service to optical and mechanical components. * Electrical power and grounding systems that provide service to the building and 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. Generic design criteria, such as siting data, seismic requirements, utility availability, and other information that contributes to the OAB design, are not addressed in this document

  5. 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.

  6. Formation of a homocitrate-free iron-molybdenum cluster on NifEN: implications for the role of homocitrate in nitrogenase assembly.

    Science.gov (United States)

    Fay, Aaron Wolfe; Blank, Michael Aaron; Yoshizawa, Janice Mariko; Lee, Chi Chung; Wiig, Jared Andrew; Hu, Yilin; Hodgson, Keith Owen; Hedman, Britt; Ribbe, Markus Walter

    2010-03-28

    Molybdenum (Mo)-dependent nitrogenase is a complex metalloprotein that catalyzes the biological reduction of dinitrogen (N(2)) to ammonia (NH(3)) at the molybdenum-iron cofactor (FeMoco) site of its molybdenum-iron (MoFe) protein component. Here we report the formation of a homocitrate-free, iron-molybdenum ("FeMo") cluster on the biosynthetic scaffold of FeMoco, NifEN. Such a NifEN-associated "FeMo" cluster exhibits EPR features similar to those of the NifEN-associated, fully-complemented "FeMoco", which originate from the presence of Mo in both cluster species; however, "FeMo" cluster and "FeMoco" display different temperature-dependent changes in the line shape and the signal intensity of their respective EPR features, which reflect the impact of homocitrate on the redox properties of these clusters. XAS/EXAFS analysis reveals that the Mo centers in both "FeMo" cluster and "FeMoco" are present in a similar coordination environment, although Mo in "FeMo" cluster is more loosely coordinated as compared to that in "FeMoco" with respect to the Mo-O distances in the cluster, likely due to the absence of homocitrate that normally serves as an additional ligand for the Mo in the cluster. Subsequent biochemical investigation of the "FeMo" cluster not only facilitates the determination of the sequence of events in the mobilization of Mo and homocitrate during FeMoco maturation, but also permits the examination of the role of homocitrate in the transfer of FeMoco between NifEN and MoFe protein. Combined outcome of these studies establishes a platform for future structural analysis of the interactions between NifEN and MoFe protein, which will provide useful insights into the mechanism of cluster transfer between the two proteins.

  7. A 3D Optical Metamaterial Made by Self-Assembly

    KAUST Repository

    Vignolini, Silvia

    2011-10-24

    Optical metamaterials have unusual optical characteristics that arise from their periodic nanostructure. Their manufacture requires the assembly of 3D architectures with structure control on the 10-nm length scale. Such a 3D optical metamaterial, based on the replication of a self-assembled block copolymer into gold, is demonstrated. The resulting gold replica has a feature size that is two orders of magnitude smaller than the wavelength of visible light. Its optical signature reveals an archetypal Pendry wire metamaterial with linear and circular dichroism. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Peptide-Assembled Optically Responsive Nanoparticle Complexes

    National Research Council Canada - National Science Library

    Slocik, Joseph M; Tam, Felicia; Halas, Naomi J; Naik, Rajesh R

    2007-01-01

    .... Here we report two types of active nanoparticle complexes, with properties controlled by near-infrared illumination, resulting from the assembly of photothermally responsive plasmonic nanoparticle...

  9. RT Self-assembly of Silica Nanoparticles on Optical Fibres

    DEFF Research Database (Denmark)

    Canning, John; Lindoy, Lachlan; Huyang, George

    2013-01-01

    The room temperature deposition of self-assembling silica nanoparticles onto D-shaped optical fibres x201c;D-fibrex201d;), drawn from milled preforms fabricated by modified chemical vapor deposition, is studied and preliminary results reported here.......The room temperature deposition of self-assembling silica nanoparticles onto D-shaped optical fibres x201c;D-fibrex201d;), drawn from milled preforms fabricated by modified chemical vapor deposition, is studied and preliminary results reported here....

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

    International Nuclear Information System (INIS)

    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)

  11. Single Chromatin Fibre Assembly Using Optical Tweezers

    NARCIS (Netherlands)

    Bennink, Martin L.; Pope, L.H.; Leuba, S.H.; de Grooth, B.G.; Greve, Jan

    2001-01-01

    Here we observe the formation of a single chromatin fibre using optical tweezers. A single -DNA molecule was suspended between two micron-sized beads, one held by a micropipette and the other in an optical trap. The constrained DNA molecule was incubated with Xenopus laevis egg extract in order to

  12. Opto-mechanical assembly procurement for the National Ignition Facility

    International Nuclear Information System (INIS)

    House, W.; Simon, T.

    1999-01-01

    A large number of the small optics procurements for the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) will be in the form of completely assembled, tested, and cleaned subsystems. These subsystems will be integrated into the NIF at LLNL. To accomplish this task, the procurement packages will include, optical and mechanical drawings, acceptance test and cleanliness requirements. In January 1999, the first such integrated opto-mechanical assembly was received and evaluated at LLNL. With the successful completion of this important trial procurement, we were able to establish the viability of purchasing clean, ready to install, opto-mechanical assemblies from vendors within the optics industry. 32 vendors were chosen from our supplier database for quote, then five were chosen to purchase from. These five vendors represented a cross section of the optics industry. From a ''value'' catalog supplier (that did the whole job internally) to a partnership between three specialty companies, these vendors demonstrated they have the ingenuity and capability to deliver cost competitive, NIF-ready, opto- mechanical assemblies. This paper describes the vendor selection for this procurement, technical requirements including packaging, fabrication, coating, and cleanliness specifications, then testing and verification. It also gives real test results gathered from inspections performed at LLNL that show how our vendors scored on the various requirements. Keywords: Opto-Mechanical, assembly, NIF, packaging, shipping, specifications, procurement, MIL-STD-1246C, surface cleanliness

  13. Engineering of automated assembly of beam-shaping optics

    Science.gov (United States)

    Haag, Sebastian; Sinhoff, Volker; Müller, Tobias; Brecher, Christian

    2014-03-01

    Beam-shaping is essential for any kind of laser application. Assembly technologies for beam-shaping subassemblies are subject to intense research and development activities and their technical feasibility has been proven in recent years while economic viability requires more efficient engineering tools for process planning and production ramp up of complex assembly tasks for micro-optical systems. The work presented in this paper aims for significant reduction of process development and production ramp up times for the automated assembly of micro-optical subassemblies for beam-collimation and beam-tilting. The approach proposed bridges the gap between the product development phase and the realization of automation control through integration of established software tools such as optics simulation and CAD modeling as well as through introduction of novel software tools and methods to efficiently describe active alignment strategies. The focus of the paper is put on the methodological approach regarding the engineering of assembly processes for beam-shaping micro-optics and the formal representation of assembly objectives similar to representation in mechanical assemblies. Main topic of the paper is the engineering methodology for active alignment processes based on the classification of optical functions for beam-shaping optics and corresponding standardized measurement setups including adaptable alignment algorithms. The concepts are applied to industrial use-cases: (1) integrated collimation module for fast- and slow-axis and (2) beam-tilting subassembly consisting of a fast-axis collimator and micro-lens array. The paper concludes with an overview of current limitations as well as an outlook on the next development steps considering adhesive bonding processes.

  14. Multi-sensor control for precise assembly of optical components

    Directory of Open Access Journals (Sweden)

    Ma Li

    2014-06-01

    Full Text Available In order to perform an optical assembly accurately, a multi-sensor control strategy is developed which includes an attitude measurement system, a vision system, a loss measurement system and a force sensor. A 3-DOF attitude measuring method using linear variable differential transformers (LVDT is designed to adjust the relation of position and attitude between the spherical mirror and the resonator. A micro vision feedback system is set up to extract the light beam and the diaphragm, which can achieve the coarse positioning of the spherical mirror in the optical assembly process. A rapid self-correlation method is presented to analyze the spectrum signal for the fine positioning. In order to prevent the damage of the optical components and realize sealing of the resonator, a hybrid force-position control is constructed to control the contact force of the optical components. The experimental results show that the proposed multi-sensor control strategy succeeds in accomplishing the precise assembly of the optical components, which consists of parallel adjustment, macro coarse adjustment, macro approach, micro fine adjustment, micro approach and optical contact. Therefore, the results validate the multi-sensor control strategy.

  15. Nuclear Physics using NIF

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, L A; Bleuel, D L; Caggiano, J A; Cerjan, C; Gostic, J; Hatarik, R; Hartouni, E; Hoffman, R D; Sayre, D; Schneider, D G; Shaughnessy, D; Stoeffl, W; Yeamans, C; Greife, U; Larson, R; Hudson, M; Herrmann, H; Kim, Y H; Young, C S; Mack, J; Wilson, D; Batha, S; Hoffman, N; Langenbrunner, J; Evans, S

    2011-09-28

    The National Ignition Facility (NIF) is the world's premier inertial confinement fusion facility designed to achieve sustained thermonuclear burn (ignition) through the compression of hydrogen isotopic fuels to densities in excess of 10{sup 3} g/cm{sup 3} and temperatures in excess of 100 MK. These plasma conditions are very similar to those found in the cores of Asymptotic Giant Branch (AGB) stars where the s-process takes place, but with a neutron fluence per year 10{sup 4} times greater than a star. These conditions make NIF an excellent laboratory to measure s-process (n,{gamma}) cross sections in a stellar-like plasma for the first time. Starting in Fall 2009, NIF has been operating regularly with 2-4 shots being performed weekly. These experiments have allowed the first in situ calibration of the detectors and diagnostics needed to measure neutron capture, including solid debris collection and prompt {gamma}-ray detection. In this paper I will describe the NIF facility and capsule environment and present two approaches for measuring s-process neutron capture cross sections using NIF.

  16. LISA telescope assembly optical stability characterization for ESA

    NARCIS (Netherlands)

    Verlaan, A.L.; Hogenhuis, H.; Pijnenburg, J.A.C.M.; Lemmen, M.H.J.; Lucarelli, S.; Scheulen, D.; Ende, D.

    2012-01-01

    The LISA Optical Stability Characterization project is part of the LISA CTP activities to achieve the required Technonlogy Readiness Level (TRL) for all of the LISA technologies used. This activity aims demonstration of the Telescope Assembly (TA), with a structure based on CFRP technology, that a

  17. Assembly of optical spark chambers for the experiment Nue

    CERN Multimedia

    1974-01-01

    To continue the research on neutral currents after their discovery in Gargamelle in 1973, the Aachen-Padua Collaboration set up in the neutrino beam of the PS South-East Area, behind Gargamelle, an assembly of 150 optical spark chambers, 2x2 m2 extending over 8 m (experiment T230, Nue). Hans Reithler stands on the right.

  18. Self-Assembled InAs Nanowires as Optical Reflectors.

    Science.gov (United States)

    Floris, Francesco; Fornasari, Lucia; Marini, Andrea; Bellani, Vittorio; Banfi, Francesco; Roddaro, Stefano; Ercolani, Daniele; Rocci, Mirko; Beltram, Fabio; Cecchini, Marco; Sorba, Lucia; Rossella, Francesco

    2017-11-21

    Subwavelength nanostructured surfaces are realized with self-assembled vertically-aligned InAs nanowires, and their functionalities as optical reflectors are investigated. In our system, polarization-resolved specular reflectance displays strong modulations as a function of incident photon energy and angle. An effective-medium model allows one to rationalize the experimental findings in the long wavelength regime, whereas numerical simulations fully reproduce the experimental outcomes in the entire frequency range. The impact of the refractive index of the medium surrounding the nanostructure assembly on the reflectance was estimated. In view of the present results, sensing schemes compatible with microfluidic technologies and routes to innovative nanowire-based optical elements are discussed.

  19. Assembly of optical-scale dumbbells into dense photonic crystals.

    Science.gov (United States)

    Forster, Jason D; Park, Jin-Gyu; Mittal, Manish; Noh, Heeso; Schreck, Carl F; O'Hern, Corey S; Cao, Hui; Furst, Eric M; Dufresne, Eric R

    2011-08-23

    We describe the self-assembly of nonspherical particles into crystals with novel structure and optical properties combining a partial photonic band gap with birefringence that can be modulated by an external field or quenched by solvent evaporation. Specifically, we study symmetric optical-scale polymer dumbbells with an aspect ratio of 1.58. Hard particles with this geometry have been predicted to crystallize in equilibrium at high concentrations. However, unlike spherical particles, which readily crystallize in the bulk, previous experiments have shown that these dumbbells crystallize only under strong confinement. Here, we demonstrate the use of an external electric field to align and assemble the dumbbells to make a birefringent suspension with structural color. When the electric field is turned off, the dumbbells rapidly lose their orientational order and the color and birefringence quickly go away. In this way, dumbbells combine the structural color of photonic crystals with the field addressability of liquid crystals. In addition, we find that if the solvent is removed in the presence of an electric field, the particles self-assemble into a novel, dense crystalline packing hundreds of particles thick. Analysis of the crystal structure indicates that the dumbbells have a packing fraction of 0.7862, higher than the densest known packings of spheres and ellipsoids. We perform numerical experiments to more generally demonstrate the importance of controlling the orientation of anisotropic particles during a concentration quench to achieve long-range order. © 2011 American Chemical Society

  20. Fiber optic assembly and method of making same

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, D.P.; Beckman, T.M.

    1995-12-31

    There is provided an assembly having a light guiding medium sealed to a holder. Preferably the holder is a metal shell and a light guiding medium is an optical fiber of glass or sapphire whisker. The assembly includes a sealing medium which sealingly engages the metal holder to the fiber. In the formation of the assembly, the seal is essentially hermetic having a capability of minimizing leakage having a helium leak rate of less than 1 {times} 10{sup {minus}8} cubic centimeters per second and high strength having a capability of withstanding pressures of 100,000 psi or greater. The features of the assembly are obtained by a specific preparation method and by selection of specific starting materials. The fiber is selected to have a sufficiently high coefficient of thermal expansion which minimizes strains in the component during fabrication, as a result of fabrication, and during use. The other components are selected to be of a material having compatible coefficients of thermal expansion (TEC) where the TEC of the holder is greater than or equal to the TEC of the sealing material. The TEC of the sealing material is in turn greater than or equal to the TEC of the fiber. It is preferred that the materials be selected so that their respective coefficients of thermal expansion are close as possible to one another and they may all be equal.

  1. Optical assembly of bio-hybrid micro-robots.

    Science.gov (United States)

    Barroso, Álvaro; Landwerth, Shirin; Woerdemann, Mike; Alpmann, Christina; Buscher, Tim; Becker, Maike; Studer, Armido; Denz, Cornelia

    2015-04-01

    The combination of micro synthetic structures with bacterial flagella motors represents an actual trend for the construction of self-propelled micro-robots. The development of methods for fabrication of these bacteria-based robots is a first crucial step towards the realization of functional miniature and autonomous moving robots. We present a novel scheme based on optical trapping to fabricate living micro-robots. By using holographic optical tweezers that allow three-dimensional manipulation in real time, we are able to arrange the building blocks that constitute the micro-robot in a defined way. We demonstrate exemplarily that our method enables the controlled assembly of living micro-robots consisting of a rod-shaped prokaryotic bacterium and a single elongated zeolite L crystal, which are used as model of the biological and abiotic components, respectively. We present different proof-of-principle approaches for the site-selective attachment of the bacteria on the particle surface. The propulsion of the optically assembled micro-robot demonstrates the potential of the proposed method as a powerful strategy for the fabrication of bio-hybrid micro-robots.

  2. Assembling optically active and nonactive metamaterials with chiral units

    Directory of Open Access Journals (Sweden)

    Xiang Xiong

    2012-12-01

    Full Text Available Metamaterials constructed with chiral units can be either optically active or nonactive depending on the spatial configuration of the building blocks. For a class of chiral units, their effective induced electric and magnetic dipoles, which originate from the induced surface electric current upon illumination of incident light, can be collinear at the resonant frequency. This feature provides significant advantage in designing metamaterials. In this paper we concentrate on several examples. In one scenario, chiral units with opposite chiralities are used to construct the optically nonactive metamaterial structure. It turns out that with linearly polarized incident light, the pure electric or magnetic resonance (and accordingly negative permittivity or negative permeability can be selectively realized by tuning the polarization of incident light for 90°. Alternatively, units with the same chirality can be assembled as a chiral metamaterial by taking the advantage of the collinear induced electric and magnetic dipoles. It follows that for the circularly polarized incident light, negative refractive index can be realized. These examples demonstrate the unique approach to achieve certain optical properties by assembling chiral building blocks, which could be enlightening in designing metamaterials.

  3. Platinum microheater integrated silicon optical bench assembly for endoscopic optical coherence tomography

    International Nuclear Information System (INIS)

    Xu, Y; Wang, M F; Premachandran, C S; Chen, K W S; Chen, N; Olivo, M

    2010-01-01

    A novel platinum microheater and comb isolator integrated silicon optical bench (SiOB) assembly method has been successfully demonstrated to provide electrical connection and high precision alignment for a two-axis gimbal-less micromirror. Localized heating and wetting of plastic core micro solder balls is achieved by the integrated platinum heater, and the maximum measured temperature of the platinum heater is about 250 °C. In addition, assembly procedures are significantly simplified by involving a comb isolator made by deep reactive ion etching (DRIE) in comparison with our previously reported design. DRIE is also applied to form a 45° trench on the lower silicon substrate with a nearly vertical sidewall for the micromirror. Hence, the overall dimensions of the SiOB assembly can be reduced further to meet the requirements of endoscopic optical coherence tomography (EOCT) for miniaturization

  4. 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...

  5. Self-Assembly of Plasmonic Nanoclusters for Optical Metauids

    Science.gov (United States)

    Schade, Nicholas Benjamin

    I discuss experimental progress towards developing a material with an isotropic, negative index of refraction at optical frequencies. The simplest way to make such a material is to create a metafluid, or a disordered collection of subwavelength, isotropic electromagnetic resonators. Small clusters of metal particles, such as tetrahedra, serve as these constituents. What is needed are methods for manufacturing these structures with high precision and in sufficient yield that their resonances are identical. Jonathan Fan et al. [Science, 328 (5982), 1135-1138, 2010] demonstrated that colloidal self-assembly is a means of preparing electromagnetic resonators from metal nanoparticles. However, the resonances are sensitive to the separation gaps between particles. Standard synthesis routes for metal nanoparticles yield crystals or nanoshells that are inadequate for metafluids due to polydispersity, faceting, and thermal instabilities. To ensure that the separation gaps and resonances are uniform, more monodisperse spherical particles are needed. An additional challenge is the self-assembly of tetrahedral clusters in high yield from these particles. In self-assembly approaches that others have examined previously, the yield of any particular type of cluster is low. In this dissertation I present solutions to several of these problems, developed in collaboration with my research group and others. We demonstrate that slow chemical etching can transform octahedral gold crystals into ultrasmooth, monodisperse nanospheres. The particles can serve as seeds for the growth of larger octahedra which can in turn be etched. The size of the gold nanospheres can therefore be adjusted as desired. We further show that in colloidal mixtures of two sphere species that strongly bind to one another, the sphere size ratio determines the size distribution of self-assembled clusters. At a critical size ratio, tetrahedral clusters assemble in high yield. We explain the experimentally observed

  6. Directed assembly of hybrid nanostructures using optically resonant nanotweezers

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, David [Cornell Univ., Ithaca, NY (United States)

    2015-09-09

    This represents the final report for this project. Over the course of the project we have made significant progress in photonically driven nano-assembly including: (1) demonstrating the first direct optical tweezer based manipulation of proteins, (2) the ability to apply optical angular torques to microtubuals and other rod-shaped microparticles, (3) direct assembly of hybrid nanostructures comprising of polymeric nanoparticles and carbon nanotubes and, (4) the ability to drive biological reactions (specifically protein aggregation) that are thermodynamically unfavorable by applying localized optical work. These advancements are described in the list of papers provided in section 2.0 of the below. Summary details are provided in prior year annual reports. We have two additional papers which will be submitted shortly based on the work done under this award. An updated publication list will be provided to the program manager when those are accepted. In this report, we report on a new advancement made in the final project year, which uses the nanotweezer technology to perform direct measurements of particle-surface interactions. Briefly, these measurements are important for characterizing the stability and behavior of colloidal and nanoparticle suspensions and current techniques are limited in their ability to measure piconewton scale interaction forces on sub-micrometer particles due to signal detection limits and thermal noise. In this project year we developed a new technique called “Nanophotonic Force Microscopy” which uses the localized region of exponentially decaying, near-field, light to confine small particles close to a surface. From the statistical distribution of the light intensity scattered by the particle the technique maps out the potential well of the trap and directly quantify the repulsive force between the nanoparticle and the surface. The major advantage of the technique is that it can measure forces and energy wells below the thermal noise

  7. Phase Transition and Optical Properties of DNA-Gold Nanoparticle Assemblies

    OpenAIRE

    Sun, Young; Harris, Nolan C.; Kiang, Ching-Hwa

    2007-01-01

    We review recent work on DNA-linked gold nanoparticle assemblies. The synthesis, properties, and phase behavior of such DNA-gold nanoparticle assemblies are described. These nanoparticle assemblies have strong optical extinction in the ultraviolet and visible light regions; hence, the technique is used to study the kinetics and phase transitions of DNA-gold nanoparticle assemblies. The melting transition of DNA-gold nanoparticle assemblies shows unusual trends compared to those of free DNA. T...

  8. Multispectral Thermal Imager Optical Assembly Performance and Integration of the Flight Focal Plane Assembly

    International Nuclear Information System (INIS)

    Blake, Dick; Byrd, Don; Christensen, Wynn; Henson, Tammy; Krumel, Les; Rappoport, William; Shen, Gon-Yen

    1999-01-01

    The Multispectral Thermal Imager Optical Assembly (OA) has been fabricated, assembled, successfully performance tested, and integrated into the flight payload structure with the flight Focal Plane Assembly (FPA) integrated and aligned to it. This represents a major milestone achieved towards completion of this earth observing E-O imaging sensor that is to be operated in low earth orbit. The OA consists of an off-axis three mirror anastigmatic (TMA) telescope with a 36 cm unobscured clear aperture, a wide-field-of-view (WFOV) of 1.82 along the direction of spacecraft motion and 1.38 across the direction of spacecraft motion. It also contains a comprehensive on-board radiometric calibration system. The OA is part of a multispectral pushbroom imaging sensor which employs a single mechanically cooled focal plane with 15 spectral bands covering a wavelength range from 0.45 to 10.7 m. The OA achieves near diffraction-limited performance from visible to the long-wave infrared (LWIR) wavelengths. The two major design drivers for the OA are 80% enpixeled energy in the visible bands and radiometric stability. Enpixeled energy in the visible bands also drove the alignment of the FPA detectors to the OA image plane to a requirement of less than 20 m over the entire visible detector field of view (FOV). Radiometric stability requirements mandated a cold Lyot stop for stray light rejection and thermal background reduction. The Lyot stop is part of the FPA assembly and acts as the aperture stop for the imaging system. The alignment of the Lyot stop to the OA drove the centering and to some extent the tilt alignment requirements of the FPA to the OA

  9. 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.

  10. 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.

  11. LISA telescope assembly optical stability characterization for ESA

    Science.gov (United States)

    Verlaan, A. L.; Hogenhuis, H.; Pijnenburg, J.; Lemmen, M.; Lucarelli, S.; Scheulen, D.; Ende, David

    2017-11-01

    The LISA Optical Stability Characterization project is part of the LISA CTP activities to achieve the required Technology Readiness Level (TRL) for all of the LISA technologies used. This activity aims demonstration of the Telescope Assembly (TA), with a structure based on CFRP technology, that a CTE of 10-7 1/K can be achieved with measures to tune the CTE to this level. In addition the demonstration is required to prove that the structure exhibits highly predictable mechanical distortion characteristics when cooling down to - 90°C, during outgassing in space and when going from 1g environment to 0g. This paper describes the test facilities as well as the first test results. A dedicated test setup is designed and realized to allow monitoring dimensional variations of the TA using three interferometers, while varying the temperature in a thermal vacuum chamber. Critical parameters of the verification setup are the length metrology accuracy in thermal vacuum and the thermal vacuum flexibility and stability. The test programme includes Telescope Assembly CTE measurements and thermal gradient characterization.

  12. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-09-01

    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.

  14. Cryogenic Fiber Optic Assemblies for Spaceflight Environments: Design, Manufacturing, Testing, and Integration

    Science.gov (United States)

    Thomes, W. Joe; Ott, Melanie N.; Chuska, Richard; Switzer, Robert; Onuma, Eleanya; Blair, Diana; Frese, Erich; Matyseck, Marc

    2016-01-01

    Fiber optic assemblies have been used on spaceflight missions for many years as an enabling technology for routing, transmitting, and detecting optical signals. Due to the overwhelming success of NASA in implementing fiber optic assemblies on spaceflight science-based instruments, system scientists increasingly request fibers that perform in extreme environments while still maintaining very high optical transmission, stability, and reliability. Many new applications require fiber optic assemblies that will operate down to cryogenic temperatures as low as 20 Kelvin. In order for the fiber assemblies to operate with little loss in optical throughput at these extreme temperatures requires a system level approach all the way from how the fiber assembly is manufactured to how it is held, routed, and integrated. The NASA Goddard Code 562 Photonics Group has been designing, manufacturing, testing, and integrating fiber optics for spaceflight and other high reliability applications for nearly 20 years. Design techniques and lessons learned over the years are consistently applied to developing new fiber optic assemblies that meet these demanding environments. System level trades, fiber assembly design methods, manufacturing, testing, and integration will be discussed. Specific recent examples of ground support equipment for the James Webb Space Telescope (JWST); the Ice, Cloud and Land Elevation Satellite-2 (ICESat-2); and others will be included.

  15. Evidence for the direct interaction of the nifW gene product with the MoFe protein.

    Science.gov (United States)

    Kim, S; Burgess, B K

    1996-04-19

    The Azotobacter vinelandii nifW gene, under control of the nifH promoter, was subcloned into the broad host range multicopy plasmid pKT230 for overexpression in both wild-type and delta nifW strains of A. vinelandii. Unlike the parent delta nifW strain, which grows slowly relative to wild-type under N2-fixing conditions, both overproduction strains grow at the same rate, showing that the overexpressed nifW product is functional in vivo. The approximately 40-fold overexpressed protein was purified, and sequence analysis confirmed its identity. During purification it was observed that NifW in crude extracts ran above the predicted molecular weight on denaturing gels and that as the purification proceeded lower molecular weight forms appeared. Mass spectrometry and studies with protease inhibitors revealed that this abnormal behavior was due to proteolysis. Native molecular weight determinations demonstrate that NifW is a homomultimer, most likely a trimer. Native gel electrophoresis analysis shows that the behavior of wild-type and overexpressed NifW are identical and that when extracts are prepared anaerobically only the homomultimeric forms of NifW are observed. When extracts are exposed to oxygen, however, NifW becomes part of a very high molecular weight complex. Immunoprecipitation with NifW antibodies demonstrate that under those conditions NifW specifically associates with the MoFe protein. These data are consistent with a model whereby NifW is not involved in the initial assembly of an active MoFe protein but rather is part of a system design to protect the MoFe protein from O2 damage.

  16. 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.

  17. Fuzzy-Based Adaptive Hybrid Burst Assembly Technique for Optical Burst Switched Networks

    Directory of Open Access Journals (Sweden)

    Abubakar Muhammad Umaru

    2014-01-01

    Full Text Available The optical burst switching (OBS paradigm is perceived as an intermediate switching technology for future all-optical networks. Burst assembly that is the first process in OBS is the focus of this paper. In this paper, an intelligent hybrid burst assembly algorithm that is based on fuzzy logic is proposed. The new algorithm is evaluated against the traditional hybrid burst assembly algorithm and the fuzzy adaptive threshold (FAT burst assembly algorithm via simulation. Simulation results show that the proposed algorithm outperforms the hybrid and the FAT algorithms in terms of burst end-to-end delay, packet end-to-end delay, and packet loss ratio.

  18. 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

  19. Fiber Optic Cable Assemblies for Space Flight 2: Thermal and Radiation Effects

    Science.gov (United States)

    Ott, Melanie N.

    1998-01-01

    Goddard Space Flight Center is conducting a search for space flight worthy fiber optic cable assemblies that will benefit all projects at all of the NASA centers. This paper is number two in a series of papers being issued as a result of this task to define and qualify space grade fiber optic cable assemblies. Though to qualify and use a fiber optic cable in space requires treatment of the cable assembly as a system, it is very important to understand the design and behavior of its parts. This paper addresses that need, providing information on cable components shrinkage testing and radiation testing results from recent experiments at Goddard Space Flight Center.

  20. 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.

  1. Peptide-Assembled Optically Responsive Nanoparticle Complexes (Preprint)

    National Research Council Canada - National Science Library

    Naik, Rajesh R; Slocik, Joseph M; Tam, Felicia; Halas, Naomi J

    2007-01-01

    .... Here we report two types of active nanoparticle complexes, with properties controlled by near infrared illumination, resulting from the assembly of photothermally responsive plasmonic nanoparticle...

  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. Recent advancements in robotic micro-optical assembly at the Lockheed Martin Optical Payload Center of Excellence

    Science.gov (United States)

    Hwang, David; Larson, Thomas M.

    2017-08-01

    Lockheed Martin Space Systems Company Optical Payloads Center of Excellence is in process of standing up the Robotic Optical Assembly System (ROAS) capability at Lockheed Martin Coherent Technologies in Colorado. This currently implemented Robotic Optical Assembly has enabled Lockheed Martin to create world-leading, ultra-lowSWAP photonic devices using a closed-loop control robot to precisely position and align micro-optics with a potential fill factor of >25 optics per square inch. This paper will discuss the anticipated applications and optical capability when ROAS is fully operational, as well as challenge the audience to update their "rules of thumb" and best practices when designing low-SWAP optical-mechanical systems that take advantage of Lockheed Martin's ROAS capability. This paper will reveal demonstrated optical pointing and stability performance achievable with ROAS and why we believe these optical specifications are relevant for the majority of anticipated applications. After a high level overview of the ROAS current state, this paper will focus in on recent results of the "Reworkable Micro-Optics Mounting IRAD". Results from this IRAD will correlate to the anticipated optical specifications required for relevant applications.

  4. A modular assembling platform for manufacturing of microsystems by optical tweezers

    Science.gov (United States)

    Ksouri, Sarah Isabelle; Aumann, Andreas; Ghadiri, Reza; Prüfer, Michael; Baer, Sebastian; Ostendorf, Andreas

    2013-09-01

    Due to the increased complexity in terms of materials and geometries for microsystems new assembling techniques are required. Assembling techniques from the semiconductor industry are often very specific and cannot fulfill all specifications in more complex microsystems. Therefore, holographic optical tweezers are applied to manipulate structures in micrometer range with highest flexibility and precision. As is well known non-spherical assemblies can be trapped and controlled by laser light and assembled with an additional light modulator application, where the incident laser beam is rearranged into flexible light patterns in order to generate multiple spots. The complementary building blocks are generated by a two-photon-polymerization process. The possibilities of manufacturing arbitrary microstructures and the potential of optical tweezers lead to the idea of combining manufacturing techniques with manipulation processes to "microrobotic" processes. This work presents the manipulation of generated complex microstructures with optical tools as well as a storage solution for 2PP assemblies. A sample holder has been developed for the manual feeding of 2PP building blocks. Furthermore, a modular assembling platform has been constructed for an `all-in-one' 2PP manufacturing process as a dedicated storage system. The long-term objective is the automation process of feeding and storage of several different 2PP micro-assemblies to realize an automated assembly process.

  5. 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

  6. Status of the NIF Project

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E

    2007-04-30

    Ground was broken for the National Ignition Facility, a stadium-sized complex, in 1997. When complete, the project will contain a 192-beam, 1.8-megajoule, 500-terawatt laser system adjoining a 10-meter-diameter target chamber with room for nearly 100 experimental diagnostics. NIF's beams will compress and heat small capsules containing a mixture of hydrogen isotopes of deuterium and tritium. These targets will undergo nuclear fusion, producing more energy than the energy in the laser pulse and achieving scientific breakeven. NIF experiments will allow scientists to study physical processes at temperatures approaching 100 million degrees Kelvin and 100 billion times atmospheric pressure--conditions that exist naturally only in the interior of stars and in nuclear weapon detonations.

  7. 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

  8. Optical Properties of the Self-Assembling Polymeric Colloidal Systems

    Directory of Open Access Journals (Sweden)

    Alexandra Mocanu

    2013-01-01

    Full Text Available In the last decade, optical materials have gained much interest due to the high number of possible applications involving path or intensity control and filtering of light. The continuous emerging technology in the field of electrooptical devices or medical applications allowed the development of new innovative cost effective processes to obtain optical materials suited for future applications such as hybrid/polymeric solar cells, lasers, polymeric optical fibers, and chemo- and biosensing devices. Considering the above, the aim of this review is to present recent studies in the field of photonic crystals involving the use of polymeric materials.

  9. 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.

  10. Self-Assembled Soft Optical Negative Index Materials

    Science.gov (United States)

    2008-08-05

    dividing the results of the closed aperture Z-scan by those from the open aperture Z-scan. The source of the Z-scan can be directly from a laser or...orientation and relative position with respect to precision scribe lines. This type of mapping enabled us to examine regions .of interest in optical...chirality of cysteine stabilizers has the distinct effect on both the growth kinetics and the optical properties of CdTe nanocrystals synthesized in

  11. Assembly and offset assignment scheme for self-similar traffic in optical burst switched networks

    CSIR Research Space (South Africa)

    Muwonge, KB

    2007-10-01

    Full Text Available Scheme for Self- similar Traffic in Optical Burst Switched Networks K. Benon Muwonge, Member, IEEE and H. Anthony Chan, Sr Member, IEEE Department of Electrical... Forward Equivalence Classification (FEC) assembly scheme to efficiently assemble self- similar traffic and a Pareto-offset assignment scheme for offset assignment. Two buffers, a packet buffer and a burst buffer, are implemented at the Label Edge...

  12. Construction and actuation of a microscopic gear assembly formed using optical tweezers

    International Nuclear Information System (INIS)

    Kim, Jung-Dae; Lee, Yong-Gu

    2013-01-01

    The assembly of micrometer-sized parts is an important manufacturing process; any development in it could potentially change the current manufacturing practices for micrometer-scale devices. Due to the lack of reliable microassembly techniques, these devices are often manufactured using silicon, which includes etching and depositions with little use of assembly processes. The result is the requirement of specialized manufacturing conditions with hazardous byproducts and limited applications where only simple mechanisms are allowed. Optical tweezers are non-contact type manipulators that are very suitable for assembling microparts and solve one of the most difficult problems for microassembly, which is the sticking of the physical manipulator to the micropart. Although contact type manipulators can be surface modified to be non-sticky, this involves extra preprocessing—optical tweezers do not require such additional efforts. The weakness of using optical tweezers is that the permanent assembly of parts is not possible as only very small forces can be applied. We introduce an advanced microassembly environment with the combined use of optical tweezers and a motorized microtip, where the former is used to position two parts and the latter is used to introduce deformation in the parts so that they form a strongly fitted assembly. (paper)

  13. Construction and actuation of a microscopic gear assembly formed using optical tweezers

    Science.gov (United States)

    Kim, Jung-Dae; Lee, Yong-Gu

    2013-06-01

    The assembly of micrometer-sized parts is an important manufacturing process; any development in it could potentially change the current manufacturing practices for micrometer-scale devices. Due to the lack of reliable microassembly techniques, these devices are often manufactured using silicon, which includes etching and depositions with little use of assembly processes. The result is the requirement of specialized manufacturing conditions with hazardous byproducts and limited applications where only simple mechanisms are allowed. Optical tweezers are non-contact type manipulators that are very suitable for assembling microparts and solve one of the most difficult problems for microassembly, which is the sticking of the physical manipulator to the micropart. Although contact type manipulators can be surface modified to be non-sticky, this involves extra preprocessing—optical tweezers do not require such additional efforts. The weakness of using optical tweezers is that the permanent assembly of parts is not possible as only very small forces can be applied. We introduce an advanced microassembly environment with the combined use of optical tweezers and a motorized microtip, where the former is used to position two parts and the latter is used to introduce deformation in the parts so that they form a strongly fitted assembly.

  14. Alignment, assembly, and testing of high-energy x-ray optics

    Science.gov (United States)

    Gubarev, Mikhail; Alexander, Cheryl; Ramsey, Brian

    2005-08-01

    We are developing grazing incidence x-ray imaging optics for a balloon-borne hard x-ray telescope (HERO). The HERO payload, scheduled for launch in May 2006, consists of 8 mirror modules with 12 mirror shells each fabricated using electroform-nickel replication off super polished cylindrical mandrels. An optical system for alignment and assembly of the shells into their modules will be described together with an assessment of the systematic errors associated with this process. Full details of the assembly procedures and results of the on-ground x-ray testing of the HERO modules will be provided.

  15. Miniaturized Optical Data Link Assembly for 360 um Guidewires

    NARCIS (Netherlands)

    Stoute, R.; Louwerse, M.C.; Van Rens, J.; Henneken, V.A.; Dekker, R.

    2015-01-01

    We propose a novel concept for a high-speed optical data link in Ø 360 µm cardiovascular interventional imaging guidewires. The concept is based on the recently introduced Flex-to-Rigid (F2R) technology platform. This technology allows for smaller intravascular imaging devices with a more compact

  16. Studying Nuclear Astrophysics at NIF

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, R; Bernstein, L; Brune, C

    2009-07-01

    The National Ignition Facility's primary goal is to generate fusion energy. But the starlike conditions that it creates will also enable NIF scientists to study astrophysically important nuclear reactions. When scientists at the stadium-sized National Ignition Facility attempt to initiate fusion next year, 192 powerful lasers will direct 1.2 MJ of light energy toward a two-mm-diameter pellet of deuterium ({sup 2}H, or D) and tritium ({sup 3}H, or T). Some of that material will be gaseous, but most will be in a frozen shell. The idea is to initiate 'inertial confinement fusion', in which the two hydrogen isotopes fuse to produce helium-4, a neutron, and 17.6 MeV of energy. The light energy will be delivered to the inside walls of a hohlraum, a heavy-metal, centimeter-sized cylinder that houses the pellet. The container's heated walls will produce x rays that impinge on the pellet and ablate its outer surface. The exiting particles push inward on the pellet and compresses the DT fuel. Ultimately a hot spot develops at the pellet's center, where fusion produces {sup 4}He nuclei that have sufficient energy to propagate outward, trigger successive reactions, and finally react the frozen shell. Ignition should last several tens of picoseconds and generate more than 10 MJ of energy and roughly 10{sup 19} neutrons. The temperature will exceed 10{sup 8} K and fuel will be compressed to a density of several hundred g/cm{sup 3}, both considerably greater than at the center of the Sun. The figure shows a cutaway view of NIF. The extreme conditions that will be produced there simulate those in nuclear weapons and inside stars. For that reason, the facility is an important part of the US stockpile stewardship program, designed to assess the nation's aging nuclear stockpile without doing nuclear tests. In this Quick Study we consider a third application of NIF - using the extraordinary conditions it will produce to perform experiments in basic

  17. Self-Assembled Polyelectrolyte Nanoparticles as Fluorophore-Free Contrast Agents for Multicolor Optical Imaging

    Directory of Open Access Journals (Sweden)

    Da Hye Shin

    2015-03-01

    Full Text Available In this work, we describe the fabrication of self-assembled polyelectrolyte nanoparticles that provide a multicolor optical imaging modality. Poly(γ-glutamic acid(γ-PGA formed self-assembled nanoparticles through electrostatic interactions with two different cationic polymers: poly(L-lysine(PLL and chitosan. The self-assembled γ-PGA/PLL and γ-PGA/chitosan nanoparticles were crosslinked by glutaraldehyde. Crosslinking of the ionic self-assembled nanoparticles with glutaraldehyde not only stabilized the nanoparticles but also generated a strong autofluorescence signal. Fluorescent Schiff base bonds (C=N and double bonds (C=C were generated simultaneously by crosslinking of the amine moiety of the cationic polyelectrolytes with monomeric glutaraldehyde or with polymeric glutaraldehyde. The unique optical properties of the nanoparticles that resulted from the crosslinking by glutaraldehyde were analyzed using UV/Vis and fluorescence spectroscopy. We observed that the fluorescence intensity of the nanoparticles could be regulated by adjusting the crosslinker concentration and the reaction time. The nanoparticles also exhibited high performance in the labeling and monitoring of therapeutic immune cells (macrophages and dendritic cells. These self-assembled nanoparticles are expected to be a promising multicolor optical imaging contrast agent for the labeling, detection, and monitoring of cells.

  18. 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

  19. Optical constants and self-assembly of phenylene ethynylene oligomer monolayers

    DEFF Research Database (Denmark)

    Marx, E.; Walzer, Karsten; Less, R.J.

    2004-01-01

    This paper studies the self-assembly on gold surfaces of 1,4-ethynylphenyl-4'-ethynylphenyl-2'-nitro-1-benzenedithiolate (EP2NO(2)), a substituted phenylene ethynylene trimer with applications in molecular electronics. We develop an ellipsometric technique to measure the optical constants...

  20. Vision feedback driven automated assembly of photopolymerized structures by parallel optical trapping and manipulation

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Perch-Nielsen, Ivan Ryberg; Rodrigo, Peter John

    2007-01-01

    We demonstrate how optical trapping and manipulation can be used to assemble microstructures. The microstructures we show being automatically recognized and manipulated are produced using the two-photon polymerization (2PP) technique with submicron resolution. In this work, we show identical shape...

  1. Toolchain concept for the automated assembly of micro-optical systems

    Science.gov (United States)

    Haag, Sebastian; Müller, Tobias; Brecher, Christian

    2014-05-01

    In micro-optical assembly, the mastering of the steps of passive and active alignment, bonding, and part feeding as well as their interdependencies are crucial to the success of an automation solution. Process development is therefore complex and time consuming. Separation of assembly process planning and assembly execution decouples both phases so that production and process development can take place in parallel and even in spatially separated stations. The work presented in this paper refines the concept of flexible assembly systems by separating the phases of assembly process planning and assembly execution by providing a dedicated process development platform on the one hand and by providing automatisms regarding the transfer from the development platform into industrial production on the other. For this purpose, two key concepts are being developed by the research carried out at Fraunhofer IPT. The paper introduces the overall approach and formalisms as well as a form of notation based on part lists, product features and key characteristics and it shows industrial use cases the approach has been applied to. Key characteristics are constraints on spatial relations and they are expressed in terms of optical functions or geometric constraints which need to be fulfilled. In the paper, special attention is paid to the illustration of the end-user perspective.

  2. Alignment and fabrication of micro-optic assemblies using fiber fusion

    Science.gov (United States)

    Florence, James M.; Hoggins, James T.

    2003-01-01

    Considerable time for alignment is typically spent in the assembly of fiber optic components and subsystems. Presented here is a process that allows for pick-and-place assembly and automated alignment of these components. Fibers that are normally pre-attached to collimating or coupling lenses are left free in this process. The fiber position can then be re-located at the point of optimum performance by actively monitoring system performance. The fiber alignment can compensate for misalignment of the primary assembly components. Once the optimum fiber position is achieved the fiber is fused to the collimating or coupling lens element to provide the best mechanical and thermal stability of the finished assembly.

  3. 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.

  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. Micro-optical components assembly for the fabrication of a miniaturized optoelectronic transducer

    Science.gov (United States)

    Corradi, P.; Ascari, L.; Menciassi, A.; Laschi, C.

    2007-10-01

    This paper describes the fabrication and, in particular, the assembly processes of a miniaturized micro-optical system, to be integrated on a hybrid flexible module, which hosts also electronics and microsensors. The whole module was conceived to be mass-produced in order to be distributed in skin-like structures for robotic tactile applications. Nevertheless, it is generally suitable for sensing applications where the flexibility and the thickness of the sensing network are primary requirements. The micro-optical system works as a part of an optoelectronic transducer where electric signals, generated by tactile MEMS sensors, are computed by a microcontroller that drives the micro-optical system. This consequently generates optical radiation, by means of integrated light emitting diodes (LEDs), to be coupled into optical fibers, which waveguide signals to a CMOS optical sensor. Micro-machining and micro-assembly processes of miniaturized components are critical steps in order to fabricate many of these modules according to the application requirements.

  6. Mitigation of BSG damage caused by upstream flaw in the final optics assembly

    Science.gov (United States)

    Jiao, Zhaoyang; Sun, Mingying; Zhao, Dongfeng; Zhu, Jianqiang

    2016-07-01

    In high-power laser facilities for the inertial confinement fusion, there are many large-radius optical elements, which inevitably have some flaws on the surface. The flaws can cause optical intensity intensification and therefore damage the optical elements in the downstream, especially for the beam sampling grating (BSG), which is an important element in the final optics assembly. In this paper, several physical models are established to study the optical field enhancement in the BSG position modulated by upstream flaw. Firstly, when only the linear transportation is considered, it is found that there is a peak or valley of the maximum intensity after the focus lens compared with the ideal wave front. Meanwhile the influence of flaw has an effective range. Secondly, when the nonlinear effect of the focus lens is also considered, the peak maximum downstream is much bigger than the one for the linear consideration and the damage risk of the BSG there is much higher too. From the simulation, we can see that it is important to place the BSG in a properly selected position to mitigate the laser induced damage. The results could give some references to the mitigation of BSG damage caused by upstream flaws and the layout of the final optics assembly.

  7. Low-stress soldering technique used to assemble an optical system for aerospace missions

    Science.gov (United States)

    Ribes-Pleguezuelo, P.; Koechlin, C.; Burkhardt, T.; Hornaff, M.; Kamm, A.; Gramens, S.; Beckert, E.; Fiault, G.; Eberhardt, R.; Tünnermann, A.

    2017-09-01

    A high-precision opto-mechanical breadboard for a lens mount has been assembled by means of a laserbased soldering process called Solderjet Bumping; which thanks to its localized and minimized input of thermal energy, is well suited for the joining of optical components made of fragile and brittle materials such as glasses. An optical element made of a silica lens and a titanium barrel has been studied to replicate the lens mounts of the afocal beam expander used in the LIDAR instrument (ATLID) of the ESA EarthCare Mission, whose aim is to monitor molecular and particle-based back-scattering in order to analyze atmosphere composition. Finally, a beam expander optical element breadboard with a silica lens and a titanium barrel was assembled using the Solderjet Bumping technology with Sn96.5Ag3Cu0.5 SAC305 alloy resulting in a low residual stress (<1 MPa) on the joining areas, a low light-depolarization (<0.2 %) and low distortion (wave-front error measurement < 5 nm rms) on the assemblies. The devices also successfully passed humidity, thermal-vacuum, vibration, and shock tests with conditions similar to the ones expected for the ESA EarthCare mission and without altering their optical performances.

  8. 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.

  9. 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.

  10. Completion of the Design of the Top End Optical Assembly for ATST

    Science.gov (United States)

    Canzian, Blaise; Barentine, J.

    2013-01-01

    L-3 Integrated Optical Systems (IOS) Division has been selected by the National Solar Observatory (NSO) to make the Top End Optical Assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope (ATST) to operate at Haleakala, Maui. ATST will perform to a very high optical performance level in a difficult operational environment. The TEOA (including a 0.65-meter silicon carbide secondary mirror and support, mirror thermal management system, mirror positioning and fast tip-tilt system, field stop with thermally managed heat dump, Lyot stop, safety interlock and control system, and support frame) operates in the “hot spot” at the prime focus of the ATST, presenting unusual challenges. L-3 IOS has passed Critical Design Review of the TEOA. In this paper, we describe L-3 IOS success meeting technical challenges, including our solutions for optic fabrication, opto-mechanical positioning, rejected and stray light control, wavefront tip-tilt compensation, and thermal management and control.

  11. Failure Analysis Study and Long-Term Reliability of Optical Assemblies with End-Face Damage

    Science.gov (United States)

    Kichak, Robert A.; Ott, Melanie N.; Leidecker, Henning W.; Chuska, Richard F.; Greenwell, Christopher J.

    2008-01-01

    In June 2005, the NESC received a multi-faceted request to determine the long term reliability of fiber optic termini on the ISS that exhibited flaws not manufactured to best workmanship practices. There was a lack of data related to fiber optic workmanship as it affects the long term reliability of optical fiber assemblies in a harsh environment. A fiber optic defect analysis was requested which would find and/or create various types of chips, spalls, scratches, etc., that were identified by the ISS personnel. Once the defects and causes were identified the next step would be to perform long term reliability testing of similar assemblies with similar defects. The goal of the defect analysis would be for the defects to be observed and documented for deterioration of fiber optic performance. Though this report mostly discusses what has been determined as evidence of poor manufacturing processes, it also concludes the majority of the damage could have been avoided with a rigorous process in place.

  12. Alignment, Assembly and Testing of High Energy X-Ray Optics

    Science.gov (United States)

    Gubarev, Mikhail; Ramsey, Brian

    2005-01-01

    We are developing grazing-incidence x-ray imaging optics for a balloon-borne hard x-ray telescope (HERO). The HERO payload, scheduled for launch in May 2005, currently consists of 8 mirror modules each containing 12 mirror shells fabricated using electroform-nickel replication off super-polished cylindrical mandrels. An optical system developed for aligning and assembling the shells in the modules will be described. Sources for systematic errors associated with this process will be discussed and results from on-ground x-ray testing of each module will be presented.

  13. Optical Fiber Array Assemblies for Space Flight on the Lunar Reconnaissance Orbiter

    Science.gov (United States)

    Ott, Jelanie; Matuszeski, Adam

    2011-01-01

    Custom fiber optic bundle array assemblies developed by the Photonics Group at NASA Goddard Space Flight Center were an enabling technology for both the Lunar Orbiter Laser Altimeter (LOLA) and the Laser Ranging (LR) Investigation on the Lunar Reconnaissance Orbiter (LRO) currently in operation. The unique assembly array designs provided considerable decrease in size and weight and met stringent system level requirements. This is the first time optical fiber array bundle assemblies were used in a high performance space flight application. This innovation was achieved using customized Diamond Switzerland AVIM optical connectors. For LOLA, a five fiber array was developed for the receiver telescope to maintain precise alignment for each of the 200/220 micron optical fibers collecting 1,064 nm wavelength light being reflected back from the moon. The array splits to five separate detectors replacing the need for multiple telescopes. An image illustration of the LOLA instrument can be found at the top of the figure. For the laser ranging, a seven-optical-fiber array of 400/440 micron fibers was developed to transmit light from behind the LR receiver telescope located on the end of the high gain antenna system (HGAS). The bundle was routed across two moving gimbals, down the HGAS boom arm, over a deployable mandrel and across the spacecraft to a detector on the LOLA instrument. The routing of the optical fiber bundle and its end locations is identified in the figure. The Laser Ranging array and bundle is currently accepting light at a wavelength of 532 nm sent to the moon from laser stations at Greenbelt MD and other stations around the world to gather precision ranging information from the Earth to the LRO spacecraft. The LR bundle assembly is capable of withstanding temperatures down to -55 C at the connectors, and 20,000 mechanical gimbal cycles at temperatures as cold as -20 C along the length of the seven-fiber bundle (that is packaged into the gimbals). The total

  14. The Optical Fiber Array Bundle Assemblies for the NASA Lunar Reconnaissance Orbiter

    Science.gov (United States)

    Ott, Melanie N.; Switzer, Rob; Thomes, William Joe; Chuska, Richard; LaRocca, Frank; MacMurphy, Shawn

    2008-01-01

    The United States, National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC), Fiber Optics Team in the Electrical Engineering Division of the Applied Engineering and Technology Directorate, designed, developed and integrated the space flight optical fiber array hardware assemblies for the Lunar Reconnaissance Orbiter (LRO). The two new assemblies that were designed and manufactured at NASA GSFC for the LRO exist in configurations that are unique in the world for the application of ranging and lidar. These assemblies were developed in coordination with Diamond Switzerland, and the NASA GSFC Mechanical Systems Division. The assemblies represent a strategic enhancement for NASA's Laser Ranging and Laser Radar (LIDAR) instrument hardware by allowing light to be moved to alternative locations that were not feasible in past space flight implementations. An account will be described of the journey and the lessons learned from design to integration for the Lunar Orbiter Laser Altimeter and the Laser Ranging Application on the LRO. The LRO is scheduled to launch end of 2008.

  15. Content Aware Burst Assembly - Supporting Telesurgery and Telemedicine in Optical Burst Switching Networks

    Directory of Open Access Journals (Sweden)

    Henry Orosco

    2010-08-01

    Full Text Available The emerging Telemedicine and Telesurgery technologies allow patients to share medical experts remotely through communication networks. However, network bandwidth, network latency and jitter (variation of latency, are the obstacles to the widespread use of this technology remotely. Optical Burst Switching (OBS networks greatly expand network bandwidth in existing network infrastructure by utilizing multiple DWDM channels within a single fiber, enabling high bandwidth applications. However, the burst assembly process in OBS networks introduces latency and jitter, making it unsuitable for high bandwidth, latency sensitive applications such as telesurgery and telemedicine. In this paper, we propose a content aware burst assembly scheme which dynamically adjusts the burst assembly parameters based on the content being assembled. The proposed content aware burst assembly minimizes the latency and jitter within a video frame, as well as across the left-view and right-view frames for 3D vision generation. Simulation results have shown that the proposed scheme can effectively reduce the latency and jitter experienced by video streams, making OBS a promising candidate for supporting telesurgery and telemedicine applications.

  16. Beta-Sheet-Forming, Self-Assembled Peptide Nanomaterials towards Optical, Energy, and Healthcare Applications.

    Science.gov (United States)

    Kim, Sungjin; Kim, Jae Hong; Lee, Joon Seok; Park, Chan Beum

    2015-08-12

    Peptide self-assembly is an attractive route for the synthesis of intricate organic nanostructures that possess remarkable structural variety and biocompatibility. Recent studies on peptide-based, self-assembled materials have expanded beyond the construction of high-order architectures; they are now reporting new functional materials that have application in the emerging fields such as artificial photosynthesis and rechargeable batteries. Nevertheless, there have been few reviews particularly concentrating on such versatile, emerging applications. Herein, recent advances in the synthesis of self-assembled peptide nanomaterials (e.g., cross β-sheet-based amyloid nanostructures, peptide amphiphiles) are selectively reviewed and their new applications in diverse, interdisciplinary fields are described, ranging from optics and energy storage/conversion to healthcare. The applications of peptide-based self-assembled materials in unconventional fields are also highlighted, such as photoluminescent peptide nanostructures, artificial photosynthetic peptide nanomaterials, and lithium-ion battery components. The relation of such functional materials to the rapidly progressing biomedical applications of peptide self-assembly, which include biosensors/chips and regenerative medicine, are discussed. The combination of strategies shown in these applications would further promote the discovery of novel, functional, small materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Irradiation effects on the optical and mechanical performance of ITER prototype window assemblies

    International Nuclear Information System (INIS)

    Gusarov, A.

    2013-01-01

    Highlights: ► Assessment of the diagnostics windows assembly technologies under ITER relevant conditions. ► Reactor irradiation of prototype ITER-compatible window assemblies up to up to a total fast (E > 0.1 MeV) fluence of ∼2 × 10 20 n/m 2 . ► Vacuum leak testing at normal and elevated temperatures before and following reactor irradiation. ► Push-out mechanical testing including the final destructive test. -- Abstract: We investigated how simulated ITER environment can influence the mechanical stability and optical characteristics of ITER prototype window assemblies. Such assemblies must transmit diagnostic signals while maintaining the vacuum boundaries continuously during the operating life of ITER. A high reliability of the window assemblies is a must. Prototype assemblies with the transmission element made of Si 3 N 4 , silica, or sapphire diffusion bonded or brazed to a stainless steel or Ti ferrule were studied in the present work. Irradiation was performed in the BR1 reactor of SCK•CEN in Mol at 150 °C during 5.5 months up to a total fast fluence of ∼2 × 10 20 n/m 2 . Post-irradiation thermo-mechanical and the He-leak tests were performed in a hot cell. The examination was concluded with the destructive push-out test. Different damage patterns were observed for different window assemblies. The general conclusion is that after thermal cycling and reactor irradiation the windows remain sufficiently strong to sustain mechanical loads relevant for the ITER operation

  18. 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.

  19. Light-enabled reversible self-assembly and tunable optical properties of stable hairy nanoparticles

    Science.gov (United States)

    Chen, Yihuang; Wang, Zewei; He, Yanjie; Yoon, Young Jun; Jung, Jaehan; Zhang, Guangzhao; Lin, Zhiqun

    2018-02-01

    The ability to dynamically organize functional nanoparticles (NPs) via the use of environmental triggers (temperature, pH, light, or solvent polarity) opens up important perspectives for rapid and convenient construction of a rich variety of complex assemblies and materials with new structures and functionalities. Here, we report an unconventional strategy for crafting stable hairy NPs with light-enabled reversible and reliable self-assembly and tunable optical properties. Central to our strategy is to judiciously design amphiphilic star-like diblock copolymers comprising inner hydrophilic blocks and outer hydrophobic photoresponsive blocks as nanoreactors to direct the synthesis of monodisperse plasmonic NPs intimately and permanently capped with photoresponsive polymers. The size and shape of hairy NPs can be precisely tailored by modulating the length of inner hydrophilic block of star-like diblock copolymers. The perpetual anchoring of photoresponsive polymers on the NP surface renders the attractive feature of self-assembly and disassembly of NPs on demand using light of different wavelengths, as revealed by tunable surface plasmon resonance absorption of NPs and the reversible transformation of NPs between their dispersed and aggregated states. The dye encapsulation/release studies manifested that such photoresponsive NPs may be exploited as smart guest molecule nanocarriers. By extension, the star-like block copolymer strategy enables the crafting of a family of stable stimuli-responsive NPs (e.g., temperature- or pH-sensitive polymer-capped magnetic, ferroelectric, upconversion, or semiconducting NPs) and their assemblies for fundamental research in self-assembly and crystallization kinetics of NPs as well as potential applications in optics, optoelectronics, magnetic technologies, sensory materials and devices, catalysis, nanotechnology, and biotechnology.

  20. 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.

  1. Color from hierarchy: Diverse optical properties of micron-sized spherical colloidal assemblies.

    Science.gov (United States)

    Vogel, Nicolas; Utech, Stefanie; England, Grant T; Shirman, Tanya; Phillips, Katherine R; Koay, Natalie; Burgess, Ian B; Kolle, Mathias; Weitz, David A; Aizenberg, Joanna

    2015-09-01

    Materials in nature are characterized by structural order over multiple length scales have evolved for maximum performance and multifunctionality, and are often produced by self-assembly processes. A striking example of this design principle is structural coloration, where interference, diffraction, and absorption effects result in vivid colors. Mimicking this emergence of complex effects from simple building blocks is a key challenge for man-made materials. Here, we show that a simple confined self-assembly process leads to a complex hierarchical geometry that displays a variety of optical effects. Colloidal crystallization in an emulsion droplet creates micron-sized superstructures, termed photonic balls. The curvature imposed by the emulsion droplet leads to frustrated crystallization. We observe spherical colloidal crystals with ordered, crystalline layers and a disordered core. This geometry produces multiple optical effects. The ordered layers give rise to structural color from Bragg diffraction with limited angular dependence and unusual transmission due to the curved nature of the individual crystals. The disordered core contributes nonresonant scattering that induces a macroscopically whitish appearance, which we mitigate by incorporating absorbing gold nanoparticles that suppress scattering and macroscopically purify the color. With increasing size of the constituent colloidal particles, grating diffraction effects dominate, which result from order along the crystal's curved surface and induce a vivid polychromatic appearance. The control of multiple optical effects induced by the hierarchical morphology in photonic balls paves the way to use them as building blocks for complex optical assemblies--potentially as more efficient mimics of structural color as it occurs in nature.

  2. 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.

  3. Assembly of a micro-optical resonator based on silicon micro mirrors for use in gyroscopes

    Science.gov (United States)

    Leber, I.; Niesel, T.; Werner, C.; Yu, L.; Flügge, J.; Dietzel, A.

    2017-08-01

    For realization of a miniaturized optical gyroscope the precise assembly of optical micro components is crucial. To detect the rotation rate the laser beam must circulate many times and not leave the resonator due to small misalignments. The assembly of a passive free space triangular ring resonator in which the light can circulate by reflections at three mirrors is investigated. The beam path encloses an area of about 100 mm2. The resonator shall be activated by an external light source at 1550 nm, a wavelength at which silicon is translucent and allowing to couple light into the resonator through the silicon mirrors. To utilize an inherent mirror alignment two of the mirrors are fabricated with a micro manufacturing process within the same crystal by wet etching resulting in very perfect {111} facets. The etching solution was optimized with respect to process time and smoothness of the mirror surfaces. To further increase the reflectivity of the mirrors different kinds of coatings are tested. With these two perfectly positioned mirrors the assembly challenge reduces to 3DOF alignment of a third {100} mirror for which a well-designed adjustable spacer is developed. In first tests resonance in a linear cavity test setup is demonstrated already.

  4. Space Qualification of the Optical Filter Assemblies for the ICESat-2/ATLAS Instrument

    Science.gov (United States)

    Troupaki, Elisavet; Denny, Zachary; Wu, Stewart; Bradshaw, Heather; Smith, Kevin; Hults, Judy; Ramos-Izquierdo, Luis; Cook, William

    2015-01-01

    The Advanced Topographic Laser Altimeter System (ATLAS) will be the only instrument on the Ice, Cloud, and Land Elevation Satellite -2 (ICESat-2). ICESat-2 is the 2nd-generation of the orbiting laser altimeter ICESat, which will continue polar ice topography measurements with improved precision laser-ranging techniques. In contrast to the original ICESat design, ICESat-2 will use a micro-pulse, multi-beam approach that provides dense cross-track sampling to help scientists determine a surface's slope with each pass of the satellite. The ATLAS laser will emit visible, green laser pulses at a wavelength of 532 nm and a rate of 10 kHz and will be split into 6 beams. A set of six identical, thermally-tuned etalon filter assemblies will be used to remove background solar radiation from the collected signal while transmitting the laser light to the detectors. A seventh etalon assembly will be used to monitor the laser center wavelength during the mission. In this paper, we present the design and optical performance measurements of the ATLAS optical filter assemblies (OFA) in air and in vacuum before integration on the ATLAS instrument.

  5. 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

  6. 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.

  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. Micro-vision servo control of a multi-axis alignment system for optical fiber assembly

    Science.gov (United States)

    Chen, Weihai; Yu, Fei; Qu, Jianliang; Chen, Wenjie; Zhang, Jianbin

    2017-04-01

    This paper describes a novel optical fiber assembly system featuring a multi-axis alignment function based on micro-vision feedback control. It consists of an active parallel alignment mechanism, a passive compensation mechanism, a micro-gripper and a micro-vision servo control system. The active parallel alignment part is a parallelogram-based design with remote-center-of-motion (RCM) function to achieve precise rotation without fatal lateral motion. The passive mechanism, with five degrees of freedom (5-DOF), is used to implement passive compensation for multi-axis errors. A specially designed 1-DOF micro-gripper mounted onto the active parallel alignment platform is adopted to grasp and rotate the optical fiber. A micro-vision system equipped with two charge-coupled device (CCD) cameras is introduced to observe the small field of view and obtain multi-axis errors for servo feedback control. The two CCD cameras are installed in an orthogonal arrangement—thus the errors can be easily measured via the captured images. Meanwhile, a series of tracking and measurement algorithms based on specific features of the target objects are developed. Details of the force and displacement sensor information acquisition in the assembly experiment are also provided. An experiment demonstrates the validity of the proposed visual algorithm by achieving the task of eliminating errors and inserting an optical fiber to the U-groove accurately.

  9. Micro-vision servo control of a multi-axis alignment system for optical fiber assembly

    International Nuclear Information System (INIS)

    Chen, Weihai; Yu, Fei; Qu, Jianliang; Chen, Wenjie; Zhang, Jianbin

    2017-01-01

    This paper describes a novel optical fiber assembly system featuring a multi-axis alignment function based on micro-vision feedback control. It consists of an active parallel alignment mechanism, a passive compensation mechanism, a micro-gripper and a micro-vision servo control system. The active parallel alignment part is a parallelogram-based design with remote-center-of-motion (RCM) function to achieve precise rotation without fatal lateral motion. The passive mechanism, with five degrees of freedom (5-DOF), is used to implement passive compensation for multi-axis errors. A specially designed 1-DOF micro-gripper mounted onto the active parallel alignment platform is adopted to grasp and rotate the optical fiber. A micro-vision system equipped with two charge-coupled device (CCD) cameras is introduced to observe the small field of view and obtain multi-axis errors for servo feedback control. The two CCD cameras are installed in an orthogonal arrangement—thus the errors can be easily measured via the captured images. Meanwhile, a series of tracking and measurement algorithms based on specific features of the target objects are developed. Details of the force and displacement sensor information acquisition in the assembly experiment are also provided. An experiment demonstrates the validity of the proposed visual algorithm by achieving the task of eliminating errors and inserting an optical fiber to the U-groove accurately. (paper)

  10. Optical spectroscopy of single, planar, self-assembled InAs/InP quantum dots

    International Nuclear Information System (INIS)

    Kim, D.; Williams, R.L.; Lefebvre, J.; Lapointe, J.; Reimer, M.E.; Mckee, J.; Poole, P.J.

    2006-01-01

    We present optical spectra from numerous, single, self-assembled InAs/InP quantum dots. More than 50 individual dots are studied that emit in the 1.1-1.6 mm wavelength range. The dots are of high optical quality as judged by the clean, single exciton emission line at low power, the resolution limited linewidth, and the brightness. Each dot exhibits similar trends in the power evolution spectra, despite large variations in height and diameter. The level splittings in the p -shell increase with decreasing height, which we interpret to be from dot elongation along the [01 anti 1] direction. The evolution of the spectra with increasing power agrees well with predictions from effective bond orbital calculations. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Collaborative Assembly Operation between Two Modular Robots Based on the Optical Position Feedback

    Directory of Open Access Journals (Sweden)

    Liying Su

    2009-01-01

    Full Text Available This paper studies the cooperation between two master-slave modular robots. A cooperative robot system is set up with two modular robots and a dynamic optical meter-Optotrak. With Optotrak, the positions of the end effectors are measured as the optical position feedback, which is used to adjust the robots' end positions. A tri-layered motion controller is designed for the two cooperative robots. The RMRC control method is adopted to adjust the master robot to the desired position. With the kinematics constraints of the two robots including position and pose, joint velocity, and acceleration constraints, the two robots can cooperate well. A bolt and nut assembly experiment is executed to verify the methods.

  12. 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

  13. Color from hierarchy: Diverse optical properties of micron-sized spherical colloidal assemblies

    Science.gov (United States)

    Vogel, Nicolas; Utech, Stefanie; England, Grant T.; Shirman, Tanya; Phillips, Katherine R.; Koay, Natalie; Burgess, Ian B.; Kolle, Mathias; Weitz, David A.; Aizenberg, Joanna

    2015-01-01

    Materials in nature are characterized by structural order over multiple length scales have evolved for maximum performance and multifunctionality, and are often produced by self-assembly processes. A striking example of this design principle is structural coloration, where interference, diffraction, and absorption effects result in vivid colors. Mimicking this emergence of complex effects from simple building blocks is a key challenge for man-made materials. Here, we show that a simple confined self-assembly process leads to a complex hierarchical geometry that displays a variety of optical effects. Colloidal crystallization in an emulsion droplet creates micron-sized superstructures, termed photonic balls. The curvature imposed by the emulsion droplet leads to frustrated crystallization. We observe spherical colloidal crystals with ordered, crystalline layers and a disordered core. This geometry produces multiple optical effects. The ordered layers give rise to structural color from Bragg diffraction with limited angular dependence and unusual transmission due to the curved nature of the individual crystals. The disordered core contributes nonresonant scattering that induces a macroscopically whitish appearance, which we mitigate by incorporating absorbing gold nanoparticles that suppress scattering and macroscopically purify the color. With increasing size of the constituent colloidal particles, grating diffraction effects dominate, which result from order along the crystal’s curved surface and induce a vivid polychromatic appearance. The control of multiple optical effects induced by the hierarchical morphology in photonic balls paves the way to use them as building blocks for complex optical assemblies—potentially as more efficient mimics of structural color as it occurs in nature. PMID:26290583

  14. Cotranscription of the electron transport protein genes nifJ and nifF in Enterobacter agglomerans 333.

    Science.gov (United States)

    Kreutzer, R; Dayananda, S; Klingmüller, W

    1991-05-01

    A nucleotide sequence showing extensive homology to the nifF gene, which codes for a flavodoxin involved in nitrogen fixation in Klebsiella pneumoniae, was localized on the plasmid pEA3 of Enterobacter agglomerans and determined. The analysis of transcriptional fusions, as well as transcript protection assays, indicated a novel nif gene organization, that is, the cotranscription of nifJ and nifF.

  15. Cotranscription of the electron transport protein genes nifJ and nifF in Enterobacter agglomerans 333.

    OpenAIRE

    Kreutzer, R; Dayananda, S; Klingmüller, W

    1991-01-01

    A nucleotide sequence showing extensive homology to the nifF gene, which codes for a flavodoxin involved in nitrogen fixation in Klebsiella pneumoniae, was localized on the plasmid pEA3 of Enterobacter agglomerans and determined. The analysis of transcriptional fusions, as well as transcript protection assays, indicated a novel nif gene organization, that is, the cotranscription of nifJ and nifF.

  16. Identification and characterization of the nifH and nifJ promoter regions located on the nif-plasmid pEA3 of Enterobacter agglomerans 333.

    Science.gov (United States)

    Kreutzer, R; Singh, M; Klingmüller, W

    1989-05-15

    Small restriction fragments of the plasmid-borne Enterobacter agglomerans 333 nif region were cloned into a promoter probe plasmid as transcriptional fusions with the lacZ gene. Identification of NifA-dependent promoters was accomplished by using a compatible plasmid which constitutively expresses the Klebsiella pneumoniae nifA gene. beta-Galactosidase assays showed strong activation of the cloned E. agglomerans promoters in Escherichia coli by the heterologous K. pneumoniae nifA gene product. The positions of the promoter fragments on the corresponding restriction map were determined by Southern hybridization. As confirmed by sequencing data, the nifH and nifJ promoters are situated at opposite end-points of the nif gene group and their -24 to -12 nucleotide sequences are similar to the consensus sequence of NtrA-dependent promoters. Also, typical NifA-binding motifs are present in both promoters. The agreement of the promoter proximal regions of nifH and nifJ with the corresponding K pneumoniae sequences is about 80%. Also the upstream regions of these genes are in agreement to some extent.

  17. 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...

  18. Synthesis, optical properties, and helical self-assembly of a bivaline-containing tetraphenylethene

    Science.gov (United States)

    Li, Hongkun; Zheng, Xiaoyan; Su, Huimin; Lam, Jacky W. Y.; Sing Wong, Kam; Xue, Shan; Huang, Xuejiao; Huang, Xuhui; Li, Bing Shi; Tang, Ben Zhong

    2016-01-01

    A chiral tetraphenylethene derivative with two valine-containing attachments (TPE-DVAL), was synthesized by Cu(I)-catalyzed azide-alkyne “click” reaction. The optical properties and self-assembling behaviours of TPE-DVAL were investigated. The molecule is non-emissive and circular dichroism (CD)-silent in solution, but shows strong fluorescence and Cotton effects in the aggregation state, demonstrating aggregation-induced emission (AIE) and CD (AICD) characteristics. TPE-DVAL exhibits good circularly polarized luminescence (CPL) when depositing on the surface of quartz to allow the evaporation of its 1,2-dichloroethane solution. SEM and TEM images of the molecule show that the molecule readily self-assembles into right-handed helical nanofibers upon the evaporation of its solvent of DCE. The molecular alignments and interactions in assembling process are further explored through XRD analysis and computational simulation. The driving forces for the formation of the helical fibers were from the cooperative effects of intermolecular hydrogen bonding, π-π interactions and steric effect.

  19. 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

  20. Progress making the top end optical assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope

    Science.gov (United States)

    Canzian, Blaise; Barentine, J.; Arendt, J.; Bader, S.; Danyo, G.; Heller, C.

    2012-09-01

    L-3 Integrated Optical Systems (IOS) Division has been selected by the National Solar Observatory (NSO) to design and produce the Top End Optical Assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope (ATST) to operate at Haleakal', Maui. ATST will perform to a very high optical performance level in a difficult thermal environment. The TEOA, containing the 0.65-meter silicon carbide secondary mirror and support, mirror thermal management system, mirror positioning and fast tip-tilt system, field stop with thermally managed heat dump, thermally managed Lyot stop, safety interlock and control system, and support frame, operates in the "hot spot" at the prime focus of the ATST and so presents special challenges. In this paper, we describe progress in the L-3 technical approach to meeting these challenges, including silicon carbide off-axis mirror design, fabrication, and high accuracy figuring and polishing all within L-3; mirror support design; the design for stray light control; subsystems for opto-mechanical positioning and high accuracy absolute mirror orientation sensing; Lyot stop design; and thermal management of all design elements to remain close to ambient temperature despite the imposed solar irradiance load.

  1. Tunable liquid optics: electrowetting-controlled liquid mirrors based on self-assembled Janus tiles.

    Science.gov (United States)

    Bucaro, Michael A; Kolodner, Paul R; Taylor, J Ashley; Sidorenko, Alex; Aizenberg, Joanna; Krupenkin, Tom N

    2009-04-09

    In this paper, we describe a tunable, high-reflectivity optofluidic device based on self-assembly of anisotropically functionalized hexagonal micromirrors (Janus tiles) on the surface of an oil droplet to create a concave liquid mirror. The liquid mirror is deposited on a patterned transparent electrode that allows the focal length and axial position to be electrically controlled. The mirror is mechanically robust and retains its integrity even at high levels of vibrational excitation of the interface. The use of reflection instead of refraction overcomes the limited available refractive-index contrast between pairs of density-matched liquids, allowing stronger focusing than is possible for a liquid lens of the same geometry. This approach is compatible with optical instruments that could provide novel functionality-for example, a dynamic 3D projector, i.e., a light source which can scan an image onto a moving, nonplanar focal surface. Janus tiles with complex optical properties can be manufactured using our approach, thus potentially enabling a wide range of novel optical elements.

  2. Optical and structural properties of InGaAs self assembled quantum dots

    CERN Document Server

    Siverns, P D

    2001-01-01

    The success of 2D quantum well (QW) based optical devices has prompted research into further reducing the dimensionality to produce 0D quantum dots (QDs). This thesis investigates self-assembled InAs/GaAs QDs using optical and structural techniques. The effects of stacking QD layers are examined and the growth conditions necessary for emission at the technologically important wavelength of 1.3 mu m. In addition hydrogenation of QWs and QDs is shown to improve the optical efficiency by passivating defects in the barriers. Bilayers of QDs grown with different spacer layers were investigated using photoluminescence (PL) and scanning transmission electron microscopy (STEM). A redshift in the emission energy and narrowing of the linewidth was observed for the stacked dots and attributed to changes in the localised strain caused by vertical correlation. Energy dispersive X-ray (EDX) measurements revealed the dots to be indium rich areas within a 2D 'confining layer' rather than the accepted view of pyramidal struct...

  3. Layer-by-layer assembly of multicolored semiconductor quantum dots towards efficient blue, green, red and full color optical films

    International Nuclear Information System (INIS)

    Zhang Jun; Li Qian; Di Xiaowei; Liu Zhiliang; Xu Gang

    2008-01-01

    Multicolored semiconductor quantum dots have shown great promise for construction of miniaturized light-emitting diodes with compact size, low weight and cost, and high luminescent efficiency. The unique size-dependent luminescent property of quantum dots offers the feasibility of constructing single-color or full-color output light-emitting diodes with one type of material. In this paper, we have demonstrated the facile fabrication of blue-, green-, red- and full-color-emitting semiconductor quantum dot optical films via a layer-by-layer assembly technique. The optical films were constructed by alternative deposition of different colored quantum dots with a series of oppositely charged species, in particular, the new use of cationic starch on glass substrates. Semiconductor ZnSe quantum dots exhibiting blue emission were deposited for fabrication of blue-emitting optical films, while semiconductor CdTe quantum dots with green and red emission were utilized for construction of green- and red-emitting optical films. The assembly of integrated blue, green and red semiconductor quantum dots resulted in full-color-emitting optical films. The luminescent optical films showed very bright emitting colors under UV irradiation, and displayed dense, smooth and efficient luminous features, showing brighter luminescence in comparison with their corresponding quantum dot aqueous colloid solutions. The assembled optical films provide the prospect of miniaturized light-emitting-diode applications.

  4. 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...

  5. Proven high-reliability assembly methods applied to avionics fiber-optics high-speed transceivers

    Science.gov (United States)

    Lauzon, Jocelyn; Leduc, Lorrain; Bessette, Daniel; Bélanger, Nicolas; Larose, Robert; Dion, Bruno

    2012-06-01

    Harsh environment avionics applications require operating temperature ranges that can extend to, and exceed -50 to 115°C. For obvious maintenance, management and cost arguments, product lifetimes as long as 20 years are also sought. This leads to mandatory long-term hermeticity that cannot be obtained with epoxy or silicone sealing; but only with glass seal or metal solder or brazing. A hermetic design can indirectly result in the required RF shielding of the component. For fiber-optics products, these specifications need to be compatible with the smallest possible size, weight and power consumption. The products also need to offer the best possible high-speed performances added to the known EMI immunity in the transmission lines. Fiber-optics transceivers with data rates per fiber channel up to 10Gbps are now starting to be offered on the market for avionics applications. Some of them are being developed by companies involved in the "normal environment" telecommunications market that are trying to ruggedize their products packaging in order to diversify their customer base. Another approach, for which we will present detailed results, is to go back to the drawing boards and design a new product that is adapted to proven MIL-PRF-38534 high-reliability packaging assembly methods. These methods will lead to the introduction of additional requirements at the components level; such as long-term high-temperature resistance for the fiber-optic cables. We will compare both approaches and demonstrate the latter, associated with the redesign, is the preferable one. The performance of the fiber-optic transceiver we have developed, in terms of qualification tests such as temperature cycling, constant acceleration, hermeticity, residual gaz analysis, operation under random vibration and mechanical shocks and accelerated lifetime tests will be presented. The tests are still under way, but so far, we have observed no performance degradation of such a product after more than

  6. 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.

  7. 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

  8. Raman laser spectrometer optical head: qualification model assembly and integration verification

    Science.gov (United States)

    Ramos, G.; Sanz-Palomino, M.; Moral, A. G.; Canora, C. P.; Belenguer, T.; Canchal, R.; Prieto, J. A. R.; Santiago, A.; Gordillo, C.; Escribano, D.; Lopez-Reyes, G.; Rull, F.

    2017-08-01

    Raman Laser Spectrometer (RLS) is the Pasteur Payload instrument of the ExoMars mission, within the ESA's Aurora Exploration Programme, that will perform for the first time in an out planetary mission Raman spectroscopy. RLS is composed by SPU (Spectrometer Unit), iOH (Internal Optical Head), and ICEU (Instrument Control and Excitation Unit). iOH focuses the excitation laser on the samples (excitation path), and collects the Raman emission from the sample (collection path, composed on collimation system and filtering system). Its original design presented a high laser trace reaching to the detector, and although a certain level of laser trace was required for calibration purposes, the high level degrades the Signal to Noise Ratio confounding some Raman peaks. So, after the bread board campaign, some light design modifications were implemented in order to fix the desired amount of laser trace, and after the fabrication and the commitment of the commercial elements, the assembly and integration verification process was carried out. A brief description of the iOH design update for the engineering and qualification model (iOH EQM) as well as the assembly process are briefly described in this papers. In addition, the integration verification and the first functional tests, carried out with the RLS calibration target (CT), results are reported on.

  9. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-13

    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.

  11. Vibration Monitoring Using Fiber Optic Sensors in a Lead-Bismuth Eutectic Cooled Nuclear Fuel Assembly

    Science.gov (United States)

    De Pauw, Ben; Lamberti, Alfredo; Ertveldt, Julien; Rezayat, Ali; van Tichelen, Katrien; Vanlanduit, Steve; Berghmans, Francis

    2016-01-01

    Excessive fuel assembly vibrations in nuclear reactor cores should be avoided in order not to compromise the lifetime of the assembly and in order to prevent the occurrence of safety hazards. This issue is particularly relevant to new reactor designs that use liquid metal coolants, such as, for example, a molten lead-bismuth eutectic. The flow of molten heavy metal around and through the fuel assembly may cause the latter to vibrate and hence suffer degradation as a result of, for example, fretting wear or mechanical fatigue. In this paper, we demonstrate the use of optical fiber sensors to measure the fuel assembly vibration in a lead-bismuth eutectic cooled installation which can be used as input to assess vibration-related safety hazards. We show that the vibration characteristics of the fuel pins in the fuel assembly can be experimentally determined with minimal intrusiveness and with high precision owing to the small dimensions and properties of the sensors. In particular, we were able to record local strain level differences of about 0.2 μϵ allowing us to reliably estimate the vibration amplitudes and modal parameters of the fuel assembly based on optical fiber sensor readings during different stages of the operation of the facility, including the onset of the coolant circulation and steady-state operation. PMID:27110782

  12. 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.

  13. 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

  14. The Eagle Nebula Science on NIF experiment

    Science.gov (United States)

    Kane, Jave; Heeter, Robert; Martinez, David; Pound, Marc; Remington, Bruce; Ryutov, Dmitri; Smalyuk, Vladimir

    2012-10-01

    The Eagle Nebula NIF experiment was one of nine selected for laser time through the Science on NIF program. The goal of this scale laboratory experiment is to study the dynamic evolution of distinctive structures in star forming regions of astrophysical molecular clouds such as the Pillars of the Eagle Nebula. That evolution is driven by photoionizing radiation from nearby stars. A critical aspect of the radiation is its very directional nature at the photoionization front. The long duration of the drive and its directionality can generate new classes of instabilities and dynamic flows at the front that may be responsible for the shapes of Pillars and other structures. The experiment will leverage and modify the existing NIF Radiation Transport platform, replacing the target at the back end of the halfraum with a collimating aperture, and extending the existing 20 ns drive to longer times, using a combination of gas fill and other new design features. The apertured, quasi-collimated drive will be used to drive a target placed 2 mm away from the aperture. The astrophysical background and the status of the experimental design will be presented.

  15. 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

  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. Nanowire assembly, e.g. for optical probes, comprises optically trapping high aspect ratio semiconductor nanowire with infrared single-beam optical trap and attaching nanowire to organic or inorganic structure

    OpenAIRE

    Pauzauskie, P.; Radenovic, A.; Trepagnier, E.; Liphardt, J.; Yang, P.

    2007-01-01

    NOVELTY - A nanowire assembly method comprises optically trapping a semiconductor nanowire with an infrared single-beam optical trap and attaching the nanowire to an organic or inorganic structure by laser fusing. The nanowire is further trapped in a fluid environment. The optical trap has a beam wavelength of 1064 nm. The nanowire has an aspect ratio greater than 100 and a diameter less than 100 (preferably less than 80) nm. The nanowire and the organic or inorganic structure form a heterost...

  18. Improving and correcting the contiguity of long-read genome assemblies of three plant species using optical mapping and chromosome conformation capture data

    OpenAIRE

    Jiao, Wen-Biao; Accinelli, Gonzalo Garcia; Hartwig, Benjamin; Kiefer, Christiane; Baker, David; Severing, Edouard; Willing, Eva-Maria; Piednoel, Mathieu; Woetzel, Stefan; Madrid-Herrero, Eva; Huettel, Bruno; Hümann, Ulrike; Reinhard, Richard; Koch, Marcus A.; Swan, Daniel

    2017-01-01

    Long-read sequencing can overcome the weaknesses of short reads in the assembly of eukaryotic genomes; however, at present additional scaffolding is needed to achieve chromosome-level assemblies. We generated Pacific Biosciences (PacBio) long-read data of the genomes of three relatives of the model plant Arabidopsis thaliana and assembled all three genomes into only a few hundred contigs. To improve the contiguities of these assemblies, we generated BioNano Genomics optical mapping and Doveta...

  19. Real-time detection of lipid bilayer assembly and detergent-initiated solubilization using optical cavities

    Science.gov (United States)

    Sun, V.; Armani, A. M.

    2015-02-01

    The cellular membrane governs numerous fundamental biological processes. Therefore, developing a comprehensive understanding of its structure and function is critical. However, its inherent biological complexity gives rise to numerous inter-dependent physical phenomena. In an attempt to develop a model, two different experimental approaches are being pursued in parallel: performing single cell experiments (top down) and using biomimetic structures (bottom up), such as lipid bilayers. One challenge in many of these experiments is the reliance on fluorescent probes for detection which can create confounds in this already complex system. In the present work, a label-free detection method based on an optical resonant cavity is used to detect one of the fundamental physical phenomena in the system: assembly and solubilization of the lipid bilayer. The evanescent field of the cavity strongly interacts with the lipid bilayer, enabling the detection of the bilayer behavior in real-time. Two independent detection mechanisms confirm the formation and detergent-assisted solubilization of the lipid bilayers: (1) a refractive index change and (2) a material loss change. Both mechanisms can be monitored in parallel, on the same device, thus allowing for cross-confirmation of the results. To verify the proposed method, we have detected the formation of self-assembled phosphatidylcholine lipid bilayers from small unilamellar vesicles on the device surface in real-time. Subsequently, we exposed the bilayers to two different detergents (non-ionic Triton X-100 and anionic sodium dodecyl sulfate) to initiate solubilization, and this process was also detected in real-time. After the bilayer solubilization, the device returned to its initial state, exhibiting minimal hysteresis. The experimental wash-off was also collected and analyzed using dynamic light scattering.

  20. Assembly and alignment method for optimized spatial resolution of off-axis three-mirror fore optics of hyperspectral imager.

    Science.gov (United States)

    Kim, Youngsoo; Hong, Jinsuk; Choi, Byungin; Lee, Jong-Ung; Kim, Yeonsoo; Kim, Hyunsook

    2017-08-21

    A fore optics for the hyperspectral spectrometer is designed, manufactured, assembled, and aligned. The optics has a telecentric off-axis three-mirror configuration with a field of view wider than 14 degrees and an f-number as small as 2.3. The primary mirror (M1) and the secondary mirror (M2) are axially symmetric aspheric surfaces to minimize the sensitivity. The tertiary mirror (M3) is a decentered aspheric surface to minimize the coma and astigmatism aberration. The M2 also has a hole for the slit to maintain the optical performance while maximizing the telecentricity. To ensure the spatial resolution performance of the optical system, an alignment procedure is established to assemble and align the entrance slit of the spectrometer to the rear end of the fore optics. It has a great advantage to confirm and maintain the alignment integrity of the fore optics module throughout the alignment procedure. To perform the alignment procedure successfully, the precision movement control requirements are calculated and applied. As a result, the alignment goal of the RMS wave front error (WFE) to be smaller than 90 nm at all fields is achieved.

  1. Symbiotic Burkholderia Species Show Diverse Arrangements of nif/fix and nod Genes and Lack Typical High-Affinity Cytochrome cbb3 Oxidase Genes.

    Science.gov (United States)

    De Meyer, Sofie E; Briscoe, Leah; Martínez-Hidalgo, Pilar; Agapakis, Christina M; de-Los Santos, Paulina Estrada; Seshadri, Rekha; Reeve, Wayne; Weinstock, George; O'Hara, Graham; Howieson, John G; Hirsch, Ann M

    2016-08-01

    Genome analysis of fourteen mimosoid and four papilionoid beta-rhizobia together with fourteen reference alpha-rhizobia for both nodulation (nod) and nitrogen-fixing (nif/fix) genes has shown phylogenetic congruence between 16S rRNA/MLSA (combined 16S rRNA gene sequencing and multilocus sequence analysis) and nif/fix genes, indicating a free-living diazotrophic ancestry of the beta-rhizobia. However, deeper genomic analysis revealed a complex symbiosis acquisition history in the beta-rhizobia that clearly separates the mimosoid and papilionoid nodulating groups. Mimosoid-nodulating beta-rhizobia have nod genes tightly clustered in the nodBCIJHASU operon, whereas papilionoid-nodulating Burkholderia have nodUSDABC and nodIJ genes, although their arrangement is not canonical because the nod genes are subdivided by the insertion of nif and other genes. Furthermore, the papilionoid Burkholderia spp. contain duplications of several nod and nif genes. The Burkholderia nifHDKEN and fixABC genes are very closely related to those found in free-living diazotrophs. In contrast, nifA is highly divergent between both groups, but the papilionoid species nifA is more similar to alpha-rhizobia nifA than to other groups. Surprisingly, for all Burkholderia, the fixNOQP and fixGHIS genes required for cbb3 cytochrome oxidase production and assembly are missing. In contrast, symbiotic Cupriavidus strains have fixNOQPGHIS genes, revealing a divergence in the evolution of two distinct electron transport chains required for nitrogen fixation within the beta-rhizobia.

  2. An optimized routing algorithm for the automated assembly of standard multimode ribbon fibers in a full-mesh optical backplane

    Science.gov (United States)

    Basile, Vito; Guadagno, Gianluca; Ferrario, Maddalena; Fassi, Irene

    2018-03-01

    In this paper a parametric, modular and scalable algorithm allowing a fully automated assembly of a backplane fiber-optic interconnection circuit is presented. This approach guarantees the optimization of the optical fiber routing inside the backplane with respect to specific criteria (i.e. bending power losses), addressing both transmission performance and overall costs issues. Graph theory has been exploited to simplify the complexity of the NxN full-mesh backplane interconnection topology, firstly, into N independent sub-circuits and then, recursively, into a limited number of loops easier to be generated. Afterwards, the proposed algorithm selects a set of geometrical and architectural parameters whose optimization allows to identify the optimal fiber optic routing for each sub-circuit of the backplane. The topological and numerical information provided by the algorithm are then exploited to control a robot which performs the automated assembly of the backplane sub-circuits. The proposed routing algorithm can be extended to any array architecture and number of connections thanks to its modularity and scalability. Finally, the algorithm has been exploited for the automated assembly of an 8x8 optical backplane realized with standard multimode (MM) 12-fiber ribbons.

  3. Helium Cryo Testing of a SLMS(TM) (Silicon Lightweight Mirrors) Athermal Optical Assembly

    Science.gov (United States)

    Jacoby, Marc T.; Goodman, William A.; Stahl, H. Philip; Keys, Andrew S.; Reily, Jack C.; Eng, Ron; Hadaway, James B.; Hogue, William D.; Kegley, Jeffrey R.; Siler, Richard

    2003-01-01

    SLMS (TM) a thermal technology has been demonstrated in the small 4-foot helium cryogenic test chamber located at the NASA/MSFC X-Ray Calibration Facility (XRCF). A SLMS (TM) Ultraviolet Demonstrator Mirror (UVDM) produced by Schafer under a NASA/MSFC Phase I SBIR was helium cryo tested both free standing and bonded to a Schafer designed prototype carbon fiber reinforced silicon carbide (Cesic) mount. Surface figure data was obtained with a test measurement system that featured an Instantaneous Phase Interferometer (IPI) by ADE Phase Shift. The test measurement system s minimum resolvable differential figure deformation and possible contributions from test chamber ambient to cryo window deformation are under investigation. The free standing results showed differential figure deformation of 10.4 nm rms from 295K to 27K and 3.9 nm rms after one cryo cycle. The surface figure of the UVDM degraded by lambda/70 rms HeNe once it was bonded to the prototype Cesic mount. The change was due to a small astigmatic aberration in the rototype Cesic mount due to lack of finish machining and not the bonding technique. This effect was seen in SLMST (TM) optical assembly results, which showed differential figure deformation of 46.5 nm rms from 294K to 27K, 42.9 nm rms from 294K to 77K, 28.0 nm rms from 294K to 193K and 6.2 nm rms after one cryo cycle.

  4. Nanogravimetric and Optical Characterizations of Thrombin Interaction with a Self-Assembled Thiolated Aptamer

    Directory of Open Access Journals (Sweden)

    Jane Politi

    2016-01-01

    Full Text Available Efficient biorecognition of thrombin (TB, a serine protease with crucial role in physiological and pathological blood coagulation, is a hot topic in medical diagnostics. In this work, we investigate the ability of synthetic thrombin aptamer (TBA, immobilized on a gold substrate, to bind thrombin by two different label-free techniques: the quartz crystal microbalance (QCM and the spectroscopic ellipsometry (SE. By QCM characterization in the range from 20 to 110 nM, we demonstrate high specificity of TBA-TB interaction and determine affinity constant (Kd of 17.7±0.3 nM, system sensitivity of 0.42±0.03 Hz nM−1, and limit of detection (LOD of 240±20 pM. The interaction between TBA and TB is also investigated by SE, an all-optical method, by quantifying the thickness increase of the TBA film assembled on gold substrate. AFM characterization of TBA and TB molecules deposited on flat silicon surface is also supplied.

  5. Computational aspects of optical lithography extension by directed self-assembly

    Science.gov (United States)

    Lai, Kafai; Liu, Chi-chun; Pitera, Jed; Dechene, Daniel J.; Schepis, Anthony; Abdallah, Jassem; Tsai, Hsinyu; Guillorn, Mike; Cheng, Joy; Doerk, Gregory; Tjio, Melia; Rettner, Charles; Odesanya, Olalekan; Ozlem, Melih; Lafferty, Neal

    2013-04-01

    EUV insertion timing for High Volume Manufacturing is still an uncertainty due to source power and EUV mask infrastructure limitations. Directed Self Assembly (DSA) processes offer the promise of providing alternative ways to extend optical lithography cost-effectively for use in the 10nm node and beyond. The goal of this paper is to look into the technical prospect of DSA technology, particularly in the computational and DFM area. We have developed a prototype computational patterning toolset in-house to enable an early Design -Technology Co-Optimization to study the feasibility of using DSA in patterning semiconductor devices and circuits. From this toolset we can identify the set of DSA specific design restrictions specific to a DSA process and plan to develop a novel full chip capable computational patterning solution with DSA. We discuss the DSA Computational Lithography (CL) infrastructure using the via and fin layers as examples. Early wafer data is collected from the DSA testmask that was built using these new toolsets. Finally we discuss the DSA ecosystem requirements for enabling DSA lithography and propose how EDA vendors can play a role in making DSA Lithography (DSAL) a full-chip viable technology for multiple process layers.

  6. Requirements validation testing on the 7 optical fiber array connector/cable assemblies for the Lunar Reconnaissance Orbiter (LRO)

    Science.gov (United States)

    Ott, Melanie N.; Jin, Xiaodan Linda; LaRocca, Frank V.; Matuszeski, Adam; Chuska, Richard F.; MacMurphy, Shawn L.

    2007-09-01

    In the past year, a unique capability has been created by NASA Goddard Space Flight Center (GSFC) in support of Lunar Exploration. The photonics group along with support from the Mechanical Systems Division, developed a seven fiber array assembly using a custom Diamond AVIM PM connector for space flight applications. This technology enabled the Laser Ranging Application for the LRO to be possible. Laser pulses at 532 nm will be transmitted from the earth to the LRO stationed at the moon and used to make distance assessments. The pulses will be collected with the Laser Ranging telescope and focused into the array assemblies. The array assemblies span down a boom, through gimbals and across the space craft to the instrument the Lunar Orbiter Laser Altimeter (LOLA). Through use of a LOLA detector the distance between the LRO and the Earth will be calculated simultaneously while LOLA is mapping the surface of the moon. The seven fiber array assemblies were designed in partnership with W.L. Gore, Diamond Switzerland, and GSFC, manufactured by the Photonics Group at NASA Goddard Space Flight Center (GSFC) and tested for environmental effects there as well. Presented here are the requirements validation testing and results used to insure that these unique assemblies would function adequately during the Laser Ranging 14-month mission. The data and results include in-situ monitoring of the optical assemblies during cold gimbal motion life-testing, radiation, vibration and thermal testing.

  7. 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.

  8. 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.

  9. 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.

  10. Application Software Structure Enables NIF Operations

    Energy Technology Data Exchange (ETDEWEB)

    Fong, K W; Estes, C M; Fisher, J M; Shelton, R T

    2001-10-17

    The NIF Integrated Computer Control System (ICCS) application software uses a set of service frameworks that assures uniform behavior spanning the front-end processors (FEPs) and supervisor programs. This uniformity is visible both in the way each program employs shared services and in the flexibility it affords for attaching graphical user interfaces (GUIs). Uniformity of structure across applications is desired for the benefit of programmers who will be maintaining the many programs that constitute the ICCS. In this paper, the framework components that have the greatest impact on the application structure are discussed.

  11. Regulation of nif gene expression in Enterobacter agglomerans: nucleotide sequence of the nifLA operon and influence of temperature and ammonium on its transcription.

    Science.gov (United States)

    Siddavattam, D; Steibl, H D; Kreutzer, R; Klingmüller, W

    1995-12-20

    The nucleotide sequence of a plasmid-borne 3.9 kb XhoI-SmaI fragment comprising the 3'-region of the nifM gene, the nifL and nifA genes and the 5'-region of nifB gene of Enterobacter agglomerans was determined. The genes were identified by their homology to the corresponding nif genes of Klebsiella pneumoniae. A typical sigma 54-dependent promoter and a consensus NtrC-binding motif were identified upstream of nifL. The predicted amino acid sequence of NifL showed close similarities to NifL of K. pneumoniae and Azotobacter vinelandii. However, no histidine residue was found to correspond to histidine-304 of A. vinelandii NifL, which had been proposed to be required for the repressor activity of NifL. The NifA sequence with a putative DNA binding motif (Q(x3) A(x3) G(x5)I) and an ATP binding site in the C-terminal and central domains, respectively, resembles that of other known NifA proteins. The function of the nifL and nifA genes was demonstrated in vivo using a binary plasmid system by their ability to activate a nifH promoter-lacZ fusion at different temperatures and concentrations of NH4+. Maximal promoter activity occurred at 25 degrees C, and it appears that the sensitivity of NifA to elevated temperatures is independent of NifL. The expression of nifL inhibited promoter activity in the presence of NifA when the initial NH4+ concentration in the medium exceeded 4 mM.

  12. 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.

  13. 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.

  14. Cloning and characterization of nif structural and regulatory genes in the purple sulfur bacterium, Halorhodospira halophila.

    Science.gov (United States)

    Tsuihiji, Hisayoshi; Yamazaki, Yoichi; Kamikubo, Hironari; Imamoto, Yasushi; Kataoka, Mikio

    2006-03-01

    Halorhodospira halophila is a halophilic photosynthetic bacterium classified as a purple sulfur bacterium. We found that H. halophila generates hydrogen gas during photoautotrophic growth as a byproduct of a nitrogenase reaction. In order to consider the applied possibilities of this photobiological hydrogen generation, we cloned and characterized the structural and regulatory genes encoding the nitrogenase, nifH, nifD and nifA, from H. halophila. This is the first description of the nif genes for a purple sulfur bacterium. The amino-acid sequences of NifH and NifD indicated that these proteins are an Fe protein and a part of a MoFe protein, respectively. The important residues are conserved completely. The sequence upstream from the nifH region and sequence similarities of nifH and nifD with those of the other organisms suggest that the regulatory system might be a NifL-NifA system; however, H. halophila lacks nifL. The amino-acid sequence of H. halophila NifA is closer to that of the NifA of the NifL-NifA system than to that of NifA without NifL. H. halophila NifA does not conserve either the residue that interacts with NifL or the important residues involved in NifL-independent regulation. These results suggest the existence of yet another regulatory system, and that the development of functional systems and their molecular counterparts are not necessarily correlated throughout evolution. All of these Nif proteins of H. halophila possess an excess of acidic residues, which acts as a salt-resistant mechanism.

  15. 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.

  16. Gene function analysis in environmental isolates: The nif regulon of the strict iron oxidizing bacterium Leptospirillum ferrooxidans

    Science.gov (United States)

    Parro, Víctor; Moreno-Paz, Mercedes

    2003-01-01

    A random genomic library from an environmental isolate of the Gram-negative bacterium Leptospirillum ferrooxidans has been printed on a microarray. Gene expression analysis was carried out with total RNA extracted from L. ferrooxidans cultures in the presence or absence of ammonium as nitrogen source under aerobic conditions. Although practically nothing is known about the genome sequence of this bacterium, this approach allowed us the selection and sequencing of only those clones bearing genes that showed an altered expression pattern. By sequence comparison, we have identified most of the genes of nitrogen fixation regulon in L. ferrooxidans, like the nifHDKENX operon, encoding the structural components of Mo-Fe nitrogenase; nifSU-hesB-hscBA-fdx operon, for Fe-S cluster assembly; the amtB gene (ammonium transporter); modA (molybdenum ABC type transporter); some regulatory genes like ntrC, nifA (the specific activator of nif genes); or two glnB-like genes (encoding the PII regulatory protein). Our results show that shotgun DNA microarrays are very powerful tools to accomplish gene expression studies with environmental bacteria whose genome sequence is still unknown, avoiding the time and effort necessary for whole genome sequencing projects. PMID:12808145

  17. 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.

  18. Characterization of the JWST Pathfinder Mirror Dynamics Using the Center of Curvature Optical Assembly (CoCOA)

    Science.gov (United States)

    Wells, C.; Hadaway, J.; Olczak, G.; Cosentino, J.; Johnston, J.; Whitman, T.; Connolly, M.; Chaney, D.; Knight, J.; Telfer, R.

    2016-01-01

    The JWST (James Webb Space Telescope) Optical Telescope Element (OTE) consists of a 6.6 meter clear aperture, 18-segment primary mirror, all-reflective, three-mirror anastigmat operating at cryogenic temperatures. To verify performance of the primary mirror, a full aperture center of curvature optical null test is performed under cryogenic conditions in Chamber A at NASA Johnson Space Center using an instantaneous phase measuring interferometer. After phasing the mirrors during the JWST Pathfinder testing, the interferometer is utilized to characterize the mirror relative piston and tilt dynamics under different facility configurations. The correlation between the motions seen on detectors at the focal plane and the interferometer validates the use of the interferometer for dynamic investigations. The success of planned test hardware improvements will be characterized by the multi-wavelength interferometer (MWIF) at the Center of Curvature Optical Assembly (CoCOA).

  19. 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.

  20. 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.

  1. Further Investigations of the Passive Optical Sample Assembly (POSA) - I Flight Experiment

    Science.gov (United States)

    Finckenor, Miria M.; Kamenetzky, Rachel R.; Vaughn, Jason A.; Mell, Richard; Deshpande, M. S.

    2001-01-01

    The Passive Optical Sample Assembly-I (POSA-I), part of the Mir Environmental Effects Payload (MEEP), was designed to study the combined effects of contamination, atomic oxygen, ultraviolet radiation, vacuum, then-nal cycling, and other constituents of the space environment on spacecraft materials. The MEEP program is a Phase I International Space Station Risk Mitigation Experiment. Candidate materials for the International Space Station (ISS) were exposed in a specially designed "suitcase" carrier, with identical specimens facing either Mir or space. The payload was attached by EVA to the exterior of the Mir docking module during the STS-76 mission (f'ig. 1). It was removed during the STS-86 mission after an 18-month exposure. During the mission, it received approximately 7 x 1019 atoMS/CM2 atomic oxygen, as calculated by polymer mass loss, and 413 ESH of solar ultraviolet radiation on the Mir-facing side. The side facing away from Mir received significant contaminant deposition, so atomic oxygen fluence has not been reliably determined. The side facing away from Mir received 571 ESH of solar UV. Contamination was observed on both the Mir-facing and space-facing sides of the POSA-I experiment , with a greater amount of deposition on the space facing side than the Mir side. The contamination has been determined to be outgassed silicone photofixed by ultraviolet radiation and converted to silicate by atomic oxygen interaction. Electron spectroscopy for chemical analysis (ESCA) with depth profiling indicated the presence of 26 - 31 nm silicate on the Mir-facing side and 500 - 1000 nm silicate on the space-facing side. The depth profiling also showed that the contaminant layer was uniform, with a small amount of carbon present on the surface and trace amounts of nitrogen, phosphorus, sulfur, and tin. The surface carbon layer is likely due to post-flight exposure in the laboratory and is similar to carbonaceous deposits on control samples. EDAX and FTIR analysis

  2. 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...

  3. 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.

  4. 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.

  5. 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

  6. Manufacturing of polymer optical waveguides using self-assembly effect on pre-conditioned 3D-thermoformed flexible substrates

    Science.gov (United States)

    Hoffmann, Gerd-Albert; Wolfer, Tim; Zeitler, Jochen; Franke, Jörg; Suttmann, Oliver; Overmeyer, Ludger

    2017-02-01

    Optical data communication is increasingly interesting for many applications in industrial processes. Therefore mass production is required to meet the requested price and lot sizes. Polymer optical waveguides show great promises to comply with price requirements while providing sufficient optical quality for short range data transmission. A high efficient fabrication technology using polymer materials could be able to create the essential backbone for 3D-optical data transmission in the future. The approach for high efficient fabrication technology of micro optics described in this paper is based on a self-assembly effect of fluids on preconditioned 3D-thermoformed polymer foils. Adjusting the surface energy on certain areas on the flexible substrate by flexographic printing mechanism is presented in this paper. With this technique conditioning lines made of silicone containing UV-varnish are printed on top of the foils and create gaps with the exposed substrate material in between. Subsequent fabrication processes are selected whether the preconditioned foil is coated with acrylate containing waveguide material prior or after the thermoforming process. Due to the different surface energy this material tends to dewet from the conditioning lines. It acts like regional barriers and sets the width of the arising waveguides. With this fabrication technology it is possible to produce multiple waveguides with a single coating process. The relevant printing process parameters that affect the quality of the generated waveguides are discussed and results of the produced waveguides with width ranging from 10 to 300 μm are shown.

  7. 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.

  8. 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

  9. 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.)

  10. Inertial Confinement Fusion and the National Ignition Facility (NIF)

    Energy Technology Data Exchange (ETDEWEB)

    Ross, P.

    2012-08-29

    Inertial confinement fusion (ICF) seeks to provide sustainable fusion energy by compressing frozen deuterium and tritium fuel to extremely high densities. The advantages of fusion vs. fission are discussed, including total energy per reaction and energy per nucleon. The Lawson Criterion, defining the requirements for ignition, is derived and explained. Different confinement methods and their implications are discussed. The feasibility of creating a power plant using ICF is analyzed using realistic and feasible numbers. The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is shown as a significant step forward toward making a fusion power plant based on ICF. NIF is the world’s largest laser, delivering 1.8 MJ of energy, with a peak power greater than 500 TW. NIF is actively striving toward the goal of fusion energy. Other uses for NIF are discussed.

  11. 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

  12. Self-Assembly of Reconfigurable By-Design Optical Materials with Molecular-Level Control

    Science.gov (United States)

    2014-09-21

    structures such as the diamond structure. It would also be possible to assemble non-symmetric particles like nanorods or nanoplatelets into a highly...uniformly distributed on the surface with minimal aggregations . As more gold nanoparticle layers were added by subsequent self-assembly processes, the...2 nm. Despite their small size, we did not observe any signs of aggregation even after several weeks in solution, supporting the notion that

  13. Luminescence-Based Optical Sensors Fabricated by Means of the Layer-by-Layer Nano-Assembly Technique.

    Science.gov (United States)

    De Acha, Nerea; Elosua, Cesar; Matias, Ignacio; Arregui, Francisco Javier

    2017-12-06

    Luminescence-based sensing applications range from agriculture to biology, including medicine and environmental care, which indicates the importance of this technique as a detection tool. Luminescent optical sensors are required to be highly stable, sensitive, and selective, three crucial features that can be achieved by fabricating them by means of the layer-by-layer nano-assembly technique. This method permits us to tailor the sensors' properties at the nanometer scale, avoiding luminophore aggregation and, hence, self-quenching, promoting the diffusion of the target analytes, and building a barrier against the undesired molecules. These characteristics give rise to the fabrication of custom-made sensors for each particular application.

  14. 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.

  15. 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.

  16. 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.

  17. National Ignition Facility quality assurance plan for laser materials and optical technology

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, C.R.

    1996-05-01

    Quality achievement is the responsibility of the line organizations of the National Ignition Facility (NIF) Project. This subtier Quality Assurance Plan (QAP) applies to activities of the Laser Materials & Optical Technology (LM&OT) organization and its subcontractors. It responds to the NIF Quality Assurance Program Plan (QAPP, L-15958-2, NIF-95-499) and Department of Energy (DOE) Order 5700.6C. This Plan is organized according to 10 Quality Assurance (QA) criteria and subelements of a management system as outlined in the NIF QAPP. This Plan describes how those QA requirements are met. This Plan is authorized by the Associate Project Leader for the LM&OT organization, who has assigned responsibility to the Optics QA engineer to maintain this plan, with the assistance of the NIF QA organization. This Plan governs quality-affecting activities associated with: design; procurement; fabrication; testing and acceptance; handling and storage; and installation of NIF Project optical components into mounts and subassemblies.

  18. Improving and correcting the contiguity of long-read genome assemblies of three plant species using optical mapping and chromosome conformation capture data.

    Science.gov (United States)

    Jiao, Wen-Biao; Accinelli, Gonzalo Garcia; Hartwig, Benjamin; Kiefer, Christiane; Baker, David; Severing, Edouard; Willing, Eva-Maria; Piednoel, Mathieu; Woetzel, Stefan; Madrid-Herrero, Eva; Huettel, Bruno; Hümann, Ulrike; Reinhard, Richard; Koch, Marcus A; Swan, Daniel; Clavijo, Bernardo; Coupland, George; Schneeberger, Korbinian

    2017-05-01

    Long-read sequencing can overcome the weaknesses of short reads in the assembly of eukaryotic genomes; however, at present additional scaffolding is needed to achieve chromosome-level assemblies. We generated Pacific Biosciences (PacBio) long-read data of the genomes of three relatives of the model plant Arabidopsis thaliana and assembled all three genomes into only a few hundred contigs. To improve the contiguities of these assemblies, we generated BioNano Genomics optical mapping and Dovetail Genomics chromosome conformation capture data for genome scaffolding. Despite their technical differences, optical mapping and chromosome conformation capture performed similarly and doubled N50 values. After improving both integration methods, assembly contiguity reached chromosome-arm-levels. We rigorously assessed the quality of contigs and scaffolds using Illumina mate-pair libraries and genetic map information. This showed that PacBio assemblies have high sequence accuracy but can contain several misassemblies, which join unlinked regions of the genome. Most, but not all, of these misjoints were removed during the integration of the optical mapping and chromosome conformation capture data. Even though none of the centromeres were fully assembled, the scaffolds revealed large parts of some centromeric regions, even including some of the heterochromatic regions, which are not present in gold standard reference sequences. © 2017 Jiao et al.; Published by Cold Spring Harbor Laboratory Press.

  19. Mounting for Fabrication, Metrology, and Assembly of Full Shell Grazing Incidence Optics

    Science.gov (United States)

    Roche, Jacqueline M.; Gubarev, Mikhail V.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Ramsey, Brian D.; Elsner, Ronald F.

    2014-01-01

    Future x-ray telescopes will likely require lightweight mirrors to attain the large collecting areas needed to accomplish the science objectives. Understanding and demonstrating processes now is critical to achieving sub-arcsecond performance in the future. Consequently, designs not only of the mirrors but of fixtures for supporting them during fabrication, metrology, handling, assembly, and testing must be adequately modeled and verified. To this end, MSFC is using finite-element modeling to study the effects of mounting on full-shell grazing-incidence mirrors, during all processes leading to flight mirror assemblies. Here we report initial results of this study.

  20. Terbium to Quantum Dot FRET Bioconjugates for Clinical Diagnostics: Influence of Human Plasma on Optical and Assembly Properties

    Directory of Open Access Journals (Sweden)

    Niko Hildebrandt

    2011-10-01

    Full Text Available Förster resonance energy transfer (FRET from luminescent terbium complexes (LTC as donors to semiconductor quantum dots (QDs as acceptors allows extraordinary large FRET efficiencies due to the long Förster distances afforded. Moreover, time-gated detection permits an efficient suppression of autofluorescent background leading to sub-picomolar detection limits even within multiplexed detection formats. These characteristics make FRET-systems with LTC and QDs excellent candidates for clinical diagnostics. So far, such proofs of principle for highly sensitive multiplexed biosensing have only been performed under optimized buffer conditions and interactions between real-life clinical media such as human serum or plasma and LTC-QD-FRET-systems have not yet been taken into account. Here we present an extensive spectroscopic analysis of absorption, excitation and emission spectra along with the luminescence decay times of both the single components as well as the assembled FRET-systems in TRIS-buffer, TRIS-buffer with 2% bovine serum albumin, and fresh human plasma. Moreover, we evaluated homogeneous LTC-QD FRET assays in QD conjugates assembled with either the well-known, specific biotin-streptavidin biological interaction or, alternatively, the metal-affinity coordination of histidine to zinc. In the case of conjugates assembled with biotin-streptavidin no significant interference with the optical and binding properties occurs whereas the histidine-zinc system appears to be affected by human plasma.

  1. 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...

  2. 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

  3. 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

  4. Large optics for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Baisden, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-01-12

    The National Ignition Facility (NIF) laser with its 192 independent laser beams is not only the world’s largest laser, it is also the largest optical system ever built. With its 192 independent laser beams, the NIF requires a total of 7648 large-aperture (meter-sized) optics. One of the many challenges in designing and building NIF has been to carry out the research and development on optical materials, optics design, and optics manufacturing and metrology technologies needed to achieve NIF’s high output energies and precision beam quality. This paper describes the multiyear, multi-supplier, development effort that was undertaken to develop the advanced optical materials, coatings, fabrication technologies, and associated process improvements necessary to manufacture the wide range of NIF optics. The optics include neodymium-doped phosphate glass laser amplifiers; fused silica lenses, windows, and phase plates; mirrors and polarizers with multi-layer, high-reflectivity dielectric coatings deposited on BK7 substrates; and potassium di-hydrogen phosphate crystal optics for fast optical switches, frequency conversion, and polarization rotation. Also included is a discussion of optical specifications and custom metrology and quality-assurance tools designed, built, and fielded at supplier sites to verify compliance with the stringent NIF specifications. In addition, a brief description of the ongoing program to improve the operational lifetime (i.e., damage resistance) of optics exposed to high fluence in the 351-nm (3ω) is provided.

  5. Small Optics Laser Damage Test Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, Justin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-19

    This specification defines the requirements and procedure for laser damage testing of coatings and bare surfaces designated for small optics in the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL).

  6. Self-Assembly of Nanocomposite Nonlinear Optical Materials for Photonic Devices, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This program targets the development of new highly anisotropic nonlinear optical nanocomposite materials for NASA and non-NASA applications in advanced photonic and...

  7. Magnetism, optical absorbance, and 19F NMR spectra of nafion films with self-assembling paramagnetic networks

    Energy Technology Data Exchange (ETDEWEB)

    Levin, E. M.; Chen, Q.; Bud' ko, S. L.

    2012-01-15

    Magnetization, optical absorbance, and {sup 19}F NMR spectra of Nafion transparent films as received and doped with Mn{sup 2+}, Co{sup 2+}, Fe{sup 2+}, and Fe{sup 3+} ions with and without treatment in 1H-1,2,4-triazole (trz) have been studied. Doping of Nafion with Fe{sup 2+} and Co{sup 2+} and their bridging to nitrogen of triazole yields a hybrid self-assembling paramagnetic system that exhibits interesting magnetic and optical properties. These include spin crossover phenomena between high-spin (HS) and low-spin (LS) states in Nafion-Fe{sup 2+}-trz and Nafion-Co{sup 2+}-trz accompanied by thermochromic effects in the visible range induced by temperature. A large shift of the magnetization curve induced by a magnetic field in the vicinity of the HS {leftrightarrow} LS, {approx}220 K, observed for Nafion-Fe{sup 2+}-trz has a rate of {approx}6 K/kOe, which is about three orders of magnitude larger than that in bulk spin crossover Fe{sup 2+} materials. Selective response of {sup 19}F NMR signals on doping with paramagnetic ions demonstrates that NMR can be used as spatially resolved method to study Nafion film with paramagnetic network. Both chemical shift and width of {sup 19}F NMR signals show that SO groups of Nafion, Fe or Co ions, and nitrogen of triazole are bonded whereas they form a spin crossover system. Based on a model of nanosize cylinders proposed for Nafion [K. Schmidt-Rohr and Q. Chen, Nat Mater (2008), 75], we suggest that paramagnetic ions are located inside these cylinders, forming self-assembling magnetically and optically active nanoscale networks.

  8. 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.

  9. 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.

  10. 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

  11. Self-assembled monolayers on gold nanospheres studied by optical second-harmonic generation

    Science.gov (United States)

    Yamaguchi, T.; Kajikawa, K.

    2008-08-01

    Recently plasmonic biosensors consisting of gold nanoparticles have been developed. In order to understand the response of the biosensors, we have investigated how are gold nanospheres immobilized on a surface covered by a self-assembled monolayer (SAM) which is formed by immersion of the substrate in a solution, by use of surface second-harmonic generation (SHG). The surface immobilized gold nanospheres (SIGNs) are supported by a self-assembled monolayer (SAM) of aminoundecanthiol on a gold thin film. The SIGN substrate was immersed in an ethanol solution of hemicyanine-terminated alkanethiol. The capping angles of the hemicyanine SAM with respect to the top of the SIGN were evaluated from polarization dependence of SHG intensity. The SIGNs are not fully covered with the SAM, and the capping angle is found to be approximately 120 degrees.

  12. Challenges and Approach for Making the Top End Optical Assembly for the 4-meter Advanced Technology Solar Telescope

    Science.gov (United States)

    Canzian, Blaise; Barentine, J.; Hull, T.

    2012-01-01

    L-3 Integrated Optical Systems (IOS) Division has been selected by the National Solar Observatory (NSO) to make the Top End Optical Assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope (ATST) to operate at Haleakala, Maui. ATST will perform to a very high optical performance level in a difficult thermal environment. The TEOA, containing the 0.65-meter silicon carbide secondary mirror and support, mirror thermal management system, mirror positioning and fast tip-tilt system, field stop with thermally managed heat dump, thermally managed Lyot stop, safety interlock and control system, and support frame, operates in the "hot spot” at the prime focus of the ATST and so presents special challenges. In this paper, we will describe the L-3 IOS technical approach to meet these challenges, including subsystems for opto-mechanical positioning, rejected and stray light control, wavefront tip-tilt compensation, and thermal management. Key words: ATST, TEOA, L-3 IOS, thermal management, silicon carbide (SiC) mirrors, hexapods, solar astronomy

  13. 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

  14. Self-transmissible nif plasmid (pEA9) of Enterobacter agglomerans 339: molecular cloning and evidence for the existence of similar nif clusters on dissimilar plasmids in Enterobacter strains.

    Science.gov (United States)

    Steibl, H D; Siddavattam, D; Klingmüller, W

    1995-11-01

    A cosmid library was generated to the 200-kb self-transmissible nif plasmid pEA9 isolated from Enterobacter agglomerans 339. The cosmid clone identified to contain the complete nif cluster was used to determine the nif gene organization and the physical map. The restriction pattern and nif gene organization of this nif cluster showed remarkable similarities to the nif cluster identified on the 110-kb plasmid pEA3 of Enterobacter agglomerans 333. Nucleotide sequence of several randomly selected regions of the nif cluster of pEA9 showed 96% similarity when compared to the known sequences of the nif cluster of pEA3. However, the homology ended abruptly at the flanking regions of the nif clusters and no similarity could be detected with the rest of the DNA of these plasmids. This reveals the existence of similar nif clusters on dissimilar plasmids, implying the horizontal transfer of the entire nif gene cluster.

  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. 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).

  17. 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.

  18. Investigation of impurity parameters and natural radioactivity of Nif Rivulet

    International Nuclear Information System (INIS)

    Yavuz, M.; Eral, M.

    2001-01-01

    The Nif Rivulet is the only flowing fountain in the region of Kemalpasa, originating from Besyol Village and flowing in to the river Gediz through Kemalpasa territories (D.S.I., 1979). The region has been losing properties of an agricultural area due to the increase in the number of recently established industrial settlements in the region. Since the region does not have a proper drainage system and some industrial establishments haven't got treatment system, the Nif Rivulet has been an area where all waste waters discharged (C.D.M.Y., 1996). In this study, the parameters determined according to the water quality standards in the water samples taken in the duration of twelve months from the seven separate places of the Nif Rivulet is classified in the fourth class water category as scheduled under the organic parameters and in the second class water category for heavy metal pollution

  19. The manufacturing, assembly and acceptance testing of the breadboard Cryogenic Optical Delay Line for DARWIN

    NARCIS (Netherlands)

    Dool, T.C. van den; Kamphues, F.G.; Gielesen, W.L.M.; Dorrepaal, M.; Doelman, N.J.; Loix, N.; Verschueren, J.P.; Kooijman, P.P.; Visser, M.; Velsink, G.; Fleury, K.

    2005-01-01

    TNO, in cooperation with Micromega-Dynamics, SRON, Dutch Space and CSL, has developed a compact breadboard cryogenic Optical Delay Line for use in future space interferometry missions. The work is performed under ESA contract in preparation for the DARWIN mission. The breadboard delay line is

  20. 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.

  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. 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

  3. 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

  4. Optical Fiber Assemblies for Space Flight from the NASA Goddard Space Flight Center, Photonics Group

    Science.gov (United States)

    Ott, Melanie N.; Thoma, William Joe; LaRocca, Frank; Chuska, Richard; Switzer, Robert; Day, Lance

    2009-01-01

    The Photonics Group at NASA Goddard Space Flight Center in the Electrical Engineering Division of the Advanced Engineering and Technologies Directorate has been involved in the design, development, characterization, qualification, manufacturing, integration and anomaly analysis of optical fiber subsystems for over a decade. The group supports a variety of instrumentation across NASA and outside entities that build flight systems. Among the projects currently supported are: The Lunar Reconnaissance Orbiter, the Mars Science Laboratory, the James Webb Space Telescope, the Express Logistics Carrier for the International Space Station and the NASA Electronic Parts. and Packaging Program. A collection of the most pertinent information gathered during project support over the past year in regards to space flight performance of optical fiber components is presented here. The objective is to provide guidance for future space flight designs of instrumentation and communication systems.

  5. A two degree of freedom micro-gripper with grasping and rotating functions for optical fibers assembling

    Science.gov (United States)

    Chen, Weihai; Shi, Xiaohui; Chen, Wenjie; Zhang, Jianbin

    2013-11-01

    In this paper, a two degree of freedom flexure-based micro-gripper is proposed and applied in the complicated assembling process of optical fibers. The design concept is modeled on the manipulation of human fingers. Therefore, the two tips of micro-gripper, just like human fingers, can easily grasp the optical fiber with a controllable force and precisely rotate it by the rubbing operation. In addition, some sensors installed on the micro-gripper can enhance the operating accuracy. In the developing process, pseudo-rigid-body model method and virtual work principle are employed to conduct theoretical design. Then the obtained theoretical model is validated and optimized by the finite element analysis. Fabrication of the micro-gripper adopts wire electro discharge machining technology and material of aluminum alloy (AL-7075). Experimental studies are carried out on the prototype to further validate the performance of micro-gripper. Experimental results indicate that the developed micro-gripper can well satisfy the requirements of our mission, which also means that it can be widely used in micro-manipulation field.

  6. Correlation between structural, optical, and electrical properties of self-assembled plasmonic nanostructures on the GaAs surface

    Energy Technology Data Exchange (ETDEWEB)

    Gladskikh, Polina V.; Gladskikh, Igor A.; Toropov, Nikita A., E-mail: nikita.a.toropov@gmail.com; Baranov, Mikhail A.; Vartanyan, Tigran A. [ITMO University (Russian Federation)

    2015-11-15

    Self-assembled silver nanostructures on the industry-grade monocrystalline GaAs (100) wafer surface were obtained via physical vapor deposition and characterized by optical reflection spectroscopy, scanning electron microscopy, and current–voltage curve measurements. Reflection spectra of the samples with Ag equivalent thicknesses of 5, 7.5, and 10 nm demonstrated wide plasmonic bands in the visible range of spectra. Thermal annealing of the nanostructures led to narrowing of the plasmonic bands caused by major transformations of the film morphology. While the As prepared films predominantly had a small-scale labyrinth structure, after annealing well-separated silver nanoislands are formed on the gallium arsenide surface. A clear correlation between films morphology and their optical and electrical properties is elucidated. Annealing of the GaAs substrate with Ag nanostructures at 100 °C under control of the resistivity allowed us to obtain and fix the structure at the percolation threshold. It is established that the samples at the percolation threshold possess the properties of resistance switching and hysteresis.Graphical Abstract.

  7. 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.

  8. Magneto-optic material selectivity in self-assembled BiFeO3-CoFe2O4 biferroic nanostructures

    Science.gov (United States)

    Postava, K.; Hrabovský, D.; Životský, O.; Pištora, J.; Dix, N.; Muralidharan, R.; Caicedo, J. M.; Sánchez, F.; Fontcuberta, J.

    2009-04-01

    Material selective sensitivity of a magneto-optical polar Kerr effect to magnetic contributions from different inclusions in self-organized magnetic nanostructures is presented. The method is supported by modeling of the magneto-optic response based on the effective medium approximation and by hysteresis loop measurement of the multiferroic BiFeO3-CoFe2O4 self-assembled nanostructure. Magneto-optic selective sensitivity is demonstrated and explained as an effect of different complex diagonal and off-diagonal permittivity tensor elements of two materials.

  9. Optical transitions and electronic interactions in self-assembled cobalt-fullerene mixture films

    Czech Academy of Sciences Publication Activity Database

    Lavrentiev, Vasyl; Chvostová, Dagmar; Lavrentieva, Inna; Vacík, Jiří; Daskal, Y.; Barchuk, M.; Rafaja, D.; Dejneka, Alexandr

    2017-01-01

    Roč. 50, č. 48 (2017), č. článku 485305. ISSN 0022-3727 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2015088; GA MŠk LM2015056 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : fullerene * cobalt * electronic interaction * optical absorption * mixture film Subject RIV: BM - Solid Matter Physics ; Magnetism; BO - Biophysics (FZU-D) OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.); Biophysics (FZU-D) Impact factor: 2.588, year: 2016

  10. Cherenkov radiation conversion and collection considerations for a gamma bang time/reaction history diagnostic for the NIF.

    Science.gov (United States)

    Herrmann, Hans W; Mack, Joseph M; Young, Carlton S; Malone, Robert M; Stoeffl, Wolfgang; Horsfield, Colin J

    2008-10-01

    Bang time and reaction history measurements are fundamental components of diagnosing inertial confinement fusion (ICF) implosions and will be essential contributors to diagnosing attempts at ignition on the National Ignition Facility (NIF). Fusion gammas provide a direct measure of fusion interaction rate without being compromised by Doppler spreading. Gamma-based gas Cherenkov detectors that convert fusion gamma rays to optical Cherenkov photons for collection by fast recording systems have been developed and fielded at Omega. These systems have established their usefulness in illuminating ICF physics in several experimental campaigns. Bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF system design requirements. A comprehensive, validated numerical study of candidate systems is providing essential information needed to make a down selection based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF logistics. This paper presents basic design considerations arising from the two-step conversion process from gamma rays to relativistic electrons to UV/visible Cherenkov radiation.

  11. 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

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

    African Journals Online (AJOL)

    The nifH gene sequence of the nitrogen-fixing bacterium Azotobacter spp. was determined with the use of polymerase chain reaction (PCR). The Azotobacter species was isolated from marine source in two different seasons. They were cultivated under laboratory conditions using Nitrogen free Azotobacter specific medium.

  13. 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.

  14. 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.

  15. 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.

  16. 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)…

  17. Identification of nif genes of heterotrophic and endophytic ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-16

    Nov 16, 2009 ... Rocha et al., 1986). Since the nif H gene only occurs in nitrogen fixing microorganisms, it has been used to monitor the presence of these diazotrophs, for example, in pure cultures ... and the remaining letters represent the location from which it was isolated with the .... 2, Washington State University Press,.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... The nifH gene sequence of the nitrogen-fixing bacterium Azotobacter spp. was determined with the use of polymerase chain reaction (PCR). The Azotobacter species was isolated from marine source in two different seasons. They were cultivated under laboratory conditions using Nitrogen free Azotobacter.

  19. First Successes and Modifications of the NIF Opacity Spectrometer

    Science.gov (United States)

    King, J. A.; Huffman, E. J.; Knight, R. A.; Opachich, Y. P.; Ross, P. W.; Heeter, R. F.; Ahmed, M. F.; Emig, J. A.; Liedahl, D. A.; Martin, M. E.; Schneider, M. B.; Thompson, N. B.; Dodd, E. S.; Flippo, K. A.; Kline, J. L.; Lopez, F. E.; Archuleta, T. N.; Perry, T. S.

    2017-10-01

    The NIF Opacity Spectrometer (OpSpec) began returning X-ray spectra on its first NIF shot in September 2016. In May 2017, OpSpec recorded the first X-ray transmission data for iron-magnesium plasmas on NIF, at ``Anchor 1'' sample conditions (150 eV and 7E21 e-/cc). OpSpec diffracts X-rays in the 540-2100 eV range off a KAP or RbAP crystal onto either image plate or X-ray film. Modifications to further improve OpSpec's performance are underway, with the largest improvements expected in resolving power (E/dE up to 1000) and reduction of background levels. Implementation is planned for NIF shots in August and December 2017. This presentation will discuss the OpSpec data and design improvements, and also future goals. This work was performed by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946-2891.

  20. Tuning the optical properties of carbon nanotube solutions using amphiphilic self-assembly

    Science.gov (United States)

    Arnold, Michael S.; Stupp, Samuel I.; Hersam, Mark C.

    2003-07-01

    Recently it has been shown that aqueous solutions of sodium dodecyl sulfate (SDS) encapsulated and polymer wrapped single-walled carbon nanotubes (SWNTs) fluoresce in the near infrared (NIR) in the regime of the E11 van Hove transitions for semiconducting SWNTs. For bundled SWNTs, fluorescence is observed to be quenched along with a shift and broadening of the absorbance spectrum. Here, we study two other commercially available surfactants, BRIJ-97 and Triton-X-100, by analysis of carbon nanotube fluorescence and absorptivity in the NIR. It is found that changing the surfactant alters the corresponding optical properties of the solubilized carbon nanotubes. The NIR absorbance spectra of BRIJ-97 and Triton-X-100 carbon nanotube solutions are also compared with the absorbance spectrum of NaCl destabilized SDS-SWNT solutions. By controlling the amount of NaCl added to an aqueous solution of SDS-SWNTs, the optical absorbance spectrum can be made to match that of BRIJ-97 and Triton-X-100 solutions. Lastly, a correlation is drawn between the amount of shift in the absorbance spectrum and the fluorescence intensity, independent of surfactant used. This shift and decrease in fluorescence intensity may be due to carbon nanotube bundling.

  1. 2-Oxoglutarate and the PII homologues NifI1 and NifI2 regulate nitrogenase activity in cell extracts of Methanococcus maripaludis.

    Science.gov (United States)

    Dodsworth, Jeremy A; Cady, Nathaniel C; Leigh, John A

    2005-06-01

    Summary Post-translational regulation of nitrogen fixation, or switch-off, in the methanogenic archaeon Methanococcus maripaludis does not involve detectable covalent modification of the dinitrogenase reductase as in some bacteria, and the genes encoding the PII homologues NifI(1) and NifI(2) are both required, indicating a novel mechanism. To further understand the mechanism of switch-off, we assayed nitrogenase activity in cell extracts from wild-type and nifI mutant strains in the absence or presence of potential signals of nitrogen status. Activity in extracts from a DeltanifI(1)nifI(2) strain was sixfold higher than in extracts from wild-type cells. Addition of 2-oxoglutarate to wild-type extracts enhanced activity up to fivefold, a level similar to that observed in DeltanifI(1)nifI(2) extracts. 2-Oxoglutarate did not affect activity in DeltanifI(1)nifI(2) or single nifI mutant extracts. Furthermore, extracts from genetically complimented nifI mutants regained wild-type characteristics, indicating an in vitro correlation with in vivo effects. Extraction and quantification of 2-oxoglutarate indicated concentrations 10-fold higher in nitrogen-fixing cells than in switched-off and ammonium-grown cells. We propose a model for switch-off where the NifI proteins have an inhibitory effect on nitrogenase activity that is counteracted by high levels of 2-oxoglutarate, which acts as a signal of nitrogen limitation.

  2. 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...

  3. Mesoporous Bragg reflectors: block-copolymer self-assembly leads to building blocks with well defined continuous pores and high control over optical properties

    KAUST Repository

    Guldin, S.

    2011-08-19

    Mesoporous distributed Bragg re ectors (MDBRs) exhibit porosity on the sub-optical length scale. This makes them ideally suited as sensing platforms in biology and chemistry as well as for light management in optoelectronic devices. Here we present a new fast forward route for the fabrication of MDBRs which relies on the self-assembling properties of the block copolymer poly(isoprene-block -ethylene oxide) (PI-b -PEO) in combination with sol-gel chemistry. The interplay between structure directing organic host and co-assembled inorganic guest allows the ne tuning of refractive index in the outcome material. The refractive index dierence between the high and low porosity layer can be as high as 0.4, with the optical interfaces being well dened. Following a 30 min annealing protocol after each layer deposition enables the fast and reliable stacking of MDBRs which exhibit a continuous TiO2 network with large accessible pores and high optical quality.

  4. Generating Bulk-Scale Ordered Optical Materials Using Shear-Assembly in Viscoelastic Media

    Directory of Open Access Journals (Sweden)

    Chris E. Finlayson

    2017-06-01

    Full Text Available We review recent advances in the generation of photonics materials over large areas and volumes, using the paradigm of shear-induced ordering of composite polymer nanoparticles. The hard-core/soft-shell design of these particles produces quasi-solid “gum-like” media, with a viscoelastic ensemble response to applied shear, in marked contrast to the behavior seen in colloidal and granular systems. Applying an oscillatory shearing method to sub-micron spherical nanoparticles gives elastomeric photonic crystals (or “polymer opals” with intense tunable structural color. The further engineering of this shear-ordering using a controllable “roll-to-roll” process known as Bending Induced Oscillatory Shear (BIOS, together with the interchangeable nature of the base composite particles, opens potentially transformative possibilities for mass manufacture of nano-ordered materials, including advances in optical materials, photonics, and metamaterials/plasmonics.

  5. Generating Bulk-Scale Ordered Optical Materials Using Shear-Assembly in Viscoelastic Media

    Science.gov (United States)

    Finlayson, Chris E.; Baumberg, Jeremy J.

    2017-01-01

    We review recent advances in the generation of photonics materials over large areas and volumes, using the paradigm of shear-induced ordering of composite polymer nanoparticles. The hard-core/soft-shell design of these particles produces quasi-solid “gum-like” media, with a viscoelastic ensemble response to applied shear, in marked contrast to the behavior seen in colloidal and granular systems. Applying an oscillatory shearing method to sub-micron spherical nanoparticles gives elastomeric photonic crystals (or “polymer opals”) with intense tunable structural color. The further engineering of this shear-ordering using a controllable “roll-to-roll” process known as Bending Induced Oscillatory Shear (BIOS), together with the interchangeable nature of the base composite particles, opens potentially transformative possibilities for mass manufacture of nano-ordered materials, including advances in optical materials, photonics, and metamaterials/plasmonics. PMID:28773044

  6. Optical absorption signature of a self-assembled dye monolayer on graphene

    Directory of Open Access Journals (Sweden)

    Tessnim Sghaier

    2016-06-01

    Full Text Available A well-organized monolayer of alkylated perylene-3,4,9,10-tetracarboxylic-3,4,9,10-diimide (PTCDI has been formed onto CVD graphene transferred on a transparent substrate. Its structure has been probed by scanning tunnelling microscopy and its optical properties by polarized transmission spectroscopy at varying incidence. The results show that the transition dipoles of adsorbed PTCDI are all oriented parallel to the substrate. The maximum absorption is consistent with the measured surface density of molecules and their absorption cross section. The spectrum presents mainly a large red-shift of the absorption line compared with the free molecules dispersed in solution, whereas the relative strengths of the vibronic structures are preserved. These changes are attributed to non-resonant interactions with the graphene layer and the neighbouring molecules.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

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

    2005-08-01

    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.

  9. 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)

  10. A concept to collect neutron and x-ray images on the same line of sight at NIF.

    Science.gov (United States)

    Merrill, F E; Danly, C R; Izumi, N; Jedlovec, D; Fittinghoff, D N; Grim, G P; Pak, A; Park, H-S; Volegov, P L; Wilde, C H

    2014-11-01

    Neutron and x-ray images are collected at the National Ignition Facility (NIF) to measure the size and shape of inertial confinement fusion implosions. The x-ray images provide a measure of the size and shape of the hot region of the deuterium-tritium fuel while the neutron images provide a measure of the size and shape of the burning plasma. Although these two types of images are collected simultaneously, they are not collected along the same line of sight (LOS). One 14 MeV neutron image is collected on the NIF equator, and two x-ray images are collected along the polar axis and nearly perpendicular to the neutron imaging line of sight on the equator. Both measurements use pinhole apertures to form the images, but existing x-ray imaging provides time-resolved measurements while the neutron images are time-integrated. Detailed comparisons of the x-ray and neutron images can provide information on the fuel assembly, but these studies have been limited because the implosions are not azimuthally symmetric and the images are collected along different LOS. We have developed a conceptual design of a time-integrated x-ray imaging system that could be added to the existing neutron imaging LOS. This new system would allow these detailed studies, providing important information on the fuel assembly of future implosions. Here we present this conceptual design and the expected performance characteristics.

  11. Defect-engineered optical bandgap in self-assembled TiO{sub 2} nanorods on Si pyramids

    Energy Technology Data Exchange (ETDEWEB)

    Saini, C. P.; Barman, A.; Kanjilal, A., E-mail: aloke.kanjilal@snu.edu.in [Department of Physics, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, Gautam Buddha Nagar, Uttar Pradesh 201 314 (India); Satpati, B.; Bhattacharyya, S. R. [Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

    2016-01-04

    Transformation of self-assembled crystalline TiO{sub 2} nanorods to amorphous layer, and the corresponding impact on optical-bandgap (E{sub g}) on Si pyramids are investigated by irradiating with 50 keV Ar{sup +}-ions. Initially, E{sub g} is found to be reduced from 3.23 to 2.94 eV up to a fluence of 1 × 10{sup 16} ions/cm{sup 2}, and discussed in terms of the rise in oxygen vacancies (V{sub O}). However, a sudden increase in E{sub g} to 3.38 eV is detected at a fluence of 1 × 10{sup 17} ions/cm{sup 2} through evolution of voids by over-saturating V{sub O}, manifesting the appearance of degenerate states by shifting the Fermi level above the conduction band minimum via Burstein-Moss effect.

  12. Self-Assembly of Semiconducting-Plasmonic Gold Nanoparticles with Enhanced Optical Property for Photoacoustic Imaging and Photothermal Therapy.

    Science.gov (United States)

    Yang, Zhen; Song, Jibin; Dai, Yunlu; Chen, Jingyi; Wang, Feng; Lin, Lisen; Liu, Yijing; Zhang, Fuwu; Yu, Guocan; Zhou, Zijian; Fan, Wenpei; Huang, Wei; Fan, Quli; Chen, Xiaoyuan

    2017-01-01

    Although various noble metal and semiconducting molecules have been developed as photoacoustic (PA) agents, the use of semiconducting polymer-metal nanoparticle hybrid materials to enhance PA signal has not been explored. A novel semiconducting-plasmonic nanovesicle was fabricated by self-assembly of semiconducting poly(perylene diimide) (PPDI) and poly(ethylene glycol (PEG) tethered gold nanoparticles (Au@PPDI/PEG). A highly localized and strongly enhanced electromagnetic (EM) field is distributed between adjacent gold nanoparticles in the vesicular shell, where the absorbing collapsed PPDI is present. Significantly, the EM field in turn enhances the light absorption efficiency of PPDI, leading to a much greater photothermal effect and a stronger photoacoustic signal compared to PDI nanoparticle or gold nanovesicle alone. The optical property of the hybrid vesicle can be further tailored by controlling the ratio of PPDI and gold nanoparticle as well as the adjustable interparticle distance of gold nanoparticles localized in the vesicular shell. In vivo imaging and therapeutic evaluation demonstrated that the hybrid vesicle is an excellent probe for cancer theranostics.

  13. Understanding the effects of packing and chemical terminations on the optical excitations of azobenzene-functionalized self-assembled monolayers

    Science.gov (United States)

    Cocchi, Caterina; Draxl, Claudia

    2017-10-01

    In a first-principles study based on many-body perturbation theory, we analyze the optical excitations of azobenzene-functionalized self-assembled monolayers (SAMs) with increasing packing density and different terminations, considering for comparison the corresponding gas-phase molecules and dimers. Intermolecular coupling increases with the density of the chromophores independently of the functional groups. The intense π → π* resonance that triggers photo-isomerization is present in the spectra of isolated dimers and diluted SAMs, but it is almost completely washed out in tightly packed architectures. Intermolecular coupling is partially inhibited by mixing differently functionalized azobenzene derivatives, in particular when large groups are involved. In this way, the excitation band inducing the photo-isomerization process is partially preserved and the effects of dense packing partly counterbalanced. Our results suggest that a tailored design of azobenzene-functionalized SAMs which optimizes the interplay between the packing density of the chromophores and their termination can lead to significant improvements in the photo-switching efficiency of these systems.

  14. Improving the off-axis spatial resolution and dynamic range of the NIF X-ray streak cameras (invited).

    Science.gov (United States)

    MacPhee, A G; Dymoke-Bradshaw, A K L; Hares, J D; Hassett, J; Hatch, B W; Meadowcroft, A L; Bell, P M; Bradley, D K; Datte, P S; Landen, O L; Palmer, N E; Piston, K W; Rekow, V V; Hilsabeck, T J; Kilkenny, J D

    2016-11-01

    We report simulations and experiments that demonstrate an increase in spatial resolution of the NIF core diagnostic x-ray streak cameras by at least a factor of two, especially off axis. A design was achieved by using a corrector electron optic to flatten the field curvature at the detector plane and corroborated by measurement. In addition, particle in cell simulations were performed to identify the regions in the streak camera that contribute the most to space charge blurring. These simulations provide a tool for convolving synthetic pre-shot spectra with the instrument function so signal levels can be set to maximize dynamic range for the relevant part of the streak record.

  15. 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

  16. Narrow optical linewidths and spin pumping on charge-tunable close-to-surface self-assembled quantum dots in an ultrathin diode

    Science.gov (United States)

    Löbl, Matthias C.; Söllner, Immo; Javadi, Alisa; Pregnolato, Tommaso; Schott, Rüdiger; Midolo, Leonardo; Kuhlmann, Andreas V.; Stobbe, Søren; Wieck, Andreas D.; Lodahl, Peter; Ludwig, Arne; Warburton, Richard J.

    2017-10-01

    We demonstrate full charge control, narrow optical linewidths, and optical spin pumping on single self-assembled InGaAs quantum dots embedded in a 162.5 -nm -thin diode structure. The quantum dots are just 88 nm from the top GaAs surface. We design and realize a p -i -n -i -n diode that allows single-electron charging of the quantum dots at close-to-zero applied bias. In operation, the current flow through the device is extremely small resulting in low noise. In resonance fluorescence, we measure optical linewidths below 2 μ eV , just a factor of 2 above the transform limit. Clear optical spin pumping is observed in a magnetic field of 0.5 T in the Faraday geometry. We present this design as ideal for securing the advantages of self-assembled quantum dots—highly coherent single-photon generation, ultrafast optical spin manipulation—in the thin diodes required in quantum nanophotonics and nanophononics applications.

  17. Experimental results of astrophysical collisionless shock experiments from NIF

    Science.gov (United States)

    Park, Hye-Sook; Higginson, D.; Huntington, C.; Pollock, B.; Remington, B.; Rinderknecht, H.; Ross, J.; Ryutov, D.; Swadling, G.; Wilks, S.; Fiuza, F.; Sakawa, Y.; Spitkovsky, A.; Petrasso, R.; Li, C.; Zylstra, A.; Lamb, D.; Tzeferacos, P.; Gregori, G.; Meinecke, J.; Manuel, M.

    2017-10-01

    We discuss our laboratory experiments using the Omega and NIF lasers to investigate the dynamics of high Mach number collisionless shock formation in two interpenetrating plasma streams. It is believed that in astrophysical environments such shocks are the sites where seed magnetic fields are generated on a cosmologically fast timescale via the Weibel instability. Particle-in-cell (PIC) numerical simulations generate magnetic fields whose magnitude and scale are consistent with this concept. We will present recent experimental results as well as simulations and theoretical interpretations of these observations. The NIF experiments were able to observe the counter-streaming flow interactions through the transition from collisional to collisionless regimes. The latest proton radiography results will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  18. 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.

  19. The optical fiber array bundle assemblies for the NASA lunar reconnaissance orbiter; evaluation lessons learned for flight implementation from the NASA electronic parts and packaging program

    Science.gov (United States)

    Ott, Melanie N.; Switzer, Robert; Chuska, Richard; LaRocca, Frank; Thomes, William J.; Day, Lance W.; MacMurphy, Shawn

    2017-11-01

    The United States, National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC), Fiber Optics Team in the Electrical Engineering Division of the Applied Engineering and Technology Directorate, designed, developed and integrated the space flight optical fiber array hardware assemblies for the Lunar Reconnaissance Orbiter (LRO). The two new assemblies that were designed and manufacturing at NASA GSFC for the LRO exist in configurations that are unique in the world for the application of ranging and lidar. These assemblies were developed in coordination with Diamond Switzerland, and the NASA GSFC Mechanical Systems Division. The assemblies represent a strategic enhancement for NASA's Laser Ranging and Laser Radar (LIDAR) instrument hardware by allowing light to be moved to alternative locations that were not feasible in past space flight implementations. An account will be described of the journey and the lessons learned from design to integration for the Lunar Orbiter Laser Altimeter and the Laser Ranging Application on the LRO. The LRO is scheduled to launch end of 2008.

  20. 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.

  1. 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.

  2. A sensorimotor area (NIf) is required for the production of learned vocalizations

    OpenAIRE

    Sharon M. H. Gobes; Bence P. Ölveczky

    2011-01-01

    Sensory feedback is essential for the acquisition of complex motor behaviors, including birdsong. In zebra finches, auditory feedback is relayed to the descending motor pathway primarily through the nucleus interfacialis nidopalii (NIf). NIf projects to HVC - a premotor region essential for song, which projects to RA, a motor cortex analogue brain area that drives muscle activity required for vocalizations. NIf is also essential for ‘sleep replay’, a recapitulation of song-relat...

  3. Gluing interface qualification test results and gluing process development of the EUCLID near-infrared spectro-photometer optical assembly

    Science.gov (United States)

    Mottaghibonab, A.; Thiele, H.; Gubbini, E.; Dubowy, M.; Gal, C.; Mecsaci, A.; Gawlik, K.; Vongehr, M.; Grupp, F.; Penka, D.; Wimmer, C.; Bender, R.

    2016-07-01

    The Near Infrared Spectro-Photometer Optical assembly (NIOA) of EUCLID satellite requires high precision large lens holders with different lens materials, shapes and diameters. The aspherical lenses are glued into their separate CTE matched lens holder. The gluing of the lenses in their holder with 2K epoxy is selected as bonding process to minimize the stress in the lenses to achieve the required surface form error (SFE) performance (32nm) and lens position stability (+/-10μm) due to glue shrinkage. Adhesive shrinkage stress occurs during the glue curing at room temperature and operation in cryogenic temperatures, which might overstress the lens, cause performance loss, lens breakage or failure of the gluing interface. The selection of the suitable glue and required bonding parameters, design and qualification of the gluing interface, development and verification of the gluing process was a great challenge because of the low TRL and heritage of the bonding technology. The different material combinations (CaF2 to SS316L, LF5G15 and S-FTM16 to Titanium, SUPRASIL3001 to Invar M93), large diameter (168mm) and thin edge of the lenses, cryogenic nonoperational temperature (100K) and high performance accuracy of the lenses were the main design driver of the development. The different coefficients of thermal expansion (CTE) between lens and lens holder produce large local mechanical stress. As hygroscopic crystal calcium fluoride (CaF2) is very sensitive to moisture therefore an additional surface treatment of the gluing area is necessary. Extensive tests e.g glue handling and single lap shear tests are performed to select the suitable adhesive. Interface connection tests are performed to verify the feasibility of selected design (double pad design), injection channel, the roughness and treatment of the metal and lens interfaces, glue thickness, glue pad diameter and the gluing process. CTE and dynamic measurements of the glue, thermal cycling, damp- heat, connection

  4. 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.

  5. The NIF LinkOut broker: a web resource to facilitate federated data integration using NCBI identifiers.

    Science.gov (United States)

    Marenco, Luis; Ascoli, Giorgio A; Martone, Maryann E; Shepherd, Gordon M; Miller, Perry L

    2008-09-01

    This paper describes the NIF LinkOut Broker (NLB) that has been built as part of the Neuroscience Information Framework (NIF) project. The NLB is designed to coordinate the assembly of links to neuroscience information items (e.g., experimental data, knowledge bases, and software tools) that are (1) accessible via the Web, and (2) related to entries in the National Center for Biotechnology Information's (NCBI's) Entrez system. The NLB collects these links from each resource and passes them to the NCBI which incorporates them into its Entrez LinkOut service. In this way, an Entrez user looking at a specific Entrez entry can LinkOut directly to related neuroscience information. The information stored in the NLB can also be utilized in other ways. A second approach, which is operational on a pilot basis, is for the NLB Web server to create dynamically its own Web page of LinkOut links for each NCBI identifier in the NLB database. This approach can allow other resources (in addition to the NCBI Entrez) to LinkOut to related neuroscience information. The paper describes the current NLB system and discusses certain design issues that arose during its implementation.

  6. OptoZIF Drive: a 3D printed implant and assembly tool package for neural recording and optical stimulation in freely moving mice

    Science.gov (United States)

    Freedman, David S.; Schroeder, Joseph B.; Telian, Gregory I.; Zhang, Zhengyang; Sunil, Smrithi; Ritt, Jason T.

    2016-12-01

    Objective. Behavioral neuroscience studies in freely moving rodents require small, light-weight implants to facilitate neural recording and stimulation. Our goal was to develop an integrated package of 3D printed parts and assembly aids for labs to rapidly fabricate, with minimal training, an implant that combines individually positionable microelectrodes, an optical fiber, zero insertion force (ZIF-clip) headstage connection, and secondary recording electrodes, e.g. for electromyography (EMG). Approach. Starting from previous implant designs that position recording electrodes using a control screw, we developed an implant where the main drive body, protective shell, and non-metal components of the microdrives are 3D printed in parallel. We compared alternative shapes and orientations of circuit boards for electrode connection to the headstage, in terms of their size, weight, and ease of wire insertion. We iteratively refined assembly methods, and integrated additional assembly aids into the 3D printed casing. Main results. We demonstrate the effectiveness of the OptoZIF Drive by performing real time optogenetic feedback in behaving mice. A novel feature of the OptoZIF Drive is its vertical circuit board, which facilities direct ZIF-clip connection. This feature requires angled insertion of an optical fiber that still can exit the drive from the center of a ring of recording electrodes. We designed an innovative 2-part protective shell that can be installed during the implant surgery to facilitate making additional connections to the circuit board. We use this feature to show that facial EMG in mice can be used as a control signal to lock stimulation to the animal’s motion, with stable EMG signal over several months. To decrease assembly time, reduce assembly errors, and improve repeatability, we fabricate assembly aids including a drive holder, a drill guide, an implant fixture for microelectode ‘pinning’, and a gold plating fixture. Significance. The

  7. Localization and physical mapping of a plasmid-borne 23-kb nif gene cluster from Enterobacter agglomerans showing homology to the entire nif gene cluster of Klebsiella pneumoniae M5a1.

    Science.gov (United States)

    Singh, M; Kreutzer, R; Acker, G; Klingmüller, W

    1988-01-01

    A physical and genetical map of the plasmid pEA3 indigenous to Enterobacter agglomerans is presented. pEA3 is a 111-kb large plasmid containing a 23-kb large cluster of nif genes which shows extensive homology (Southern hybridization and heteroduplex analysis) to the entire nif gene cluster of Klebsiella pneumoniae (Kp) M5a1. All the nif genes on pEA3 are organized in the same manner as in K. pneumoniae, except nifJ, which is located on the left end of pEA3 nif gene cluster (near nifQB). A BamHI restriction map of pEA3 and a detailed restriction map of the 23-kb nif region on pEA3 is also presented. The nif genes of pEA3 showed a low level of acetylene reduction in Escherichia coli, demonstrating that these genes are functional and contain the whole genetic information required to fix nitrogen. The origin of vegetative replication (OriV) of pEA3 was localized about 5.5 kb from the right end of the nif gene cluster. In addition to pEA3, large plasmids from four other strains of E. agglomerans showed homology to all the Kp nif genes tested, indicating that in diazotrophic strains of E. agglomerans nif genes are usually located on plasmids. In contrast, in most of the free-living, nitrogen-fixing bacteria the nif genes are on chromosome.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. On the Origin of the Chiro-Optical Activity in Supramolecular Assemblies: A Quantum Chemical Study of C3 Octopolar Systems.

    Science.gov (United States)

    Nieto-Ortega, Belén; Casado, Juan; López Navarrete, Juan T; Hennrich, Gunter; Ramírez, Francisco J

    2011-10-11

    First-principles quantum chemical approach has been used to understand the origin of the chiro-optical signal induced by the chiral aggregation of an achiral chromophore. The study was focused in predicting the circular dichroism (CD) spectra of different π-stacked columnar oligomers built with C3 star-shape molecular bricks. We studied the influence of the relevant structural self-assembly parameters on the CD spectra (i.e., the number of units, the rotation angle and the intermonomer distance). A detailed analysis was based on the MO topologies and the magnetic and electric transition dipole moments, the vectors which determine the CD intensities, has been conducted. We have rationalized the influence of the various structural factors of supramolecular self-assemblies in connection with the nature of their CD spectroscopic signal, which provides new avenues for structure-spectroscopic relationships.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. Measurement of Fluorescence in a Rhodamine-123 Doped Self-Assembled “Giant” Mesostructured Silica Sphere Using a Smartphone as Optical Hardware

    Directory of Open Access Journals (Sweden)

    Ingemar Petermann

    2011-07-01

    Full Text Available The blue OLED emission from a mobile phone was characterised, revealing a sharp emission band centred at λ = 445 nm with a 3dB bandwidth Δλ ~ 20 nm. It was used to excite Rhodamine 123 doped within a “giant” mesostructured silica sphere during fabrication through evaporative self-assembly of silica nanoparticles. Fluorescence was able to be detected using a standard optical microscope fitted with a green transmission pass filter and cooled CCD and with 1 ms exposure time demonstrating the potential of mobile platforms as the basis for portable diagnostics in the field.

  19. 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

  20. Limiting the Accidental Pressure Drop in NIF Beam Tubes

    International Nuclear Information System (INIS)

    Garcia, M

    2000-01-01

    This report summarizes the use of a one-dimensional model of a time-dependent compressible flow condition to validate the results from a more sophisticated three-dimensional model. The flow conditions consist of the sudden decompression of a pressurized tube joined to an evacuated sphere, where the tube also has a leak to external atmosphere that is triggered open at a given pressure difference below sea-level pressure. This flow model is used to calculate conditions in a NIF beam tube if an internal vacuum barrier fails, and to calculate how the size and timing of an opening to external atmosphere changes tube pressure. Decompression of a NIF beam tube is a potential safety hazard since the tube could collapse if the tube pressure is reduced below the buckling limit. To prevent this from occurring, each pressurized section includes a rupture panel which is designed to open to external atmosphere at a given pressure difference. The inrush of external atmosphere through the rupture panel fills both the tube and the vacuum drawing on it, and in this way the pressure drop in the tube is quickly limited and reversed. In summary, the results from the 1D model indicate that the 3-D calculations are accurate and reasonable

  1. 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)

  2. 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.

  3. 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

  4. 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.

  5. In-Situ Preparation of Radioactive Tracers in NIF Capsules

    Science.gov (United States)

    Stoyer, Mark

    2011-04-01

    Inertial Confinement Fusion (ICF) experiments at the National Ignition Facility (NIF) will probe fundamental high energy density physics of plasmas. Radiochemical diagnostics will provide information on ablator and fuel rho-R, yield, asymmetry, and mix by collecting both gaseous and solid debris samples following an implosion. Many experiments utilize ratios of produced activities, but full utilization of the technique requires knowledge of sample collection efficiencies. Gaseous samples are expected to be collected with high efficiency, but solid sample collection is typically limited by location of the collecting apparatus. Activation of ICF capsules has been utilized at other laser facilities [1-2] to produce a radioactive tracer in the ablator of the capsule that can be used to measure the solid collection efficiency. This talk will describe preliminary experiments activating CH(Ge) NIF capsules and Au hohlraums in the High Flux Isotope Reactor (HFIR) at ORNL in order to produce Ge, As, and Au isotopes for determination of collection efficiency, spatial distribution of the debris, efficacy of various collectors, and if there are preferred locations for debris collection. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. S.M. Lane and M.B. Nelson, Rev. Sci. Inst. 61 (1990) 3298.

  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. Whole-genome shotgun optical mapping of Rhodobacter sphaeroides strain 2.4. 1 and its use for whole-genome shotgun sequence assembly

    Energy Technology Data Exchange (ETDEWEB)

    Shou, S. [Univ. Wisc.-Madison; Kvikstad, E. [Univ. Wisc.-Madison; Kile, A. [Univ. Wisc.-Madison; Severin, J. [Whole-genome shotgun optical mapping of Rhodobacter sphaeroides strain 2.4. 1 and its use for whole-genome shotgun sequence assembly; Forrest, D. [Univ. Wisc.-Madison; Runnheim, R. [Univ. Wisc.-Madison; Churas, C. [Univ. Wisc.-Madison; Hickman, J. W. [Univ. Wisc.-Madison; Mackenzie, C. [University of Texas–Houston Medical School; Choudhary, M. [University of Texas–Houston Medical School; Donohue, T. [Univ. Wisc.-Madison; Kaplan, S. [University of Texas–Houston Medical School; Schwartz, D. C. [Univ. Wisc.-Madison

    2003-09-01

    Rhodobacter sphaeroides 2.4.1 is a facultative photoheterotrophic bacterium with tremendous metabolic diversity, which has significantly contributed to our understanding of the molecular genetics of photosynthesis, photoheterotrophy, nitrogen fixation, hydrogen metabolism, carbon dioxide fixation, taxis, and tetrapyrrole biosynthesis. To further understand this remarkable bacterium, and to accelerate an ongoing sequencing project, two whole-genome restriction maps (EcoRI and HindIII) of R. sphaeroides strain 2.4.1 were constructed using shotgun optical mapping. The approach directly mapped genomic DNA by the random mapping of single molecules. The two maps were used to facilitate sequence assembly by providing an optical scaffold for high-resolution alignment and verification of sequence contigs. Our results show that such maps facilitated the closure of sequence gaps by the early detection of nascent sequence contigs during the course of the whole-genome shotgun sequencing process.

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Rocket Assembly and Checkout Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Integrates, tests, and calibrates scientific instruments flown on sounding rocket payloads. The scientific instruments are assembled on an optical bench;...

  14. 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.

  15. 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.

  16. Cluster assembly in nitrogenase.

    Science.gov (United States)

    Sickerman, Nathaniel S; Rettberg, Lee A; Lee, Chi Chung; Hu, Yilin; Ribbe, Markus W

    2017-05-09

    The versatile enzyme system nitrogenase accomplishes the challenging reduction of N 2 and other substrates through the use of two main metalloclusters. For molybdenum nitrogenase, the catalytic component NifDK contains the [Fe 8 S 7 ]-core P-cluster and a [MoFe 7 S 9 C-homocitrate] cofactor called the M-cluster. These chemically unprecedented metalloclusters play a critical role in the reduction of N 2 , and both originate from [Fe 4 S 4 ] clusters produced by the actions of NifS and NifU. Maturation of P-cluster begins with a pair of these [Fe 4 S 4 ] clusters on NifDK called the P*-cluster. An accessory protein NifZ aids in P-cluster fusion, and reductive coupling is facilitated by NifH in a stepwise manner to form P-cluster on each half of NifDK. For M-cluster biosynthesis, two [Fe 4 S 4 ] clusters on NifB are coupled with a carbon atom in a radical-SAM dependent process, and concomitant addition of a 'ninth' sulfur atom generates the [Fe 8 S 9 C]-core L-cluster. On the scaffold protein NifEN, L-cluster is matured to M-cluster by the addition of Mo and homocitrate provided by NifH. Finally, matured M-cluster in NifEN is directly transferred to NifDK, where a conformational change locks the cofactor in place. Mechanistic insights into these fascinating biosynthetic processes are detailed in this chapter. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  17. 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.

  18. Optics

    CERN Document Server

    Mathieu, Jean Paul

    1975-01-01

    Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

  19. 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)

  20. Novel nonlinear optical material with poly(3-hexylthiophene) thin film prepared on quartz glass surface modified by self-assembled monolayer

    Science.gov (United States)

    Ochiai, Shizuyasu; Mototani, Suguru; Ramajothi, Jayaraman; Kojima, Kenzo; Mizutani, Teruyoshi

    2008-08-01

    The third-order nonlinear optical properties of regioregular poly(3-hexylthiophene) (RR-P3HT) thin films prepared on fused glass substrate were evaluated. The surface modification by hexamethyldisilazane (HMDS) and octadecyltrichlorosilane (ODTS) was performed on the glass substrate to form self-assembled monolayer (SAM) layers. The formation of SAM layers on the glass substrate increase the contact angle of the solution and the optical property of the RR-P3HT thin films is enhanced due to the excellent orientation and alignment of the thin film. The π-conjugated macromolecule thin films can be prepared by spin-coating and drop-casting methods and the structure and orientation alignment of thin films can be controlled by the solution processing and deposition techniques. The nonlinear optical property, third-harmonic generation of RR-P3HT thin films has been evaluated by Maker-fringe method. The third-order nonlinear optical susceptibilities χ(3) (-3ω ω, ω, ω) of drop-cast RR-P3HT thin films on quartz glass substrate were estimated from optical third-harmonics (TH) intensity measurement. An Nd:YAG laser with a wavelength of 1064 nm, pulse width of 5 ns and a repetition frequency of 10 Hz was used to evaluate the TH intensity. The effect of surface modification of quartz glass substrate by HMDS and ODTS on the RR-P3HT film structure was also investigated. The orientation alignment and crystallinity of the RR-P3HT thin films were evaluated using X-ray diffraction (XRD) and UV-vis absorption spectra. The UV-vis and XRD profile reveals the better orientation and crystallinity of the RR-P3HT thin film after surface modification by HMDS and ODTS. Moreover the incident angle dependences of third harmonic (TH) intensity was measured and the TH intensity of RR-P3HT thin film prepared on glass substrate with SAM layer was found to higher than that of non-treated substrate. The SAM layers significantly enhances the optical property of the material and the third

  1. 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)].

  2. Neutron Skyshine Considerations For The NIF Shielding Design

    Energy Technology Data Exchange (ETDEWEB)

    Singh, M S; Mecozzi, J M; Tobin, M T

    2004-01-28

    A series of coupled neutron-photon transport Monte-Carlo calculations was performed to estimate the roof shielding required to limit the skyshine dose to less than 1 mrem/y at the site boundary when conducting DT experiments with annual fusion yields up to 1200 MJ (4.2E20 neutrons/y). The NIF shielding design consists of many different components. The basic components include 10-cm-thick Al chamber with 40-cm-thick target chamber gunite shield having multiple penetrations, 1.83-m-thick concrete Target Bay walls, 1.37-m-thick concrete roof, and multiple concrete floors with numerous penetrations. Under this shielding configuration, the skyshine dose at the nearest site-boundary was calculated to be less than 0.2 mrem/y for all possible target illumination configurations. The potential dose at the site boundary would be about one-tenth of the cosmic neutron dose that we measured with bubble neutron detectors on board a commercial roundtrip flight from SF to Rochester. This incremental dose increase is well within the normal fluctuations (noise) of the natural background radiation in the Livermore area. The skyshine dose has no impact on the public. The skyshine dose trends at ground and elevated levels are plotted as a function of distance from 20 m to 1000 m from the center of the target bay. The differential neutron and photon energy flux emerging from the NIF roof and at several locations on the ground is plotted to show how it shifts with distance. The results of this study are compared with the neutron skyshine studies done at high-energy accelerators by R. H. Thomas.

  3. Effects of annealing temperature and duration on the morphological and optical evolution of self-assembled Pt nanostructures on c-plane sapphire.

    Directory of Open Access Journals (Sweden)

    Mao Sui

    Full Text Available Metallic nanostructures (NSs have been widely adapted in various applications and their physical, chemical, optical and catalytic properties are strongly dependent on their surface morphologies. In this work, the morphological and optical evolution of self-assembled Pt nanostructures on c-plane sapphire (0001 is demonstrated by the control of annealing temperature and dwelling duration with the distinct thickness of Pt films. The formation of Pt NSs is led by the surface diffusion, agglomeration and surface and interface energy minimization of Pt thin films, which relies on the growth parameters such as system temperature, film thickness and annealing duration. The Pt layer of 10 nm shows the formation of overlaying NPs below 650°C and isolated Pt nanoparticles above 700°C based on the enhanced surface diffusion and Volmer-Weber growth model whereas larger wiggly nanostructures are formed with 20 nm thick Pt layers based on the coalescence growth model. The morphologies of Pt nanostructures demonstrate a sharp distinction depending on the growth parameters applied. By the control of dwelling duration, the gradual transition from dense Pt nanoparticles to networks-like and large clusters is observed as correlated to the Rayleigh instability and Ostwald ripening. The various Pt NSs show a significant distinction in the reflectance spectra depending on the morphology evolution: i.e. the enhancement in UV-visible and NIR regions and the related optical properties are discussed in conjunction with the Pt NSs morphology and the surface coverage.

  4. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  5. 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

  6. Facilitization of the National Ignition Facility (NIF) for radiation sciences experiments

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.F.

    1995-12-15

    This report will provide a summary report of work performed under Subcontract B324681 from November 1 through December 14, 1995 and covers work relevant to Subtasks 1-11. The work performed under this contract was presented and reviewed at the NIF Radiation Sciences Users Group meeting held on November 29-30. Present where senior representatives from the NIF Project, the DOE Office of the NIF, the DOE ICF program, and the Defense Nuclear Agency. This report is divided into seven sections, not including the Introduction to include; Potential Test Capability, Operational Scenarios, Facilitization Issues, Security Issues, Performance/Cost/Risk Considerations, a Summary of Requested Modifications to the NIF and finally, Conclusions. Within each section will be a short narrative and a copy of the view graph presentation.

  7. 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

  8. Site-specific mutagenesis in Enterobacter agglomerans: construction of nif B mutants and analysis of the gene's structure and function.

    Science.gov (United States)

    Siddavattam, D; Nickles, A; Herterich, S; Steibl, H D; Kreutzer, R; Klingmüller, W

    1995-12-15

    A novel technique was developed which may be generally well suited to the site-specific construction of mutations in Enterobacter agglomerans. The method is based on the observation that E. agglomerans can be cured of a plasmid of the incompatibility group IncQ by cultivation on citrate-containing medium. To test the applicability of this technique, we inserted a kanamycin cassette into the cloned nifB gene, transferred it into E. agglomerans, and selected for recombinants in which the wild-type nifB was replaced by the mutated gene by growing transformants on citrate medium with kanamycin. The nifB- mutants with the kanamycin cassette inserted in either orientation showed a nif- phenotype. Further, we determined the nucleotide sequence of nifB. A typical sigma 54-dependent promoter and a consensus NifA binding site were found upstream of nifB. Activation of this promoter by both heterologous and homologous NifA proteins was observed in vivo. The predicted amino acid sequence of the NifB protein showed strong similarity to the NifB sequences of other diazotrophic bacteria. The typical clustering of cysteine residues at the N-terminal end indicates its involvement in Fe-Mo cofactor biosynthesis.

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

    Energy Technology Data Exchange (ETDEWEB)

    Moses, E

    2009-10-15

    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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Use of Zernike polynomials and interferometry in the optical design and assembly of large carbon-dioxide laser systems

    International Nuclear Information System (INIS)

    Viswanathan, V.K.

    1981-01-01

    This paper describes the need for non-raytracing schemes in the optical design and analysis of large carbon-dioxide lasers like the Gigawatt, Gemini, and Helios lasers currently operational at Los Alamos, and the Antares laser fusion system under construction. The scheme currently used at Los Alamos involves characterizing the various optical components with a Zernike polynomial set obtained by the digitization of experimentally produced interferograms of the components. A Fast Fourier Transform code then propagates the complex amplitude and phase of the beam through the whole system and computes the optical parameters of interest. The analysis scheme is illustrated through examples of the Gigawatt, Gemini, and Helios systems. A possible way of using the Zernike polynomials in optical design problems of this type is discussed. Comparisons between the computed values and experimentally obtained results are made and it is concluded that this appears to be a valid approach. As this is a review article, some previously published results are also used where relevant

  15. Preparation and Characterization of Self-Assembled Thin Film of MPS-Capped ZnS Quantum Dots for Optical Applications

    Directory of Open Access Journals (Sweden)

    Kenan Koç

    2012-01-01

    Full Text Available For this study, we prepared colloidal ZnS quantum dots using 3-mercaptopropyltrimethoxysilane (MPS as the capping agent. Colloidal ZnS quantum dots were directly deposited on glass substrates by a spin coating process. Therefore, self-assembled films made of ZnS quantum dots in a SiO2 network were obtained using only one production step. The films were heat-treated at 100°, 125°, 150°, 175° and 200°C in an N2 atmosphere. The results showed that the dimension of quantum dots changed from 2.8 nm to 3.2 nm by heat treatment. The refractive index, extinction coefficient, thickness, and dielectric coefficient values of the films were calculated. The present study showed that size and the refractive indices of films can be controlled by the heat treatment. Therefore, such films can be a good candidate in optical filter applications.

  16. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  17. Fluorescence detection using optical waveguide collection device with high efficiency on assembly of nitrogen vacancy centers in diamond

    Science.gov (United States)

    Zhang, Shaowen; Ma, Zongmin; Qin, Li; Fu, Yueping; Shi, Yunbo; Liu, Jun; Li, Yan Jun

    2018-01-01

    In this letter, we propose a fluorescence waveguide excitation and collection (FWEC) method that allows for an excess of 45% collection efficiency of pump photons into optically detected magnetic resonance. The FWEC system used can collect fluorescence 96 times higher than the confocal system under spin manipulation with a microwave. Furthermore, the signal-to-noise ratio (SNR) of the FWEC system is improved 9 times compared with that of the confocal system. In addition, the increase in contrast observed using the FWEC system shows that the integration of the system is much improved with 3D printing technology. Thus, this research has a great potential application in subsequent magnetic detection and quantum optics.

  18. Discrete Dipole Approximation Simulation of Nearly Touching Plasmonic Au Dimers and Influence of Particle Shape Assembly on Optical Response.

    Science.gov (United States)

    Xu, Xi-Bin; Wang, Yu-Ying; Yi, Zao; Li, Xi-Bo; Luo, Jiang-Shan; Luo, Bing-Chi; Yi, You-Gen; Tang, Yong-Jian

    2016-01-01

    The method Discrete Dipole Approximation (DDA) is used to calculate the extinction spectra and field distribution of three types of dimers. In the paper we provide a systematic analysis of the optical response of different nanoscopic dimer structures with relatively small gap distances. A description is given about how the energy and excitation cross sections of dimer plasmons depend on nanoparticle separation. Resonance peaks of dimers show red-shift compared with single nanoparticle. Dimers formed by different single particle display distinct optical response. Interaction junctions in dimers can serve as hot spots for field enhancement. Field distribution in gaps made of two flat planes is nearly continuous. Changing gaps between two particles in dimers can tune the resonance wavelength effectively as well as different particle ensembles. Existence of sharp corners can attract and change field distribution. It is not effective volume but the effective cross-section that dominates the extinction efficiency.

  19. Shielding Design for the South Pole nToF Diagnostic at the NIF

    Directory of Open Access Journals (Sweden)

    Khater Hesham

    2017-01-01

    Full Text Available Neutron time of flight (nToF detectors are fielded at the National Ignition Facility (NIF to measure neutron yield, ion temperature, and downscattering in the cold fuel for D-T implosions. Anisotropically assembled cold fuel may generate different nToF data when measured by detectors located at the Target Chamber equator and poles. A collimated nToF line of sight has been fielded near the Target Chamber South Pole (SP to examine any possible anisotropy in the cold fuel. The SP nToF detector is located in the lowest floor level of the NIF’s Target Bay and at a distance of ~ 18 m from the Target Chamber Center. The detector utilizes a solid bibenzyl scintillator and four photomultiplier tubes. The line of sight includes a port collimator that is attached to the Target Chamber and a bore hole collimator in the concrete floor above the detector. In addition, a beam line get lost hole is constructed in the Target Bay floor to minimize the backscattered radiation at the detector location. Initial measurements indicated the need for installation of additional shielding to eliminate gamma background during the period before arrival of the 14.1 MeV neutrons to the detector. A set of MCNP Monte Carlo simulations with the full Target Bay model were conducted to provide an estimate of the expected neutron and gamma backgrounds during D-T shots. A new shielding scheme is designed to reduce the gamma background by an order of magnitude.

  20. 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

  1. Formation of Merocyanine Self-Assembled Monolayer and Its Nonlinear Optical Properties Probed by Second-Harmonic Generation and Surface Plasmon Resonance

    Science.gov (United States)

    Tsuboi, Kazuma; Seki, Kazuhiko; Ouchi, Yukio; Fujita, Katsuhiko; Kajikawa, Kotaro

    2003-02-01

    Nonlinear optical responses of a self-assembled monolayer (SAM) containing merocyanine chromophore, 1-alkyl-4-(4-hydroxystyryl) pyridinium bromide (HSP), on gold in water and in ethanol were studied by second-harmonic generation (SHG). The pH dependence of the SHG response clearly showed a solvatochromic characteristic of the merocyanine from a protonated form to a zwitterionic form. A large second-order susceptibility χzzz=5.0× 10-7 esu (2.1× 102 pm/V) was found in a basic solution of ethanol where the merocyanine is in the zwitterionic form. Combination of the SHG and surface plasmon resonance (SPR) spectroscopy measurements also provides us with details of the formation process of the merocyanine SAMs in the ethanol solution of the HSP-terminated-alkyldisulfide, ω,ω\\prime-dithiodi[1-undecyl-4-(4-hydroxystyryl)pyridinium bromide](HSPC11SS). A considerable difference was found in the kinetics between SPR and SHG, because SHG probes the molecules in a noncentrosymmetric fashion on the gold surface while SPR probes the optical thickness of the film. The difference enabled us to separate the chemisorption from the physisorption in the adsorption process. Interestingly, both probes showed slower kinetics in the solution of higher concentration, suggesting association of the disulfide molecules in the solution of high concentration.

  2. Fiber-optic pH-sensors in long-period fiber gratings using electrostatic self-assembly

    Science.gov (United States)

    Corres, Jesus M.; Del Villar, Ignacio; Matias, Ignacio R.; Arregui, Francisco J.

    2007-01-01

    A novel pH sensor based on the deposition of electrostatic self-assembled polyallylamine hydrochloride and polyacrylic acid on the cladding of a long-period fiber grating has been designed. The overlay thickness is of the order of magnitude of the light wavelength used to interrogate the sensor. A theoretical model of multilayer cylindrical waveguides based on coupled-mode theory has been used to predict the position of the attenuation bands as a function of the overlay thickness. A study of the role that pH plays in the thickness of the sensitive overlay was carried out. Experimentally, a wavelength shift of the attenuation bands of up to 85 nm was obtained in the 4-7 range of pH units. The results are reproducible, which indicates the possibilities of a multiple-use sensor.

  3. Optical and AFM study of electrostatically assembled films of CdS and ZnS colloid nanoparticles

    International Nuclear Information System (INIS)

    Suryajaya; Nabok, A.; Davis, F.; Hassan, A.; Higson, S.P.J.; Evans-Freeman, J.

    2008-01-01

    CdS and ZnS semiconducting colloid nanoparticles coated with the organic shell, containing either SO 3 - or NH 2 + groups, were prepared using the aqueous phase synthesis. The multilayer films of CdS (or ZnS) were deposited onto glass, quartz and silicon substrates using the technique of electrostatic self-assembly. The films produced were characterized with UV-vis spectroscopy, spectroscopic ellipsometry and atomic force microscopy. A substantial blue shift of the main absorption band with respect to the bulk materials was found for both CdS and ZnS films. The Efros equation in the effective mass approximation (EMA) theoretical model allowed the evaluation of the nanoparticle radius of 1.8 nm, which corresponds well to the ellipsometry results. AFM shows the formation of larger aggregates of nanoparticles on solid surfaces

  4. The Defect Induced Mix Experiment (DIME) for NIF

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Mark J [Los Alamos National Laboratory; Bradley, Paul A [Los Alamos National Laboratory; Cobble, James A [Los Alamos National Laboratory; Hakel, Peter [Los Alamos National Laboratory; Hsu, Scott C [Los Alamos National Laboratory; Krasheninnikova, Natalia S [Los Alamos National Laboratory; Kyrala, George A [Los Alamos National Laboratory; Murphy, Thomas J [Los Alamos National Laboratory; Obrey, Kimberly A [Los Alamos National Laboratory; Shah, Rahul C [Los Alamos National Laboratory; Tregillis, Ian L [Los Alamos National Laboratory

    2012-06-18

    LANL will perform two Defect Induced Mix Experiment (DIME) implosion campaigns on NIF in July and September, 2012. This presentation describes the goals for these shots and the experimental configuration and diagnostic set up to collect the appropriate data. The first two-shot campaign will focus on executing polar direct drive (PDD) implosions of plastic CH capsules filled with deuterium gas. Gas filling will be performed through a fill tube at target chamber center. A vanadium backligher foil will provide x-rays to radiograph the last half of the implosion to compare the implosion trajectory with modeling predictions. An equatorial groove in one of the capsules will be present to determine its effect on implosion dynamics. The second DIME campaign will commission and use a spectral imager (MMI) to examine the evolution of thin capsule layers doped with either Ge or Ga at 1.85%. Spectral line emission from these layers will quantify the mix width at the inner shell radius and near an equatorial groove feature.

  5. Shock Timing and Yield Sensitivity Studies for NIF Ignition Capsules

    International Nuclear Information System (INIS)

    Olson, Richard E.

    1999-01-01

    A cryogenic, β-layered NIF ignition capsule with a beryllium ablator that employs a BeO dopant (2% O) for opacity control is described. The design has an optimized yield of 12 MJ and uses a reduced drive hohlraum temperature pulse shape that peaks at ∼ 250 eV. Shock timing sensitivity calculations have been performed for this capsule design. Individual uncertainties of: (1) ∼200 ps in the timing of the foot pulse; (2) ∼5% in the x-ray flux of the foot pulse and first step; (3) ∼10% in the ablator EOS; or (4) ∼ 5 microm in the DT ice layer thickness each have a significant impact on thermonuclear yield. Combined uncertainties have greater impact than isolated, individual issues. For example, a combination of uncertainties of 200 ps in the foot + 2 eV in the foot + 5 microm in the DT thickness results in a calculation that produces only ∼ 1% of the original design yield. A second, more speculative, capsule concept utilizing a liquid DT ablator is also discussed. This design produces a 5 MJ yield in a 250 eV peak drive calculation

  6. 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)

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Low convergence path to fusion II: An integrated NIF design

    Science.gov (United States)

    Schmitt, Mark J.; Molvig, K.; McCall, G. H.; Edgel, D. H.; Myatt, J. E.; Betti, R.; Froula, D. H.; Campbell, E. M.

    2016-10-01

    We report on the Revolver design methodology for achieving ignition using large diameter (6mm) Be shells to efficiently ( 10%) convert laser energy from a short, 5 ns, 320TW laser pulse on the National Ignition Facility (NIF) into a dynamic pressure source for inertial confinement fusion. It is shown that this source can be used to kinetically drive two nested internal shells to achieve ignition conditions inside a central liquid DT core. Using principles recently elucidated [K. Molvig, et al., Phys. Rev. Lett. 116, 255003, 2016], we formulate a robust optimization of a triple shell target that mitigates long-standing issues with conventional ignition schemes including drive non-uniformities, laser plasma instabilities (including the hot electrons they produce), non-local heat conduction and deceleration Rayleigh-Taylor (RT) mix. Rad-hydro simulations predict ignition initiating at 2.5keV with 90% of the maximum inner shell velocity remaining (before deceleration RT can cause significant mix in the compressed DT fuel). Simulations in 2D show that the short pulse design produces a spatially uniform kinetic drive that is tolerant to random 5% variations in laser cone power. Moreover, it will be shown that intra-shell parameters can be adjusted to mitigate convergence growth of capsule spatial non-uniformities. This research supported by the US DOE/NNSA, performed in part at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

  14. Scanning second-harmonic optical microscopy of self-assembled InAlGaAs quantum dots

    DEFF Research Database (Denmark)

    Vohnsen, B.; Bozhevolnyi, S. I.; Pedersen, K.

    2001-01-01

    or in the illumination itself. Thus, a combination of scanning microscopy with SH detection may be a highly suitable candidate to reveal the presence of QD's embedded in an otherwise isotropic material. We have used scanning far-field (SFOM) and scanning near field optical microscopy (SNOM) techniques to locally probe......Microscopy provides a suitable technique for local probing of small ensembles of (or even individual) QD's, and when combined with the detection of second-harmonic (SH) generation the technique becomes suitable to reveal tiny changes of symmetry originating either in the material structures...

  15. Self-assembled monolayers of Lewis bases: effects on surface and interfacial electronic properties in III-V optical semiconductors

    Science.gov (United States)

    Dorsten, J. F.; Maslar, James E.; Zhang, Ying; Rauchfuss, T. B.; Bohn, Paul W.; Agarwala, S.; Adesida, Ilesanmi; Caneau, Catherine; Bhat, Rajaram J.

    1994-07-01

    The nature and disposition of surface states can have a dramatic effect on the near-surface electronic properties in semiconductor heterostructures. In particular the lack of a well-defined surface oxide in III-V materials means that surface band bending can cause surface recombination velocities to be up to 103 larger than in Si-based materials. Raman scattering by coupled longitudinal optic phonons and 2D electron gas electrons in In0.52Al0.48AsIn0.53Ga0.47As (delta) -doped heterostructures is used to demonstrate the extreme sensitivity to surface states. The two highest frequency modes, of the three coupled electron-phonon modes expected in this system, were observed, with the L+ mode being identified for the first time in InGaAs-based systems. The large dispersion of this mode makes it a particularly sensitive probe for changes in such properties as carrier concentration and subband energy. For structures with higher carrier concentrations coupling of the longitudinal optic phonon to multiple electron intersubband transitions is resolved. In order to passivate native surface states organic thiols are being investigated. Measurements on bulk GaAs indicate a change in the surface depletion region thickness, within the abrupt junction model, of up to 50 angstrom (ca. 30%). Changes in carrier scattering times up to 50% have also been observed.

  16. National Ignition Facility quality assurance plan for laser materials and optical technology

    International Nuclear Information System (INIS)

    Wolfe, C.R.

    1996-05-01

    Quality achievement is the responsibility of the line organizations of the National Ignition Facility (NIF) Project. This subtier Quality Assurance Plan (QAP) applies to activities of the Laser Materials ampersand Optical Technology (LM ampersand OT) organization and its subcontractors. It responds to the NIF Quality Assurance Program Plan (QAPP, L-15958-2, NIF-95-499) and Department of Energy (DOE) Order 5700.6C. This Plan is organized according to 10 Quality Assurance (QA) criteria and subelements of a management system as outlined in the NIF QAPP. This Plan describes how those QA requirements are met. This Plan is authorized by the Associate Project Leader for the LM ampersand OT organization, who has assigned responsibility to the Optics QA engineer to maintain this plan, with the assistance of the NIF QA organization. This Plan governs quality-affecting activities associated with: design; procurement; fabrication; testing and acceptance; handling and storage; and installation of NIF Project optical components into mounts and subassemblies

  17. DFT computations on: Crystal structure, vibrational studies and optical investigations of a luminescent self-assembled material

    Science.gov (United States)

    Kessentini, A.; Ben Ahmed, A.; Dammak, T.; Belhouchet, M.

    2018-02-01

    The current work undertakes the growth and the physicochemical properties of a novel green-yellow luminescence semi-organic material, the 3-picolylammonium bromide abbreviated (Pico-Br). In this paper, we report the X-ray diffraction measurements which show that the crystal lattice consists of distinct 3-picolylammonium cations and free bromide anions connected via Nsbnd H ⋯ Br and Nsbnd H ⋯ N hydrogen bonds leading to form a two dimensional frameworks. Molecular geometry compared with its optimized counterpart shows that the quantum chemical calculations carried out with density functional method (DFT) well produce the perceived structure by X-ray resolution of the studied material. To provide further insight into the spectroscopic properties, additional characterization of this material have been performed with Raman and infrared studies at room temperature. Theoretical computations have been computed using the (DFT) method at B3LYP/LanL2DZ level of theory implemented within Gaussian 03 program to study the vibrational spectra of the investigated molecule in the ground state. Optical absorption spectrum inspected by UV-visible absorption reveals the appearance of sharp optical gap of 280 nm (4.42 eV) as well as a strong green photoluminescence emission at 550 nm (2.25 eV) is detected on the photoluminescence (PL) spectrum at room temperature. Using the TD/DFT method, HOMO-LUMO energy gap and the Mulliken atomic charges were calculated in order to get an insight into the material. Good agreement between the theoretical results and the experimental ones was predicted.

  18. DFT computations on: Crystal structure, vibrational studies and optical investigations of a luminescent self-assembled material.

    Science.gov (United States)

    Kessentini, A; Ben Ahmed, A; Dammak, T; Belhouchet, M

    2018-02-15

    The current work undertakes the growth and the physicochemical properties of a novel green-yellow luminescence semi-organic material, the 3-picolylammonium bromide abbreviated (Pico-Br). In this paper, we report the X-ray diffraction measurements which show that the crystal lattice consists of distinct 3-picolylammonium cations and free bromide anions connected via NH⋯Br and NH⋯N hydrogen bonds leading to form a two dimensional frameworks. Molecular geometry compared with its optimized counterpart shows that the quantum chemical calculations carried out with density functional method (DFT) well produce the perceived structure by X-ray resolution of the studied material. To provide further insight into the spectroscopic properties, additional characterization of this material have been performed with Raman and infrared studies at room temperature. Theoretical computations have been computed using the (DFT) method at B3LYP/LanL2DZ level of theory implemented within Gaussian 03 program to study the vibrational spectra of the investigated molecule in the ground state. Optical absorption spectrum inspected by UV-visible absorption reveals the appearance of sharp optical gap of 280nm (4.42eV) as well as a strong green photoluminescence emission at 550nm (2.25eV) is detected on the photoluminescence (PL) spectrum at room temperature. Using the TD/DFT method, HOMO-LUMO energy gap and the Mulliken atomic charges were calculated in order to get an insight into the material. Good agreement between the theoretical results and the experimental ones was predicted. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. 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

  20. 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.

  1. Effects of Optical Purity and Finite System Size on Self-Assembly of 12-Hydroxystearic Acid in Hexane: Molecular Dynamics Simulations.

    Science.gov (United States)

    Gordon, Ryan; Stober, Spencer T; Abrams, Cameron F

    2017-10-05

    12-Hydroxystearic acid (12HSA) and its derivatives are well-known organogelators, and they play critical roles in a variety of applications. The overall aggregate structure of 12HSA is sensitive to the chirality at the 12th carbon, but a fundamental understanding of this dependence is lacking. In this study, molecular dynamics simulations were conducted on microsecond long time scales for (1) (R)-12HSA, (2) (S)-12HSA, and (3) a 50/50 racemic mixture, each solvated at 12.5 wt % in explicit hexane. Self-assembly was accelerated by turning off alkyl chain dihedral gauche states and forcing the molecules to adopt an all-trans conformation. The stability of the resulting aggregates was tested by quenching them with access to gauche states restored. Ordered aggregates produced from optically pure (R)- and (S)-12HSA remained stable for at least 1 μs. The characteristic ordered structure observed is termed a "ring-of-rings" motif, and it contains two twisted six-membered ringlike bundles connected through acetic acid dimerization and surrounded by six satellite bundles. The chirality at the 12th carbon dictates the overall twist of the rings and thereby the handedness of the aggregates. Racemic mixtures did not produce stable ordered aggregates likely due to insufficient enantiomerically pure ring formation. The most prevalent finite-size effect observed was the stochastic formation of percolating aggregates, which were later avoided by using solvent-permeable, solute-impermeable, confining walls. The resulting ordered aggregates were in all important ways identical to those produced in unconfined systems. The combination of cycling off and on gauche states and the semipermeable walls may be an important new way to study the self-assembly underlying aggregation at industrially relevant concentrations of surfactants in organic solvents.

  2. Recent progress in self-assembled quantum-dot optical devices for optical telecommunication: temperature-insensitive 10 Gb s-1 directly modulated lasers and 40 Gb s-1 signal-regenerative amplifiers

    International Nuclear Information System (INIS)

    Sugawara, M; Hatori, N; Ishida, M; Ebe, H; Arakawa, Y; Akiyama, T; Otsubo, K; Yamamoto, T; Nakata, Y

    2005-01-01

    This paper presents recent progress in the field of semiconductor lasers and optical amplifiers with InAs-based self-assembled quantum dots in the active region for optical telecommunication. Based on our design in terms of the maximum bandwidth for high-speed modulation and p-type doping in quantum dots for high temperature stability, we realized temperature-insensitive 10 Gb s -1 laser diodes on a GaAs substrate at 1.3 μm. The output waveform at 10 Gb s -1 maintained a clear eye opening, average output power and extinction ratio without current adjustments from 20 deg. C to 70 deg. C. We developed ultrawide-band high-power amplifiers in the 1.5 μm wavelength region on an InP substrate. The amplifier showed ultrafast gain response under gain saturation, and enabled signal regeneration at 40 Gb s -1 by suppressing the '1'-level noise due to the beating between the signal and amplified spontaneous emission. We present our amplifier module with polarization diversity to enable a stable polarization-insensitive performance, and also, discuss prospects for polarization-insensitive quantum dots by the close stacking technique

  3. Ammonia Switch-Off of Nitrogen Fixation in the Methanogenic Archaeon Methanococcus maripaludis: Mechanistic Features and Requirement for the Novel GlnB Homologues, NifI1 and NifI2

    Science.gov (United States)

    Kessler, Peter S.; Daniel, Catherine; Leigh, John A.

    2001-01-01

    Ammonia switch-off is the immediate inactivation of nitrogen fixation that occurs when a superior nitrogen source is encountered. In certain bacteria switch-off occurs by reversible covalent ADP-ribosylation of the dinitrogenase reductase protein, NifH. Ammonia switch-off occurs in diazotrophic species of the methanogenic Archaea as well. We showed previously that in Methanococcus maripaludis switch-off requires at least one of two novel homologues of glnB, a family of genes whose products play a central role in nitrogen sensing and regulation in bacteria. The novel glnB homologues have recently been named nifI1 and nifI2. Here we use in-frame deletions and genetic complementation analysis in M. maripaludis to show that the nifI1 and nifI2 genes are both required for switch-off. We could not detect ADP-ribosylation or any other covalent modification of dinitrogenase reductase during switch-off, suggesting that the mechanism differs from the well-studied bacterial system. Furthermore, switch-off did not affect nif gene transcription, nifH mRNA stability, or NifH protein stability. Nitrogenase activity resumed within a short time after ammonia was removed from a switched-off culture, suggesting that whatever the mechanism, it is reversible. We demonstrate the physiological importance of switch-off by showing that it allows growth to accelerate substantially when a diazotrophic culture is switched to ammonia. PMID:11208785

  4. IMAC fractionation in combination with LC-MS reveals H2B and NIF-1 peptides as potential bladder cancer biomarkers.

    Science.gov (United States)

    Frantzi, Maria; Zoidakis, Jerome; Papadopoulos, Theofilos; Zürbig, Petra; Katafigiotis, Ioannis; Stravodimos, Konstantinos; Lazaris, Andreas; Giannopoulou, Ioanna; Ploumidis, Achilles; Mischak, Harald; Mullen, William; Vlahou, Antonia

    2013-09-06

    Improvement in bladder cancer (BC) management requires more effective diagnosis and prognosis of disease recurrence and progression. Urinary biomarkers attract special interest because of the noninvasive means of urine collection. Proteomic analysis of urine entails the adoption of a fractionation methodology to reduce sample complexity. In this study, we applied immobilized metal affinity chromatography in combination with high-resolution LC-MS/MS for the discovery of native urinary peptides potentially associated with BC aggressiveness. This approach was employed toward urine samples from patients with invasive BC, noninvasive BC, and benign urogenital diseases. A total of 1845 peptides were identified, corresponding to a total of 638 precursor proteins. Specific enrichment for proteins involved in nucleosome assembly and for zinc-finger transcription factors was observed. The differential expression of two candidate biomarkers, histone H2B and NIF-1 (zinc finger 335) in BC, was verified in independent sets of urine samples by ELISA and by immunohistochemical analysis of BC tissue. The results collectively support changes in the expression of both of these proteins with tumor progression, suggesting their potential role as markers for discriminating BC stages. In addition, the data indicate a possible involvement of NIF-1 in BC progression, likely as a suppressor and through interactions with Sox9 and HoxA1.

  5. Radiochemistry: A versatile diagnostic for the NIF ignition campaign

    Energy Technology Data Exchange (ETDEWEB)

    Stoyer, M A; Cerjan, C J; Moody, K J; Hoffman, R D; Bernstein, L A; Shaughnessy, D A

    2008-06-17

    The purpose of this paper is to provide quick, clear, concise information about radiochemical diagnostics for the NIF program. Radiochemistry is perhaps the most versatile, flexible and dynamic of all nuclear diagnostics because it provides quantitative data on multiple capsule performance parameters such as mix, asymmetry of implosion, shell and fuel {rho}R, yield, neutron spectral information, high energy neutron information, fill tube jets, charged particle stopping, and the fission yield of the hohlraum by employing a variety of nuclear reactions on materials either present naturally in the capsule or specifically doped into the capsule. The choice and location of the doped material, together with the specific nuclear reaction used to produce a measurable product nuclide or ratio of nuclides, provides significant diagnostic information on the performance of the capsule during the experiment. The nature of the experiment, design of the capsule including fuel(s), and desired diagnostic information would dictate the radiochemical dopants used on any given shot--not all reactions would be possible nor monitored on any given experiment. Some of this diagnostic information is obtainable with other diagnostics, for example, the neutron yield is measured using Cu-activation pucks or nTOF. The unique niche of radiochemistry, for which few other measurements are currently planned, is the quantification of ablator/fuel mix. This diagnostic can supply complementary information on ablator {rho}R, asymmetry and unique information on mix--three of the four important concerns of the ignition campaign. This paper will not discuss the additional nuclear chemistry and physics possible by utilizing radiochemistry collection and similar nuclear reactions.

  6. VIRUS instrument collimator assembly

    Science.gov (United States)

    Marshall, Jennifer L.; DePoy, Darren L.; Prochaska, Travis; Allen, Richard D.; Williams, Patrick; Rheault, Jean-Philippe; Li, Ting; Nagasawa, Daniel Q.; Akers, Christopher; Baker, David; Boster, Emily; Campbell, Caitlin; Cook, Erika; Elder, Alison; Gary, Alex; Glover, Joseph; James, Michael; Martin, Emily; Meador, Will; Mondrik, Nicholas; Rodriguez-Patino, Marisela; Villanueva, Steven; Hill, Gary J.; Tuttle, Sarah; Vattiat, Brian; Lee, Hanshin; Chonis, Taylor S.; Dalton, Gavin B.; Tacon, Mike

    2014-07-01

    The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.

  7. A rheo-optical apparatus for real time kinetic studies on shear-induced alignment of self-assembled soft matter with small sample volumes

    Science.gov (United States)

    Laiho, Ari; Ikkala, Olli

    2007-01-01

    In soft materials, self-assembled nanoscale structures can allow new functionalities but a general problem is to align such local structures aiming at monodomain overall order. In order to achieve shear alignment in a controlled manner, a novel type of rheo-optical apparatus has here been developed that allows small sample volumes and in situ monitoring of the alignment process during the shear. Both the amplitude and orientation angles of low level linear birefringence and dichroism are measured while the sample is subjected to large amplitude oscillatory shear flow. The apparatus is based on a commercial rheometer where we have constructed a flow cell that consists of two quartz teeth. The lower tooth can be set in oscillatory motion whereas the upper one is connected to the force transducers of the rheometer. A custom made cylindrical oven allows the operation of the flow cell at elevated temperatures up to 200 °C. Only a small sample volume is needed (from 9 to 25 mm3), which makes the apparatus suitable especially for studying new materials which are usually obtainable only in small quantities. Using this apparatus the flow alignment kinetics of a lamellar polystyrene-b-polyisoprene diblock copolymer is studied during shear under two different conditions which lead to parallel and perpendicular alignment of the lamellae. The open device geometry allows even combined optical/x-ray in situ characterization of the alignment process by combining small-angle x-ray scattering using concepts shown by Polushkin et al. [Macromolecules 36, 1421 (2003)].

  8. National Ignition Facility (NIF) Neutron time-of-flight (nTOF) Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, R A; Glebov, V Y; Moran, M J; McNaney, J M; Kilkenny, J D; Eckart, M; Zacharias, R A; Haslam, J J; Clancy, T J; Yeoman, M F; Warwas, D P; Sangster, T C; Stoeckl, C; Knauer, J; Horsfield, C J

    2010-05-13

    The first three of eighteen neutron time-of-flight (nTOF) channels have been installed at the National Ignition Facility (NIF). The role of these detectors includes yield, temperature, and bang time measurements. This article focuses on nTOF data analysis and quality of results obtained for the first set of experiments to use all 192 NIF beams. Targets produced up to 2 x 10{sup 10} 2.45-MeV neutrons for initial testing of the nTOF detectors. Differences in neutron scattering at the OMEGA laser facility where the detectors were calibrated and at NIF result in different response functions at the two facilities. Monte Carlo modeling shows this difference. The nTOF performance on these early experiments indicates the nTOF system with its full complement of detectors should perform well in future measurements of yield, temperature, and bang time.

  9. 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.

  10. 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.

  11. 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.

  12. Structure of the Redox Sensor Domain of Azotobacter vinelandii NifL at Atomic Resolution: Signaling, Dimerization, and Mechanism.

    NARCIS (Netherlands)

    Key, J.; Hefti, M.H.; Purcell, E.B.; Moffat, K.

    2007-01-01

    NifL is a multidomain sensor protein responsible for the transcriptional regulation of genes involved in response to changes in cellular redox state and ADP concentration. Cellular redox is monitored by the N-terminal PAS domain of NifL which contains an FAD cofactor. Flavin-based PAS domains of

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

    Energy Technology Data Exchange (ETDEWEB)

    Logan, B.G.

    1995-03-16

    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-{micro}m-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.

  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. 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.

  16. 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

  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. 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.

  19. Surface Contaminant Control Technologies to Improve Laser Damage Resistance of Optics

    Directory of Open Access Journals (Sweden)

    Xiaofeng Cheng

    2014-01-01

    Full Text Available The large high-power solid lasers, such as the National Ignition Facility (NIF of America and the Shenguang-III (SG-III laser facility of China, can output over 2.1 MJ laser pulse for the inertial confinement fusion (ICF experiments. Because of the enhancement of operating flux and the expansion of laser driver scale, the problem of contamination seriously influences their construction period and operation life. During irradiation by intense laser beams, the contaminants on the metallic surface of beam tubes can be transmitted to the optical surfaces and lead to damage of optical components. For the high-power solid-state laser facilities, contamination control focuses on the slab amplifiers, spatial filters, and final-optical assemblies. In this paper, an effective solution to control contaminations including the whole process of the laser driver is put forward to provide the safe operation of laser facilities, and the detailed technical methods of contamination control such as washing, cleanliness metrology, and cleanliness protecting are also introduced to reduce the probability of laser-induced damage of optics. The experimental results show that the cleanliness level of SG-III laser facility is much better to ensure that the laser facility can safely operate at high energy flux.

  20. 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.

  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.

    2012-01-01

    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 σ54 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. PMID:22267004

  2. 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.

  3. 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.

  4. Formação e caracterização óptica de filmes automontados de POMA/PPV Formation and optical characterization of POMA/PPV self-assembly films

    Directory of Open Access Journals (Sweden)

    Rodrigo M. Melo

    2003-03-01

    Full Text Available A study is presented of the formation and optical properties of polymeric heterostructures from poly(p-phenylene vinylene (PPV and poly(o-methoxyaniline (POMA produced via the self-assembly technique. POMA layers were obtained in a non self-limiting process from its emeraldine salt, semiconducting form in HCl solution. Thermal conversion of PPV was performed at low temperatures with the substitution of the counter-ion Cl in the PPV precursor by a long sulfonic chain, the dodecylbenzenesulfonate (DBS ion. The optical properties of PPV films converted in this way are not affected by POMA, which can be used as transparent electrode of PPV luminescent devices.

  5. Large-aperture, high-damage-threshold optics for beamlet

    International Nuclear Information System (INIS)

    Campbell, J.H.; Atherton, L.J.; DeYoreo, J.J.; Kozlowski, M.R.; Maney, R.T.; Montesanti, R.C.; Sheehan, L.M.; Barker, C.E.

    1995-01-01

    Beamlet serves as a test bed for the proposed NIF laser design and components. Therefore, its optics are similar in size and quality to those proposed for the NIF. In general, the optics in the main laser cavity and transport section of Beamlet are larger and have higher damage thresholds than the optics manufactured for any of our previous laser systems. In addition, the quality of the Beamlet optical materials is higher, leading to better wavefront quality, higher optical transmission, and lower-intensity modulation of the output laser beam than, for example, that typically achieved on Nova. In this article, we discuss the properties and characteristics of the large-aperture optics used on Beamlet

  6. The CETUS Probe Mission Concept 1.5m Optical Telescope Assembly: A high A-Omega approach for ultraviolet astrophysics

    Science.gov (United States)

    Hull, Anthony; Heap, Sara; Woodruff, Robert; Mehle, Greg; Tomic, Matt; Dodson, Kelly; Burge, Jim; Lewis, Ben; Valente, Martin; Kendrick, Stephen E.; Purves, Lloyd; Danchi, William

    2018-01-01

    We describe the 1.5-m Cosmic Evolution Through Ultraviolet Spectroscopy (CETUS) Optical Telescope Assembly (OTA), a Three Mirror Anastigmat (TMA), providing a large usable focus, which permits non-shared locations for several Ultraviolet (UV) instruments. NASA has selected CETUS as a Probe Mission Concept for consideration by The Decadal Survey ASTRO2020. CETUS will fly in a L2 halo orbit and typically be pointing between 85 degrees and 135 degrees from the sun, and looking at galaxies at redshifts between z=1 and z=2. However, the CETUS payload also will be able to rapidly slew to sun angles between 85 degrees and 180 degrees to reach objects of opportunity, an example of which is a neutron star merger event. CETUS thermal stability starts with lightweighted ZERODUR® mirrors, that are an excellent thermal match to a metering structure of carbon fiber reinforced polymer (CFRP) M55J. This basic passive athermalization approach will be supplemented with controlled heaters, especially at metallic mounts, composite terminations and mechanisms. After launch, solid body metering errors will be optimized by an actuated hexapod in the secondary mirror assembly (SMA). Thus the CETUS telescope can respond to any pointing induced change in solar view factors. Contamination is managed by commissioning heaters radiating to each mirror surface, and a capping shutter over the telescope aperture. The instruments include a wide-field-of-view (WFoV) multi-object spectrometer (MOS), and a complimentary WFoV camera, as well as high-resolution point source Echelle spectrometers (R~40,000). They do not require that the OTA deliver diffraction limited performance over the extent of the instrument wavelength range (115nm to 400nm). The camera and spectrometer each cover a field of view of ~ 1000 arcsec by ~ 1000 arcsec compared to ~ 150 arcsec by ~ 150 arcsec for WFC3 on the Hubble Space Telescope (HST). Thus, the AW (etendue) factor for CETUS is ~700 m^2-arcmin^2, compared to the AW

  7. Synthesis, transfer printing, electrical and optical properties, and applications of materials composed of self-assembled, aligned single-walled carbon nanotubes

    Science.gov (United States)

    Pint, Cary L.

    Super growth of single-walled carbon nanotubes (SWNTs) has emerged as a unique method for synthesizing self-assembled, pristine, aligned SWNT materials composed of ultra-long (millimeter-long) nanotubes. This thesis focuses on novel routes of synthesizing such self-assembled SWNTs and the challenges that arise in integrating this material into next-generation applications. First of all, this work provides unique insight into growth termination of aligned SWNTs, emphasizing the mechanism that inhibits the growth of infinitely long nanotubes. Exhaustive real-time growth studies, combined with ex-situ and in-situ TEM characterization emphasizes that Ostwald ripening and subsurface diffusion of catalyst particles play a key role in growth termination. As a result, rational steps to solving this problem can enhance growth, and may ultimately lead to the meter or kilometer-long SWNTs that are necessary for a number of applications. In addition, other novel synthesis routes are discussed, such as the ability to form macroscopic fibrils of SWNTs, called "flying carpets" from 40 nm thick substrates, and the ability to achieve supergrowth of SWNTs that are controllably doped with nitrogen. In the latter case, molecular heterojunctions of doped and undoped sections in a single strand of ultralong SWNTs are demonstrated Secondly, as supergrowth is conducted on alumina coated SiO2 substrates, any applications will require that one can transfer the SWNTs to host surfaces with minimal processing. This work demonstrates a unique contact transfer route by which both patterned arrays of SWNTs, or homogenous SWNT carpets, can be transferred to any host surface. In the first case, the SWNTs are grown vertically aligned, and transferred in patterns of horizontally aligned SWNT. This transfer process relies on simple water-vapor etching of amorphous carbons at the catalyst following growth, and strong van der Waals adhesion of the high surface-area SWNT to host surfaces (gecko effect

  8. 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.

  9. 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.

  10. 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…

  11. 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.

  12. pMH2, a small plasmid bearing the nif gene cluster of Enterobacter agglomerans 333 as an excisable cassette.

    Science.gov (United States)

    Stumpf, F; Halda, L; Klingmüller, W

    1993-10-01

    A small plasmid containing the entire nif gene cluster of Enterobacter agglomerans 333 as an excisable cassette has been constructed, using pACYC177 as a vector. Two cosmid clones taken from a gene library of E. agglomerans plasmid pEA3 were used as a source of nif genes. A SmaI fragment of peaMS2-2, containing the H,D,K,Y,E,N,X,U,S,V,W,Z,M,L,A and B genes and an ApaI fragment of peaMS2-16 containing nif A,B,Q,F and J were selected to construct pMH2. The resulting plasmid of 33 kb carries the complete nif gene cluster as a nif cassette on a single XbaI fragment. The nif construct pMH2 in Escherichia coli strains has significant nitrogenase activity compared to wild-type E. agglomerans 333. The nif gene cluster construct was found to be very stable.

  13. 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.

  14. 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

  15. CORBA-Based Distributed Software Framework for the NIF Integrated Computer Control System

    Energy Technology Data Exchange (ETDEWEB)

    Stout, E A; Carey, R W; Estes, C M; Fisher, J M; Lagin, L J; Mathisen, D G; Reynolds, C A; Sanchez, R J

    2007-11-20

    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. The NIF is operated by the Integrated Computer Control System (ICCS) which is a scalable, framework-based control system distributed over 800 computers throughout the NIF. The framework provides templates and services at multiple levels of abstraction for the construction of software applications that communicate via CORBA (Common Object Request Broker Architecture). Object-oriented software design patterns are implemented as templates and extended by application software. Developers extend the framework base classes to model the numerous physical control points and implement specializations of common application behaviors. An estimated 140 thousand software objects, each individually addressable through CORBA, will be active at full scale. Many of these objects have persistent configuration information stored in a database. The configuration data is used to initialize the objects at system start-up. Centralized server programs that implement events, alerts, reservations, data archival, name service, data access, and process management provide common system wide services. At the highest level, a model-driven, distributed shot automation system provides a flexible and scalable framework for automatic sequencing of work-flow for control and monitoring of NIF shots. The shot model, in conjunction with data defining the parameters and goals of an experiment, describes the steps to be performed by each subsystem in order to prepare for and fire a NIF shot. Status and usage of this distributed framework are described.

  16. CORBA-based distributed software framework for the NIF integrated computer control system

    Energy Technology Data Exchange (ETDEWEB)

    Stout, E.A. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550 (United States)], E-mail: stout6@llnl.gov; Carey, R.W.; Estes, C.M.; Fisher, J.M.; Lagin, L.J.; Mathisen, D.G.; Reynolds, C.A.; Sanchez, R.J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550 (United States)

    2008-04-15

    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 MJ, 500 TW, ultra-violet laser system together with a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. The NIF is operated by the Integrated Computer Control System (ICCS) which is a scalable, framework-based control system distributed over 800 computers throughout the NIF. The framework provides templates and services at multiple levels of abstraction for the construction of software applications that communicate via CORBA (Common Object Request Broker Architecture). Object-oriented software design patterns are implemented as templates and extended by application software. Developers extend the framework base classes to model the numerous physical control points and implement specializations of common application behaviors. An estimated 140,000 software objects, each individually addressable through CORBA, will be active at full scale. Many of these objects have persistent configuration information stored in a database. The configuration data is used to initialize the objects at system start-up. Centralized server programs that implement events, alerts, reservations, data archival, name service, data access, and process management provide common system wide services. At the highest level, a model-driven, distributed shot automation system provides a flexible and scalable framework for automatic sequencing of workflow for control and monitoring of NIF shots. The shot model, in conjunction with data defining the parameters and goals of an experiment, describes the steps to be performed by each subsystem in order to prepare for and fire a NIF shot. Status and usage of this distributed framework are described.

  17. Mesoscale Polymer Assemblies

    Science.gov (United States)

    Choudhary, Satyan; Pham, Jonathan; Crosby, Alfred

    2015-03-01

    Materials encompassing structural hierarchy and multi-functionality allow for remarkable physical properties across different length scales. Mesoscale Polymer (MSP) assemblies provide a critical link, from nanometer to centimeter scales, in the definition of such hierarchical structures. Recent focus has been on exploiting these MSP assemblies for optical, electronic, photonics and biological applications. We demonstrate a novel fabrication method for MSP assemblies. Current fabrication methods restrict the length scale and volume of such assemblies. A new method developed uses a simple piezo-actuated motion for de-pinning of a polymer solution trapped by capillary forces between a flexible blade and a rigid substrate. The advantages of new method include ability to make MSP of monodisperse length and to fabricate sufficient volumes of MSP to study their physical properties and functionality in liquid dispersions. We demonstrate the application of MSP as filler for soft materials, providing rheological studies of the MSP with surrounding matrices.

  18. The NifA-RpoN Regulon of Mesorhizobium loti Strain R7A and Its Symbiotic Activation by a Novel LacI/GalR-Family Regulator

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, John T.; Brown, Steven D.; Ronson, Clive W.; de Crécy-Lagard, Valerie

    2013-01-07

    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 ICEMlSymR7A. M. loti R7A also contains two rpoN genes, rpoN1 located on the chromosome outside of ICEMlSymR7A and rpoN2 that is located on ICEMlSymR7A. 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 ICEMlSymR7A 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.

  19. 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.

  20. 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.

  1. EXAFS reveals two Mo environments in the nitrogenase iron-molybdenum cofactor biosynthetic protein NifQ†

    OpenAIRE

    George, Simon J.; Hernandez, Jose A.; Jimenez-Vicente, Emilio; Echavarri-Erasun, Carlos; Rubio, Luis M.

    2016-01-01

    Mo and Fe K-edge EXAFS analysis of NifQ shows the presence of a [MoFe3S4] cluster and a second independent Mo environment that includes Mo-O bonds and Mo-S bonds. Both environments are relevant to FeMo-co biosynthesis and may represent different stages of Mo biochemical transformations catalyzed by NifQ.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. CAD Model and Visual Assisted Control System for NIF Target Area Positioners

    International Nuclear Information System (INIS)

    Tekle, E A; Wilson, E F; Paik, T S

    2007-01-01

    The National Ignition Facility (NIF) target chamber contains precision motion control systems that reach up to 6 meters into the target chamber for handling targets and diagnostics. Systems include the target positioner, an alignment sensor, and diagnostic manipulators (collectively called positioners). Target chamber shot experiments require a variety of positioner arrangements near the chamber center to be aligned to an accuracy of 10 micrometers. Positioners are some of the largest devices in NIF, and they require careful monitoring and control in 3 dimensions to prevent interferences. The Integrated Computer Control System provides efficient and flexible multi-positioner controls. This is accomplished through advanced video-control integration incorporating remote position sensing and realtime analysis of a CAD model of target chamber devices. The control system design, the method used to integrate existing mechanical CAD models, and the offline test laboratory used to verify proper operation of the control system are described

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Development of the real-time neutron activation diagnostic system for NIF

    Science.gov (United States)

    Root, Jaben R.; Jedlovec, Donald R.; Edwards, Ellen R.; Yeamans, Charles B.; Golod, Tony; Hernandez, Jose; Adams, Phil; Brunton, Gordon

    2017-08-01

    The National Ignition Facility (NIF) is one of the highest fluence neutron sources provided by the nuclear fusion of deuterium and tritium nuclei. One of the resultant products is 14.1 MeV neutrons which provide key information to the conditions in which they were formed. The degree of polar and azimuthal symmetry of the neutron flux is a key metric for the performance of the capsule, thus a spatially-resolved measurement of the neutron distribution is critical. Implementing a suite of 48 lanthanum bromide detectors with zirconium activation samples around the target chamber has been developed to measure the neutron distribution. The system provides near real-time time estimates of the neutron fluence distribution. It is designed to operate over six orders of magnitude of neutron yield, providing overall yield estimates precise to 2%. The system is designed to operate continuously through the NIF shot cycles, accommodating high data rates. We will describe the nuclear counting system, data acquisition and archiving, analysis, and yield distribution results for some NIF high yield shots. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-CONF-736439

  20. Status of the Use of Large-Scale Corba-Distributed Software Framework for NIF Controls

    Energy Technology Data Exchange (ETDEWEB)

    Carey, R W; Bettenhausen, R C; Estes, C M; Fisher, J M; Krammen, J E; Lagin, L J; Ludwigsen, A P; Mathisen, D G; Matone, J T; Patterson, R W; Reynolds, C A; Sanchez, R J; Stout, E A; Tappero, J D; Van Arsdall, P J

    2005-09-09

    The Integrated Computer Control System (ICCS) for the National Ignition Facility (NIF) is based on a scalable software framework that will be distributed over some 750 Computers throughout the NIF. The framework provides templates and services at multiple levels of abstraction for the construction of software applications that communicate via CORBA (Common Object Request Broker Architecture). Object-oriented software design patterns are implemented as templates to be extended by application software. Developers extend the framework base classes to model the numerous physical control points. About 140 thousand software objects, each individually addressable through CORBA, will be active at full scale. Most of the objects have persistent state that is initialized at system start-up and stored in a database. Centralized server programs that implement events, alerts, reservations, message logging, data archive, name services, and process management provide additional framework services. A higher-level model-based, distributed shot automation framework also provides a flexible and scalable scripted framework for automatic sequencing of work-flow for control and monitoring of NIF shots. The ICCS software framework has allowed for efficient construction of a software system that supports a large number of distributed control points representing a complex control application. Status of the use of this framework during first experimental shot campaigns and initial commissioning and build-out of the laser facility is described.

  1. 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

  2. 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.

  3. Vector assembly of colloids on monolayer substrates

    Science.gov (United States)

    Jiang, Lingxiang; Yang, Shenyu; Tsang, Boyce; Tu, Mei; Granick, Steve

    2017-06-01

    The key to spontaneous and directed assembly is to encode the desired assembly information to building blocks in a programmable and efficient way. In computer graphics, raster graphics encodes images on a single-pixel level, conferring fine details at the expense of large file sizes, whereas vector graphics encrypts shape information into vectors that allow small file sizes and operational transformations. Here, we adapt this raster/vector concept to a 2D colloidal system and realize `vector assembly' by manipulating particles on a colloidal monolayer substrate with optical tweezers. In contrast to raster assembly that assigns optical tweezers to each particle, vector assembly requires a minimal number of optical tweezers that allow operations like chain elongation and shortening. This vector approach enables simple uniform particles to form a vast collection of colloidal arenes and colloidenes, the spontaneous dissociation of which is achieved with precision and stage-by-stage complexity by simply removing the optical tweezers.

  4. 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.

  5. 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

  6. Directed-Assembly of Block Copolymers for Large-Scale, Three-Dimensional, Optical Metamaterials at Visible Wavelengths. Final LDRD Report

    Energy Technology Data Exchange (ETDEWEB)

    Hiszpanski, Anna M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-26

    Metamaterials are composites with patterned subwavelength features where the choice of materials and subwavelength structuring bestows upon the metamaterials unique optical properties not found in nature, thereby enabling optical applications previously considered impossible. However, because the structure of optical metamaterials must be subwavelength, metamaterials operating at visible wavelengths require features on the order of 100 nm or smaller, and such resolution typically requires top-down lithographic fabrication techniques that are not easily scaled to device-relevant areas that are square centimeters in size. In this project, we developed a new fabrication route using block copolymers to make over large device-relevant areas optical metamaterials that operate at visible wavelengths. Our structures are smaller in size (sub-100 nm) and cover a larger area (cm2) than what has been achieved with traditional nanofabrication routes. To guide our experimental efforts, we developed an algorithm to calculate the expected optical properties (specifically the index of refraction) of such metamaterials that predicts that we can achieve surprisingly large changes in optical properties with small changes in metamaterials’ structure. In the course of our work, we also found that the ordered metal nanowires meshes produced by our scalable fabrication route for making optical metamaterials may also possibly act as transparent electrodes, which are needed in electrical displays and solar cells. We explored the ordered metal nanowires meshes’ utility for this application and developed design guidelines to aide our experimental efforts.

  7. Structure of the nifQ gene from Enterobacter agglomerans 333 and its overexpression in Escherichia coli.

    Science.gov (United States)

    Siddavattam, D; Singh, M; Klingmüller, W

    1993-06-01

    The nifQ gene, involved in early stages of iron-molybdenum cofactor (FeMo-co) biosynthesis, was identified downstream of the nifB and nifF genes of Enterobacter agglomerans. This gene was cloned and its nucleotide sequence determined. The amino acid sequence, as deduced from the nucleotide sequence, revealed an accumulation of cysteine amino acid residues at the C-terminal end of the protein. The cysteine cluster showed the following consensus sequence Cys-X4-Cys-X2-Cys-X5-Cys, which is a typical characteristic of metal-binding proteins. Further, the nifQ gene was cloned downstream of strong transcriptional (bacteriophage lambda PLPR) and translational (atpE) signals of the expression vector pCYTEXP1 and expressed as an unfused, soluble protein in Escherichia coli. The molecular mass of 19 kDa, as deduced by SDS-PAGE, is in good agreement with the molecular mass deduced from the nucleotide sequence. The availability of high-level expression clones should facilitate purification of large quantities of the recombinant NifQ protein and elucidation of its properties.

  8. Phylogenetic diversity of nitrogen-fixing bacteria and the nifH gene from mangrove rhizosphere soil.

    Science.gov (United States)

    Liu, Jianyin; Peng, Mengjun; Li, Youguo

    2012-04-01

    Nine types of nitrogen-fixing bacterial strains were isolated from 3 rhizosphere soil samples taken from mangrove plants in the Dongzhaigang National Mangrove Nature Reserve of China. Most isolates belonged to Gammaproteobacteria Pseudomonas, showing that these environments constituted favorable niches for such abundant nitrogen-fixing bacteria. New members of the diazotrophs were also found. Using a soil DNA extraction and PCR-cloning-sequencing approach, 135 clones were analyzed by restriction fragment length polymorphism (RFLP) analysis, and 27 unique nifH sequence phylotypes were identified, most of which were closely related to sequences from uncultured bacteria. The diversity of nitrogen-fixing bacteria was assessed by constructing nifH phylogenetic trees from sequences of all isolates and clones in this work, together with related nifH sequences from other mangrove ecosystems in GenBank. The nifH diversity varied among soil samples, with distinct biogeochemical properties within a mangrove ecosystem. When comparing different mangrove ecosystems, the nifH gene sequences from a specific site tended to cluster as individual groups. The results provided interesting data and novel information on our understanding of diazotroph community diversity in the mangrove ecosystems.

  9. Modeling for deformable mirrors and the adaptive optics optimization program

    International Nuclear Information System (INIS)

    Henesian, M.A.; Haney, S.W.; Trenholme, J.B.; Thomas, M.

    1997-01-01

    We discuss aspects of adaptive optics optimization for large fusion laser systems such as the 192-arm National Ignition Facility (NIF) at LLNL. By way of example, we considered the discrete actuator deformable mirror and Hartmann sensor system used on the Beamlet laser. Beamlet is a single-aperture prototype of the 11-0-5 slab amplifier design for NIF, and so we expect similar optical distortion levels and deformable mirror correction requirements. We are now in the process of developing a numerically efficient object oriented C++ language implementation of our adaptive optics and wavefront sensor code, but this code is not yet operational. Results are based instead on the prototype algorithms, coded-up in an interpreted array processing computer language

  10. Directed Assembly of Gold Nanoparticles

    DEFF Research Database (Denmark)

    Westerlund, Axel Rune Fredrik; Bjørnholm, Thomas

    2009-01-01

    As a complement to common "top-down" lithography techniques, "bottom-up" assembly techniques are emerging as promising tools to build nanoscale structures in a predictable way. Gold nanoparticles that are stable and relatively easy to synthesize are important building blocks in many such structures...... due to their useful optical and electronic properties. Programmed assembly of gold nanoparticles in one, two, and three dimensions is therefore of large interest. This review focuses on the progress from the last three years in the field of directed gold nanoparticle and nanorod assembly using...

  11. 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.

  12. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. 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.

  15. Optical transmission of glass for the National Ignition Facility near backscatter imagers under x-ray exposurea)

    Science.gov (United States)

    London, R. A.; Froula, D. H.; Sorce, C. M.; Moody, J. D.; Suter, L. J.; Glenzer, S. H.; Jones, O. S.; Meezan, N. B.; Rosen, M. D.

    2008-10-01

    In experiments at the National Ignition Facility (NIF), the near backscatter imager materials need to maintain high optical transmission while exposed to hohlraum generated x rays. Glass plates are incorporated in the design to protect the optical scattering plates from x-ray damage. Radiation environments spanning those expected on NIF have been produced at the Omega Laser Facility by symmetric laser illumination of 1mm sized gold spheres. The time-dependent ultraviolet transmission of sample glass plates was measured. The data are interpreted with a free electron absorption model. Combined with the simulations of the hohlraum x-ray emission, this model is used to predict the transmission of the glass plates on the NIF. We predict that the plates should perform adequately up to the peak of the laser pulse.

  16. DNA Scaffolds for the Dictated Assembly of Left-/Right-Handed Plasmonic Au NP Helices with Programmed Chiro-Optical Properties.

    Science.gov (United States)

    Cecconello, Alessandro; Kahn, Jason S; Lu, Chun-Hua; Khosravi Khorashad, Larousse; Govorov, Alexander O; Willner, Itamar

    2016-08-10

    Within the broad interest of assembling chiral left- and right-handed helices of plasmonic nanoparticles (NPs), we introduce the DNA-guided organization of left- or right-handed plasmonic Au NPs on DNA scaffolds. The method involves the self-assembly of stacked 12 DNA quasi-rings interlinked by 30 staple-strands. By the functionalization of one group of staple units with programmed tether-nucleic acid strands and additional staple elements with long nucleic acid chains, acting as promoter strands, the promoter-guided assembly of barrels modified with 12 left- or right-handed tethers is achieved. The subsequent hybridization of Au NPs functionalized with single nucleic acid tethers yields left- or right-handed structures of plasmonic NPs. The plasmonic NP structures reveal CD spectra at the plasmon absorbance, and the NPs are imaged by HR-TEM. Using geometrical considerations corresponding to the left- and right-handed helices of the Au NPs, the experimental CD spectra of the plasmonic Au NPs are modeled by theoretical calculations.

  17. Fuel assembly

    International Nuclear Information System (INIS)

    Abe, Hideaki; Sakai, Takao; Ishida, Tomio; Yokota, Norikatsu.

    1992-01-01

    The lower ends of a plurality of plate-like shape memory alloys are secured at the periphery of the upper inside of the handling head of a fuel assembly. As the shape memory alloy, a Cu-Zn alloy, a Ti-Pd alloy or a Fe-Ni alloy is used. When high temperature coolants flow out to the handling head, the shape memory alloy deforms by warping to the outer side more greatly toward the upper portion thereof with the temperature increase of the coolants. As the result, the shape of the flow channel of the coolants is changed so as to enlarge at the exit of the upper end of the fuel assembly. Then, the pressure loss of the coolants in the fuel assembly is decreased by the enlargement. Accordingly, the flow rate of the coolants in the fuel assembly is increased to lower the temperature of the coolants. Further, high temperature coolants and low temperature coolants are mixed sufficiently just above the fuel assembly. This can suppress the temperature fluctuation of the mixed coolants in the upper portion of the reactor core, thereby enabling to decrease a fatigue and failures of the structural components in the upper portion of the reactor core. (I.N.)

  18. 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.

  19. Fuel assembly

    International Nuclear Information System (INIS)

    Nakatsuka, Masafumi; Matsuzuka, Ryuji.

    1976-01-01

    Object: To provide a fuel assembly which can decrease pressure loss of coolant to uniform temperature. Structure: A sectional area of a flow passage in the vicinity of an inner peripheral surface of a wrapper tube is limited over the entire length to prevent the temperature of a fuel element in the outermost peripheral portion from being excessively decreased to thereby flatten temperature distribution. To this end, a plurality of pincture-frame-like sheet metals constituting a spacer for supporting a fuel assembly, which has a plurality of fuel elements planted lengthwise and in given spaced relation within the wrapper tube, is disposed in longitudinal grooves and in stacked fashion to form a substantially honeycomb-like space in cross section. The fuel elements are inserted and supported in the space to form a fuel assembly. (Kamimura, M.)

  20. 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)

  1. Influence of PAS domain flanking regions on oligomerisation and redox signalling by NifL.

    Directory of Open Access Journals (Sweden)

    Richard Little

    Full Text Available Per-ARNT-Sim (PAS domains constitute a typically dimeric, conserved α/β tertiary fold of approximately 110 amino acids that perform signalling roles in diverse proteins from all kingdoms of life. The amino terminal PAS1 domain of NifL from Azotobacter vinelandii accommodates a redox-active FAD group; elevation of cytosolic oxygen concentrations result in FAD oxidation and a concomitant conformational re-arrangement that is relayed via a short downstream linker to a second PAS domain, PAS2. At PAS2, the signal is amplified and passed on to effector domains generating the 'on' (inhibitory state of the protein. Although the crystal structure of oxidised PAS1 reveals regions that contribute to the dimerisation interface, 21 amino acids at the extreme N-terminus of NifL, are unresolved. Furthermore, the structure and function of the linker between the two PAS domains has not been determined. In this study we have investigated the importance to signalling of residues extending beyond the core PAS fold. Our results implicate the N-terminus of PAS1 and the helical linker connecting the two PAS domains in redox signal transduction and demonstrate a role for these flanking regions in controlling the oligomerisation state of PAS1 in solution.

  2. 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)

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  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. 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.

  9. A Modern Educationalist in I. Constitutionalism Period: Münif Pasha

    Directory of Open Access Journals (Sweden)

    Hikmet Yıldırım Celkan

    2008-12-01

    Full Text Available Münif Pasha was a distinguised stateman and a scientist. While he was studing in “Mederese”, he had the chance of studing Western education. He had worked as a Minister of National education three times and as a minister of Commerse for some time. Later he worked in Germany as a diplomat and in Persia as an ambassador. He tougt students in the School of Law and he wrote various article on Humanities and Social sciences in a periodical called “Mecmua-i Fünun”. One of his noteworhty articles was titled as “ Ehemmiyet-i Terbiye-i Sıbyan” ( The Importance of Child Education. In this article, Münif Pasha wrote about basic issues such as the impotance of compulsory primary education, teaching language and mathematics, industrialization, improvement of tecahing merthods, vocational education, teacher training and improvements to be made in National Education System. These issues are still of importance in Turkish Education

  10. Fuel assemblies

    International Nuclear Information System (INIS)

    Nakamura, Mitsuya; Yamashita, Jun-ichi; Mochida, Takaaki.

    1986-01-01

    Purpose: To improve the fuel economy by increasing the reactivity at the latter burning stage of fuel assemblies and thereby increasing the burn-up degree. Constitution: At the later stage of the burning where the infinite multiplication factor of a fuel assembly is lowered, fuel rods are partially discharged to increase the fuel-moderator volume ratio in the fuel assembly. Then, plutonium is positively burnt by bringing the ratio near to an optimum point where the infinite multiplication factor becomes maximum and the reactivity of the fuel assembly is increased by utilizing the spectral shift effect. The number of the fuel rods to be removed is selected so as to approach the fuel-moderator atom number ratio where the infinite multiplication factor is maximum. Further, the positions where the thermal neutron fluxes are low are most effective for removing the rods and those positions between which no fuel rods are present and which are adjacent with neither the channel box nor the water rods are preferred. The rods should be removed at the time when the burning is proceeded at lest for one cycle. The reactivity is thus increased and the burn-up degree of fuels upon taking-out can be improved. (Kamimura, M.)

  11. Valve assembly

    International Nuclear Information System (INIS)

    Sandling, M.

    1981-01-01

    An improved valve assembly, used for controlling the flow of radioactive slurry, is described. Radioactive contamination of the air during removal or replacement of the valve is prevented by sucking air from the atmosphere through a portion of the structure above the valve housing. (U.K.)

  12. Characterization of assembled MEMS

    Science.gov (United States)

    Jandric, Zoran; Randall, John N.; Saini, Rahul; Nolan, Michael; Skidmore, George

    2005-01-01

    Zyvex is developing a low-cost high-precision method for manufacturing MEMS-based three-dimensional structures/assemblies. The assembly process relies on compliant properties of the interconnecting components. The sockets and connectors are designed to benefit from their compliant nature by allowing the mechanical component to self-align, i.e. reposition themselves to their designed, stable position, independent of the initial placement of the part by the external robot. Thus, the self-aligning property guarantees the precision of the assembled structure to be very close to, or the same, as the precision of the lithography process itself. A three-dimensional (3D) structure is achieved by inserting the connectors into the sockets through the use of a passive end-effector. We have developed the automated, high-yield, assembly procedure which permits connectors to be picked up from any location within the same die, or a separate die. This general procedure allows for the possibility to assemble parts of dissimilar materials. We have built many 3D MEMS structures, including several 3D MEMS devices such as a scanning electron microscope (SEM) micro column, mass-spectrometer column, variable optical attenuator. For these 3D MEMS structures we characterize their mechanical strength through finite element simulation, dynamic properties by finite-element analysis and experimentally with UMECH"s MEMS motion analyzer (MMA), alignment accuracy by using an in-house developed dihedral angle measurement laser autocollimator, and impact properties by performing drop tests. The details of the experimental set-ups, the measurement procedures, and the experimental data are presented in this paper.

  13. National Ignition Facility Incorporates P2/E2 in Aqueous Parts Cleaning of Optics Hardware

    International Nuclear Information System (INIS)

    Gabor, K

    2001-01-01

    When completed, Lawrence Livermore National Laboratory's (LLNL) National Ignition Facility (NIF) will be the world's largest laser with experimental capabilities applicable to stockpile stewardship, energy research, science and astrophysics. As construction of the conventional facilities nears completion, operations supporting the installation of specialized laser equipment have come online. Playing a critical role in the precision cleaning of mechanical parts from the NIF beamline are three pieces of aqueous cleaning equipment. Housed in the Optics Assembly Building (OAB), adjacent to NIF's laser bay, are the large mechanical parts gross cleaner (LMPGC), the large mechanical parts precision cleaner (LMPPC), and the small mechanical parts gross and precision cleaner (SMPGPC). These aqueous units, designed and built by Sonic Systems, Inc., of Newtown, Pennsylvania, not only accommodate parts that vary greatly in size, weight, geometry, surface finish and material, but also produce cleaned parts that meet the stringent NIF cleanliness standards (MIL-STD-1246C Level 83 for particles and A/10 for non-volatile residue). Each unit was designed with extensive water- and energy-conserving features, and the technology used minimizes hazardous waste generation associated with solvent wipe cleaning, the traditional method for cleaning laser mechanical components. The LMPGC provides preliminary gross cleaning for large mechanical parts. Collection, filtration and reuse of the wash and primary rinse water in the LMPGC limit its routine discharge to the volume of the low-pressure, deionized secondary rinse. After an initial gross cleaning in the LMPGC, a large mechanical part goes to the LMPPC. This piece of equipment, unique because of its size, consists of four 2700-gallon tanks. Parts held securely on specialized metal pallets (jointly weighing up to 1500 pounds) move through the tanks on an automated system. Operators program all movement, speeds and process times to

  14. Fuel assemblies

    International Nuclear Information System (INIS)

    Echigoya, Hironori; Nomata, Terumitsu.

    1983-01-01

    Purpose: To render the axial distribution relatively flat. Constitution: First nuclear element comprises a fuel can made of zircalloy i.e., the metal with less neutron absorption, which is filled with a plurality of UO 2 pellets and sealed by using a lower end plug, a plenum spring and an upper end plug by means of welding. Second fuel element is formed by substituting a part of the UO 2 pellets with a water tube which is sealed with water and has a space for allowing the heat expansion. The nuclear fuel assembly is constituted by using the first and second fuel elements together. In such a structure, since water reflects neutrons and decrease their leakage to increase the temperature, reactivity is added at the upper portion of the fuel assembly to thereby flatten the axial power distribution. Accordingly, stable operation is possible only by means of deep control rods while requiring no shallow control rods. (Sekiya, K.)

  15. Assembling consumption

    DEFF Research Database (Denmark)

    Assembling Consumption marks a definitive step in the institutionalisation of qualitative business research. By gathering leading scholars and educators who study markets, marketing and consumption through the lenses of philosophy, sociology and anthropology, this book clarifies and applies...... the investigative tools offered by assemblage theory, actor-network theory and non-representational theory. Clear theoretical explanation and methodological innovation, alongside empirical applications of these emerging frameworks will offer readers new and refreshing perspectives on consumer culture and market...

  16. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    5th April, 2016 – Ordinary General Assembly of the Staff Association! In the first semester of each year, the Staff Association (SA) invites its members to attend and participate in the Ordinary General Assembly (OGA). This year the OGA will be held on Tuesday, April 5th 2016 from 11:00 to 12:00 in BE Auditorium, Meyrin (6-2-024). During the Ordinary General Assembly, the activity and financial reports of the SA are presented and submitted for approval to the members. This is the occasion to get a global view on the activities of the SA, its financial management, and an opportunity to express one’s opinion, including taking part in the votes. Other points are listed on the agenda, as proposed by the Staff Council. Who can vote? Only “ordinary” members (MPE) of the SA can vote. Associated members (MPA) of the SA and/or affiliated pensioners have a right to vote on those topics that are of direct interest to them. Who can give his/her opinion? The Ordinary General Asse...

  17. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Sei; Ando, Ryohei; Mitsutake, Toru.

    1995-01-01

    The present invention concerns a fuel assembly suitable to a BWR-type reactor and improved especially with the nuclear characteristic, heat performance, hydraulic performance, dismantling or assembling performance and economical property. A part of poison rods are formed as a large-diameter/multi-region poison rods having a larger diameter than a fuel rod. A large number of fuel rods are disposed surrounding a large diameter water rod and a group of the large-diameter/multi-region poison rods in adjacent with the water rod. The large-diameter water rod has a burnable poison at the tube wall portion. At least a portion of the large-diameter poison rods has a coolant circulation portion allowing coolants to circulate therethrough. Since the large-diameter poison rods are disposed at a position of high neutron fluxes, a large neutron multiplication factor suppression effect can be provided, thereby enabling to reduce the number of burnable poison rods relative to fuels. As a result, power peaking in the fuel assembly is moderated and a greater amount of plutonium can be loaded. In addition the flow of cooling water which tends to gather around the large diameter water rod can be controlled to improve cooling performance of fuels. (N.H.)

  18. 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.

  19. 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.

  20. Nanocomposites based on self-assembly poly(hydroxypropyl methacrylate)-block-poly(N-phenylmaleimide) and Fe3O4-NPs. Thermal stability, morphological characterization and optical properties

    Science.gov (United States)

    Pizarro, Guadalupe del C.; Marambio, Oscar G.; Jeria-Orell, Manuel; Sánchez, Julio; Oyarzún, Diego P.

    2018-02-01

    The current work presents the synthesis, characterization and preparation of organic-inorganic hybrid polymer films that contain inorganic magnetic nanoparticles (NPs). The block copolymer, prepared by Atom-Transfer Radical Polymerization (ATRP), was used as a nanoreactor for iron oxide NPs. The NPs were embedded in poly(hydroxypropyl methacrylate)-block-poly(N-phenylmaleimide) matrix. The following topographical modifications of the surface of the film were specially analyzed: control of pore features and changes in surface roughness. Finally, the NPs functionality inside the polymer matrix and how it may affect the thermal and optical properties of the films were assessed.

  1. Magnetic and optical holonomic manipulation of colloids, structures and topological defects in liquid crystals for characterization of mesoscale self-assembly and dynamics

    Science.gov (United States)

    Varney, Michael C. M.

    Colloidal systems find important applications ranging from fabrication of photonic crystals to direct probing of phenomena encountered in atomic crystals and glasses; topics of great interest for physicists exploring a broad range of scientific, industrial and biomedical fields. The ability to accurately control particles of mesoscale size in various liquid host media is usually accomplished through optical trapping methods, which suffer limitations intrinsic to trap laser intensity and force generation. Other limitations are due to colloid properties, such as optical absorptivity, and host properties, such as viscosity, opacity and structure. Therefore, alternative and/or novel methods of colloidal manipulation are of utmost importance in order to advance the state of the art in technical applications and fundamental science. In this thesis, I demonstrate a magnetic-optical holonomic control system to manipulate magnetic and optical colloids in liquid crystals and show that the elastic structure inherent to nematic and cholesteric liquid crystals may be used to assist in tweezing of particles in a manner impossible in other media. Furthermore, I demonstrate the utility of this manipulation in characterizing the structure and microrheology of liquid crystals, and elucidating the energetics and dynamics of colloids interacting with these structures. I also demonstrate the utility of liquid crystal systems as a table top model system to probe topological defects in a manner that may lead to insights into topologically related phenomena in other fields, such as early universe cosmology, sub-atomic and high energy systems, or Skrymionic structures. I explore the interaction of colloid surface anchoring with the structure inherent in cholesteric liquid crystals, and how this affects the periodic dynamics and localization metastability of spherical colloids undergoing a "falling" motion within the sample. These so called "metastable states" cause colloidal dynamics to

  2. Temporal multiplexing for economical measurement of power versus time on NIF

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.; Boyd, B.; Davis, D.T.; Hall, B.

    1996-10-01

    The researchers have designed an economical device to measure the power time history in the National Ignition Facility`s (NIF) 192 beam laser. The heart of the system is a commercial, high-speed, four-channel digitizer with a 15,000 point record length. Samples of several beams are taken with fiberoptic pickoffs, separated in time with appropriate fiberoptic delays and presented to high-speed vacuum photodiodes, which convert the samples to electrical signals for the digitizer. Amplitude and time multiplexing are used to cover the required dynamic range and to record 12 samples on the digitizer, making the cost per sample competitive with alternative approaches. Forty-eight digitizers can record the required three samples from each of the 192 beams. An additional similar but lower bandwidth system is used to record the backreflected light from the main laser amplifiers and elsewhere. The recording electronics are discussed in detail.

  3. [Labelling of nif-plasmid pEA9 from Enterobacter agglomerans 339].

    Science.gov (United States)

    Liu, Cheng-jun; Klingmüller, Walter

    2002-07-01

    The authors describe the in vivo labelling of the plasmid pEA9 in Enterobacter agglomerans 339 with a kanamycin resistance gene. For labelling purposes the donor plasmid pST5 was constructed. This plasmid contains the nif ENX region from pEA9,in which a kanamycin resistance gene is cloned.pST5 was transformed into E.a.339 and subsequently cured from the host. Curing was achieved with AP medium. Fourty strains that had lost pST5,but retained the kanamycin resistance, could be isolated. It showed that none of these clones contained co-integrates of pST5 and pEA9. This is evident that in all clones the kanamycin resistance gene was integrated into pEA9 by homologous recombination.

  4. Characterizing NIF hohlraum energy and particle transport using mid-Z spectroscopic tracer materials

    Science.gov (United States)

    Moody, J. D.; Barrios, M. A.; Widmann, K.; Suter, L. J.; Liedahl, D. A.; Schneider, M. B.; Thorn, D. B.; Farmer, W. A.; Landen, O. L.; Kauffman, R. L.; Jarrott, C.; Sherlock, M. W.; Chen, H.; Jones, O.; MacLaren, S. A.; Eder, D.; Strozzi, D. J.; Meezan, N. B.; Nikroo, A.; Kroll, J. J.; Johnson, S.; Jaquez, J.; Huang, H.

    2017-10-01

    Line emission from mid-Z dopants placed at several spatial locations is used to determine the electron temperature (Te) and plasma flow in NIF hohlraums. Laser drive ablates the dopant and launches it on a trajectory recorded with a framing camera. Analysis of temporally streaked spectroscopy provides an estimate of the time-resolved Te. The estimated temperature gradients show evidence for significantly restricted thermal conduction. Non-local thermal conductivity can account for part of this; additional effects due to magnetic fields, return-current instabilities, ion acoustic turbulence and other physics are considered. We describe our findings and discuss interpretations. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  5. Analysis of BigFoot HDC SymCap experiment N161205 on NIF

    Science.gov (United States)

    Dittrich, T. R.; Baker, K. L.; Thomas, C. A.; Berzak Hopkins, L. F.; Harte, J. A.; Zimmerman, G. B.; Woods, D. T.; Kritcher, A. L.; Ho, D. D.; Weber, C. R.; Kyrala, G.

    2017-10-01

    Analysis of NIF implosion experiment N161205 provides insight into both hohlraum and capsule performance. This experiment used an undoped High Density Carbon (HDC) ablator driven by a BigFoot x-ray profile in a Au hohlraum. Observations from this experiment include DT fusion yield, bang time, DSR, Tion and time-resolved x-ray emission images around bang time. These observations are all consistent with an x-ray spectrum having significantly reduced Au m-band emission that is present in a standard hohlraum simulation. Attempts to justify the observations using several other simulation modifications will be presented. This work was performed under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  6. Enhanced electron/fuel-ion equilibration through impurity ions: Studies applicable to NIF and Omega

    Science.gov (United States)

    Petrasso, R. D.; Sio, H.; Kabadi, N.; Lahmann, B.; Simpson, R.; Parker, C.; Frenje, J.; Gatu Johnson, M.; Li, C. K.; Seguin, F. H.; Rinderknecht, H.; Casey, D.; Grabowski, P.; Graziani, F.; Taitano, W.; Le, A.; Chacon, L.; Hoffman, N.; Kagan, G.; Simakov, A.; Zylstra, A.; Rosenberg, M.; Betti, R.; Srinivasan, B.; Mancini, R.

    2017-10-01

    In shock-driven exploding-pushers, a platform used extensively to study multi-species and kinetic effects, electrons and fuel ions are far out of equilibrium, as reflected by very different temperatures. However, impurity ions, even in small quantities, can couple effectively to the electrons, because of a Z2 dependence, and in turn, impurity ions can then strongly couple to the fuel ions. Through this mechanism, electrons and fuel-ions can equilibrate much faster than they otherwise would. This is a quantitative issue, depending upon the amount and Z of the impurity. For NIF and Omega, we consider the role of this process. Coupled non-linear equations, reflecting the temperatures of the three species, are solved for a range of conditions. Consideration is also given to ablatively driven implosions, since impurities can similarly affect the equilibration. This work was supported in part by DOE/NNSA DE-NA0002949 and DE-NA0002726.

  7. Upgrade and benchmarking of the NIFS physics-engineering-cost code

    International Nuclear Information System (INIS)

    Dolan, T.J.; Yamazaki, K.

    2004-07-01

    The NIFS Physics-Engineering-Cost (PEC) code for helical and tokamak fusion reactors is upgraded by adding data from three blanket-shield designs, a new cost section based on the ARIES cost schedule, more recent unit costs, and improved algorithms for various computations. The PEC code is also benchmarked by modeling the ARIES-AT (advanced technology) tokamak and the ARIES-SPPS (stellarator power plant system). The PEC code succeeds in predicting many of the pertinent plasma parameters and reactor component masses within about 10%. There are cost differences greater than 10% for some fusion power core components, which may be attributed to differences of unit costs used by the codes. The COEs estimated by the PEC code differ from the COEs of the ARIES-AT and ARIES-SPPS studies by 5%. (author)

  8. Temporal multiplexing for economical measurement of power versus time on NIF

    International Nuclear Information System (INIS)

    Thomas, S.; Boyd, B.; Davis, D.T.; Hall, B.

    1996-10-01

    The researchers have designed an economical device to measure the power time history in the National Ignition Facility's (NIF) 192 beam laser. The heart of the system is a commercial, high-speed, four-channel digitizer with a 15,000 point record length. Samples of several beams are taken with fiberoptic pickoffs, separated in time with appropriate fiberoptic delays and presented to high-speed vacuum photodiodes, which convert the samples to electrical signals for the digitizer. Amplitude and time multiplexing are used to cover the required dynamic range and to record 12 samples on the digitizer, making the cost per sample competitive with alternative approaches. Forty-eight digitizers can record the required three samples from each of the 192 beams. An additional similar but lower bandwidth system is used to record the backreflected light from the main laser amplifiers and elsewhere. The recording electronics are discussed in detail

  9. National Ingition Facility subsystem design requirements optics subsystems SSDR 1.6

    International Nuclear Information System (INIS)

    English, R.E.

    1996-01-01

    This Subsystems Design Requirement (SSDR) document specifies the functions to be performed and the subsystems design requirements for the major optical components. These optical components comprise those custom designed and fabricated for amplification and transport of the full aperture NIF beam and does not include those off-the-shelf components that may be part of other optical sub-systems (i.e. alignment or diagnostic systems). This document also describes the optical component processing requirements and the QA/damage testing necessary to ensure that the optical components meet or exceed the requirements

  10. Performance of high-density-carbon (HDC) ablator implosion experiments on the National Ignition Facility (NIF)

    Science.gov (United States)

    MacKinnon, Andy

    2013-10-01

    A series of experiments on the National Ignition Facility (NIF) have been performed to measure high-density carbon (HDC) ablator performance for indirect drive inertial confinement fusion (ICF). HDC is a very promising ablator material; being 3x denser than plastic, it absorbs more hohlraum x-rays, leading to higher implosion efficiency. For the HDC experiments the NIF laser generated shaped laser pulses with peak power up to 410 TW and total energy of 1.3 MJ. Pulse shapes were designed to drive 2, 3 or 4 shocks in cryogenic layered implosions. The 2-shock pulse, with a designed fuel adiabat of ~3 is 6-7ns in duration, allowing use of near vacuum hohlraums, which greatly increases the coupling efficiency due to low backscatter losses. Excellent results were obtained for 2,3 and 4 shock pulses. In particular a deuterium-tritium gas filled HDC capsule driven by a 4-shock pulse in a gas-filled hohlraum produced a neutron yield of 1.6 × 1015, a record for a non-cryogenically layered capsule driven by a gas-filled hohlraum. The first 2-shock experiment used a vacuum hohlraum to drive a DD gas filled HDC capsule with a 6.5 ns, laser pulse. This hohlraum was 40% more efficient than the gas-filled counterpart used for 3 and 4 shock experiments, producing near 1D performance at 11 x convergence ratio, peak radiation temperature of 317 eV, 98% laser-hohlraum coupling, and DD neutron yield of 2.2e13, a record for a laser driven DD implosion. The HDC campaigns will be presented, including options for pushing towards the alpha dominated regime. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  11. NeuroMorpho.Org implementation of digital neuroscience: dense coverage and integration with the NIF.

    Science.gov (United States)

    Halavi, Maryam; Polavaram, Sridevi; Donohue, Duncan E; Hamilton, Gail; Hoyt, Jeffrey; Smith, Kenneth P; Ascoli, Giorgio A

    2008-09-01

    Neuronal morphology affects network connectivity, plasticity, and information processing. Uncovering the design principles and functional consequences of dendritic and axonal shape necessitates quantitative analysis and computational modeling of detailed experimental data. Digital reconstructions provide the required neuromorphological descriptions in a parsimonious, comprehensive, and reliable numerical format. NeuroMorpho.Org is the largest web-accessible repository service for digitally reconstructed neurons and one of the integrated resources in the Neuroscience Information Framework (NIF). Here we describe the NeuroMorpho.Org approach as an exemplary experience in designing, creating, populating, and curating a neuroscience digital resource. The simple three-tier architecture of NeuroMorpho.Org (web client, web server, and relational database) encompasses all necessary elements to support a large-scale, integrate-able repository. The data content, while heterogeneous in scientific scope and experimental origin, is unified in format and presentation by an in house standardization protocol. The server application (MRALD) is secure, customizable, and developer-friendly. Centralized processing and expert annotation yields a comprehensive set of metadata that enriches and complements the raw data. The thoroughly tested interface design allows for optimal and effective data search and retrieval. Availability of data in both original and standardized formats ensures compatibility with existing resources and fosters further tool development. Other key functions enable extensive exploration and discovery, including 3D and interactive visualization of branching, frequently measured morphometrics, and reciprocal links to the original PubMed publications. The integration of NeuroMorpho.Org with version-1 of the NIF (NIFv1) provides the opportunity to access morphological data in the context of other relevant resources and diverse subdomains of neuroscience, opening

  12. Lab-in-a-drop: controlled self-assembly of CdSe/ZnS quantum dots and quantum rods into polycrystalline nanostructures with desired optical properties

    International Nuclear Information System (INIS)

    Sukhanova, Alyona; Volkov, Yuri; Rogach, Andrey L; Baranov, Alexander V; Susha, Andrei S; Klinov, Dmitriy; Oleinikov, Vladimir; Cohen, Jacques H M; Nabiev, Igor

    2007-01-01

    Among the different nanometre-scale building blocks, colloidal nanocrystals are of special interest in construction of ordered assemblies to be used in optoelectronics, photonics and biosensing. It is important that the nanocrystal properties essential to allow the arrangement process, including their size, shape, surface protection, stabilization and charge, can be controlled along with the electronic structure of each nanocrystal. Here, we describe an operation of the 'lab-in-a-drop', droplets of the aqueous solutions of the water-solubilized CdSe/ZnS core/shell nanocrystal quantum dots and quantum rods, in which a variety of nanostructures with desired properties may be produced. We show that, upon incubation and controlled evaporation of the solvent from the aqueous droplets of nanocrystals, one may produce either nanowires or polycrystalline dendrites of different morphologies and dimensions, depending on the nanocrystal shape and on the very narrow concentration and temperature specific ranges. Hence, the operation of this 'lab-in-a-drop' is controlled by external parameters providing the fluorescent nanostructures of desired size and morphology. Although a majority of the results presented here were obtained with CdSe/ZnS quantum dots and rods, similar polycrystalline patterns may be produced in the aqueous suspensions of other nanocrystals

  13. Shingle assembly

    Science.gov (United States)

    Dinwoodie, Thomas L.

    2007-02-20

    A barrier, such as a PV module, is secured to a base by a support to create a shingle assembly with a venting region defined between the barrier and base for temperature regulation. The first edge of one base may be interengageable with the second edge of an adjacent base to be capable of resisting first and second disengaging forces oriented perpendicular to the edges and along planes oriented parallel to and perpendicular to the base. A deflector may be used to help reduce wind uplift forces.

  14. Heater assembly

    International Nuclear Information System (INIS)

    Lee, K.; Ueng, Tzoushin.

    1991-01-01

    An electrical resistance heater, installed in the H1 borehole, is used to thermally perturb the rock mass through a controlled heating and cooling cycle. Heater power levels are controlled by a Variac power transformer and are measured by wattmeters. Temperatures are measured by thermocouples on the borehole wall and on the heater assembly. Power and temperature values are recorded by the DAS described in Chapter 12. The heater assembly consists of a 3.55-m (11.6-ft) long by 20.3-cm (8-in.) O.D., Type 304 stainless steel pipe, containing a tubular hairpin heating element. The element has a heated length of 3 m (9.84 ft). The power rating of the element is 10 kW; however, we plan to operate the unit at a maximum power of only 3 kW. The heater is positioned with its midpoint directly below the axis of the P2 borehole, as shown in the borehole configuration diagram. This heater midpoint position corresponds to a distance of approximately 8.5 m (27.9 ft) from the H1 borehole collar. A schematic of the heater assembly in the borehole is shown. The distance from the borehole collar to the closest point on the assembly (the front end) is 6.5 m (21.3 ft). A high-temperature inflatable packer, used to seal the borehole for moisture collection, is positioned 50 cm (19.7 in.) ahead of the heater front end. The heater is supported and centralized within the borehole by two skids, fabricated from 25-mm (1-in.) O.D. stainless steel pipe. Thermocouples are installed at a number of locations in the H1 borehole. Four thermocouples that are attached to the heater skin monitor temperatures on the outer surface of the can, while three thermocouples that are held in place by rock sections monitor borehole wall temperatures beneath the heater. Temperatures are also monitored at the heater terminal and on the packer hardware

  15. Assembling consumption

    DEFF Research Database (Denmark)

    Assembling Consumption marks a definitive step in the institutionalisation of qualitative business research. By gathering leading scholars and educators who study markets, marketing and consumption through the lenses of philosophy, sociology and anthropology, this book clarifies and applies the i...... societies. This is an essential reading for both seasoned scholars and advanced students of markets, economies and social forms of consumption....... the investigative tools offered by assemblage theory, actor-network theory and non-representational theory. Clear theoretical explanation and methodological innovation, alongside empirical applications of these emerging frameworks will offer readers new and refreshing perspectives on consumer culture and market...

  16. Fuel assembly

    International Nuclear Information System (INIS)

    Chaki, Masao; Nishida, Koji; Karasawa, Hidetoshi; Kanazawa, Toru; Orii, Akihito; Nagayoshi, Takuji; Kashiwai, Shin-ichi; Masuhara, Yasuhiro

    1998-01-01

    The present invention concerns a fuel assembly, for a BWR type nuclear reactor, comprising fuel rods in 9 x 9 matrix. The inner width of the channel box is about 132mm and the length of the fuel rods which are not short fuel rods is about 4m. Two water rods having a circular cross section are arranged on a diagonal line in a portion of 3 x 3 matrix at the center of the fuel assembly, and two fuel rods are disposed at vacant spaces, and the number of fuel rods is 74. Eight fuel rods are determined as short fuel rods among 74 fuel rods. Assuming the fuel inventory in the short fuel rod as X(kg), and the fuel inventory in the fuel rods other than the short fuel rods as Y(kg), X and Y satisfy the relation: X + Y ≥ 173m, Y ≤ - 9.7X + 292, Y ≤ - 0.3X + 203 and X > 0. Then, even when the short fuel rods are used, the fuel inventory is increased and fuel economy can be improved. (I.N.)

  17. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    Mardi 5 avril à 11 h 00 BE Auditorium Meyrin (6-2-024) Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 mai 2015. Présentation et approbation du rapport d’activités 2015. Présentation et approbation du rapport financier 2015. Présentation et approbation du rapport des vérificateurs aux comptes pour 2015. Programme de travail 2016. Présentation et approbation du projet de budget 2016 Approbation du taux de cotisation pour 2017. Modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commissio...

  18. General Assembly

    CERN Multimedia

    Staff Association

    2017-01-01

    Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 avril 2016. Présentation et approbation du rapport d’activités 2016. Présentation et approbation du rapport financier 2016. Présentation et approbation du rapport des vérificateurs aux comptes pour 2016. Programme de travail 2017. Présentation et approbation du projet de budget 2017 Approbation du taux de cotisation pour 2018. Modifications aux Statuts de l'Association du personnel proposées. Élections des membres de la Commission électorale. Élections des vérifica...

  19. General Assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : 1- Adoption de l’ordre du jour. 2- Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. 3- Présentation et approbation du rapport d’activités 2014. 4- Présentation et approbation du rapport financier 2014. 5- Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. 6- Programme 2015. 7- Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. 8- Pas de modifications aux Statuts de l'Association du personnel proposée. 9- Élections des membres de la Commission é...

  20. General assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. Présentation et approbation du rapport d’activités 2014. Présentation et approbation du rapport financier 2014. Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. Programme 2015. Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. Pas de modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commission électorale. &am...

  1. Fuel assembly

    International Nuclear Information System (INIS)

    Nomata, Terumitsu.

    1993-01-01

    Among fuel pellets to be loaded to fuel cans of a fuel assembly, fuel pellets having a small thermal power are charged in a region from the end of each of spacers up to about 50mm on the upstream of coolants that flow vertically at the periphery of fuel rods. Coolants at the periphery of fuel rods are heated by the heat generation, to result in voids. However, since cooling effect on the upstream of the spacers is low due to influences of the spacers. Further, since the fuel pellets disposed in the upstream region have small thermal power, a void coefficient is not increased. Even if a thermal power exceeding cooling performance should be generated, there is no worry of causing burnout in the upstream region. Even if burnout should be caused, safety margin and reliability relative to burnout are improved, to increase an allowable thermal power, thereby enabling to improve integrity and reliability of fuel rods and fuel assemblies. (N.H.)

  2. Non-image-forming light driven functions are preserved in a mouse model of autosomal dominant optic atrophy.

    Directory of Open Access Journals (Sweden)

    Georgia Perganta

    Full Text Available Autosomal dominant optic atrophy (ADOA is a slowly progressive optic neuropathy that has been associated with mutations of the OPA1 gene. In patients, the disease primarily affects the retinal ganglion cells (RGCs and causes optic nerve atrophy and visual loss. A subset of RGCs are intrinsically photosensitive, express the photopigment melanopsin and drive non-image-forming (NIF visual functions including light driven circadian and sleep behaviours and the pupil light reflex. Given the RGC pathology in ADOA, disruption of NIF functions might be predicted. Interestingly in ADOA patients the pupil light reflex was preserved, although NIF behavioural outputs were not examined. The B6; C3-Opa1(Q285STOP mouse model of ADOA displays optic nerve abnormalities, RGC dendropathy and functional visual disruption. We performed a comprehensive assessment of light driven NIF functions in this mouse model using wheel running activity monitoring, videotracking and pupillometry. Opa1 mutant mice entrained their activity rhythm to the external light/dark cycle, suppressed their activity in response to acute light exposure at night, generated circadian phase shift responses to 480 nm and 525 nm pulses, demonstrated immobility-defined sleep induction following exposure to a brief light pulse at night and exhibited an intensity dependent pupil light reflex. There were no significant differences in any parameter tested relative to wildtype littermate controls. Furthermore, there was no significant difference in the number of melanopsin-expressing RGCs, cell morphology or melanopsin transcript levels between genotypes. Taken together, these findings suggest the preservation of NIF functions in Opa1 mutants. The results provide support to growing evidence that the melanopsin-expressing RGCs are protected in mitochondrial optic neuropathies.

  3. Constraints on the Assembly and Dynamics of Galaxies. II. Properties of Kiloparsec-scale Clumps in Rest-frame Optical Emission of z ~ 2 Star-forming Galaxies

    Science.gov (United States)

    Förster Schreiber, N. M.; Shapley, A. E.; Genzel, R.; Bouché, N.; Cresci, G.; Davies, R.; Erb, D. K.; Genel, S.; Lutz, D.; Newman, S.; Shapiro, K. L.; Steidel, C. C.; Sternberg, A.; Tacconi, L. J.

    2011-09-01

    We study the properties of luminous stellar "clumps" identified in deep, high-resolution Hubble Space Telescope NIC2/F160W imaging at 1.6 μm of six z ~ 2 star-forming galaxies with existing near-infrared integral field spectroscopy from SINFONI at the Very Large Telescope. Individual clumps contribute ~0.5%-15% of the galaxy-integrated rest-frame ≈5000 Å emission, with median of ≈2% the total contribution of clump light ranges from 10% to 25%. The median intrinsic clump size and stellar mass are ~1 kpc and ~109 M sun, in the ranges for clumps identified in rest-UV or line emission in other studies. The clump sizes and masses in the subset of disks are broadly consistent with expectations for clump formation through gravitational instabilities in gas-rich, turbulent disks given the host galaxies' global properties. By combining the NIC2 data with Advanced Camera for Surveys (ACS)/F814W imaging available for one source, and adaptive-optics-assisted SINFONI Hα data for another, we infer modest color, M/L, and stellar age variations within each galaxy. In these two objects, sets of clumps identified at different wavelengths do not fully overlap; NIC2-identified clumps tend to be redder/older than ACS- or Hα-identified clumps without rest-frame optical counterparts. There is evidence for a systematic trend of older ages at smaller galactocentric radii among the clumps, consistent with scenarios where inward migration of clumps transports material toward the central regions. From constraints on a bulge-like component at radii <~ 1-3 kpc, none of the five disks in our sample appears to contain a compact massive stellar core, and we do not discern a trend of bulge stellar mass fraction with stellar age of the galaxy. Further observations are necessary to probe the buildup of stellar bulges and the role of clumps in this process. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated

  4. 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 microb...... of N(2) fixation over the diel cycle.The ISME Journal (2008) 2, 364-378; doi:10.1038/ismej.2007.117; published online 6 March 2008. Udgivelsesdato: 2008-Apr...

  5. Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense.

    Science.gov (United States)

    Sotomaior, P; Araújo, L M; Nishikawa, C Y; Huergo, L F; Monteiro, R A; Pedrosa, F O; Chubatsu, L S; Souza, E M

    2012-12-01

    Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate.

  6. Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense

    Science.gov (United States)

    Sotomaior, P.; Araújo, L.M.; Nishikawa, C.Y.; Huergo, L.F.; Monteiro, R.A.; Pedrosa, F.O.; Chubatsu, L.S.; Souza, E.M.

    2012-01-01

    Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate. PMID:22983183

  7. Effect of ATP and 2-oxoglutarate on the in vitro interaction between the NifA GAF domain and the GlnB protein of Azospirillum brasilense

    Energy Technology Data Exchange (ETDEWEB)

    Sotomaior, P.; Araújo, L.M.; Nishikawa, C.Y.; Huergo, L.F.; Monteiro, R.A.; Pedrosa, F.O.; Chubatsu, L.S.; Souza, E.M. [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR (Brazil)

    2012-09-21

    Azospirillum brasilense is a diazotroph that associates with important agricultural crops and thus has potential to be a nitrogen biofertilizer. The A. brasilense transcription regulator NifA, which seems to be constitutively expressed, activates the transcription of nitrogen fixation genes. It has been suggested that the nitrogen status-signaling protein GlnB regulates NifA activity by direct interaction with the NifA N-terminal GAF domain, preventing the inhibitory effect of this domain under conditions of nitrogen fixation. In the present study, we show that an N-terminal truncated form of NifA no longer required GlnB for activity and lost regulation by ammonium. On the other hand, in trans co-expression of the N-terminal GAF domain inhibited the N-truncated protein in response to fixed nitrogen levels. We also used pull-down assays to show in vitro interaction between the purified N-terminal GAF domain of NifA and the GlnB protein. The results showed that A. brasilense GlnB interacts directly with the NifA N-terminal domain and this interaction is dependent on the presence of ATP and 2-oxoglutarate.

  8. Dilation x-ray imager a new∕faster gated x-ray imager for the NIF.

    Science.gov (United States)

    Nagel, S R; Hilsabeck, T J; Bell, P M; Bradley, D K; Ayers, M J; Barrios, M A; Felker, B; Smith, R F; Collins, G W; Jones, O S; Kilkenny, J D; Chung, T; Piston, K; Raman, K S; Sammuli, B; Hares, J D; Dymoke-Bradshaw, A K L

    2012-10-01

    As the yield on implosion shots increases it is expected that the peak x-ray emission reduces to a duration with a FWHM as short as 20 ps for ∼7 × 10(18) neutron yield. However, the temporal resolution of currently used gated x-ray imagers on the NIF is 40-100 ps. We discuss the benefits of the higher temporal resolution for the NIF and present performance measurements for dilation x-ray imager, which utilizes pulse-dilation technology [T. J. Hilsabeck et al., Rev. Sci. Instrum. 81, 10E317 (2010)] to achieve x-ray imaging with temporal gate times below 10 ps. The measurements were conducted using the COMET laser, which is part of the Jupiter Laser Facility at the Lawrence Livermore National Laboratory.

  9. Imaging of high-energy x-ray emission from cryogenic thermonuclear fuel implosions on the NIF.

    Science.gov (United States)

    Ma, T; Izumi, N; Tommasini, R; Bradley, D K; Bell, P; Cerjan, C J; Dixit, S; Döppner, T; Jones, O; Kline, J L; Kyrala, G; Landen, O L; LePape, S; Mackinnon, A J; Park, H-S; Patel, P K; Prasad, R R; Ralph, J; Regan, S P; Smalyuk, V A; Springer, P T; Suter, L; Town, R P J; Weber, S V; Glenzer, S H

    2012-10-01

    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 broadband time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered implosions. This diagnostic measures the temperature- and density-sensitive bremsstrahlung emission and provides estimates of hot spot mass, mix mass, and pressure.

  10. Hohlraum glint and laser pre-pulse detector for NIF experiments using velocity interferometer system for any reflector.

    Science.gov (United States)

    Moody, J D; Clancy, T J; Frieders, G; Celliers, P M; Ralph, J; Turnbull, D P

    2014-11-01

    Laser pre-pulse and early-time laser reflection from the hohlraum wall onto the capsule (termed "glint") can cause capsule imprint and unwanted early-time shocks on indirect drive implosion experiments. In a minor modification to the existing velocity interferometer system for any reflector diagnostic on NIF a fast-response vacuum photodiode was added to detect this light. The measurements show evidence of laser pre-pulse and possible light reflection off the hohlraum wall and onto the capsule.

  11. Characterizing Hohlraum Plasma Conditions at the National Ignition Facility (NIF) Using X-ray Spectroscopy

    Science.gov (United States)

    Barrios, Maria Alejandra

    2015-11-01

    Improved hohlraums will have a significant impact on increasing the likelihood of indirect drive ignition at the NIF. In indirect-drive Inertial Confinement Fusion (ICF), a high-Z hohlraum converts laser power into a tailored x-ray flux that drives the implosion of a spherical capsule filled with D-T fuel. The x-radiation drive to capsule coupling sets the velocity, adiabat, and symmetry of the implosion. Previous experiments in gas-filled hohlraums determined that the laser-hohlraum energy coupling is 20-25% less than modeled, therefore identifying energy loss mechanisms that reduce the efficacy of the hohlraum drive is central to improving implosion performance. Characterizing the plasma conditions, particularly the plasma electron temperature (Te) , is critical to understanding mechanism that affect the energy coupling such as the laser plasma interactions (LPI), hohlraum x-ray conversion efficiency, and dynamic drive symmetry. The first Te measurements inside a NIF hohlraum, presented here, were achieved using K-shell X-ray spectroscopy of an Mn-Co tracer dot. The dot is deposited on a thin-walled CH capsule, centered on the hohlraum symmetry axis below the laser entrance hole (LEH) of a bottom-truncated hohlraum. The hohlraum x-ray drive ablates the dot and causes it to flow upward, towards the LEH, entering the hot laser deposition region. An absolutely calibrated streaked spectrometer with a line of sight into the LEH records the temporal history of the Mn and Co X-ray emission. The measured (interstage) Lyα/ Heα line ratios for Co and Mn and the Mn-Heα/Co-Heα isoelectronic line ratio are used to infer the local plasma Te from the atomic physics code SCRAM. Time resovled x-ray images perpendicular to the hohlraum axis record the dot expansion and trajectory into the LEH region. The temporal evolution of the measured Te and dot trajectory are compared with simulations from radiation-hydrodynamic codes. This work was performed under the auspices of the U

  12. 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.

  13. Expansion of ribosomally produced natural products: a nitrile hydratase- and Nif11-related precursor family

    Directory of Open Access Journals (Sweden)

    Mitchell Douglas A

    2010-05-01

    Full Text Available Abstract Background A new family of natural products has been described in which cysteine, serine and threonine from ribosomally-produced peptides are converted to thiazoles, oxazoles and methyloxazoles, respectively. These metabolites and their biosynthetic gene clusters are now referred to as thiazole/oxazole-modified microcins (TOMM. As exemplified by microcin B17 and streptolysin S, TOMM precursors contain an N-terminal leader sequence and C-terminal core peptide. The leader sequence contains binding sites for the posttranslational modifying enzymes which subsequently act upon the core peptide. TOMM peptides are small and highly variable, frequently missed by gene-finders and occasionally situated far from the thiazole/oxazole forming genes. Thus, locating a substrate for a particular TOMM pathway can be a challenging endeavor. Results Examination of candidate TOMM precursors has revealed a subclass with an uncharacteristically long leader sequence closely related to the enzyme nitrile hydratase. Members of this nitrile hydratase leader peptide (NHLP family lack the metal-binding residues required for catalysis. Instead, NHLP sequences display the classic Gly-Gly cleavage motif and have C-terminal regions rich in heterocyclizable residues. The NHLP family exhibits a correlated species distribution and local clustering with an ABC transport system. This study also provides evidence that a separate family, annotated as Nif11 nitrogen-fixing proteins, can serve as natural product precursors (N11P, but not always of the TOMM variety. Indeed, a number of cyanobacterial genomes show extensive N11P paralogous expansion, such as Nostoc, Prochlorococcus and Cyanothece, which replace the TOMM cluster with lanthionine biosynthetic machinery. Conclusions This study has united numerous TOMM gene clusters with their cognate substrates. These results suggest that two large protein families, the nitrile hydratases and Nif11, have been retailored for

  14. Fuel assembly

    International Nuclear Information System (INIS)

    Bessho, Yasunori; Ishii, Yoshihiko; Sadaoka, Noriyuki.

    1990-01-01

    Burnable poisons are disposed in the lower portions of a water rod, a channel box and a control rod guide pipe in a fuel assembly, and the amount for each of them is set to burn out in one operation cycle. Since the inner side of the water rod and the control rod guide pipe and gaps are filled with steams at the initial and the intermediate stages of the operation cycle, moderation of neutrons is delayed to harden the spectrum. On the other hand, since the burnable poisons are burnt out in the final stage of the operation cycle, γ-ray heating is not expected and since the insides of the water rod and the control rod guide pipe and the gaps are filled with water of great moderation effect, the neutron spectrum arae softened. In view of the above, void coefficient is increased to promote conversion from U-235 to Pu-239 by utilizing exothermic reaction of burnable poisons at the initial and the intermediate stages in the operation cycle and generation of voids are eliminated at the final stage where the burnable poisons are burnt out, thereby enabling effective burning of Pu-239. (N.H.)

  15. Fuel assembly

    International Nuclear Information System (INIS)

    Yamazaki, Hajime.

    1995-01-01

    In a fuel assembly having fuel rods of different length, fuel pellets of mixed oxides of uranium and plutonium are loaded to a short fuel rod. The volume ratio of a pellet-loaded portion to a plenum portion of the short fuel rod is made greater than the volume ratio of a fuel rod to which uranium fuel pellets are loaded. In addition, the volume of the plenum portion of the short fuel rod is set greater depending on the plutonium content in the loaded fuel pellets. MOX fuel pellets are loaded on the short fuel rods having a greater degree of freedom relevant to the setting for the volume of the plenum portion compared with that of a long rod fuel, and the volume of the plenum portion is ensured greater depending on the plutonium content. Even if a large amount of FP gas and He gas are discharged from the MOX fuels compared with that from the uranium fuels, the internal pressure of the MOX fuel rod during operation is maintained substantially identical with that of the uranium fuel rod, so that a risk of generating excess stresses applied to the fuel cladding tubes and rupture of fuels are greatly reduced. (N.H.)

  16. Fuel assembly

    International Nuclear Information System (INIS)

    Nakajima, Akiyoshi; Bessho, Yasunori; Aoyama, Motoo; Koyama, Jun-ichi; Hirakawa, Hiromasa; Yamashita, Jun-ichi; Hayashi, Tatsuo

    1998-01-01

    In a fuel assembly of a BWR type reactor in which a water rod of a large diameter is disposed at the central portion, the cross sectional area perpendicular to the axial direction comprises a region a of a fuel rod group facing to a wide gap water region to which a control rod is inserted, a region b of a fuel rod group disposed on the side of the wide gap water region other than the region a, a region d of a fuel rod group facing to a narrow gap water region and a region c of a fuel rod group disposed on the side of the narrow gap water region other than the region d. When comparing an amount of fission products contained in the four regions relative to that in the entire regions and average enrichment degrees of fuel rods for the four regions, the relative amount and the average enrichment degree of the fuel rod group of the region a is minimized, and the relative amount and the average enrichment degree of the fuel rod group in the region b is maximized. Then, reactor shut down margin during cold operation can be improved while flattening the power in the cross section perpendicular to the axial direction. (N.H.)

  17. Progress towards materials science above 1000 GPa (10 Mbar) on the NIF laser

    International Nuclear Information System (INIS)

    Remington, B.A.; Park, H.; Prisbrey, S.T.; Pollaine, S.M.; Cavallo, R.M.; Rudd, R.E.; Lorenz, K.T.; Becker, R.; Bernier, J.; Barton, N.; Arsenlis, T.; Glendinning, S.G.; Hamza, A.; Swift, D.; Jankowski, A.; Meyers, M.A.

    2009-01-01

    Solid state dynamics experiments at extreme pressures, P > 1000 GPa (10 Mbar), and ultrahigh strain rates (1.e6-1.e8 1/s) are being developed for the National Ignition Facility (NIF) laser. These experiments will open up exploration of new regimes of materials science at an order of magnitude higher pressures than have been possible to date. Such extreme, solid state conditions can be accessed with a ramped pressure drive. The experimental, computational, and theoretical techniques are being developed and tested on the Omega laser. Velocity interferometer measurements (VISAR) establish the high pressure conditions generated by the ramped drive. Constitutive models for solid state strength under these conditions are tested by comparing simulations with experiments measuring perturbation growth from the Rayleigh-Taylor instability in solid state samples of vanadium. Radiography techniques using synchronized bursts of x-rays have been developed to diagnose this perturbation growth. Experiments on Omega demonstrating these techniques at peak pressures of ∼1 Mbar will be discussed. The time resolved observation of foil cracking and void formation show the need for tamped samples and a planar drive

  18. 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.

  19. Demonstration of high coupling efficiency to Al capsule in rugby hohlraum on NIF

    Science.gov (United States)

    Ping, Y.; Smalyuk, V.; Amendt, P.; Bennett, D.; Chen, H.; Dewald, E.; Goyon, C.; Graziani, F.; Johnson, S.; Khan, S.; Landen, O.; Nikroo, A.; Pino, J.; Ralph, J.; Seugling, R.; Strozzi, D.; Tipton, R.; Tommasini, R.; Wang, M.; Loomis, E.; Merritt, E.; Montgomery, D.

    2017-10-01

    A new design of the double-shell approach predicts a high coupling efficiency from the hohlraum to the capsule, with 700 kJ in the capsule instead of 200kJ in the conventional low-Z single-shell scheme, improving prospects of double-shell performance. A recent experiment on NIF has evaluated a first step toward this goal of energy coupling using 0.7x subscale Al capsule, Au rugby hohlraum and 1MJ drive. A shell velocity of 150 μm/ns was measured, DANTE peak temperature of 255 eV was measured, and shell kinetic energy of 36 kJ was inferred using a rocket model, all close to predictions and consistent with 330kJ of total energy coupled to the capsule. Data analysis and more results from subsequent experiments will be presented. In the next step, an additional 2x increase of total coupled energy up to 700 kJ is projected for full-scale 2-MJ drive in U Rugby hohlraum. This work was performed under DOE contract DE-AC52-07NA27344.

  20. Electron temperature from x-ray continuum measurements on the NIF

    Science.gov (United States)

    Jarrott, Leonard; Bachmann, Benjamin; Benedetti, Robin; Izumi, Nobuhiko; Khan, Shahab; Landen, Otto; Ma, Tammy; Nagel, Sabrina; Pak, Arthur; Patel, Prav; Schneider, Marilyn; Springer, Paul; LLNL Collaboration

    2017-10-01

    We report on measurements of the electron temperature within the hot spot of inertially confined, layered implosions on the NIF using a titanium differential filtering x-ray diagnostic. The electron temperature from x-ray emission is insensitive to non-thermal velocity flows as is the case with ion temperature measurements and is thus a critical parameter in interpreting stagnated hot spot conditions. Here we discuss measurements using titanium filters ranging from 10 μm to 1mm in thickness with a sensitivity band of 10-30keV coupled with penumbral pinholes. The use of larger pinhole diameters increases x-ray fluence improving sensitivity of photon energies with minimal attenuation from the compressed fuel/shell. This diagnostic has been fielded on a series of cryogenic shots with DT ion temperatures ranging from 2-5keV. Analysis of the measurement will be presented along with a comparison against simulated electron temperatures and x-ray spectra as well as a comparison to DT ion temperature measurements. This work was performed under the auspices of U.S. DoE by LLNL under Contract No. DE-AC52-07NA27344.

  1. Using deep neural networks to augment NIF post-shot analysis

    Science.gov (United States)

    Humbird, Kelli; Peterson, Luc; McClarren, Ryan; Field, John; Gaffney, Jim; Kruse, Michael; Nora, Ryan; Spears, Brian

    2017-10-01

    Post-shot analysis of National Ignition Facility (NIF) experiments is the process of determining which simulation inputs yield results consistent with experimental observations. This analysis is typically accomplished by running suites of manually adjusted simulations, or Monte Carlo sampling surrogate models that approximate the response surfaces of the physics code. These approaches are expensive and often find simulations that match only a small subset of observables simultaneously. We demonstrate an alternative method for performing post-shot analysis using inverse models, which map directly from experimental observables to simulation inputs with quantified uncertainties. The models are created using a novel machine learning algorithm which automates the construction and initialization of deep neural networks to optimize predictive accuracy. We show how these neural networks, trained on large databases of post-shot simulations, can rigorously quantify the agreement between simulation and experiment. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  2. Using NIF to Test Theories of High-Pressure, High-Rate Plastic Flow in Metals

    Science.gov (United States)

    Rudd, Robert E.; Arsenlis, A.; Cavallo, R. M.; Huntington, C. M.; McNaney, J. M.; Park, H. S.; Powell, P.; Prisbrey, S. T.; Remington, B. A.; Swift, D.; Wehrenberg, C. E.; Yang, L.

    2017-10-01

    Precisely controlled plasmas are playing key roles both as pump and probe in experiments to understand the strength of solid metals at high energy density (HED) conditions. In concert with theoretical advances, these experiments have enabled a predictive capability to model material strength at Mbar pressures and high strain rates. Here we describe multiscale strength models developed for tantalum starting with atomic bonding and extending up through the mobility of individual dislocations, the evolution of dislocation networks and so on until the ultimate material response at the scale of an experiment. Experiments at the National Ignition Facility (NIF) probe strength in metals ramp compressed to 1-8 Mbar. The model is able to predict 1 Mbar experiments without adjustable parameters. The combination of experiment and theory has shown that solid metals can behave significantly differently at HED conditions. We also describe recent studies of lead compressed to 3-5 Mbar. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA273.

  3. 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.

  4. 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.

  5. Approach towards the digital optical twin

    Science.gov (United States)

    Prochnau, Marcel; Stollenwerk, Jochen; Loosen, Peter

    2017-11-01

    This paper discusses the idea of a Digital Optical Twin (DOT) in the field of optical system assembly. Furthermore, steps required towards this goal concerning the digital representation of a physical system are presented.

  6. A database of wavefront measurements for laser system modeling, optical component development and fabrication process qualification

    International Nuclear Information System (INIS)

    Wolfe, C.R.; Lawson, J.K.; Aikens, D.M.; English, R.E.

    1995-01-01

    In the second half of the 1990's, LLNL and others anticipate designing and beginning construction of the National Ignition Facility (NIF). The NIF will be capable of producing the worlds first laboratory scale fusion ignition and bum reaction by imploding a small target. The NIF will utilize approximately 192 simultaneous laser beams for this purpose. The laser will be capable of producing a shaped energy pulse of at least 1.8 million joules (MJ) with peak power of at least 500 trillion watts (TV). In total, the facility will require more than 7,000 large optical components. The performance of a high power laser of this kind can be seriously degraded by the presence of low amplitude, periodic modulations in the surface and transmitted wavefronts of the optics used. At high peak power, these phase modulations can convert into large intensity modulations by non-linear optical processes. This in turn can lead to loss in energy on target via many well known mechanisms. In some cases laser damage to the optics downstream of the source of the phase modulation can occur. The database described here contains wavefront phase maps of early prototype optical components for the NIF. It has only recently become possible to map the wavefront of these large aperture components with high spatial resolution. Modem large aperture static fringe and phase shifting interferometers equipped with large area solid state detectors have made this possible. In a series of measurements with these instruments, wide spatial bandwidth can be detected in the wavefront

  7. Optics/Optical Diagnostics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

  8. Overlapped optics induced perfect coherent effects

    Science.gov (United States)

    Li, Jian Jie; Zang, Xiao Fei; Mao, Jun Fa; Tang, Min; Zhu, Yi Ming; Zhuang, Song Lin

    2013-12-01

    For traditional coherent effects, two separated identical point sources can be interfered with each other only when the optical path difference is integer number of wavelengths, leading to alternate dark and bright fringes for different optical path difference. For hundreds of years, such a perfect coherent condition seems insurmountable. However, in this paper, based on transformation optics, two separated in-phase identical point sources can induce perfect interference with each other without satisfying the traditional coherent condition. This shifting illusion media is realized by inductor-capacitor transmission line network. Theoretical analysis, numerical simulations and experimental results are performed to confirm such a kind of perfect coherent effect and it is found that the total radiation power of multiple elements system can be greatly enhanced. Our investigation may be applicable to National Ignition Facility (NIF), Inertial Confined Fusion (ICF) of China, LED lighting technology, terahertz communication, and so on.

  9. Overlapped optics induced perfect coherent effects.

    Science.gov (United States)

    Li, Jian Jie; Zang, Xiao Fei; Mao, Jun Fa; Tang, Min; Zhu, Yi Ming; Zhuang, Song Lin

    2013-12-20

    For traditional coherent effects, two separated identical point sources can be interfered with each other only when the optical path difference is integer number of wavelengths, leading to alternate dark and bright fringes for different optical path difference. For hundreds of years, such a perfect coherent condition seems insurmountable. However, in this paper, based on transformation optics, two separated in-phase identical point sources can induce perfect interference with each other without satisfying the traditional coherent condition. This shifting illusion media is realized by inductor-capacitor transmission line network. Theoretical analysis, numerical simulations and experimental results are performed to confirm such a kind of perfect coherent effect and it is found that the total radiation power of multiple elements system can be greatly enhanced. Our investigation may be applicable to National Ignition Facility (NIF), Inertial Confined Fusion (ICF) of China, LED lighting technology, terahertz communication, and so on.

  10. Synthesis and crystal structure of K2NiF4-type novel Gd1+xCa1−xAlO4−xNx oxynitrides

    International Nuclear Information System (INIS)

    Masubuchi, Yuji; Hata, Tomoyuki; Motohashi, Teruki; Kikkawa, Shinichi

    2014-01-01

    Highlights: • Novel gadolinium calcium aluminum oxynitride was prepared by solid state reaction. • Crystal structure of the oxynitride was refined by using synchrotron X-ray diffraction. • Gd 1.2 Ca 0.8 AlO 3.8 N 0.2 has a layered K 2 NiF 4 -type structure with the I4mm space group. • Nitride ions preferentially occupy the apical site of aluminum octahedron. -- Abstract: Novel gadolinium calcium aluminum oxynitrides, Gd 1+x Ca 1−x AlO 4−x N x , were prepared in x = 0.15–0.25 by the solid state reaction of a nitrogen–rich mixture with AlN as an aluminum source; the mixture was sintered twice at 1500 °C for 5 h under 0.5 MPa of nitrogen gas. Shift in the optical absorption edge was observed in their diffuse reflectance spectra from 4.46 eV for the oxide (x = 0) to 2.94 eV for the oxynitride at x = 0.2. The crystal structure of Gd 1.2 Ca 0.8 AlO 3.8 N 0.2 at x = 0.2 was refined using a synchrotron X-ray diffraction data as a layered K 2 NiF 4 -type structure with the I4mm space group. Longer Al–O/N bond lengths in the oxynitride than those in GdCaAlO 4 suggest that the nitride ions are in the apical site of aluminum polyhedron, similar to those in Nd 2 AlO 3 N

  11. Optical design and testing: introduction.

    Science.gov (United States)

    Liang, Chao-Wen; Koshel, John; Sasian, Jose; Breault, Robert; Wang, Yongtian; Fang, Yi Chin

    2014-10-10

    Optical design and testing has numerous applications in industrial, military, consumer, and medical settings. Assembling a complete imaging or nonimage optical system may require the integration of optics, mechatronics, lighting technology, optimization, ray tracing, aberration analysis, image processing, tolerance compensation, and display rendering. This issue features original research ranging from the optical design of image and nonimage optical stimuli for human perception, optics applications, bio-optics applications, 3D display, solar energy system, opto-mechatronics to novel imaging or nonimage modalities in visible and infrared spectral imaging, modulation transfer function measurement, and innovative interferometry.

  12. Extending the NIF DISCO framework to automate complex workflow: coordinating the harvest and integration of data from diverse neuroscience information resources.

    Science.gov (United States)

    Marenco, Luis N; Wang, Rixin; Bandrowski, Anita E; Grethe, Jeffrey S; Shepherd, Gordon M; Miller, Perry L

    2014-01-01

    This paper describes how DISCO, the data aggregator that supports the Neuroscience Information Framework (NIF), has been extended to play a central role in automating the complex workflow required to support and coordinate the NIF's data integration capabilities. The NIF is an NIH Neuroscience Blueprint initiative designed to help researchers access the wealth of data related to the neurosciences available via the Internet. A central component is the NIF Federation, a searchable database that currently contains data from 231 data and information resources regularly harvested, updated, and warehoused in the DISCO system. In the past several years, DISCO has greatly extended its functionality and has evolved to play a central role in automating the complex, ongoing process of harvesting, validating, integrating, and displaying neuroscience data from a growing set of participating resources. This paper provides an overview of DISCO's current capabilities and discusses a number of the challenges and future directions related to the process of coordinating the integration of neuroscience data within the NIF Federation.

  13. Characterization of a 65 kDa NIF in the nuclear matrix of the monocot Allium cepa that interacts with nuclear spectrin-like proteins.

    Science.gov (United States)

    Pérez-Munive, Clara; Blumenthal, Sonal S D; de la Espina, Susana Moreno Díaz

    2012-01-01

    Plant cells have a well organized nucleus and nuclear matrix, but lack orthologues of the main structural components of the metazoan nuclear matrix. Although data is limited, most plant nuclear structural proteins are coiled-coil proteins, such as the NIFs (nuclear intermediate filaments) in Pisum sativum that cross-react with anti-intermediate filament and anti-lamin antibodies, form filaments 6-12 nm in diameter in vitro, and may play the role of lamins. We have investigated the conservation and features of NIFs in a monocot species, Allium cepa, and compared them with onion lamin-like proteins. Polyclonal antisera against the pea 65 kDa NIF were used in 1D and 2D Western blots, ICM (imunofluorescence confocal microscopy) and IEM (immunoelectron microscopy). Their presence in the nuclear matrix was analysed by differential extraction of nuclei, and their association with structural spectrin-like proteins by co-immunoprecipitation and co-localization in ICM. NIF is a conserved structural component of the nucleus and its matrix in monocots with Mr and pI values similar to those of pea 65 kDa NIF, which localized to the nuclear envelope, perichromatin domains and foci, and to the nuclear matrix, interacting directly with structural nuclear spectrin-like proteins. Its similarities with some of the proteins described as onion lamin-like proteins suggest that they are highly related or perhaps the same proteins.

  14. Optical Comb Generation for Streak Camera Calibration for Inertial Confinement Fusion Experiments

    International Nuclear Information System (INIS)

    Ronald Justin; Terence Davies; Frans Janson; Bruce Marshall; Perry Bell; Daniel Kalantar; Joseph Kimbrough; Stephen Vernon; Oliver Sweningsen

    2008-01-01

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) is coming on-line to support physics experimentation for the U.S. Department of Energy (DOE) programs in Inertial Confinement Fusion (ICF) and Stockpile Stewardship (SS). Optical streak cameras are an integral part of the experimental diagnostics instrumentation at NIF. To accurately reduce streak camera data a highly accurate temporal calibration is required. This article describes a technique for simultaneously generating a precise +/- 2 ps optical marker pulse (fiducial reference) and trains of precisely timed, short-duration optical pulses (so-called 'comb' pulse trains) that are suitable for the timing calibrations. These optical pulse generators are used with the LLNL optical streak cameras. They are small, portable light sources that, in the comb mode, produce a series of temporally short, uniformly spaced optical pulses, using a laser diode source. Comb generators have been produced with pulse-train repetition rates up to 10 GHz at 780 nm, and somewhat lower frequencies at 664 nm. Individual pulses can be as short as 25-ps FWHM. Signal output is via a fiber-optic connector on the front panel of the generator box. The optical signal is transported from comb generator to streak camera through multi-mode, graded-index optical fiber

  15. 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.

  16. Gemini NIFS survey of feeding and feedback processes in nearby active galaxies - I. Stellar kinematics

    Science.gov (United States)

    Riffel, Rogemar A.; Storchi-Bergmann, Thaisa; Riffel, Rogerio; Dahmer-Hahn, Luis G.; Diniz, Marlon R.; Schönell, Astor J.; Dametto, Natacha Z.

    2017-09-01

    We use the Gemini Near-Infrared Integral Field Spectrograph (NIFS) to map the stellar kinematics of the inner few hundred parsecs of a sample of 16 nearby Seyfert galaxies, at a spatial resolution of tens of parsecs and spectral resolution of 40 km s- 1. We find that the line-of-sight (LOS) velocity fields for most galaxies are well reproduced by rotating disc models. The kinematic position angle (PA) derived for the LOS velocity field is consistent with the large-scale photometric PA. The residual velocities are correlated with the hard X-ray luminosity, suggesting that more luminous active galactic nuclei have a larger impact in the surrounding stellar dynamics. The central velocity dispersion values are usually higher than the rotation velocity amplitude, what we attribute to the strong contribution of bulge kinematics in these inner regions. For 50 per cent of the galaxies, we find an inverse correlation between the velocities and the h3 Gauss-Hermitte moment, implying red wings in the blueshifted side and blue wings in the redshifted side of the velocity field, attributed to the movement of the bulge stars lagging the rotation. Two of the 16 galaxies (NGC 5899 and Mrk 1066) show an S-shape zero velocity line, attributed to the gravitational potential of a nuclear bar. Velocity dispersion (σ) maps show rings of low-σ values (˜50-80 km s- 1) for four objects and 'patches' of low σ for six galaxies at 150-250 pc from the nucleus, attributed to young/ intermediate age stellar populations.

  17. 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

  18. A new synthetic approach to the science of complexity: the MISSION project at NIFS

    International Nuclear Information System (INIS)

    Tetsuya Sato

    1999-01-01

    The present day stage of computer simulation has entered into the third phase. The age of computer simulation in plasma physics dawned in the late 1950's when Oscar Buneman and John Dawson developed the sheet particle model. In 1960's and the early part of 1970's, one devoted oneself to refine the particle model and to develop, more practically, fluid magnetic hydrodynamic models so that the feasibility of the computer simulation methodology could be tested. This age can be called 'dawning of computer simulation'. The so-called supercomputer appeared in the late 1970's and the computer simulation entered the second phase where individual nonlinear phenomena have become possible to be attacked. At present when a supercomputer with the ability of higher than 100 GFlops speed and lager than 10GBytes common memory is available, almost any individual nonlinear phenomenon, whatever it may look complex, can be solved. This age may well be called 'the age of nonlinear solver'. However, as far as the authors are satisfied with using a supercomputer for simply solving an individual nonlinear problem, the computer simulation plays only a passive role in science and would never cause a catastrophic transition to it. Then, the modern science of the 20th century based on reductionism would continue in the coming 21st century, thus the 21st century's science would stay boring and tedious. It must be the computer simulation that can refresh this boring state. At NIFS an extensive effort has been made to establish a new paradigm of science in the 21st century by developing a new synthetic methodology of computer simulation, which the authors call the MISSION Project. The authors present this MISSION Project and propose a working hypothesis of the science of complexity in this talk

  19. Formulación de las NIF en México: referente de convergencia a NIIF

    Directory of Open Access Journals (Sweden)

    Helda María Fuentes Gómez

    2011-06-01

    Full Text Available El presente artículo se desarrolla en un momento coyuntural de la profesión contable a nivel mundial, debido a que las Normas Internacionales de Información Financiera (NIIF han cobrado gran importancia desde su creación, "como normatividad contable universal reconocida por las empresas, que permite cada vez más comparar la información financiera entre entidades de un mismo sector, aunque la base de sus negocios se encuentre en diferentes países, "destaca Alberto del Castillo Socio de Auditoria de la firma Price Wáter House Coopers". El resultado de la aplicación de estas normas permitirá que las decisiones de inversión se agilicen y los mercados actúen con rapidez, permitiendo un mayor volumen de operaciones. (Pérez, 2009. De cara a esta realidad, Colombia a través de la Ley 1314 de 2009, a partir del 1 de enero del año 2010, inicia el proceso de convergencia hacia las NIIF delegando al Consejo Técnico de la Contaduría Pública (CTCP como ente normalizador. De esta manera, para la profesión contable colombiana resulta conveniente dar una mirada a países que han desarrollado procesos similares, como lo es, el caso mexicano. Dado que México inició este proceso desde el año 2002 construyendo su cuerpo normativo contable denominado NIF (Normas de Información Financiera de México sin perder de vista las NIIF (Normas Internacionales de Información Financiera emitidas por la IASB (Junta de Normas Internacionales de Contabilidad.

  20. Failure Rates for Fiber Optic Assemblies

    Science.gov (United States)

    1980-10-01

    operation of a p-i-n photodiode is illustrated schematically in Figure 2.2. "P-i-n" refers to the doping profile of the diodes; "p" refers + oxide RL OUTPUT...shallow p-diffusion.and thin oxides necessary to allow sufficient photon penetration leave the p-i-n photodiode particularly vulnerable to ionic... AMPHOTERICALLY Si DOPED GaAs LEDS. IEEE Trans. on Nuclear Science, Vol. NS-23, no. 6, Dec. 1976. Barnes, C.E. NEUTRON DAMAGE IN EPITAXIAL GaAs LASER DIODES J. of

  1. Self-Assembled Thin Films: Optical Characterization

    NARCIS (Netherlands)

    Wormeester, Herbert; Kooij, Ernst S.; Poelsema, Bene; Schwarz, James A.; Contescu, Cristian I.; Putyera, Karol

    2004-01-01

    Many different materials with truly new physical and chemical properties, consisting of controllably deposited colloid particles, are being developed. Particles with a variety of intrinsic properties are used, their sizes varying over at least three orders of magnitude. For photonic band gap

  2. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  3. Nacira Guénif-Souilamas, dir., La République mise à nu par son immigration

    OpenAIRE

    Trémel, Laurent

    2013-01-01

    Cet ouvrage collectif rassemble les contributions de huit auteurs : Saïd Bouamama (socio-économiste), Christine Delphy (sociologue), Nacira Guénif-Souilamas (sociologue), Éric Macé (sociologue), Joëlle Marelli (philosophe), Laurent Mucchielli (sociologue et historien), Joël Roman (philosophe), Patrick Simon (socio-démographe). D’emblée, on se rend compte que nous affaire à un propos engagé, pour ne pas dire dénonciateur. Le but de l’ouvrage est de montrer le paradoxe d’une République se reven...

  4. Proceedings of joint meeting of the 6th simulation science symposium and the NIFS collaboration research 'large scale computer simulation'

    International Nuclear Information System (INIS)

    2003-03-01

    Joint meeting of the 6th Simulation Science Symposium and the NIFS Collaboration Research 'Large Scale Computer Simulation' was held on December 12-13, 2002 at National Institute for Fusion Science, with the aim of promoting interdisciplinary collaborations in various fields of computer simulations. The present meeting attended by more than 40 people consists of the 11 invited and 22 contributed papers, of which topics were extended not only to fusion science but also to related fields such as astrophysics, earth science, fluid dynamics, molecular dynamics, computer science etc. (author)

  5. Experimental study on the resistance to hydrogen embrittlement of NIFS-V4Cr4Ti alloy

    International Nuclear Information System (INIS)

    Chen Jiming; Xu Zengyu; Den Ying; Muroga, T.

    2002-01-01

    SWIP (Southwestern Institute of Physics) has joined an international collaboration on the hydrogen embrittlement resistance evaluation of the vanadium alloy. This paper presents some experiments on the tensile properties and Charpy impact properties of the NIFS-V4Cr4Ti alloy with high-level hydrogen concentration. The experiment results show different properties against hydrogen embrittlement in static tension and impact load. The critical hydrogen concentration required to embrittle the alloy was about 215 - 310 mg·kg -1 on static tension load, but less than 130 mg·kg -1 on impact loading

  6. Three phylogenetic groups of nodA and nifH genes in Sinorhizobium and Mesorhizobium isolates from leguminous trees growing in Africa and Latin America.

    Science.gov (United States)

    Haukka, K; Lindström, K; Young, J P

    1998-02-01

    The diversity and phylogeny of nodA and nifH genes were studied by using 52 rhizobial isolates from Acacia senegal, Prosopis chilensis, and related leguminous trees growing in Africa and Latin America. All of the strains had similar host ranges and belonged to the genera Sinorhizobium and Mesorhizobium, as previously determined by 16S rRNA gene sequence analysis. The restriction patterns and a sequence analysis of the nodA and nifH genes divided the strains into the following three distinct groups: sinorhizobia from Africa, sinorhizobia from Latin America, and mesorhizobia from both regions. In a phylogenetic tree also containing previously published sequences, the nodA genes of our rhizobia formed a branch of their own, but within the branch no correlation between symbiotic genes and host trees was apparent. Within the large group of African sinorhizobia, similar symbiotic gene types were found in different chromosomal backgrounds, suggesting that transfer of symbiotic genes has occurred across species boundaries. Most strains had plasmids, and the presence of plasmid-borne nifH was demonstrated by hybridization for some examples. The nodA and nifH genes of Sinorhizobium teranga ORS1009T grouped with the nodA and nifH genes of the other African sinorhizobia, but Sinorhizobium saheli ORS609T had a totally different nodA sequence, although it was closely related based on the 16S rRNA gene and nifH data. This might be because this S. saheli strain was originally isolated from Sesbania sp., which belongs to a different cross-nodulation group than Acacia and Prosopis spp. The factors that appear to have influenced the evolution of rhizobial symbiotic genes vary in importance at different taxonomic levels.

  7. Three Phylogenetic Groups of nodA and nifH Genes in Sinorhizobium and Mesorhizobium Isolates from Leguminous Trees Growing in Africa and Latin America

    Science.gov (United States)

    Haukka, Kaisa; Lindström, Kristina; Young, J. Peter W.

    1998-01-01

    The diversity and phylogeny of nodA and nifH genes were studied by using 52 rhizobial isolates from Acacia senegal, Prosopis chilensis, and related leguminous trees growing in Africa and Latin America. All of the strains had similar host ranges and belonged to the genera Sinorhizobium and Mesorhizobium, as previously determined by 16S rRNA gene sequence analysis. The restriction patterns and a sequence analysis of the nodA and nifH genes divided the strains into the following three distinct groups: sinorhizobia from Africa, sinorhizobia from Latin America, and mesorhizobia from both regions. In a phylogenetic tree also containing previously published sequences, the nodA genes of our rhizobia formed a branch of their own, but within the branch no correlation between symbiotic genes and host trees was apparent. Within the large group of African sinorhizobia, similar symbiotic gene types were found in different chromosomal backgrounds, suggesting that transfer of symbiotic genes has occurred across species boundaries. Most strains had plasmids, and the presence of plasmid-borne nifH was demonstrated by hybridization for some examples. The nodA and nifH genes of Sinorhizobium teranga ORS1009T grouped with the nodA and nifH genes of the other African sinorhizobia, but Sinorhizobium saheli ORS609T had a totally different nodA sequence, although it was closely related based on the 16S rRNA gene and nifH data. This might be because this S. saheli strain was originally isolated from Sesbania sp., which belongs to a different cross-nodulation group than Acacia and Prosopis spp. The factors that appear to have influenced the evolution of rhizobial symbiotic genes vary in importance at different taxonomic levels. PMID:9464375

  8. 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

  9. TESS Lens-Bezel Assembly Modal Testing

    Science.gov (United States)

    Dilworth, Brandon J.; Karlicek, Alexandra

    2017-01-01

    The Transiting Exoplanet Survey Satellite (TESS) program, led by the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT) will be the first-ever spaceborne all-sky transit survey. MIT Lincoln Laboratory is responsible for the cameras, including the lens assemblies, detector assemblies, lens hoods, and camera mounts. TESS is scheduled to be launched in August of 2017 with the primary goal to detect small planets with bright host starts in the solar neighborhood, so that detailed characterizations of the planets and their atmospheres can be performed. The TESS payload consists of four identical cameras and a data handling unit. Each camera consists of a lens assembly with seven optical elements and a detector assembly with four charge-coupled devices (CCDs) including their associated electronics. The optical prescription requires that several of the lenses are in close proximity to a neighboring element. A finite element model (FEM) was developed to estimate the relative deflections between each lens-bezel assembly under launch loads to predict that there are adequate clearances preventing the lenses from making contact. Modal tests using non-contact response measurements were conducted to experimentally estimate the modal parameters of the lens-bezel assembly, and used to validate the initial FEM assumptions. Key Words Non-contact measurements, modal analysis, model validation

  10. Fuel assembly cleaning device

    International Nuclear Information System (INIS)

    Kikuchi, Akira.

    1981-01-01

    Purpose: To enable efficient and sufficient cleaning of a fuel assembly even in corners without disassembling the assembly and to effectively remove crud. Constitution: Cleaning water mixed with abrasive is injected into a fuel assembly contained within a cleaning device body to remove crud adhering to the fuel assembly. Since a coolant passage from the opening of the bottom surface is of the fuel assembly to the opening of the top surface is utilized as the cleaning water passage at this, the crud can be removed by the abrasive in the water stream even from narrow gaps of the fuel assembly. (Aizawa, K.)

  11. Amorphous Metals and Composites as Mirrors and Mirror Assemblies

    Science.gov (United States)

    Hofmann, Douglas C. (Inventor); Davis, Gregory L. (Inventor); Agnes, Gregory S. (Inventor); Shapiro, Andrew A. (Inventor)

    2016-01-01

    A mirror or mirror assembly fabricated by molding, pressing, assembling, or depositing one or more bulk metal glass (BMG), bulk metal glass composite (BMGMC), or amorphous metal (AM) parts and where the optical surface and backing of the mirror can be fabricated without machining or polishing by utilizing the unique molding capabilities of this class of materials.

  12. Synthetic Approach to Controlled Assembly of Metal Nanoparticles

    Science.gov (United States)

    2016-12-01

    project is to develop synthetic methods to form well-defined colloidal assemblies of metal nanoparticles and to understand their unique optical...raspberry-type nanoparticles. Silver particles possess higher extinction cross section than go 15. SUBJECT TERMS Nanoparticles, Synthetic Chemistry ... Colloidal Assemblies, Energy Harvesting, Templated Growth, Nanoshells, SERS, Spiky Shells, Superparticles, Raspberry Shells 16. SECURITY CLASSIFICATION OF

  13. Computer-aided lens assembly

    Science.gov (United States)

    Tomlinson, Richard; Alcock, Rob; Petzing, Jon; Coupland, Jeremy

    2004-01-01

    We propose a computer-aided method of lens manufacture that allows assembly, adjustment, and test phases to be run concurrently until an acceptable level of optical performance is reached. Misalignment of elements within a compound lens is determined by a comparison of the results of physical ray tracing by use of an array of Gaussian laser beams with numerically obtained geometric ray traces. An estimate of misalignment errors is made, and individual elements are adjusted in an iterative manner until performance criteria are achieved. The method is illustrated for the alignment of an air-spaced doublet.

  14. 3D Simulations of NIF Wetted Foam Experiments to Understand the Transition from 2D to 3D Implosion Behavior

    Science.gov (United States)

    Haines, Brian; Olson, Richard; Yi, Austin; Zylstra, Alex; Peterson, Robert; Bradley, Paul; Shah, Rahul; Wilson, Doug; Kline, John; Leeper, Ramon; Batha, Steve

    2017-10-01

    The high convergence ratio (CR) of layered Inertial Confinement Fusion capsule implosions contribute to high performance in 1D simulations yet make them more susceptible to hydrodynamic instabilities, contributing to the development of 3D flows. The wetted foam platform is an approach to hot spot ignition to achieve low-to-moderate convergence ratios in layered implosions on the NIF unobtainable using an ice layer. Detailed high-resolution modeling of these experiments in 2D and 3D, including all known asymmetries, demonstrates that 2D hydrodynamics explain capsule performance at CR 12 but become less suitable as the CR increases. Mechanisms for this behavior and detailed comparisons of simulations to experiments on NIF will be presented. To evaluate the tradeoff between increased instability and improved 1D performance, we present a full-scale wetted foam capsule design with 17

  15. Calibration of a High Resolution X-ray Spectrometer for High-Energy-Density Plasmas on NIF

    Science.gov (United States)

    Kraus, B.; Gao, L.; Hill, K. W.; Bitter, M.; Efthimion, P.; Schneider, M. B.; Chen, H.; Ayers, J.; Beiersdorfer, P.; Liedahl, D.; Macphee, A. G.; Thorn, D. B.; Bettencourt, R.; Kauffman, R.; Le, H.; Nelson, D.

    2017-10-01

    A high-resolution, DIM-based (Diagnostic Instrument Manipulator) x-ray crystal spectrometer has been calibrated for and deployed at the National Ignition Facility (NIF) to diagnose plasma conditions and mix in ignition capsules near stagnation times. Two conical crystals in the Hall geometry focus rays from the Kr He- α, Ly- α, and He- β complexes onto a streak camera for time-resolved spectra, in order to measure electron density and temperature by observing Stark broadening and relative intensities of dielectronic satellites. Signals from these two crystals are correlated with a third crystal that time-integrates the intervening energy range. The spectrometer has been absolutely calibrated using a microfocus x-ray source, an array of CCD and single-photon-counting detectors, and K- and L-absorption edge filters. Measurements of the integrated reflectivity, energy range, and energy resolution for each crystal will be presented. The implications of the calibration on signal levels from NIF implosions and x-ray filter choices will be discussed. This work was performed under the auspices of the U.S. DoE by Princeton Plasma Physics Laboratory under contract DE-AC02-09CH11466 and by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  16. Deuterium-tritium neutron yield measurements with the 4.5 m neutron-time-of-flight detectors at NIF.

    Science.gov (United States)

    Moran, M J; Bond, E J; Clancy, T J; Eckart, M J; Khater, H Y; Glebov, V Yu

    2012-10-01

    The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator∕photodetector neutron-time-of-flight (nTOF) detectors for measuring deuterium-deuterium (DD) and DT neutron yields. The detectors provided consistent neutron yield (Y(n)) measurements from below 10(9) (DD) to nearly 10(15) (DT). The detectors initially demonstrated detector-to-detector Y(n) precisions better than 5%, but lacked in situ absolute calibrations. Recent experiments at NIF now have provided in situ DT yield calibration data that establish the absolute sensitivity of the 4.5 m differential tissue harmonic imaging (DTHI) detector with an accuracy of ± 10% and precision of ± 1%. The 4.5 m nTOF calibration measurements also have helped to establish improved detector impulse response functions and data analysis methods, which have contributed to improving the accuracy of the Y(n) measurements. These advances have also helped to extend the usefulness of nTOF measurements of ion temperature and downscattered neutron ratio (neutron yield 10-12 MeV divided by yield 13-15 MeV) with other nTOF detectors.

  17. Protective effects of a bacterially expressed NIF-KGF fusion protein against bleomycin-induced acute lung injury in mice.

    Science.gov (United States)

    Li, Xinping; Li, Shengli; Zhang, Miaotao; Li, Xiukun; Zhang, Xiaoming; Zhang, Wenlong; Li, Chuanghong

    2010-08-01

    Current evidence suggests that the keratinocyte growth factor (KGF) and the polymorphonuclear leukocyte may play key roles in the development of lung fibrosis. Here we describe the construction, expression, purification, and identification of a novel NIF (neutrophil inhibitory factor)-KGF mutant fusion protein (NKM). The fusion gene was ligated via a flexible octapeptide hinge and expressed as an insoluble protein in Escherichia coli BL21 (DE3). The fusion protein retained the activities of KGF and NIF, as it inhibited both fibroblast proliferation and leukocyte adhesion. Next, the effects of NKM on bleomycin-induced lung fibrosis in mice were examined. The mice were divided into the following four groups: (i) saline group; (ii) bleomycin group (instilled with 5 mg/kg bleomycin intratracheally); (iii) bleomycin plus dexamethasone (Dex) group (Dex was given intraperitoneally (i.p.) at 1 mg/kg/day 2 days prior to bleomycin instillation and daily after bleomycin instillation until the end of the treatment); and (iv) bleomycin plus NKM group (NKM was given i.p. at 2 mg/kg/day using the same protocol as the Dex group). NKM significantly improved the survival rates of mice exposed to bleomycin. The marked morphological changes and increased hydroxyproline levels resulted from the instillation of bleomycin (on Day 17) in the lungs were significantly inhibited by NKM. These results revealed that NKM can attenuate bleomycin-induced lung fibrosis, suggesting that NKM could be used to prevent bleomycin-induced lung damage or other interstitial pulmonary fibrosis.

  18. Using embedded systems for the remote delivery and recovery of National Ignition Facility and optical line replaceable units

    International Nuclear Information System (INIS)

    Perez, M. L.

    1999-01-01

    This paper describes the design and development of the embedded control systems used to deliver and recover the National Ignition Facility (NIF) optical line replaceable units (LRUs). As part of the NIF Operations Special Equipment Control System (OSECS), the embedded control systems form a part of the front end processor (FEP) layer of the OSECS. During the start-up and operations phases of the NIF project, it is anticipated that a significant number of LRUs will be delivered to the laser beamline structure. The frequency of LRU delivery combined with the design of the facility pose severe constraints for human-only delivery and recovery operations. To reduce the risks to personnel and to allow for safe and efficient delivery of equipment, LLNL engineers are designing and developing embedded control systems for the low-level device control of NIF Transport and Handling mechanical delivery system components. The design of the embedded control system makes use of advanced PC-based motion control technology commonly found in industrial applications. The PC-based platform consists of commercial-off-the-shelf (COTS) hardware and software such as industrial computers, motion controllers, data acquisition boards, sensors technology, networking capabilities, development languages and operating system. Wireless networking technology is also being employed in the design to achieve a distributed control architecture for operator mobility during operations. Additionally, the PC-based platform provides the greatest degree of flexibility in satisfying a diverse set of motion control requirements and helps to maintain low maintenance and future upgrade costs

  19. Controlled manipulation of giant hybrid inorganic nanowire assemblies.

    Science.gov (United States)

    Ou, Fung Suong; Shaijumon, Manikoth M; Ajayan, Pulickel M

    2008-07-01

    The ultimate goal of nanotechnology is the design and fabrication of nanosize building blocks with multiple functionalities and their assembly into large-scale functional structures that can be controllably manipulated. Here we show that hybrid inorganic multisegmented nanowires, with hydrophobic carbon nanotube tails and hydrophilic metal nanowire heads, allow the assembly and manipulation of massive ordered structures in solution, reminiscent of the organic molecular micellar assembly. Further, properly designed assemblies can be manipulated using external stimuli such as magnetic field and light. The hybrid nanowires can have multiple segments including magnetic components, allowing the assembly to be manipulated by external magnetic field. The assembled structures can also be manipulated by modifying the hydrophobicity of the respective components via chemical functionalization and optical irradiation. This approach brings the concept of environment sensitive self-assembling nanomaterials closer to reality.

  20. Membrane module assembly

    Science.gov (United States)

    Kaschemekat, Jurgen

    1994-01-01

    A membrane module assembly adapted to provide a flow path for the incoming feed stream that forces it into prolonged heat-exchanging contact with a heating or cooling mechanism. Membrane separation processes employing the module assembly are also disclosed. The assembly is particularly useful for gas separation or pervaporation.