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.

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.

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

User Interface Framework for the National Ignition Facility (NIF)

International Nuclear Information System (INIS)

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

2007-01-01

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

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.

High-Gain Shock Ignition on the National Ignition Facility

Science.gov (United States)

Perkins, L. J.; Lafortune, K.; Bailey, D.; Lambert, M.; MacKinnon, A.; Blackfield, D.; Comley, A.; Schurtz, G.; Ribeyre, X.; Lebel, E.; Casner, A.; Craxton, R. S.; Betti, R.; McKenty, P.; Anderson, K.; Theobald, W.; Schmitt, A.; Atzeni, S.; Schiavi, A.

2010-11-01

Shock ignition offers the possibility for a near-term test of high-gain ICF on the NIF at less than 1MJ drive energy and with day-1 laser hardware. We will summarize the status of target performance simulations, delineate the critical issues and describe the R&D program to be performed in order to test the potential of a shock-ignited target on NIF. In shock ignition, compressed fuel is separately ignited by a late-time laser-driven shock and, because capsule implosion velocities are significantly lower than those required for conventional hotpot ignition, simulations indicate that fusion energy gains of 60 may be achievable at laser energies around 0.5MJ. Like fast ignition, shock ignition offers high gain but requires only a single laser with less demanding timing and focusing requirements. Conventional symmetry and stability constraints apply, thus a key immediate step towards attempting shock ignition on NIF is to demonstrate adequacy of low-mode uniformity and shock symmetry under polar drive

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.

Status of the US inertial fusion program and the National Ignition Facility

International Nuclear Information System (INIS)

Crandall, D.H.

1997-01-01

Research programs supported by the United States Office of Inertial Fusion and the NIF are summarized. The US inertial fusion program has developed an approach to high energy density physics and fusion ignition in the laboratory relying on the current physics basis of capsule drive by lasers and on the National Ignition Facility which is under construction. (AIP) copyright 1997 American Institute of Physics

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

International Nuclear Information System (INIS)

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

2006-01-01

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

The National Ignition Facility. The path to ignition and inertial fusion energy

International Nuclear Information System (INIS)

Eric Storm

2010-01-01

will focus the world's attention on the possibility of IFE as a virtually inexhaustible, carbon free, energy option. This talk will summarize the capabilities of NIF, discuss NIF ignition, NIF's experimental program in HED science and the potential for laser-based fusion energy.

Target Diagnostics Supports NIF's Path to Ignition

International Nuclear Information System (INIS)

Shelton, R.

2011-01-01

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

Status and update of the National Ignition Facility radiation effects testing program

International Nuclear Information System (INIS)

Davis, J F; Serduke, F J; Wuest, C R.

1998-01-01

We are progressing in our efforts to make the National Ignition Facility (NIF) available to the nation as a radiation effects simulator to support the Services needs for nuclear hardness and survivability testing and validation. Details of our program were summarized in a paper presented at the 1998 HEART Conference [1]. This paper describes recent activities and updates plans for NIF radiation effects testing. research. Radiation Effects Testing

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.

A polar-drive shock-ignition design for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Anderson, K. S.; McKenty, P. W.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Marozas, J. A.; Skupsky, S.; Shvydky, A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Betti, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Hohenberger, M.; Theobald, W.; Lafon, M.; Nora, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States)

2013-05-15

Shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)] is being pursued as a viable option to achieve ignition on the National Ignition Facility (NIF). Shock-ignition target designs use a high-intensity laser spike at the end of a low-adiabat assembly pulse to launch a spherically convergent strong shock to ignite the hot spot of an imploding capsule. A shock-ignition target design for the NIF is presented. One-dimensional simulations indicate an ignition threshold factor of 4.1 with a gain of 58. A polar-drive beam-pointing configuration for shock-ignition experiments on the NIF at 750 kJ is proposed. The capsule design is shown to be robust to the various one- and two-dimensional effects and nonuniformities anticipated on the NIF. The target is predicted to ignite with a gain of 38 when including all anticipated levels of nonuniformity and system uncertainty.

Resolving a central ICF issue for ignition: Implosion symmertry

International Nuclear Information System (INIS)

Cray, M.; Delamater, N.D.; Fernandez, J.C.

1994-01-01

The Los Alamos National Laboratory Inertial Confinement Fusion (ICF) Program focuses on resolving key target-physics issues and developing technology needed for the National Ignition Facility (NIF). This work is being performed in collaboration with Lawrence Livermore National Laboratory (LLNL). A major requirement for the indirect-drive NIF ignition target is to achieve the irradiation uniformity on the capsule surface needed for a symmetrical high-convergence implosion. Los Alamos employed an integrated modeling technique using the Lasnex radiation-hydrodynamics code to design two different targets that achieve ignition and moderate gain. Los Alamos is performing experiments on the Nova Laser at LLNL in order to validate our NIF ignition calculations

Overview of the gamma reaction history diagnostic for the national ignition facility (NIF)

International Nuclear Information System (INIS)

Kim, Yong Ho; Evans, Scott C.; Herrmann, Hans W.; Mack, Joseph M.; Young, Carl S.; Malone, Robert M.; Cox, Brian C.; Frogget, Brent C.; Kaufman, Morris I.; Tunnell, Thomas W.; Tibbitts, Aric; Palagi, Martin J.; Stoeffl, Wolfgang

2010-01-01

The National Ignition Facility (NIF) has a need for measuring gamma radiation as part of a nuclear diagnostic program. A new gamma-detection diagnostic uses 900 off-axis parabolic mirrors to rel ay Cherenkov light from a volume of pressurized gas. This non imaging optical system has the high-speed detector placed at a stop position with the Cherenkov light delayed until after the prompt gammas have passed through the detector. Because of the wavelength range (250 to 700 nm), the optical element surface finish was a key design constraint. A cluster of four channels (each set to a different gas pressure) will collect the time histories for different energy ranges of gammas.

National Ignition Facility Cryogenic Target Systems Interim Management Plan

International Nuclear Information System (INIS)

Warner, B

2002-01-01

Restricted availability of funding has had an adverse impact, unforeseen at the time of the original decision to projectize the National Ignition Facility (NIF) Cryogenic Target Handling Systems (NCTS) Program, on the planning and initiation of these efforts. The purpose of this document is to provide an interim project management plan describing the organizational structure and management processes currently in place for NCTS. Preparation of a Program Execution Plan (PEP) for NCTS has been initiated, and a current draft is provided as Attachment 1 to this document. The National Ignition Facility is a multi-megajoule laser facility being constructed at Lawrence Livermore National Laboratory (LLNL) by the National Nuclear Security Administration (NNSA) in the Department of Energy (DOE). Its primary mission is to support the Stockpile Stewardship Program (SSP) by performing experiments studying weapons physics, including fusion ignition. NIF also supports the missions of weapons effects, inertial fusion energy, and basic science in high-energy-density physics. NIF will be operated by LLNL under contract to the University of California (UC) as a national user facility. NIF is a low-hazard, radiological facility, and its operation will meet all applicable federal, state, and local Environmental Safety and Health (ES and H) requirements. The NCTS Interim Management Plan provides a summary of primary design criteria and functional requirements, current organizational structure, tracking and reporting procedures, and current planning estimates of project scope, cost, and schedule. The NIF Director controls the NIF Cryogenic Target Systems Interim Management Plan. Overall scope content and execution schedules for the High Energy Density Physics Campaign (SSP Campaign 10) are currently undergoing rebaselining and will be brought into alignment with resources expected to be available throughout the NNSA Future Years National Security Plan (FYNSP). The revised schedule for

Orchestrating Shots for the National Ignition Facility (NIF)

International Nuclear Information System (INIS)

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

2005-01-01

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

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

International Nuclear Information System (INIS)

Hackel, L; Chen, H L

2003-01-01

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

The physics basis for ignition using indirect-drive targets on the National Ignition Facility

International Nuclear Information System (INIS)

Lindl, John D.; Amendt, Peter; Berger, Richard L.; Glendinning, S. Gail; Glenzer, Siegfried H.; Haan, Steven W.; Kauffman, Robert L.; Landen, Otto L.; Suter, Laurence J.

2004-01-01

The 1990 National Academy of Science final report of its review of the Inertial Confinement Fusion Program recommended completion of a series of target physics objectives on the 10-beam Nova laser at the Lawrence Livermore National Laboratory as the highest-priority prerequisite for proceeding with construction of an ignition-scale laser facility, now called the National Ignition Facility (NIF). These objectives were chosen to demonstrate that there was sufficient understanding of the physics of ignition targets that the laser requirements for laboratory ignition could be accurately specified. This research on Nova, as well as additional research on the Omega laser at the University of Rochester, is the subject of this review. The objectives of the U.S. indirect-drive target physics program have been to experimentally demonstrate and predictively model hohlraum characteristics, as well as capsule performance in targets that have been scaled in key physics variables from NIF targets. To address the hohlraum and hydrodynamic constraints on indirect-drive ignition, the target physics program was divided into the Hohlraum and Laser-Plasma Physics (HLP) program and the Hydrodynamically Equivalent Physics (HEP) program. The HLP program addresses laser-plasma coupling, x-ray generation and transport, and the development of energy-efficient hohlraums that provide the appropriate spectral, temporal, and spatial x-ray drive. The HEP experiments address the issues of hydrodynamic instability and mix, as well as the effects of flux asymmetry on capsules that are scaled as closely as possible to ignition capsules (hydrodynamic equivalence). The HEP program also addresses other capsule physics issues associated with ignition, such as energy gain and energy loss to the fuel during implosion in the absence of alpha-particle deposition. The results from the Nova and Omega experiments approach the NIF requirements for most of the important ignition capsule parameters, including

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.

Ultra-stable, diode-pumped Nd-doped glass regenerative amplifier for the National Ignition Facility (NIF)

International Nuclear Information System (INIS)

Crane, J.K.; Martinez, M.; Beach, R.J.; Mitchell, S.; Pratt, G.; Christensen, J.J.

1995-12-01

We describe a diode laser-pumped Nd:glass regenerative amplifier that amplifies temporally shaped pulses with low distortion, high pulse-to- pulse stability, and high gain. This laser amplifier is a prototype subsystem for the National Ignition Facility (NIF) laser system. 2 refs., 1 fig

The Ignition Target for the National Ignition Facility

International Nuclear Information System (INIS)

Atherton, L J; Moses, E I; Carlisle, K; Kilkenny, J

2007-01-01

The National Ignition Facility (NIF) is a 192 beam Nd-glass laser facility presently under construction at Lawrence Livermore National Laboratory (LLNL) for performing inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. When completed in 2009, NIF will be able to produce 1.8 MJ, 500 TW of ultraviolet light for target experiments that will create conditions of extreme temperatures (>10 8 K), pressures (10-GBar) and matter densities (> 100 g/cm 3 ). A detailed program called the National Ignition Campaign (NIC) has been developed to enable ignition experiments in 2010, with the goal of producing fusion ignition and burn of a deuterium-tritium (DT) fuel mixture in millimeter-scale target capsules. The first of the target experiments leading up to these ignition shots will begin in 2008. Targets for the National Ignition Campaign are both complex and precise, and are extraordinarily demanding in materials fabrication, machining, assembly, cryogenics and characterization. An overview of the campaign for ignition will be presented, along with technologies for target fabrication, assembly and metrology and advances in growth and x-ray imaging of DT ice layers. The sum of these efforts represents a quantum leap in target precision, characterization, manufacturing rate and flexibility over current state-of-the-art

Magnetic Fields on the National Ignition Facility (MagNIF)

International Nuclear Information System (INIS)

Mason, D.; Folta, J.

2016-01-01

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

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.

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.

NIF Projects Controls and Information Systems Software Quality Assurance Plan

International Nuclear Information System (INIS)

Fishler, B.

2011-01-01

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

Opportunities for Integrated Fast Ignition program

International Nuclear Information System (INIS)

Mackinnon, A. J.; Key, M. H.; Hatchett, S. P.; Tabak, M.; Town, R.; Gregori, G.; Patel, P. K.; Snavely, R.; Freeman, R. R.; Stephens, R. B.; Beg, F.

2005-01-01

Experiments designed to investigate the physics of particle transport and heating of dense plasmas have been carried out in an number of facilities around the world since the publication of the fast ignition concept in 1997. To date a number of integrated experiments, examining the capsule implosion and subsequent heating have been carried out on the Gekko facility at the Institute of Laser Engineering (ILE) Osaka, Japan. The coupling of energy by the short pulse into the pre-compressed core in these experiments was very encouraging. More facilities capable of carrying out integrated experiments are currently under construction: Firex at ILEm the Omega EP facility at the University of Rochester, Z PW at Sandia National Lab, LIL in France and eventually high energy PW beams on the NIF. This presentation will review the current status of experiments in this area and discuss the capabilities of integrated fast ignition research that will be required to design the proof of principle and scaling experiments for fast ignition to be carried on the NIF. (Author)

The national ignition facility: path to ignition in the laboratory

International Nuclear Information System (INIS)

Moses, E.I.; Bonanno, R.E.; Haynam, C.A.; Kauffman, R.L.; MacGowan, B.J.; Patterson Jr, R.W.; Sawicki, R.H.; Van Wonterghem, B.M.

2007-01-01

The National Ignition Facility (NIF) is a 192-beam laser facility presently under construction at Lawrence Livermore National Laboratory. When completed, NIF will be a 1.8-MJ, 500-TW ultraviolet laser system. Its missions are to obtain fusion ignition of deuterium-tritium plasmas in ICF (Inertial Confinement Fusion) targets and to perform high energy density experiments in support of the U.S. nuclear weapons stockpile. The NIF facility will consist of 2 laser bays, 4 capacitor areas, 2 laser switchyards, the target area and the building core. The laser is configured in 4 clusters of 48 beams, 2 in each laser bay. Four of the NIF beams have been already commissioned to demonstrate laser performance and to commission the target area including target and beam alignment and laser timing. During this time, NIF has demonstrated on a single-beam basis that it will meet its performance goals and has demonstrated its precision and flexibility for pulse shaping, pointing, timing and beam conditioning. It also performed 4 important experiments for ICF and High Energy Density Science. Presently, the project is installing production hardware to complete the project in 2009 with the goal to begin ignition experiments in 2010. An integrated plan has been developed including the NIF operations, user equipment such as diagnostics and cryogenic target capability, and experiments and calculations to meet this goal. This talk will provide NIF status, the plan to complete NIF, and the path to ignition. (authors)

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.

Ignition on the National Ignition Facility: a path towards inertial fusion energy

International Nuclear Information System (INIS)

Moses, Edward I.

2009-01-01

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0 MJ of light at the fundamental wavelength of 1053 nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications. The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus

Ignition on the National Ignition Facility: a path towards inertial fusion energy

Science.gov (United States)

Moses, Edward I.

2009-10-01

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0 MJ of light at the fundamental wavelength of 1053 nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications. The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus

Possible version of the compression degradation of the thermonuclear indirect-irradiation targets at the national ignition facility and a reason for the failure of ignition

Energy Technology Data Exchange (ETDEWEB)

Rozanov, V. B., E-mail: rozanov@sci.lebedev.ru; Vergunova, G. A., E-mail: verg@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2017-01-15

The main parameters of compression of a target and tendencies at change in the irradiation conditions are determined by analyzing the published results of experiments at the megajoule National Ignition Facility (NIF) on the compression of capsules in indirect-irradiation targets by means of the one-dimensional RADIAN program in the spherical geometry. A possible version of the “failure of ignition” of an indirect-irradiation target under the NIF conditions is attributed to radiation transfer. The application of onedimensional model to analyze the National Ignition Campaign (NIC) experiments allows identifying conditions corresponding to the future ignition regime and distinguishing them from conditions under which ignition does not occur.

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.

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

Preparing for polar-drive ignition on the National Ignition Facility

Directory of Open Access Journals (Sweden)

McKenty P.W.

2013-11-01

Full Text Available The implementation of polar drive (PD at the National Ignition Facility (NIF will enable the execution of direct-drive implosions while the facility is configured for x-ray drive. The Laboratory for Laser Energetics (LLE, in collaboration with LLNL, LANL and GA, is implementing PD on the NIF. LLE has designed and participates in the use of PD implosions for diagnostic commissioning on the NIF. LLE has an active experimental campaign to develop PD in both warm and cryogenic target experiments on OMEGA. LLE and its partners are developing a Polar Drive Project Execution Plan, which will provide a detailed outline of the requirements, resources, and timetable leading to PD-ignition experiments on the NIF.

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.

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

International Nuclear Information System (INIS)

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

2002-01-01

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

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.

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.

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

Progress Towards Ignition on the National Ignition Facility

Science.gov (United States)

Edwards, John

2012-10-01

Since completion of the National Ignition Facility (NIF) construction project in March 2009, a wide variety of diagnostics, facility infrastructure, and experimental platforms have been commissioned in pursuit of generating the conditions necessary to reach thermonuclear ignition in the laboratory via the inertial confinement approach. NIF's capabilities and infrastructure include over 50 X-ray, optical, and nuclear diagnostics systems and the ability to shoot cryogenic DT layered capsules. There are two main approaches to ICF: direct drive in which laser light impinges directly on a capsule containing a solid layer of DT fuel, and indirect drive in which the laser light is first converted to thermal X-rays. To date NIF has been conducting experiments using the indirect drive approach, injecting up to 1.8MJ of ultraviolet light (0.35 micron) into 1 cm scale cylindrical gold or gold-coated uranium, gas-filled hohlraums, to implode 1mm radius plastic capsules containing solid DT fuel layers. In order to achieve ignition conditions the implosion must be precisely controlled. The National Ignition Campaign (NIC), an international effort with the goal of demonstrating thermonuclear burn in the laboratory, is making steady progress toward this. Utilizing precision pulse-shaping experiments in early 2012 the NIC achieve fuel rhoR of approximately 1.2 gm/cm^2 with densities of around 600-800 g/cm^3 along with neutron yields within about a factor of 5 necessary to enter a regime in which alpha particle heating will become important. To achieve these results, experimental platforms were developed to carefully control key attributes of the implosion. This talk will review NIF's capabilities and the progress toward ignition, as well as the physics of ignition targets on NIF and on other facilities. Acknowledgement: this work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Review of the National Ignition Campaign 2009-2012

International Nuclear Information System (INIS)

Lindl, John; Landen, Otto; Edwards, John; Moses, Ed

2014-01-01

The National Ignition Campaign (NIC) was a multi-institution effort established under the National Nuclear Security Administration of DOE in 2005, prior to the completion of the National Ignition Facility (NIF) in 2009. The scope of the NIC was the planning and preparation for and the execution of the first 3 yr of ignition experiments (through the end of September 2012) as well as the development, fielding, qualification, and integration of the wide range of capabilities required for ignition. Besides the operation and optimization of the use of NIF, these capabilities included over 50 optical, x-ray, and nuclear diagnostic systems, target fabrication facilities, experimental platforms, and a wide range of NIF facility infrastructure. The goal of ignition experiments on the NIF is to achieve, for the first time, ignition and thermonuclear burn in the laboratory via inertial confinement fusion and to develop a platform for ignition and high energy density applications on the NIF. The goal of the NIC was to develop and integrate all of the capabilities required for a precision ignition campaign and, if possible, to demonstrate ignition and gain by the end of FY12. The goal of achieving ignition can be divided into three main challenges. The first challenge is defining specifications for the target, laser, and diagnostics with the understanding that not all ignition physics is fully understood and not all material properties are known. The second challenge is designing experiments to systematically remove these uncertainties. The third challenge is translating these experimental results into metrics designed to determine how well the experimental implosions have performed relative to expectations and requirements and to advance those metrics toward the conditions required for ignition. This paper summarizes the approach taken to address these challenges, along with the progress achieved to date and the challenges that remain. At project completion in 2009, NIF lacked

Design of a deuterium and tritium-ablator shock ignition target for the National Ignition Facility

International Nuclear Information System (INIS)

Terry, Matthew R.; Perkins, L. John; Sepke, Scott M.

2012-01-01

Shock ignition presents a viable path to ignition and high gain on the National Ignition Facility (NIF). In this paper, we describe the development of the 1D design of 0.5 MJ class, all-deuterium and tritium (fuel and ablator) shock ignition target that should be reasonably robust to Rayleigh-Taylor fluid instabilities, mistiming, and hot electron preheat. The target assumes “day one” NIF hardware and produces a yield of 31 MJ with reasonable allowances for laser backscatter, absorption efficiency, and polar drive power variation. The energetics of polar drive laser absorption require a beam configuration with half of the NIF quads dedicated to launching the ignitor shock, while the remaining quads drive the target compression. Hydrodynamic scaling of the target suggests that gains of 75 and yields 70 MJ may be possible.

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)

Status of NIF mirror technologies for completion of the NIF facility

International Nuclear Information System (INIS)

Stolz, C.J.

2008-01-01

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

Development of the re-emit technique for ICF foot symmetry tuning for indirect drive ignition on NIF

Science.gov (United States)

Dewald, Eduard; Milovich, Jose; Edwards, John; Thomas, Cliff; Kalantar, Dan; Meeker, Don; Jones, Ogden

2007-11-01

Tuning of the the symmetry of the hohlraum radiation drive for the first 2 ns of the ICF pulse on NIF will be assessed by the re-emit technique [1] which measures the instantaneous x-ray drive asymmetry based on soft x-ray imaging of the re-emission of a high-Z sphere surrogate capsule. We will discuss the design of re-emit foot symmetry tuning measurements planned on NIF and their surrogacy for ignition experiments, including assessing the residual radiation asymmetry of the patches required for soft x-ray imaging. We will present the tuning strategy and expected accuracies based on calculations, analytical estimates and first results from scaled experiments performed at the Omega laser facility. [1] N. Delamater, G. Magelssen, A. Hauer, Phys. Rev. E 53, 5241 (1996.)

NIF Laser Line Replaceable Units (LRUs)

International Nuclear Information System (INIS)

Larson, D W

2003-01-01

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

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.

Contributions of the National Ignition Facility to the development of Inertial Fusion Energy

International Nuclear Information System (INIS)

Tobin, M.; Logan, G.; Diaz De La Rubia, T.; Schrock, V.; Schultz, K.; Tokheim, R.; Abdou, M.; Bangerter, R.

1994-06-01

The Department of Energy is proposing to construct the National Ignition Facility (NIF) to embark on a program to achieve ignition and modest gain in the laboratory early in the next century. The NIF will use a ≥ 1.8-MJ, 0.35-mm laser with 192 independent beams, a fifty-fold increase over the energy of the Nova laser. System performance analyses suggest yields as great as 20 MJ may be achievable. The benefits of a micro-fusion capability in the laboratory include: essential contributions to defense programs, resolution of important Inertial Fusion Energy issues, and unparalleled conditions of energy density for basic science and technology research. We have begun to consider the role the National Ignition Facility will fill in the development of Inertial Fusion Energy. While the achievement of ignition and gain speaks for itself in terms of its impact on developing IFE, we believe there are areas of IFE development such as fusion power technology, IFE target design and fabrication, and understanding chamber dynamics, that would significantly benefit from NIF experiments. In the area of IFE target physics, ion targets will be designed using the NIF laser, and feasibility of high gain targets will be confirmed. Target chamber dynamics experiments will benefit from x-ray and debris energies that mimic in-IFE-chamber conditions. Fusion power technology will benefit from using single-shot neutron yields to measure spatial distribution of neutron heating, activation, and tritium breeding in relevant materials. IFE target systems will benefit from evaluating low-cost target fabrication techniques by testing such targets on NIF. Additionally, we believe it is feasible to inject up to four targets and engage them with the NIF laser by triggering the beams in groups of ∼50 separated in time by ∼0.1 s. Sub-ignition neutron yields would allow an indication of symmetry achieved in such proof-of-principle rep-rate experiments

Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs

International Nuclear Information System (INIS)

Clark, D. S.; Haan, S. W.; Cook, A. W.; Edwards, M. J.; Hammel, B. A.; Koning, J. M.; Marinak, M. M.

2011-01-01

Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and, most recently, experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as 2000, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to 200 on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode 1200 have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.

National NIF Diagnostic Program Fiscal Year 2002 Second Quarter Report

International Nuclear Information System (INIS)

MacGowan, B

2002-01-01

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

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

National Ignition Facility project acquisition plan

International Nuclear Information System (INIS)

Callaghan, R.W.

1996-04-01

The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility (NIF) Project. The scope of the plan describes the procurement activities and acquisition strategy for the following phases of the NIF Project, each of which receives either plant and capital equipment (PACE) or other project cost (OPC) funds: Title 1 and 2 design and Title 3 engineering (PACE); Optics manufacturing facilitization and pilot production (OPC); Convention facility construction (PACE); Procurement, installation, and acceptance testing of equipment (PACE); and Start-up (OPC). Activities that are part of the base Inertial Confinement Fusion (ICF) Program are not included in this plan. The University of California (UC), operating Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory, and Lockheed-Martin, which operates Sandia National Laboratory (SNL) and the University of Rochester Laboratory for Laser Energetics (UR-LLE), will conduct the acquisition of needed products and services in support of their assigned responsibilities within the NIF Project structure in accordance with their prime contracts with the Department of Energy (DOE). LLNL, designated as the lead Laboratory, will have responsibility for all procurements required for construction, installation, activation, and startup of the NIF

The national ignition facility performance status

Energy Technology Data Exchange (ETDEWEB)

Haynam, C.; Auerbach, J.; Bowers, M.; Di-Nicola, J.M.; Dixit, S.; Erbert, G.; Heestand, G.; Henesian, M.; Jancaitis, K.; Manes, K.; Marshall, C.; Mehta, N.; Nostrand, M.; Orth, C.; Sacks, R.; Shaw, M.; Sutton, S.; Wegner, P.; Williams, W.; Widmayer, C.; White, R.; Yang, S.; Van Wonterghem, B. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

2006-06-15

The National Ignition Facility (NIF) laser has been designed to support high energy density science, including the demonstration of fusion ignition through Inertial Confinement. NIF operated a single 'quad' of 4 beams from December 2002 through October 2004 in order to gain laser operations experience, support target experiments, and demonstrate laser performance consistent with NIF's design requirement. During this two-year period, over 400 Main Laser shots were delivered at 1{omega} to calorimeters for diagnostic calibration purposes, at 3{omega} to the Target Chamber, and at 1{omega}, 2{omega}, and 3{omega} to the precision diagnostic system (PDS). The PDS includes its own independent single beam transport system, NIF design frequency conversion hardware and optics, and laser sampling optics that deliver light to a broad range of laser diagnostics. Highlights of NIF laser performance will be discussed including the results of high energy 2{omega} and 3{omega} experiments, the use of multiple focal spot beam conditioning techniques, the reproducibility of laser performance on multiple shots, the generation on a single beam of a 3{omega} temporally shaped ignition pulse at full energy and power, and recent results on full bundle (8 beamline) performance. NIF's first quad laser performance meets or exceeds NIF's design requirements. (authors)

The National Ignition Facility Performance Status

Energy Technology Data Exchange (ETDEWEB)

Haynam, C; Auerbach, J; Nicola, J D; Dixit, S; Heestand, G; Henesian, M; Jancaitis, K; Manes, K; Marshall, C; Mehta, N; Nostrand, M; Orth, C; Sacks, R; Shaw, M; Sutton, S; Wegner, P; Williams, W; Widmayer, C; White, R; Yang, S; Van Wonterghem, B

2005-08-30

The National Ignition Facility (NIF) laser has been designed to support high energy density science (HEDS), including the demonstration of fusion ignition through Inertial Confinement. NIF operated a single ''quad'' of 4 beams from December 2002 through October 2004 in order to gain laser operations experience, support target experiments, and demonstrate laser performance consistent with NIF's design requirement. During this two-year period, over 400 Main Laser shots were delivered at 1{omega} to calorimeters for diagnostic calibration purposes, at 3{omega} to the Target Chamber, and at 1{omega}, 2{omega}, and 3{omega} to the Precision Diagnostics System (PDS). The PDS includes its own independent single beam transport system, NIF design frequency conversion hardware and optics, and laser sampling optics that deliver light to a broad range of laser diagnostics. Highlights of NIF laser performance will be discussed including the results of high energy 2{omega} and 3{omega} experiments, the use of multiple focal spot beam conditioning techniques, the reproducibility of laser performance on multiple shots, the generation on a single beam of a 3{omega} temporally shaped ignition pulse at full energy and power, and recent results on full bundle (8 beamline) performance. NIF's first quad laser performance meets or exceeds NIF's design requirements.

Construction safety program for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Cerruti, S.J.

1997-01-01

The Construction Safety Program (CSP) for NIF sets forth the responsibilities, guidelines, rules, policies and regulations for all workers involved in the construction, special equipment installation, acceptance testing, and initial activation and operation of NIF at LLNL during the construction period of NIF. During this period, all workers are required to implement measures to create a universal awareness which promotes safe practice at the work site, and which will achieve NIF`s management objectives in preventing accidents and illnesses. Construction safety for NIF is predicated on everyone performing their jobs in a manner which prevents job-related disabling injuries and illnesses. The CSP outlines the minimum environment, safety, and health (ES&H) standards, LLNL policies and the Construction Industry Institute (CII) Zero Injury Techniques requirements that all workers at the NIF construction site shall adhere to during the construction period of NIF. It identifies the safety requirements which the NIF organizational Elements, construction contractors and construction subcontractors must include in their safety plans for the construction period of NIF, and presents safety protocols and guidelines which workers shall follow to assure a safe and healthful work environment. The CSP also identifies the ES&H responsibilities of LLNL employees, non-LLNL employees, construction contractors, construction subcontractors, and various levels of management within the NIF Program at LLNL. In addition, the CSP contains the responsibilities and functions of ES&H support organizations and administrative groups, and describes their interactions with the NIF Program.

Construction safety program for the National Ignition Facility

International Nuclear Information System (INIS)

Cerruti, S.J.

1997-01-01

The Construction Safety Program (CSP) for NIF sets forth the responsibilities, guidelines, rules, policies and regulations for all workers involved in the construction, special equipment installation, acceptance testing, and initial activation and operation of NIF at LLNL during the construction period of NIF. During this period, all workers are required to implement measures to create a universal awareness which promotes safe practice at the work site, and which will achieve NIF's management objectives in preventing accidents and illnesses. Construction safety for NIF is predicated on everyone performing their jobs in a manner which prevents job-related disabling injuries and illnesses. The CSP outlines the minimum environment, safety, and health (ES ampersand H) standards, LLNL policies and the Construction Industry Institute (CII) Zero Injury Techniques requirements that all workers at the NIF construction site shall adhere to during the construction period of NIF. It identifies the safety requirements which the NIF organizational Elements, construction contractors and construction subcontractors must include in their safety plans for the construction period of NIF, and presents safety protocols and guidelines which workers shall follow to assure a safe and healthful work environment. The CSP also identifies the ES ampersand H responsibilities of LLNL employees, non-LLNL employees, construction contractors, construction subcontractors, and various levels of management within the NIF Program at LLNL. In addition, the CSP contains the responsibilities and functions of ES ampersand H support organizations and administrative groups, and describes their interactions with the NIF Program

Introduction to the National Ignition Facility

International Nuclear Information System (INIS)

Moses, E I

2004-01-01

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. NIF will be the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion and matter at extreme energy densities and pressures. NIF's energetic laser beams will compress fusion targets to conditions required for thermonuclear bum, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will study physical processes at temperatures approaching 10 8 K and 10 11 bar, conditions that exist naturally only in the interior of stars, planets and in nuclear weapons. NIF has completed the first phases of its laser commissioning program. The first four beams of NIF have generated 106 kilojoules of infrared light and over 16 kJ at the third harmonic (351 nm). NIF's target experimental systems are being commissioned and experiments have begun. This paper provides a detailed look the NIF laser systems, laser and optical performance and results from recent laser commissioning shots, and plans for commissioning diagnostics for experiments on NIF

Software quality assurance plan for the National Ignition Facility integrated computer control system

Energy Technology Data Exchange (ETDEWEB)

Woodruff, J.

1996-11-01

Quality achievement is the responsibility of the line organizations of the National Ignition Facility (NIF) Project. This Software Quality Assurance Plan (SQAP) applies to the activities of the Integrated Computer Control System (ICCS) organization and its subcontractors. The Plan describes the activities implemented by the ICCS section to achieve quality in the NIF Project`s controls software and implements the NIF Quality Assurance Program Plan (QAPP, NIF-95-499, L-15958-2) and the Department of Energy`s (DOE`s) Order 5700.6C. This SQAP governs the quality affecting activities associated with developing and deploying all control system software during the life cycle of the NIF Project.

Software quality assurance plan for the National Ignition Facility integrated computer control system

International Nuclear Information System (INIS)

Woodruff, J.

1996-11-01

Quality achievement is the responsibility of the line organizations of the National Ignition Facility (NIF) Project. This Software Quality Assurance Plan (SQAP) applies to the activities of the Integrated Computer Control System (ICCS) organization and its subcontractors. The Plan describes the activities implemented by the ICCS section to achieve quality in the NIF Project's controls software and implements the NIF Quality Assurance Program Plan (QAPP, NIF-95-499, L-15958-2) and the Department of Energy's (DOE's) Order 5700.6C. This SQAP governs the quality affecting activities associated with developing and deploying all control system software during the life cycle of the NIF Project

Preparing for polar-drive ignition on the National Ignition Facility

OpenAIRE

McKenty P.W.; Collins T.J.B.; Marozas J.A.; Kessler T.J.; Zuegel J.D.; Shoup M.J.; Craxton R.S.; Marshall F.J.; Shvydky A.; Skupsky S.; Goncharov V.N.; Radha P.B.; Epstein R.; Sangster T.C.; Meyerhofer D.D.

2013-01-01

The implementation of polar drive (PD) at the National Ignition Facility (NIF) will enable the execution of direct-drive implosions while the facility is configured for x-ray drive. The Laboratory for Laser Energetics (LLE), in collaboration with LLNL, LANL and GA, is implementing PD on the NIF. LLE has designed and participates in the use of PD implosions for diagnostic commissioning on the NIF. LLE has an active experimental campaign to develop PD in both warm and cryogenic target experimen...

Shock timing technique for the National Ignition Facility

International Nuclear Information System (INIS)

Munro, David H.; Celliers, Peter M.; Collins, Gilbert W.; Gold, David M.; Silva, Luiz B. da; Haan, Steven W.; Cauble, Robert C.; Hammel, Bruce A.; Hsing, Warren W.

2001-01-01

Among the final shots at the Nova laser [Campbell et al., Rev. Sci. Instrum. 57, 2101 (1986)] was a series testing the VISAR (velocity interferometry system for any reflector) technique that will be the primary diagnostic for timing the shocks in a NIF (National Ignition Facility) ignition capsule. At Nova, the VISAR technique worked over the range of shock strengths and with the precision required for the NIF shock timing job--shock velocities in liquid D 2 from 12 to 65 μm/ns with better than 2% accuracy. VISAR images showed stronger shocks overtaking weaker ones, which is the basis of the plan for setting the pulse shape for the NIF ignition campaign. The technique is so precise that VISAR measurements may also play a role in certifying beam-to-beam and shot-to-shot repeatability of NIF laser pulses

Radiological assessments for the National Ignition Facility

International Nuclear Information System (INIS)

Hong, Kou-John; Lazaro, M.A.

1996-01-01

The potential radiological impacts of the National Ignition Facility (NIF), a proposed facility for fusion ignition and high energy density experiments, were assessed for five candidate sites to assist in site selection. The GENII computer program was used to model releases of radionuclides during normal NIF operations and a postulated accident and to calculate radiation doses to the public. Health risks were estimated by converting the estimated doses into health effects using a standard cancer fatality risk factor. The greatest calculated radiation dose was less than one thousandth of a percent of the dose received from natural background radiation; no cancer fatalities would be expected to occur in the public as the result of normal operations. The highest dose conservatively estimated to result from a postulated accident could lead to one in one million risk of cancer

NIF Ignition Target 3D Point Design

Energy Technology Data Exchange (ETDEWEB)

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

2008-11-05

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

Tritium and ignition target management at the National Ignition Facility.

Science.gov (United States)

Draggoo, Vaughn

2013-06-01

Isotopic mixtures of hydrogen constitute the basic fuel for fusion targets of the National Ignition Facility (NIF). A typical NIF fusion target shot requires approximately 0.5 mmoles of hydrogen gas and as much as 750 GBq (20 Ci) of 3H. Isotopic mix ratios are specified according to the experimental shot/test plan and the associated test objectives. The hydrogen isotopic concentrations, absolute amounts, gas purity, configuration of the target, and the physical configuration of the NIF facility are all parameters and conditions that must be managed to ensure the quality and safety of operations. An essential and key step in the preparation of an ignition target is the formation of a ~60 μm thick hydrogen "ice" layer on the inner surface of the target capsule. The Cryogenic Target Positioning System (Cryo-Tarpos) provides gas handling, cyro-cooling, x-ray imaging systems, and related instrumentation to control the volumes and temperatures of the multiphase (solid, liquid, and gas) hydrogen as the gas is condensed to liquid, admitted to the capsule, and frozen as a single spherical crystal of hydrogen in the capsule. The hydrogen fuel gas is prepared in discrete 1.7 cc aliquots in the LLNL Tritium Facility for each ignition shot. Post-shot hydrogen gas is recovered in the NIF Tritium Processing System (TPS). Gas handling systems, instrumentation and analytic equipment, material accounting information systems, and the shot planning systems must work together to ensure that operational and safety requirements are met.

Technical documentation in support of the project-specific analysis for construction and operation of the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Lazaro, M.A.; Vinikour, W. [Argonne National Lab., IL (United States). Environmental Assessment Div.; Allison, T. [Argonne National Lab., IL (United States). Decision and Information Sciences Div.] [and others

1996-09-01

This document provides information that supports or supplements the data and impact analyses presented in the National Ignition Facility (NIF) Project-Specific Analysis (PSA). The purposes of NIF are to achieve fusion ignition in the laboratory for the first time with inertial confinement fusion (ICF) technology and to conduct high- energy-density experiments ins support of national security and civilian application. NIF is an important element in the DOE`s science-based SSM Program, a key mission of which is to ensure the reliability of the nation`s enduring stockpile of nuclear weapons. NIF would also advance the knowledge of basic and applied high-energy- density science and bring the nation a large step closer to developing fusion energy for civilian use. The NIF PSA includes evaluations of the potential environmental impacts of constructing and operating the facility at one of five candidate site and for two design options.

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.

Construction safety program for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Cerruti, S.J.

1997-06-26

The Construction Safety Program (CSP) for NIF sets forth the responsibilities, guidelines, rules, policies and regulations for all workers involved in the construction, special equipment installation, acceptance testing, and initial activation and operation of NIF at LLNL during the construction period of NIF.

Construction safety program for the National Ignition Facility

International Nuclear Information System (INIS)

Cerruti, S.J.

1997-01-01

The Construction Safety Program (CSP) for NIF sets forth the responsibilities, guidelines, rules, policies and regulations for all workers involved in the construction, special equipment installation, acceptance testing, and initial activation and operation of NIF at LLNL during the construction period of NIF

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

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

International Nuclear Information System (INIS)

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

2007-01-01

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

Development of IFE target systems on the NIF

International Nuclear Information System (INIS)

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

1995-01-01

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

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

Science.gov (United States)

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

2017-01-01

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

Status of the National Ignition Facility Integrated Computer Control System (ICCS) on the Path to Ignition

International Nuclear Information System (INIS)

Lagin, L J; Bettenhauasen, R C; Bowers, G A; Carey, R W; Edwards, O D; Estes, C M; Demaret, R D; Ferguson, S W; Fisher, J M; Ho, J C; Ludwigsen, A P; Mathisen, D G; Marshall, C D; Matone, J M; McGuigan, D L; Sanchez, R J; Shelton, R T; Stout, E A; Tekle, E; Townsend, S L; Van Arsdall, P J; Wilson, E F

2007-01-01

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility under construction that will contain a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for multiple experimental diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. NIF's laser beams are designed to compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. NIF is comprised of 24 independent bundles of 8 beams each using laser hardware that is modularized into more than 6,000 line replaceable units such as optical assemblies, laser amplifiers, and multifunction sensor packages containing 60,000 control and diagnostic points. NIF is operated by the large-scale Integrated Computer Control System (ICCS) in an architecture partitioned by bundle and distributed among over 800 front-end processors and 50 supervisory servers. NIF's automated control subsystems are built from a common object-oriented software framework based on CORBA distribution that deploys the software across the computer network and achieves interoperation between different languages and target architectures. A shot automation framework has been deployed during the past year to orchestrate and automate shots performed at the NIF using the ICCS. In December 2006, a full cluster of 48 beams of NIF was fired simultaneously, demonstrating that the independent bundle control system will scale to full scale of 192 beams. At present, 72 beams have been commissioned and have demonstrated 1.4-Megajoule capability of infrared light. During the next two years, the control system will be expanded to include automation of target area systems including final optics, target positioners and

Status of the National Ignition Facility Integrated Computer Control System (ICCS) on the path to ignition

International Nuclear Information System (INIS)

Lagin, L.J.; Bettenhausen, R.C.; Bowers, G.A.; Carey, R.W.; Edwards, O.D.; Estes, C.M.; Demaret, R.D.; Ferguson, S.W.; Fisher, J.M.; Ho, J.C.; Ludwigsen, A.P.; Mathisen, D.G.; Marshall, C.D.; Matone, J.T.; McGuigan, D.L.; Sanchez, R.J.; Stout, E.A.; Tekle, E.A.; Townsend, S.L.; Van Arsdall, P.J.

2008-01-01

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility under construction that will contain a 192-beam, 1.8-MJ, 500-TW, ultraviolet laser system together with a 10-m diameter target chamber with room for multiple experimental diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. NIF's laser beams are designed to compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. NIF is comprised of 24 independent bundles of eight beams each using laser hardware that is modularized into more than 6000 line replaceable units such as optical assemblies, laser amplifiers, and multi-function sensor packages containing 60,000 control and diagnostic points. NIF is operated by the large-scale Integrated Computer Control System (ICCS) in an architecture partitioned by bundle and distributed among over 800 front-end processors and 50 supervisory servers. NIF's automated control subsystems are built from a common object-oriented software framework based on CORBA distribution that deploys the software across the computer network and achieves interoperation between different languages and target architectures. A shot automation framework has been deployed during the past year to orchestrate and automate shots performed at the NIF using the ICCS. In December 2006, a full cluster of 48 beams of NIF was fired simultaneously, demonstrating that the independent bundle control system will scale to full scale of 192 beams. At present, 72 beams have been commissioned and have demonstrated 1.4-MJ capability of infrared light. During the next 2 years, the control system will be expanded in preparation for project completion in 2009 to include automation of target area systems including final optics

Progress towards ignition on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Edwards, M. J.; Patel, P. K.; Lindl, J. D.; Atherton, L. J.; Glenzer, S. H.; Haan, S. W.; Landen, O. L.; Moses, E. I.; Springer, P. T.; Benedetti, R.; Bernstein, L.; Bleuel, D. L.; Bradley, D. K.; Caggiano, J. A.; Callahan, D. A.; Celliers, P. M.; Cerjan, C. J.; Clark, D. S.; Collins, G. W.; Dewald, E. L. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); and others

2013-07-15

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory includes a precision laser system now capable of delivering 1.8 MJ at 500 TW of 0.35-μm light to a target. NIF has been operational since March 2009. A variety of experiments have been completed in support of NIF's mission areas: national security, fundamental science, and inertial fusion energy. NIF capabilities and infrastructure are in place to support its missions with nearly 60 X-ray, optical, and nuclear diagnostic systems. A primary goal of the National Ignition Campaign (NIC) on the NIF was to implode a low-Z capsule filled with ∼0.2 mg of deuterium-tritium (DT) fuel via laser indirect-drive inertial confinement fusion and demonstrate fusion ignition and propagating thermonuclear burn with a net energy gain of ∼5–10 (fusion yield/input laser energy). This requires assembling the DT fuel into a dense shell of ∼1000 g/cm{sup 3} with an areal density (ρR) of ∼1.5 g/cm{sup 2}, surrounding a lower density hot spot with a temperature of ∼10 keV and a ρR ∼0.3 g/cm{sup 2}, or approximately an α-particle range. Achieving these conditions demand precise control of laser and target parameters to allow a low adiabat, high convergence implosion with low ablator fuel mix. We have demonstrated implosion and compressed fuel conditions at ∼80–90% for most point design values independently, but not at the same time. The nuclear yield is a factor of ∼3–10× below the simulated values and a similar factor below the alpha dominated regime. This paper will discuss the experimental trends, the possible causes of the degraded performance (the off-set from the simulations), and the plan to understand and resolve the underlying physics issues.

Conceptual design of the National Ignition Facility

International Nuclear Information System (INIS)

Paisner, J.A.; Kumpan, S.A.; Lowdermilk, W.H.; Boyes, J.D.; Sorem, M.

1995-01-01

DOE commissioned a Conceptual Design Report (CDR) for the National Ignition Facility (NIF) in January 1993 as part of a Key Decision Zero (KDO), justification of Mission Need. Motivated by the progress to date by the Inertial Confinement Fusion (ICF) program in meeting the Nova Technical Contract goals established by the National Academy of Sciences in 1989, the Secretary requested a design using a solid-state laser driver operating at the third harmonic (0.35 μm) of neodymium (Nd) glass. The participating ICF laboratories signed a Memorandum of Agreement in August 1993, and established a Project organization, including a technical team from the Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratories (SNL), and the Laboratory for Laser Energetics at the University of Rochester. Since then, we completed the NIF conceptual design, based on standard construction at a generic DOE Defense Program's site, and issued a 7,000-page, 27-volume CDR in May 1994.2 Over the course of the conceptual design study, several other key documents were generated, including a Facilities Requirements Document, a Conceptual Design Scope and Plan, a Target Physics Design Document, a Laser Design Cost Basis Document, a Functional Requirements Document, an Experimental Plan for Indirect Drive Ignition, and a Preliminary Hazards Analysis (PHA) Document. DOE used the PHA to categorize the NIF as a low-hazard, non-nuclear facility. On October 21, 1994 the Secretary of Energy issued a Key Decision One (KD1) for the NIF, which approved the Project and authorized DOE to request Office of Management and Budget-approval for congressional line-item FY 1996 NIF funding for preliminary engineering design and for National Environmental Policy Act activities. In addition, the Secretary declared Livermore as the preferred site for constructing the NIF. The Project will cost approximately $1.1 billion and will be completed at the end of FY 2002

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.

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

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.

Risk management plan for the National Ignition Facility

International Nuclear Information System (INIS)

Brereton, S.; Lane, M.; Smith, C.; Yatabe, J.

1998-01-01

The National Ignition Facility (NIF) is a U.S. Department of Energy inertial confinement laser fusion facility, currently under construction at the Lawrence Livermore National Laboratory (LLNL). NIF is a critical tool for the Department of Energy (DOE) science- based Stockpile Stewardship and Management Program. In addition, it represents a major step towards realizing inertial confinement fusion as a source of energy. The NIF will focus 192 laser beams onto spherical targets containing a mixture of deuterium and tritium, causing them to implode. This will create the high temperatures and pressures necessary for these targets to undergo fusion. The plan is for NIF to achieve ignition (i.e., self-heating of the fuel) and energy gain (i.e., more fusion energy produced than laser energy deposited) in the laboratory for the first time. A Risk Management Plan was prepared for the NIF design and construction Project. The plan was prepared in accordance with the DOE Life Cycle Asset Management Good Practice Guide. The objectives of the plan were to: (1) identify the risks to the completion of the Project in terms of meeting technical and regulatory requirements, cost, and schedule, (2) assess the risks in terms of likelihood of occurrence and their impact potential relative to technical performance, ES ampersand H (environment, safety and health), costs, and schedule, and (3) address each risk in terms of suitable risk management measures. Major risk elements were identified for the NIF Project. A risk assessment methodology was developed, which was utilized to rank the Project risks with respect to one another. Those elements presenting greater risk were readily identified by this process. This paper describes that methodology and the results

On the Fielding of a High Gain, Shock-Ignited Target on the National Ignitiion Facility in the Near Term

International Nuclear Information System (INIS)

Perkins, L.J.; Betti, R.; Schurtz, G.P.; Craxton, R.S.; Dunne, A.M.; LaFortune, K.N.; Schmitt, A.J.; McKenty, P.W.; Bailey, D.S.; Lambert, M.A.; Ribeyre, X.; Theobald, W.R.; Strozzi, D.J.; Harding, D.R.; Casner, A.; Atzemi, S.; Erbert, G.V.; Andersen, K.S.; Murakami, M.; Comley, A.J.; Cook, R.C.; Stephens, R.B.

2010-01-01

Shock ignition, a new concept for igniting thermonuclear fuel, offers the possibility for a near-term (∼3-4 years) test of high gain inertial confinement fusion on the National Ignition Facility at less than 1MJ drive energy and without the need for new laser hardware. In shock ignition, compressed fusion fuel is separately ignited by a strong spherically converging shock and, because capsule implosion velocities are significantly lower than those required for conventional hotpot ignition, fusion energy gains of ∼60 may be achievable on NIF at laser drive energies around ∼0.5MJ. Because of the simple all-DT target design, its in-flight robustness, the potential need for only 1D SSD beam smoothing, minimal early time LPI preheat, and use of present (indirect drive) laser hardware, this target may be easier to field on NIF than a conventional (polar) direct drive hotspot ignition target. Like fast ignition, shock ignition has the potential for high fusion yields at low drive energy, but requires only a single laser with less demanding timing and spatial focusing requirements. Of course, conventional symmetry and stability constraints still apply. In this paper we present initial target performance simulations, delineate the critical issues and describe the immediate-term R and D program that must be performed in order to test the potential of a high gain shock ignition target on NIF in the near term.

Progress Toward Ignition on the National Ignition Facility

International Nuclear Information System (INIS)

Kauffman, R.L.

2011-01-01

The principal approach to ignition on the National Ignition Facility (NIF) is indirect drive. A schematic of an ignition target is shown in Figure 1. The laser beams are focused through laser entrance holes at each end of a high-Z cylindrical case, or hohlraum. The lasers irradiate the hohlraum walls producing x-rays that ablate and compress the fuel capsule in the center of the hohlraum. The hohlraum is made of Au, U, or other high-Z material. For ignition targets, the hohlraum is ∼0.5 cm diameter by ∼1 cm in length. The hohlraum absorbs the incident laser energy producing x-rays for symmetrically imploding the capsule. The fuel capsule is a ∼2-mm-diameter spherical shell of CH, Be, or C filled with DT fuel. The DT fuel is in the form of a cryogenic layer on the inside of the capsule. X-rays ablate the outside of the capsule, producing a spherical implosion. The imploding shell stagnates in the center, igniting the DT fuel. NIC has overseen installation of all of the hardware for performing ignition experiments, including commissioning of approximately 50 diagnostic systems in NIF. The diagnostics measure scattered optical light, x-rays from the hohlraum over the energy range from 100 eV to 500 keV, and x-rays, neutrons, and charged particles from the implosion. An example of a diagnostic is the Magnetic Recoil Spectrometer (MRS) built by a collaboration of scientists from MIT, UR-LLE, and LLNL shown in Figure 2. MRS measures the neutron spectrum from the implosion, providing information on the neutron yield and areal density that are metrics of the quality of the implosion. Experiments on NIF extend ICF research to unexplored regimes in target physics. NIF can produce more than 50 times the laser energy and more than 20 times the power of any previous ICF facility. Ignition scale hohlraum targets are three to four times larger than targets used at smaller facilities, and the ignition drive pulses are two to five times longer. The larger targets and longer

IGNITOR, ITER and NIF in the Context of the World Effort on Fusion Burning Plasmas

Science.gov (United States)

Azizov, E.; Coppi, B.; Velikhov, E.

2012-03-01

As of last summer, the ITER program has been recognized as being directed at providing an ``International Platform for Fusion Technology.'' Then, the two experimental programs that have the explicit goal to approach ignition conditions with D-T plasmas are NIF and IGNITOR. NIF, the National Ignition Facility, is based on the inertial confinement principle using a laser system capable of delivering 1.6 MJ and is being operated in Livermore. IGNITOR will be operated by the Kurchatov Institute within the research center of Troitzk presently owned by Rosatom and involves a high level collaboration between Italy and Russia. For this, Ignitor has been defined as a Flagship Project by Italy and the construction of its core has been funded. The Ignitor design is based on the experimental results obtained by the high field line of experiments carried out at MIT, within the Alcator Program, and in Italy within the Frascati Torus Program. A wide set of experiments in Japan, on high density plasmas, in the US, Russia and Europe have produced plasma physics results and technology developments that have guided the evolution of the Ignitor design. The main theoretical plasma physics issues to be dealt with in connection with this program are discussed.

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.

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.

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

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.

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

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.

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

International Nuclear Information System (INIS)

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

2005-01-01

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

Impacts assessment for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Bay Area Economics

1996-12-01

This report documents the economic and other impacts that will be created by the National Ignition Facility (NIF) construction and ongoing operation, as well as the impacts that may be created by new technologies that may be developed as a result of NIF development and operation.

Target designs for energetics experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Meezan, N B; Glenzer, S H; Suter, L J

2008-01-01

The goal of the first hohlraum energetics experiments on the National Ignition Facility (NIF) [G. H. Miller et al, Optical Eng. 43, 2841 (2004)] is to select the hohlraum design for the first ignition experiments. Sub-scale hohlraums heated by 96 of the 192 laser beams on the NIF are used to emulate the laser-plasma interaction behavior of ignition hohlraums. These 'plasma emulator' targets are 70% scale versions of the 1.05 MJ, 300 eV ignition hohlraum and have the same energy-density as the full-scale ignition designs. Radiation-hydrodynamics simulations show that the sub-scale target is a good emulator of plasma conditions inside the ignition hohlraum, reproducing density n e within 10% and temperature T e within 15% along a laser beam path. Linear backscatter gain analysis shows the backscatter risk to be comparable to that of the ignition target. A successful energetics campaign will allow the National Ignition Campaign to focus its efforts on optimizing ignition hohlraums with efficient laser coupling

Safety overview of the National Ignition Facility

International Nuclear Information System (INIS)

Brereton, S.J.; McLouth, L.; Odell, B.; Singh, M.; Tobin, M.; Trent, M.

1996-01-01

The National Ignition Facility (NIF) is a proposed US Department of Energy inertial confinement laser fusion facility. The candidate sites for locating the NIF are: Los Alamos National Laboratory, Sandia National Laboratory, the Nevada Test Site, and Lawrence Livermore National Laboratory (LLNL), the preferred site. The NIF will operate by focusing 192 laser beams onto a tiny deuterium- tritium target located at the center of a spherical target chamber. The NIF mission is to achieve inertial confinement fusion (ICF) ignition, access physical conditions in matter of interest to nuclear weapons physics, provide an above ground simulation capability for nuclear weapons effects testing, and contribute to the development of inertial fusion for electrical power production. The NIF has been classified as a radiological, low hazard facility on the basis of a preliminary hazards analysis and according to the DOE methodology for facility classification. This requires that a safety analysis be prepared under DOE Order 5481.1B, Safety Analysis and Review System. A draft Preliminary Safety Analysis Report (PSAR) has been written, and this will be finalized later in 1996. This paper summarizes the safety issues associated with the operation of the NIF. It provides an overview of the hazards, estimates maximum routine and accidental exposures for the preferred site of LLNL, and concludes that the risks from NIF operations are low

Characterizing high energy spectra of NIF ignition Hohlraums using a differentially filtered high energy multipinhole x-ray imager.

Science.gov (United States)

Park, Hye-Sook; Dewald, E D; Glenzer, S; Kalantar, D H; Kilkenny, J D; MacGowan, B J; Maddox, B R; Milovich, J L; Prasad, R R; Remington, B A; Robey, H F; Thomas, C A

2010-10-01

Understanding hot electron distributions generated inside Hohlraums is important to the national ignition campaign for controlling implosion symmetry and sources of preheat. While direct imaging of hot electrons is difficult, their spatial distribution and spectrum can be deduced by detecting high energy x-rays generated as they interact with target materials. We used an array of 18 pinholes with four independent filter combinations to image entire Hohlraums with a magnification of 0.87× during the Hohlraum energetics campaign on NIF. Comparing our results with Hohlraum simulations indicates that the characteristic 10-40 keV hot electrons are mainly generated from backscattered laser-plasma interactions rather than from Hohlraum hydrodynamics.

The National Ignition Facility and the Promise of Inertial Fusion Energy

International Nuclear Information System (INIS)

Moses, E.I.

2010-01-01

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world's most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm 3 -sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm 3 , and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices, as well as the advantages of both pure fusion and fusion-fission schemes. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

The National Ignition Facility and the Promise of Inertial Fusion Energy

Energy Technology Data Exchange (ETDEWEB)

Moses, E I

2010-12-13

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world's most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices, as well as the advantages of both pure fusion and fusion-fission schemes. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

Control System For Cryogenic THD Layering At The National Ignition Facility

International Nuclear Information System (INIS)

Fedorov, M.; Blubaugh, J.; Edwards, O.; Mauvais, M.; Sanchez, R.; Wilson, B.

2011-01-01

The National Ignition Facility (NIF) is the world largest and most energetic laser system for Inertial Confinement Fusion (ICF). In 2010, NIF began ignition experiments using cryogenically cooled targets containing layers of the tritium-hydrogen-deuterium (THD) fuel. The 75 (micro)m thick layer is formed inside of the 2 mm target capsule at temperatures of approximately 18 K. The ICF target designs require sub-micron smoothness of the THD ice layers. Formation of such layers is still an active research area, requiring a flexible control system capable of executing the evolving layering protocols. This task is performed by the Cryogenic Target Subsystem (CTS) of the NIF Integrated Computer Control System (ICCS). The CTS provides cryogenic temperature control with the 1 mK resolution required for beta-layering and for the thermal gradient fill of the capsule. The CTS also includes a 3-axis x-ray radiography engine for phase contrast imaging of the ice layers inside of the plastic and beryllium capsules. In addition to automatic control engines, CTS is integrated with the Matlab interactive programming environment to allow flexibility in experimental layering protocols. The CTS Layering Matlab Toolbox provides the tools for layer image analysis, system characterization and cryogenic control. The CTS Layering Report tool generates qualification metrics of the layers, such as concentricity of the layer and roughness of the growth boundary grooves. The CTS activities are automatically coordinated with other NIF controls in the carefully orchestrated NIF Shot Sequence.

Fault tolerance of the NIF power conditioning system

International Nuclear Information System (INIS)

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

1995-01-01

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

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.

National Ignition Facility project acquisition plan revision 1

International Nuclear Information System (INIS)

Clobes, A.R.

1996-01-01

The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility M Project. It was prepared for the NIP Prood Office by the NIF Procurement Manager

Mini-chamber, an advanced protection concept for NIF

International Nuclear Information System (INIS)

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

1996-01-01

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

National Ignition Facility site requirements

International Nuclear Information System (INIS)

1996-07-01

The Site Requirements (SR) provide bases for identification of candidate host sites for the National Ignition Facility (NIF) and for the generation of data regarding potential actual locations for the facilities. The SR supplements the NIF Functional Requirements (FR) with information needed for preparation of responses to queries for input to HQ DOE site evaluation. The queries are to include both documents and explicit requirements for the potential host site responses. The Sr includes information extracted from the NIF FR (for convenience), data based on design approaches, and needs for physical and organization infrastructure for a fully operational NIF. The FR and SR describe requirements that may require new construction or may be met by use or modification of existing facilities. The SR do not establish requirements for NIF design or construction project planning. The SR document does not constitute an element of the NIF technical baseline

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.

Automated optics inspection analysis for NIF

Energy Technology Data Exchange (ETDEWEB)

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

2012-12-15

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

Power conditioning development for the National Ignition Facility

International Nuclear Information System (INIS)

Newton, M.A.; Larson, D.W.; Wilson, J.M.; Harjes, H.C.; Savage, M.E.; Anderson, R.L.

1996-10-01

The National Ignition Facility (NIF) is a high energy glass laser system and target chamber that will be used for research in inertial confinement fusion. The 192 beams of the NIF laser system are pumped by over 8600 Xenon flashlamps. The power conditioning system for NIF must deliver nearly 300 MJ of energy to the flashlamps in a cost effective and reliable manner. The present system design has over 200 capacitive energy storage modules that store approximately 1.7 MJ each and deliver that energy through a single switch assembly to 20 parallel sets of two series flashlamps. Although there are many possible system designs, few will meet the aggressive cost goals necessary to make the system affordable. Sandia National Laboratory (SNL) and Lawrence Livermore National Laboratory (LLNL) are developing the system and component technologies that will be required to build the power conditioning system for the National Ignition Facility. This paper will describe the ongoing development activities for the NIF power conditioning system

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

Energy Technology Data Exchange (ETDEWEB)

Nora, R.; Betti, R.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Fusion Science Center, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Anderson, K. S.; Shvydky, A.; Marozas, J. A.; Collins, T. J. B.; Radha, P. B.; Hu, S. X.; Epstein, R.; Marshall, F. J.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); McCrory, R. L. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

2014-05-15

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Core science and technology development plan for indirect-drive ICF ignition. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Powell, H.T.; Kilkenny, J.D. [eds.

1995-12-01

To define the development work needed to support inertial confinement fusion (ICF) program goals, the authors have assembled this Core Science and Technology (CS and T) Plan that encompasses nearly all science research and technology development in the ICF program. The objective of the CS and T Plan described here is to identify the development work needed to ensure the success of advanced ICF facilities, in particular the National Ignition Facility (NIF). This plan is intended as a framework to facilitate planning and coordination of future ICF programmatic activities. The CS and T Plan covers all elements of the ICF program including laser technology, optic manufacturing, target chamber, target diagnostics, target design and theory, target components and fabrication, and target physics experiments. The CS and T Plan has been divided into these seven different technology development areas, and they are used as level-1 categories in a work breakdown structure (WBS) to facilitate the organization of all activities in this plan. The scope of the CS and T Plan includes all research and development required to support the NIF leading up to the activation and initial operation as an indirect-drive facility. In each of the CS and T main development areas, the authors describe the technology and issues that need to be addressed to achieve NIF performance goals. To resolve all issues and achieve objectives, an extensive assortment of tasks must be performed in a coordinated and timely manner. The authors describe these activities and present planning schedules that detail the flow of work to be performed over a 10-year period corresponding to estimated time needed to demonstrate fusion ignition with the NIF. Besides the benefits to the ICF program, the authors also discuss how the commercial sector and the nuclear weapons science may profit from the proposed research and development program.

Core science and technology development plan for indirect-drive ICF ignition. Revision 1

International Nuclear Information System (INIS)

Powell, H.T.; Kilkenny, J.D.

1995-12-01

To define the development work needed to support inertial confinement fusion (ICF) program goals, the authors have assembled this Core Science and Technology (CS and T) Plan that encompasses nearly all science research and technology development in the ICF program. The objective of the CS and T Plan described here is to identify the development work needed to ensure the success of advanced ICF facilities, in particular the National Ignition Facility (NIF). This plan is intended as a framework to facilitate planning and coordination of future ICF programmatic activities. The CS and T Plan covers all elements of the ICF program including laser technology, optic manufacturing, target chamber, target diagnostics, target design and theory, target components and fabrication, and target physics experiments. The CS and T Plan has been divided into these seven different technology development areas, and they are used as level-1 categories in a work breakdown structure (WBS) to facilitate the organization of all activities in this plan. The scope of the CS and T Plan includes all research and development required to support the NIF leading up to the activation and initial operation as an indirect-drive facility. In each of the CS and T main development areas, the authors describe the technology and issues that need to be addressed to achieve NIF performance goals. To resolve all issues and achieve objectives, an extensive assortment of tasks must be performed in a coordinated and timely manner. The authors describe these activities and present planning schedules that detail the flow of work to be performed over a 10-year period corresponding to estimated time needed to demonstrate fusion ignition with the NIF. Besides the benefits to the ICF program, the authors also discuss how the commercial sector and the nuclear weapons science may profit from the proposed research and development program

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

Absolute measurement of the DT primary neutron yield on the National Ignition Facility

Directory of Open Access Journals (Sweden)

Leeper R.J.

2013-11-01

Full Text Available The measurement of the absolute neutron yield produced in inertial confinement fusion target experiments conducted on the National Ignition Facility (NIF is essential in benchmarking progress towards the goal of achieving ignition on this facility. This paper describes three independent diagnostic techniques that have been developed to make accurate and precise DT neutron yield measurements on the NIF.

Shock timing on the National Ignition Facility: First Experiments

International Nuclear Information System (INIS)

Celliers, P.M.; Robey, H.F.; Boehly, T.R.; Alger, E.; Azevedo, S.; Berzins, L.V.; Bhandarkar, S.D.; Bowers, M.W.; Brereton, S.J.; Callahan, D.; Castro, C.; Chandrasekaran, H.; Choate, C.; Clark, D.; Coffee, K.R.; Datte, P.S.; Dewald, E.L.; DiNicola, P.; Dixit, S.; Doeppner, T.; Dzenitis, E.; Edwards, M.J.; Eggert, J.H.; Fair, J.; Farley, D.R.; Frieders, G.; Gibson, C.R.; Giraldez, E.; Haan, S.; Haid, B.; Hamza, A.V.; Haynam, C.; Hicks, D.G.; Holunga, D.M.; Horner, J.B.; Jancaitis, K.; Jones, O.S.; Kalantar, D.; Kline, J.L.; Krauter, K.G.; Kroll, J.J.; LaFortune, K.N.; Pape, S.L.; Malsbury, T.; Maypoles, E.R.; Milovich, J.L.; Moody, J.D.; Moreno, K.; Munro, D.H.; Nikroo, A.; Olson, R.E.; Parham, T.; Pollaine, S.; Radousky, H.B.; Ross, G.F.; Sater, J.; Schneider, M.B.; Shaw, M.; Smith, R.F.; Thomas, C.A.; Throop, A.; Town, R.J.; Trummer, D.; Van Wonterghem, B.M.; Walters, C.F.; Widmann, K.; Widmayer, C.; Young, B.K.; Atherton, L.J.; Collins, G.W.; Landen, O.L.; Lindl, J.D.; MacGowan, B.J.; Meyerhofer, D.D.; Moses, E.I.

2011-01-01

An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF) was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a reentrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

National Ignition Facility Title II Design Plan

International Nuclear Information System (INIS)

Kumpan, S

1997-01-01

This National Ignition Facility (NIF) Title II Design Plan defines the work to be performed by the NIF Project Team between November 1996, when the U.S. Department of Energy (DOE) reviewed Title I design and authorized the initiation of Title H design and specific long-lead procurements, and September 1998, when Title 11 design will be completed

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.

NIF optical specifications - the importance of the RMS gradient specification

International Nuclear Information System (INIS)

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

1998-01-01

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

Role of the laboratory for laser energetics in the National Ignition Facility Project

International Nuclear Information System (INIS)

Soures, J.M.; Loucks, S.J.; McCrory, R.L.

1996-01-01

The National Ignition Facility (NIF) is a 192-beam, 1.8-MJ (ultraviolet) laser facility that is currently planned to start operating in 2002. The NIF mission is to provide data critical to this Nation's science-based stockpile stewardship (SBSS) program and to advance the understanding of inertial confinement fusion and assess its potential as an energy source. The NIF project involves a collaboration among the Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), and the University of Rochester's Laboratory for Laser Energetics (UR/LLE). In this paper, the role of the University of Rochester in the research, development, and planning required to assure the success of the NIF will be presented. The principal roles of the UR/LLE in the NIF are (1) validation of the direct-drive approach to NIF using the OMEGA 60-beam, 40-kJ UV laser facility; (2) support of indirect-drive physics experiments using OMEGA in collaboration with LLNL and LANL; (3) development of plasma diagnostics for NIF; (4) development of beam-smoothing techniques; and (5) development of thin-film coatings for NIF and cryogenic-fuel-layer targets for eventual application to NIF. 3 refs., 6 figs

Large optics for the National Ignition Facility

International Nuclear Information System (INIS)

Baisden, P.

2015-01-01

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.

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.

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

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.

NIF total neutron yield diagnostic

International Nuclear Information System (INIS)

Cooper, Gary W.; Ruiz, Carlos L.

2001-01-01

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

Shock timing on the National Ignition Facility: First experiments

Directory of Open Access Journals (Sweden)

Celliers P.M.

2013-11-01

Full Text Available An experimental campaign to tune the initial shock compression sequence of capsule implosions on the National Ignition Facility (NIF was initiated in late 2010. The experiments use a NIF ignition-scale hohlraum and capsule that employs a re-entrant cone to provide optical access to the shocks as they propagate in the liquid deuterium-filled capsule interior. The strength and timing of the shock sequence is diagnosed with velocity interferometry that provides target performance data used to set the pulse shape for ignition capsule implosions that follow. From the start, these measurements yielded significant new information on target performance, leading to improvements in the target design. We describe the results and interpretation of the initial tuning experiments.

Direct-drive–ignition designs with mid-Z ablators

Energy Technology Data Exchange (ETDEWEB)

Lafon, M.; Betti, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Anderson, K. S.; Collins, T. J. B.; Epstein, R.; McKenty, P. W.; Myatt, J. F.; Shvydky, A.; Skupsky, S. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2015-03-15

Achieving thermonuclear ignition using direct laser illumination relies on the capability to accelerate spherical shells to high implosion velocities while maintaining shell integrity. Ablator materials of moderate atomic number Z reduce the detrimental effects of laser–plasma instabilities in direct-drive implosions. To validate the physics of moderate-Z ablator materials for ignition target designs on the National Ignition Facility (NIF), hydro-equivalent targets are designed using pure plastic (CH), high-density carbon, and glass (SiO{sub 2}) ablators. The hydrodynamic stability of these targets is investigated through two-dimensional (2D) single-mode and multimode simulations. The overall stability of these targets to laser-imprint perturbations and low-mode asymmetries makes it possible to design high-gain targets. Designs using polar-drive illumination are developed within the NIF laser system specifications. Mid-Z ablator targets are an attractive candidate for direct-drive ignition since they present better overall performance than plastic ablator targets through reduced laser–plasma instabilities and a similar hydrodynamic stability.

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

Polar-Drive Experiments at the National Ignition Facility

Science.gov (United States)

Hohenberger, M.

2014-10-01

To support direct-drive inertial confinement fusion (ICF) experiments at the National Ignition Facility (NIF) in its indirect-drive beam configuration, the polar-drive (PD) concept has been proposed. It requires direct-drive-specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments testing the performance of ignition-relevant PD implosions at the NIF have been performed. The goal of these early experiments was to develop a stable, warm implosion platform to investigate laser deposition and laser-plasma instabilities at ignition-relevant plasma conditions, and to develop and validate ignition-relevant models of laser deposition and heat conduction. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Warm, 2.2-mm-diam plastic shells were imploded with total drive energies ranging from ~ 350 to 750 kJ with peak powers of 60 to 180 TW and peak on-target intensities from 4 ×1014 to 1 . 2 ×1015 W/cm2. Results from these initial experiments are presented, including the level of hot-electron preheat, and implosion symmetry and shell trajectory inferred via self-emission imaging and backlighting. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray trace to model oblique beams, and a model for cross-beam energy transfer (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

National Ignition Facility design focuses on optics

International Nuclear Information System (INIS)

Hogan, W.J.; Atherton, L.J.; Paisner, J.A.

1996-01-01

Sometime in the year 2002, scientists at the National Ignition Facility (NIF) will focus 192 separate high-power ultraviolet laser beams onto a tiny capsule of deuterium and tritium, heating and compressing the material until it ignites and burns with a burst of fusion energy. The mission of NIF, which will contain the largest laser in the world, is to obtain fusion ignition and gain and to use inertial confinement fusion capabilities in nuclear weapons science experiments. The physics data provided by NIF experiments will help scientists ensure nuclear weapons reliability without the need for actual weapons tests; basic sciences such as astrophysics will also benefit. The facility faces stringent weapons-physics user requirements demanding peak pulse powers greater than 750 TW at 0.35 microm (only 500 TW is required for target ignition), pulse durations of 0.1 to 20 ns, beam steering on the order of several degrees, and target isolation from residual 1- and 0.5-microm radiation. Additional requirements include 50% fractional encircled beam energy in a 100-microm-diameter spot, with 95% encircled in a 200-microm spot. The weapons-effects community requires 1- and 0.5-microm light on target, beam steering to widely spaced targets, a target chamber accommodating oversized objects, well-shielded diagnostic areas, and elimination of stray light in the target chamber. The beamline design, amplifier configuration and requirements for optics are discussed here

Progress toward ignition with direct-drive

International Nuclear Information System (INIS)

McCrory, R.L. Jr.

1993-01-01

The goal of the direct-drive laser fusion program is to validate high-performance, direct-drive targets. A decision to construct a direct-drive capability on the proposed 1-to-2-MJ National Ignition Facility (NIF) in the USA will be based on target physics experiments conducted on the OMEGA Upgrade laser system now under construction at the LLE. The OMEGA Upgrade will provide up to 30 kJ of UV laser energy in precisely shaped pulses with irradiation nonuniformities in the range of 1 pc. to 2 pc. An understanding and predictive capability for direct-drive targets are required to assure reliable estimates of ignition and gain with 1-2 MJ of incident laser energy. This paper reviews the target physics efforts currently underway to assess the critical physics issues of direct-drive ICF; plans for the experimental program to be carried out on the OMEGA Upgrade laser are also presented. 14 figs., 15 refs

The National Ignition Facility 2007 laser performance status

Energy Technology Data Exchange (ETDEWEB)

Haynam, C A; Sacks, R A; Wegner, P J; Bowers, M W; Dixit, S N; Erbert, G V; Heestand, G M; Henesian, M A; Hermann, M R; Jancaitis, K S; Manes, K R; Marshall, C D; Mehta, N C; Menapace, J; Nostrand, M C; Orth, C D; Shaw, M J; Sutton, S B; Williams, W H; Widmayer, C C [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA, 94550 (United States)], E-mail: haynam1@llnl.gov (and others)

2008-05-15

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory contains a 192-beam 3.6 MJ neodymium glass laser that is frequency converted to 351nm light. It has been designed to support high energy density science (HEDS), including the demonstration of fusion ignition through Inertial Confinement. To meet this goal, laser design criteria include the ability to generate pulses of up to 1.8-MJ total energy at 351nm, with peak power of 500 TW and precisely-controlled temporal pulse shapes spanning two orders of magnitude. The focal spot fluence distribution of these pulses is conditioned, through a combination of special optics in the 1{omega} (1053 nm) portion of the laser (continuous phase plates), smoothing by spectral dispersion (SSD), and the overlapping of multiple beams with orthogonal polarization (polarization smoothing). In 2006 and 2007, a series of measurements were performed on the NIF laser, at both 1{omega} and 3{omega} (351 nm). When scaled to full 192-beam operation, these results lend confidence to the claim that NIF will meet its laser performance design criteria and that it will be able to simultaneously deliver the temporal pulse shaping, focal spot conditioning, peak power, shot-to-shot reproducibility, and power balance requirements of indirect-drive fusion ignition campaigns. We discuss the plans and status of NIF's commissioning, and the nature and results of these measurement campaigns.

U.S. ICF program: status and accomplishments

Science.gov (United States)

Crandall, D. H.; Keane, Christopher J.; Bieg, K.; Powers, L. V.; Sluyter, Marshall M.

1997-12-01

The paper describes the structure of the ICF program and highlights its latest results. The pre-construction activities of the National Ignition Facility (NIF) project have increased their momentum as a result of the recent Congressional decision to appropriate the requested funds for Fiscal Year 1997 to continue the project. The facility is an essential part of United States nuclear defense program in the absence of underground testing. The near-term goal of the U.S. ICF program is to achieve ignition in the laboratory (i.e. NIF) and to achieve high yield in the future. This paper describes some current results in ignition physics and related areas, as well as the progress in some new concepts that may have application to high yield. International collaborations that have been developed in recent years have contributed to the increased rate of progress. The paper closes with a summary of current and planned international initiatives.

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

Developing the Physics Basis of Fast Ignition Experiments at Future Large Fusion-class lasers

International Nuclear Information System (INIS)

Mackinnon, A J; Key, M H; Hatchett, S; MacPhee, A G; Foord, M; Tabak, M; Town, R J; Patel, P K

2008-01-01

The Fast Ignition (FI) concept for Inertial Confinement Fusion (ICF) has the potential to provide a significant advance in the technical attractiveness of Inertial Fusion Energy (IFE) reactors. FI differs from conventional 'central hot spot' (CHS) target ignition by using one driver (laser, heavy ion beam or Z-pinch) to create a dense fuel and a separate ultra-short, ultra-intense laser beam to ignite the dense core. FI targets can burn with ∼ 3X lower density fuel than CHS targets, resulting in (all other things being equal) lower required compression energy, relaxed drive symmetry, relaxed target smoothness tolerances, and, importantly, higher gain. The short, intense ignition pulse that drives this process interacts with extremely high energy density plasmas; the physics that controls this interaction is only now becoming accessible in the lab, and is still not well understood. The attraction of obtaining higher gains in smaller facilities has led to a worldwide explosion of effort in the studies of FI. In particular, two new US facilities to be completed in 2009/2010, OMEGA/OMEGA EP and NIF-ARC (as well as others overseas) will include FI investigations as part of their program. These new facilities will be able to approach FI conditions much more closely than heretofore using direct drive (dd) for OMEGA/OMEGA EP and indirect drive (id) for NIF-ARC. This LDRD has provided the physics basis for the development of the detailed design for integrated Fast ignition experiments on these facilities on the 2010/2011 timescale. A strategic initiative LDRD has now been formed to carry out integrated experiments using NIF ARC beams to heat a full scale FI assembled core by the end of 2010

The National Ignition Facility

International Nuclear Information System (INIS)

Hogan, W.J.; Moses, E.; Warner, B.; Sorem, M.; Soures, J.M.

2001-01-01

The National Ignition Facility (NIF) is the largest construction project ever undertaken at Lawrence Livermore National Laboratory (LLNL). NIF consists of 192 forty-centimeter-square laser beams and a 10-m-diameter target chamber. NIF is being designed and built by an LLNL-led team from Los Alamos National Laboratory, Sandia National Laboratories, the University of Rochester, and LLNL. Physical construction began in 1997. The Laser and Target Area Building and the Optics Assembly Building were the first major construction activities, and despite several unforeseen obstacles, the buildings are now 92% complete and have been done on time and within cost. Prototype component development and testing has proceeded in parallel. Optics vendors have installed full-scale production lines and have done prototype production runs. The assembly and integration of the beampath infrastructure has been reconsidered and a new approach has been developed. This paper will discuss the status of the NIF project and the plans for completion. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-05-15

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

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

International Nuclear Information System (INIS)

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

2008-01-01

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

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

Los Alamos contribution to target diagnostics on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Mack, J.M.; Baker, D.A.; Caldwell, S.E. [and others

1994-07-01

The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ``phase I diagnostics.`` Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given.

Los Alamos contribution to target diagnostics on the National Ignition Facility

International Nuclear Information System (INIS)

Mack, J.M.; Baker, D.A.; Caldwell, S.E.

1994-01-01

The National Ignition Facility (NIF) will have a large suite of sophisticated target diagnostics. This will allow thoroughly diagnosed experiments to be performed both at the ignition and pre-ignition levels. As part of the national effort Los Alamos National Laboratory will design, construct and implement a number of diagnostics for the NIF. This paper describes Los Alamos contributions to the ''phase I diagnostics.'' Phase I represents the most fundamental and basic measurement systems that will form the core for most work on the NIF. The Los Alamos effort falls into four categories: moderate to hard X-ray (time resolved imaging neutron spectroscopy- primarily with neutron time of flight devices; burn diagnostics utilizing gamma ray measurements; testing measurement concepts on the TRIDENT laser system at Los Alamos. Because of the high blast, debris and radiation environment, the design of high resolution X-ray imaging systems present significant challenges. Systems with close target proximity require special protection and methods for such protection is described. The system design specifications based on expected target performance parameters is also described. Diagnosis of nuclear yield and burn will be crucial to the NIF operation. Nuclear reaction diagnosis utilizing both neutron and gamma ray detection is discussed. The Los Alamos TRIDENT laser system will be used extensively for the development of new measurement concepts and diagnostic instrumentation. Some its potential roles in the development of diagnostics for NIF are given

Progress in the US ICF Program

International Nuclear Information System (INIS)

Sluyter, M.M.

1996-01-01

The ICF Program has made exciting progress in the past year towards its goal of the achievement of fusion ignition and gain in the laboratory. A series of experiments on the Nova laser facility has resolved the major technical issues involved in the design of an ignition target. A baseline target has been designed that ignites (calculationally) with a nominal drive of 1.35 MJ (at 351 nm). In parallel, a detailed conceptual design for the National Ignition Facility (NIF-a 1.8 MJ glass laser) has been completed and a successful laser beam line prototype has validated its architecture. As a result, the Department of Energy has requested funding for the preliminary design for the NIF from the U.S. Congress. With these developments, the attainment of the long-sought goal is in sight. In addition, two new laser facilities (OMEGA Upgrade and Nike) have recently been completed, and ion-beam fusion driver development is encouraging. Their availability expands the capability of the program to perform advanced ICF and plasma experiments. copyright 1996 American Institute of Physics

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.

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...

Hydrodynamic instabilities in beryllium targets for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

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

2014-09-15

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

Safety analysis and risk assessment of the National Ignition Facility

International Nuclear Information System (INIS)

Brereton, S.; McLouth, L.; Odell, B.

1996-01-01

The National Ignition Facility (NIF) is a proposed U.S. Department of Energy inertial confinement laser fusion facility. The candidate sites for locating the NIF are: Los Alamos National Laboratory, Sandia National Laboratory, the Nevada Test Site, and Lawrence Livermore National Laboratory (LLNL), the preferred site. The NIF will operate by focusing 192 laser beams onto a tiny deuterium-tritium target located at the center of a spherical target chamber. The NIF mission is to achieve inertial confinement fusion (ICF) ignition, access physical conditions in matter of interest to nuclear weapons physics, provide an above ground simulation capability for nuclear weapons effects testing, and contribute to the development of inertial fusion for electrical power production. The NIF has been classified as a radiological, low hazard facility on the basis of a preliminary hazards analysis and according to the DOE methodology for facility classification. This requires that a safety analysis be prepared under DOE Order 5481.1B, Safety Analysis and Review System. A draft Preliminary Safety Analysis Report (PSAR) has been written, and this will be finalized later in 1996. This paper summarizes the safety issues associated with the operation of the NIF and the methodology used to study them. It provides a summary of the methodology, an overview of the hazards, estimates maximum routine and accidental exposures for the preferred site of LLNL, and concludes that the risks from NIF operations are low

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.

Backscatter measurements for NIF ignition targets (invited)

Energy Technology Data Exchange (ETDEWEB)

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

2010-10-15

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

Backscatter measurements for NIF ignition targets (invited)

International Nuclear Information System (INIS)

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

2010-01-01

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

Confinement of ignition and yield on the National Ignition Facility

International Nuclear Information System (INIS)

Tobin, M.; Karpenko, V.; Foley, D.; Anderson, A.; Burnham, A.; Reitz, T.; Latkowski, J.; Bernat, T.

1996-01-01

The National Ignition Facility Target Areas and Experimental Systems has reached mid-Title I design. Performance requirements for the Target Area are reviewed and design changes since the Conceptual Design Report are discussed. Development activities confirm a 5-m radius chamber and the viability of a boron carbide first wall. A scheme for cryogenic target integration with the NIF Target Area is presented

Hydrodynamic modeling and simulations of shock ignition thresholds

Directory of Open Access Journals (Sweden)

Lafon M.

2013-11-01

Full Text Available The Shock Ignition (SI scheme [1] offers to reduce the laser requirements by relaxing the implosion phase to sub-ignition velocities and later adding an intense laser spike. Depending on laser energy, target characteristics and implosion velocity, high gains are expected [2,3]. Relevant intensities for scaled targets imploded in the velocity range from 150 to 400 km/s are defined at ignition thresholds. A range of moderate implosion velocities is specified to match safe implosions. These conditions for target design are then inferred for relevant NIF and LMJ shock-ignited targets.

A Computational Study of Re-emission Balls Proposed for the NIF Ignition Symmetry Campaign

Science.gov (United States)

Meeker, D. J.; Amendt, P.; Dewald, E.; Edwards, M. J.; Milovich, J.; Suter, L.

2006-10-01

Re-emission balls are high-Z spheres used as surrogates for ICF ignition capsules to detect and correct early-time asymmetries of radiation flux at the target. Emission from these balls mimics the incoming flux due to their high albedo, providing a useful symmetry diagnostic. Experiments on Nova by LANL [1] and LLNL used bismuth (Bi) as the surrogate, selected for its high albedo and insensitivity to the fluorescence of the gold hohlraum wall. We are studying the applicability of these capsules to the NIF symmetry campaign as a potential tuning mechanism to achieve the accuracies required for symmetric implosions. We will describe 2-D simulations that predict the emission of the Bi ball as a function of time, frequency, and spatial distribution, as well as quantifying surrogacy of re- emission balls. Using several tuning examples, we will show the resolution expected from this diagnostic. Suggestions for extending this technique to longer times will be discussed as well as describing 3-D effects from diagnostic viewing ports and an opposing hole to eliminate competing wall emission. [1] Delamater, Phys. Rev. E 53, 5240 (1996), Magelssen, Phys. Rev. E 57, 4663 (1998)

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.

The neutron imaging diagnostic at NIF (invited)

Energy Technology Data Exchange (ETDEWEB)

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

2012-10-15

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

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.

Inertial Confinement Fusion: steady progress towards ignition and high gain (summary talk)

International Nuclear Information System (INIS)

Basko, M.M.

2005-01-01

Most important recent advances in inertial confinement fusion (ICF) are highlighted. With the construction of the NIF and LMJ facilities, and a number of improvements in the target design, the conventional indirect-drive approach is making a steady progress towards demonstration of ignition and high gain. The development of the polar direct-drive concept made also the prospects for direct-drive ignition on the NIF extremely favorable. A substantial progress has been reported from the Institute of Laser Engineering in Osaka on exploration of the fast-ignition approach to ICF. Parallel to that, multi-wire Z-pinches have become a competitive driver option for achieving ignition at a lowest possible cost. In heavy ion fusion, experiments have been devoted so far to studying the generation, transport, and final focusing of high-current ion beams. A new concept for a power plant with a heavy-ion driver, based on a cylindrical direct-drive target compressed and ignited (in the fast-ignition mode) by two separate beams of very energetic (E i > or ∼ 0.5 GeV/u) heavy ions, has been proposed. (author)

Analysis of NIF experiments with the minimal energy implosion model

Energy Technology Data Exchange (ETDEWEB)

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

2015-08-15

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

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

Systems reliability analysis for the national ignition facility

International Nuclear Information System (INIS)

Majumdar, K.C.; Annese, C.E.; MacIntyre, A.T.; Sicherman, A.

1996-01-01

A Reliability, Availability and Maintainability (RAM) analysis was initiated for the National Ignition Facility (NIF). The NIF is an inertial confinement fusion research facility designed to achieve controlled thermonuclear reaction; the preferred site for the NIF is the Lawrence Livermore National Laboratory (LLNL). The NIF RAM analysis has three purposes: (1) to allocate top level reliability and availability goals for the systems, (2) to develop an operability model for optimum maintainability, and (3) to determine the achievability of the allocated goals of the RAM parameters for the NIF systems and the facility operation as a whole. An allocation model assigns the reliability and availability goals for front line and support systems by a top-down approach; reliability analysis uses a bottom-up approach to determine the system reliability and availability from component level to system level

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

Status and plans of the united states ICF program

Science.gov (United States)

Matzen, M. K.

2008-05-01

Inertial confinement fusion research in the United States focuses on demonstrating ignition on the NIF at the beginning of the next decade and on broad high energy density science (HEDS) research. Three facilities (OMEGA EP, the refurbished Z, and NIF) will be completed in the next two years. The US approach emphasizes lasers and pulsed power and both direct and indirect drive. Since IFSA 2005 in Biarritz, France significant advances have been made towards demonstrating ignition in a joint effort by LLNL, LLE, LANL, SNL, and GA. An active HEDS research program will also be pursued on these new facilities.

Status and plans of the united states ICF program

International Nuclear Information System (INIS)

Matzen, M K

2008-01-01

Inertial confinement fusion research in the United States focuses on demonstrating ignition on the NIF at the beginning of the next decade and on broad high energy density science (HEDS) research. Three facilities (OMEGA EP, the refurbished Z, and NIF) will be completed in the next two years. The US approach emphasizes lasers and pulsed power and both direct and indirect drive. Since IFSA 2005 in Biarritz, France significant advances have been made towards demonstrating ignition in a joint effort by LLNL, LLE, LANL, SNL, and GA. An active HEDS research program will also be pursued on these new facilities

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.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Progress on the physics of ignition for radiation driven inertial confinement fusion (ICF) targets

International Nuclear Information System (INIS)

Lindl, J.D.; Marinak, M.M.

1996-09-01

Extensive modeling of proposed National Ignition Facility (NIF) ignition targets has resulted in a variety of targets using different materials in the fuel shell, using driving temperatures which range from 250-300 eV, and requiring energies from 15 W/cm 2 for this type of hohlraum. The symmetry in Nova gas- filled hohlraums is affected by the gas fill. A large body of evidence now exists which indicates that this effect is due to laser beam filamentation which can be largely controlled by beam smoothing. We present here the firs 3-D simulations of hydrodynamic instability for the NIF point design capsule. These simulations, with the HYDRA radiation hydrodynamics code, indicate that spikes can penetrate up to 10 μm into the 30μm radius hot spot before ignition is quenched. Using capsules whose surface is modified by laser ablation, Nova experiments have been used to quantify the degradation of implosions subject to near NIF levels of hydrodynamic instability

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

Inertial confinement fusion: steady progress towards ignition and high gain (summary talk)

International Nuclear Information System (INIS)

Basko, M.M.

2005-01-01

Based on the results presented at the 20th IAEA Fusion Energy Conference 2004, this paper highlights the most important recent advances in inertial confinement fusion (ICF). With the construction of the National Ignition Facility (NIF) and the Laser Megajoule facility and many improvements in the target design, the conventional indirect-drive approach is advancing steadily towards the demonstration of ignition and high gain. The development of the polar direct-drive concept also made the prospects for direct-drive ignition on the NIF very favourable. Substantial progress was reported on the exploration of the fast-ignition approach to ICF. Parallel to that, multi-wire Z-pinches have become a competitive driver option for achieving ignition at the lowest possible cost. In heavy-ion fusion, experiments have been devoted so far to studying the generation, transport, and final focusing of high-current ion beams. A new concept for a power plant with a heavy-ion driver, based on a cylindrical direct-drive target compressed and ignited (in the fast-ignition mode) by two separate beams of very energetic (E i ≥ 0.5 GeV u -1 ) heavy ions, has been proposed

Inertial confinement fusion: steady progress towards ignition and high gain (summary talk)

Science.gov (United States)

Basko, M. M.

2005-10-01

Based on the results presented at the 20th IAEA Fusion Energy Conference 2004, this paper highlights the most important recent advances in inertial confinement fusion (ICF). With the construction of the National Ignition Facility (NIF) and the Laser Mégajoule facility and many improvements in the target design, the conventional indirect-drive approach is advancing steadily towards the demonstration of ignition and high gain. The development of the polar direct-drive concept also made the prospects for direct-drive ignition on the NIF very favourable. Substantial progress was reported on the exploration of the fast-ignition approach to ICF. Parallel to that, multi-wire Z-pinches have become a competitive driver option for achieving ignition at the lowest possible cost. In heavy-ion fusion, experiments have been devoted so far to studying the generation, transport, and final focusing of high-current ion beams. A new concept for a power plant with a heavy-ion driver, based on a cylindrical direct-drive target compressed and ignited (in the fast-ignition mode) by two separate beams of very energetic (Ei>~ 0.5 GeV u-1) heavy ions, has been proposed.

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

Science.gov (United States)

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

2008-05-01

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

Safety and environmental process for the design and construction of the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Brereton, S.J., LLNL

1998-05-27

The National Ignition Facility (NIF) is a U.S. Department of Energy (DOE) laser fusion experimental facility currently under construction at the Lawrence Livermore National Laboratory (LLNL). This paper describes the safety and environmental processes followed by NIF during the design and construction activities.

Integrated thermodynamic model for ignition target performance

Directory of Open Access Journals (Sweden)

Springer P.T.

2013-11-01

Full Text Available We have derived a 3-dimensional synthetic model for NIF implosion conditions, by predicting and optimizing fits to a broad set of x-ray and nuclear diagnostics obtained on each shot. By matching x-ray images, burn width, neutron time-of-flight ion temperature, yield, and fuel ρr, we obtain nearly unique constraints on conditions in the hotspot and fuel in a model that is entirely consistent with the observables. This model allows us to determine hotspot density, pressure, areal density (ρr, total energy, and other ignition-relevant parameters not available from any single diagnostic. This article describes the model and its application to National Ignition Facility (NIF tritium–hydrogen–deuterium (THD and DT implosion data, and provides an explanation for the large yield and ρr degradation compared to numerical code predictions.

Capsule physics comparison of National Ignition Facility implosion designs using plastic, high density carbon, and beryllium ablators

Science.gov (United States)

Clark, D. S.; Kritcher, A. L.; Yi, S. A.; Zylstra, A. B.; Haan, S. W.; Weber, C. R.

2018-03-01

Indirect drive implosion experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] have now tested three different ablator materials: glow discharge polymer plastic, high density carbon, and beryllium. How do these different ablators compare in current and proposed implosion experiments on NIF? What are the relative advantages and disadvantages of each? This paper compares these different ablator options in capsule-only simulations of current NIF experiments and potential 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 on NIF.

National Ignition Facility environmental protection systems

International Nuclear Information System (INIS)

Mintz, J.M.; Reitz, T.C.; Tobin, M.T.

1994-06-01

The conceptual design of Environmental Protection Systems (EPS) for the National Ignition Facility (NIF) is described. These systems encompass tritium and activated debris handling, chamber, debris shield and general decontamination, neutron and gamma monitoring, and radioactive, hazardous and mixed waste handling. Key performance specifications met by EPS designs include limiting the tritium inventory to 300 Ci and total tritium release from NIF facilities to less than 10 Ci/yr. Total radiation doses attributable to NIF shall remain below 10 mrem/yr for any member of the general public and 500 mrem/yr for NIF staff. ALARA-based design features and operational procedures will, in most cases, result in much lower measured exposures. Waste minimization, improved cycle time and reduced exposures all result from the proposed CO2 robotic arm cleaning and decontamination system, while effective tritium control is achieved through a modern system design based on double containment and the proven detritiation technology

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.

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.

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

International Nuclear Information System (INIS)

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

2008-01-01

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 γ rays to relativistic electrons to UV/visible Cherenkov radiation.

Gain measurements on a prototype NIF/LMJ amplifier pump cavity

International Nuclear Information System (INIS)

Rotter, M.D.; McCracken, R.; Erlandson, A.; Guenet, M.

1996-12-01

We are currently developing large-aperture amplifiers for the National Ignition Facility (NIF) and Laser Megajoules (LMJ) lasers. These multisegment amplifiers are of the flashlamp-pumped, Nd:Glass qW and are designed to propagate a nominally 36 cm square beam. The apertures within a particular amplifier bundle are arranged in a four-high by two-wide configuration and utilize two side lamp arrays and a central flashlamp array for pumping. The configuration is very similar to that used in the Beamlet laser, a single-beam prototype for the NIF/LMJ lasers, which has four apertures arranged in a two- high by two-wide configuration

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

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)

Assessing the prospects for achieving double-shell ignition on the National Ignition Facility using vacuum hohlraums

Science.gov (United States)

Amendt, Peter

2006-10-01

The goal of demonstrating ignition on the National Ignition Facility (NIF) has motivated a revisit of double-shell (DS) [1] targets as a complementary path to the baseline cryogenic single-shell approach [2]. Benefits of DS targets include room-temperature deuterium-tritium (DT) fuel preparation, minimal hohlraum-plasma-mediated laser backscatter, low threshold-ignition temperatures (4 keV) for relaxed hohlraum x-ray flux asymmetry tolerances [3], and loose shock timing requirements. On the other hand, DS ignition presents several challenges, including room-temperature containment of high-pressure DT (790 atm) in the inner shell; strict concentricity requirements on the two shells; development of nanoporous, low-density, metallic foams for structural support of the inner shell and hydrodynamic instability mitigation; and effective control of perturbation growth on the high-Atwood number interface between the DT fuel and the high-Z inner shell. Recent progress in DS ignition target designs using vacuum hohlraums is described, offering the potential for low levels of laser backscatter from stimulated Raman and Brillouin processes. In addition, vacuum hohlraums have the operational advantages of room temperature fielding and fabrication simplicity, as well as benefiting from extensive benchmarking on the Nova and Omega laser facilities. As an alternative to standard cylindrical hohlraums, a rugby-shaped geometry is also introduced that may provide energetics and symmetry tuning benefits for more robust DS designs with yields exceeding 10 MJ for 2 MJ of 3w laser energy. The recent progress in hohlraum designs and required advanced materials development are scheduled to culminate in a prototype demonstration of a NIF-scale ignition-ready DS in 2007. [1] P. Amendt et al., PoP 9, 2221 (2002). [2] J.D. Lindl et al., PoP 11, 339 (2004). [3] M.N. Chizhkov et al., Laser Part. Beams 23, 261 (2005). In collaboration with C. Cerjan, A. Hamza, J. Milovich and H. Robey.

Demonstration of Efficient Core Heating of Magnetized Fast Ignition in FIREX project

Science.gov (United States)

Johzaki, Tomoyuki

2017-10-01

Extensive theoretical and experimental research in the FIREX ``I project over the past decade revealed that the large angular divergence of the laser generated electron beam is one of the most critical problems inhibiting efficient core heating in electron-driven fast ignition. To solve this problem, beam guiding using externally applied kilo-tesla class magnetic field was proposed, and its feasibility has recently been numerically demonstrated. In 2016, integrated experiments at ILE Osaka University demonstrated core heating efficiencies reaching > 5 % and heated core temperatures of 1.7 keV. In these experiments, a kilo-tesla class magnetic field was applied to a cone-attached Cu(II) oleate spherical solid target by using a laser-driven capacitor-coil. The target was then imploded by G-XII laser and heated by the PW-class LFEX laser. The heating efficiency was evaluated by measuring the number of Cu-K- α photons emitted. The heated core temperature was estimated by the X-ray intensity ratio of Cu Li-like and He-like emission lines. To understand the detailed dynamics of the core heating process, we carried out integrated simulations using the FI3 code system. Effects of magnetic fields on the implosion and electron beam transport, detailed core heating dynamics, and the resultant heating efficiency and core temperature will be presented. I will also discuss the prospect for an ignition-scale design of magnetized fast ignition using a solid ball target. This work is partially supported by JSPA KAKENHI Grant Number JP16H02245, JP26400532, JP15K21767, JP26400532, JP16K05638 and is performed with the support and the auspices of the NIFS Collaboration Research program (NIFS12KUGK057, NIFS15KUGK087).

Implementation of ISO 10110 optics drawing standards for the National Ignition Facility

International Nuclear Information System (INIS)

Aikens, D. M.; English, R. E.; Wang, D. Y.

1999-01-01

The National Ignition Facility (NIF) project elected to implement ISO 10110 standard for the specifications of NIF optics drawings in 1996. More than 7,000 NIF large optics and 20,000 NIF small optics will be manufactured based on ISO 10110 indications. ISO 10110 standard meets many of the needs of the NIF optics specifications. It allows the optical engineer to quantify and clearly communicate the desired optical specifications. While no single drawing standard specifies all the requirements of high energy laser system, a combination of ISO 10110 standard with detailed notes make it possible to apply international drawing standards to the NIF laser system. This paper will briefly describe LLNL's interpretation and implementation of the ISO 10110 drawing standard, present some examples of NIF optics drawings, and discuss pros and cons of the indications from the perspective of this application. Emphasis will be given to the surface imperfection specifications, known as 5/, for the NIF optics

Implementation of ISO 10110 optics drawing standards for the National Ignition Facility

Science.gov (United States)

Wang, David Y.; English, R. Edward, Jr.; Aikens, David M.

1999-11-01

The National Ignition Facility (NIF) project elected to implement ISO 10110 standard for the specifications of NIF optics drawings in 1996. More than 7,000 NIF large optics and 20,000 NIF small optics will be manufactured based on ISO 10110 indications. ISO 10110 standard meets many of the needs of the NIF optics specifications. It allows the optical engineer to quantify and clearly communicate the desired optical specifications. While no single drawing standard specifies all the requirements of high energy laser system, a combination of ISO 10110 standard with detailed notes make it possible to apply international drawing standards to the NIF laser system. This paper will briefly describe LLNL's interpretation and implementation of the ISO 10110 drawing standard, present some examples of NIF optics drawings, and discuss pros and cons of the indications from the perspective of this application. Emphasis will be given to the surface imperfection specifications, known as 5/, for the NIF optics.

Power conditioning for the National Ignition Facility

International Nuclear Information System (INIS)

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

1994-01-01

A cost-effective, 320-MJ power-conditioning system has been completed for the proposed National Ignition Facility (NIF). The design features include metallized dielectric capacitors, a simple topology, and large (1.6-MJ) module size. Experimental results address the technical risks associated with the design

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.

Advances in NIF Shock Timing Experiments

Science.gov (United States)

Robey, Harry

2012-10-01

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

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.

National Ignition Facility Control and Information System Operational Tools

International Nuclear Information System (INIS)

Marshall, C.D.; Beeler, R.G.; Bowers, G.A.; Carey, R.W.; Fisher, J.M.; Foxworthy, C.B.; Frazier, T.M.; Mathisen, D.G.; Lagin, L.J.; Rhodes, J.J.; Shaw, M.J.

2009-01-01

The National Ignition Facility (NIF) in Livermore, California, is the world's highest-energy laser fusion system and one of the premier large scale scientific projects in the United States. The system is designed to setup and fire a laser shot to a fusion ignition or high energy density target at rates up to a shot every 4 hours. NIF has 192 laser beams delivering up to 1.8 MJ of energy to a ∼2 mm target that is planned to produce >100 billion atm of pressure and temperatures of >100 million degrees centigrade. NIF is housed in a ten-story building footprint the size of three football fields as shown in Fig. 1. Commissioning was recently completed and NIF will be formally dedicated at Lawrence Livermore National Laboratory on May 29, 2009. The control system has 60,000 hardware controls points and employs 2 million lines of control system code. The control room has highly automated equipment setup prior to firing laser system shots. This automation has a data driven implementation that is conducive to dynamic modification and optimization depending on the shot goals defined by the end user experimenters. NIF has extensive facility machine history and infrastructure maintenance workflow tools both under development and deployed. An extensive operational tools suite has been developed to support facility operations including experimental shot setup, machine readiness, machine health and safety, and machine history. The following paragraphs discuss the current state and future upgrades to these four categories of operational tools.

Optimized beryllium target design for indirectly driven inertial confinement fusion experiments on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Simakov, Andrei N., E-mail: simakov@lanl.gov; Wilson, Douglas C.; Yi, Sunghwan A.; Kline, John L.; Batha, Steven H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, Daniel S.; Milovich, Jose L.; Salmonson, Jay D. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

2014-02-15

For indirect drive inertial confinement fusion, Beryllium (Be) ablators offer a number of important advantages as compared with other ablator materials, e.g., plastic and high density carbon. In particular, the low opacity and relatively high density of Be lead to higher rocket efficiencies giving a higher fuel implosion velocity for a given X-ray drive; and to higher ablation velocities providing more ablative stabilization and reducing the effect of hydrodynamic instabilities on the implosion performance. Be ablator advantages provide a larger target design optimization space and can significantly improve the National Ignition Facility (NIF) [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] ignition margin. Herein, we summarize the Be advantages, briefly review NIF Be target history, and present a modern, optimized, low adiabat, Revision 6 NIF Be target design. This design takes advantage of knowledge gained from recent NIF experiments, including more realistic levels of laser-plasma energy backscatter, degraded hohlraum-capsule coupling, and the presence of cross-beam energy transfer.

First Liquid Layer Inertial Confinement Fusion Implosions at the National Ignition Facility

Science.gov (United States)

Olson, R. E.; Leeper, R. J.; Kline, J. L.; Zylstra, A. B.; Yi, S. A.; Biener, J.; Braun, T.; Kozioziemski, B. J.; Sater, J. D.; Bradley, P. A.; Peterson, R. R.; Haines, B. M.; Yin, L.; Berzak Hopkins, L. F.; Meezan, N. B.; Walters, C.; Biener, M. M.; Kong, C.; Crippen, J. W.; Kyrala, G. A.; Shah, R. C.; Herrmann, H. W.; Wilson, D. C.; Hamza, A. V.; Nikroo, A.; Batha, S. H.

2016-12-01

The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D2 and DT layer inertial confinement fusion (ICF) implosions that can access a low-to-moderate hot-spot convergence ratio (12 30 ) DT ice layer implosions. Although high CR is desirable in an idealized 1D sense, it amplifies the deleterious effects of asymmetries. To date, these asymmetries prevented the achievement of ignition at the NIF and are the major cause of simulation-experiment disagreement. In the initial liquid layer experiments, high neutron yields were achieved with CRs of 12-17, and the hot-spot formation is well understood, demonstrated by a good agreement between the experimental data and the radiation hydrodynamic simulations. These initial experiments open a new NIF experimental capability that provides an opportunity to explore the relationship between hot-spot convergence ratio and the robustness of hot-spot formation during ICF implosions.

Laser coupling to reduced-scale targets at Nif Early Light

Energy Technology Data Exchange (ETDEWEB)

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

2006-06-15

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

Three-Dimensional Simulations of Flat-Foil Laser-Imprint Experiments at the National Ignition Facility

Science.gov (United States)

Shvydky, A.; Radha, P. B.; Rosenberg, M. J.; Anderson, K. S.; Goncharov, V. N.; Marozas, J. A.; Marshall, F. J.; McKenty, P. W.; Regan, S. P.; Sangster, T. C.; Hohenberger, M.; di Nicola, J. M.; Koning, J. M.; Marinak, M. M.; Masse, L.; Karasik, M.

2017-10-01

Control of shell nonuniformities imprinted by the laser and amplified by hydrodynamic instabilities in the imploding target is critical for the success of direct-drive ignition at the National Ignition Facility (NIF). To measure a level of imprint and its reduction by the NIF smoothing by spectral dispersion (SSD), we performed experiments that employed flat CH foils driven with a single NIF beam with either no SSD or the NIF indirect-drive SSD applied to the laser pulse. Face-on x-ray radiography was used to measure optical depth variations, from which the amplitudes of the foil areal-density modulations were obtained. Results of 3-D, radiation-hydrodynamic code HYDRA simulations of the growth of the imprint-seeded perturbations are presented and compared with the experimental data. This work was supported by the U.S. Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract Number DE-AC52-07NA27344.

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).

Laser imprint and implications for direct drive ignition with the National Ignition Facility

International Nuclear Information System (INIS)

Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Remington, B.A.; Rothenberg, J.E.

1996-01-01

For direct drive ICF, nonuniformities in laser illumination can seed ripples at the ablation front in a process called imprint. Such nonuniformities will grow during the capsule implosion and can penetrate the capsule shell impede ignition, or degrade burn. We have simulated imprint for a number of experiments on tile Nova laser. Results are in generally good agreement with experimental data. We leave also simulated imprint upon National Ignition Facility (NIF) direct drive ignition capsules. Imprint modulation amplitude comparable to the intrinsic surface finish of ∼40 nm is predicted for a laser bandwidth of 0.5 THz. Ablation front modulations experience growth factors up to several thousand, carrying modulation well into the nonlinear regime. Saturation modeling predicts that the shell should remain intact at the time of peak velocity, but penetration at earlier times appears more marginal

Image processing for the Advanced Radiographic Capability (ARC) at the National Ignition Facility

Science.gov (United States)

Leach, Richard R.; Awwal, Abdul A. S.; Lowe-Webb, Roger; Miller-Kamm, Victoria; Orth, Charles; Roberts, Randy; Wilhelmsen, Karl

2016-09-01

The Advance Radiographic Capability (ARC) at the National Ignition Facility (NIF) is a laser system that employs up to four petawatt (PW) lasers to produce a sequence of short-pulse kilo-Joule laser pulses with controllable delays that generate X-rays to provide backlighting for high-density internal confinement fusion (ICF) capsule targets. Multi-frame, hard-X-ray radiography of imploding NIF capsules is a capability which is critical to the success of NIF's missions. ARC is designed to employ up to eight backlighters with tens-of-picosecond temporal resolution, to record the dynamics and produce an X-ray "motion picture" of the compression and ignition of cryogenic deuterium-tritium targets. ARC will generate tens-of-picosecond temporal resolution during the critical phases of ICF shots. Additionally, ARC supports a variety of other high energy density experiments including fast ignition studies on NIF. The automated alignment image analysis algorithms use digital camera sensor images to direct ARC beams onto the tens-of-microns scale metal wires. This paper describes the ARC automatic alignment sequence throughout the laser chain from pulse initiation to target with an emphasis on the image processing algorithms that generate the crucial alignment positions for ARC. The image processing descriptions and flow diagrams detail the alignment control loops throughout the ARC laser chain beginning in the ARC high-contrast front end (HCAFE), on into the ARC main laser area, and ending in the ARC target area.

AN UPDATE ON THE STATUS OF THE NIF POWER CONDITIONING SYSTEM

International Nuclear Information System (INIS)

Arnold, P A; Hulsey, S; Ullery, G T; Petersen, D E; Pendleton, D L; Ollis, C W; Newton, M A; Harwell, T; Cordoza, D; Hadovski, L

2007-01-01

The National Ignition Facility (NIF) Power Conditioning System provides the pulsed excitation required to drive flashlamps in the laser's optical amplifiers. Modular in design, each of the 192 Main Energy Storage Modules (MESMs) stores up to 2.2 MJ of electrical energy in its capacitor bank before delivering the energy to 20 pairs of flashlamps in a 400 (micro)s pulse (10% power points). The peak current of each MESM discharge is 0.5 MA. Production, installation, commissioning and operation of the NIF Power Conditioning continue to progress rapidly, with the goals of completing accelerated production and commissioning by early 2008, while maintaining an aggressive operation schedule. To date, more than 97% of the required modules have been assembled, shipped and installed in the facility, representing more that 380 MJ of stored energy available for driving NIF flashlamps. The MESMs have displayed outstanding reliability during daily, multiple-shift operations

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

International Nuclear Information System (INIS)

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

2002-01-01

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

LLE 2008 annual report, October 2007 - September 2008

Energy Technology Data Exchange (ETDEWEB)

None

2009-01-31

The research program at the University of Rochester’s Laboratory for Laser Energetics (LLE) focuses on inertial confinement fusion (ICF) research supporting the goal of achieving ignition on the National Ignition Facility (NIF). This program includes the full use of the OMEGA EP Laser System. Within the National Ignition Campaign (NIC), LLE is the lead laboratory for the validation of the performance of cryogenic target implosions, essential to all forms of ICF ignition. LLE has taken responsibility for a number of critical elements within the Integrated Experimental Teams (IET’s) supporting the demonstration of indirect-drive ignition on the NIF and is the lead laboratory for the validation of the polardrive approach to ignition on the NIF. LLE is also developing, testing, and building a number of diagnostics to be deployed on the NIF for the NIC.

Wavelength Detuning Cross-Beam Energy Transfer Mitigation Scheme for Direct-Drive: Modeling and Evidence from National Ignition Facility Implosions

Science.gov (United States)

Marozas, J. A.

2017-10-01

Cross-beam energy transfer (CBET) has been shown to significantly reduce the laser absorption and implosion speed in direct-drive implosion experiments on OMEGA and the National Ignition Facility (NIF). Mitigating CBET assists in achieving ignition-relevant hot-spot pressures in deuterium-tritium cryogenic OMEGA implosions. In addition, reducing CBET permits lower, more hydrodynamically stable, in-flight aspect ratio ignition designs with smaller nonuniformity growth during the acceleration phase. Detuning the wavelengths of the crossing beams is one of several techniques under investigation at the University of Rochester to mitigate CBET. This talk will describe these techniques with an emphasis on wavelength detuning. Recent experiments designed and predicted using multidimensional hydrodynamic simulations including CBET on the NIF have exploited the wavelength arrangement of the NIF beam geometry to demonstrate CBET mitigation through wavelength detuning in polar-direct-drive (PDD) implosions. Shapes and trajectories inferred from time-resolved x-ray radiography of the imploding shell, scattered-light spectra, and hard x-ray spectra generated by suprathermal electrons all indicate a reduction in CBET. These results and their implications for direct-drive ignition will be presented and discussed. In addition, hydrodynamically scaled ignition-relevant designs for OMEGA implosions exploiting wavelength detuning will be presented. Changes required to the OMEGA laser to permit wavelength detuning will be discussed. Future plans for PDD on the NIF including more-uniform implosions with CBET mitigation will be explored. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

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.

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

The design of the optical Thomson scattering diagnostic for the National Ignition Facility.

Science.gov (United States)

Datte, P S; Ross, J S; Froula, D H; Daub, K D; Galbraith, J; Glenzer, S; Hatch, B; Katz, J; Kilkenny, J; Landen, O; Manha, D; Manuel, A M; Molander, W; Montgomery, D; Moody, J; Swadling, G F; Weaver, J

2016-11-01

The National Ignition Facility (NIF) is a 192 laser beam facility designed to support the Stockpile Stewardship, High Energy Density and Inertial Confinement Fusion (ICF) programs. We report on the design of an Optical Thomson Scattering (OTS) diagnostic that has the potential to transform the community's understanding of NIF hohlraum physics by providing first principle, local, time-resolved measurements of under-dense plasma conditions. The system design allows operation with different probe laser wavelengths by manual selection of the appropriate beam splitter and gratings before the shot. A deep-UV probe beam (λ 0 -210 nm) will be used to optimize the scattered signal for plasma densities of 5 × 10 20 electrons/cm 3 while a 3ω probe will be used for experiments investigating lower density plasmas of 1 × 10 19 electrons/cm 3 . We report the phase I design of a two phase design strategy. Phase I includes the OTS telescope, spectrometer, and streak camera; these will be used to assess the background levels at NIF. Phase II will include the design and installation of a probe laser.

The US inertial confinement fusion (ICF) ignition programme and the inertial fusion energy (IFE) programme

Science.gov (United States)

Lindl, J. D.; Hammel, B. A.; Logan, B. Grant; Meyerhofer, David D.; Payne, S. A.; Sethian, John D.

2003-12-01

There has been rapid progress in inertial fusion in the past few years. This progress spans the construction of ignition facilities, a wide range of target concepts and the pursuit of integrated programmes to develop fusion energy using lasers, ion beams and z-pinches. Two ignition facilities are under construction, the national ignition facility (NIF) in the United States and the laser megajoule (LMJ) in France, and both projects are progressing towards an initial experimental capability. The laser integration line prototype beamline for LMJ and the first four beams of NIF will be available for experiments in 2003. The full 192 beam capability of NIF will be available in 2009 and ignition experiments are expected to begin shortly after that time. There is steady progress in target science and target fabrication in preparation for indirect-drive ignition experiments on NIF. Advanced target designs may lead to 5 10 times more yield than initial target designs. There has also been excellent progress on the science of ion beam and z-pinch-driven indirect-drive targets. Excellent progress on direct-drive targets has been obtained on the Omega laser at the University of Rochester. This includes improved performance of targets with a pulse shape predicted to result in reduced hydrodynamic instability. Rochester has also obtained encouraging results from initial cryogenic implosions. There is widespread interest in the science of fast ignition because of its potential for achieving higher target gain with lower driver energy and relaxed target fabrication requirements. Researchers from Osaka have achieved outstanding implosion and heating results from the Gekko XII Petawatt facility and implosions suitable for fast ignition have been tested on the Omega laser. A broad-based programme to develop lasers and ion beams for inertial fusion energy (IFE) is under way with excellent progress in drivers, chambers, target fabrication and target injection. KrF and diode pumped solid

The US inertial confinement fusion (ICF) ignition programme and the inertial fusion energy (IFE) programme

International Nuclear Information System (INIS)

Lindl, J D; Hammel, B A; Logan, B Grant; Meyerhofer, David D; Payne, S A; Sethian, John D

2003-01-01

There has been rapid progress in inertial fusion in the past few years. This progress spans the construction of ignition facilities, a wide range of target concepts and the pursuit of integrated programmes to develop fusion energy using lasers, ion beams and z-pinches. Two ignition facilities are under construction, the national ignition facility (NIF) in the United States and the laser megajoule (LMJ) in France, and both projects are progressing towards an initial experimental capability. The laser integration line prototype beamline for LMJ and the first four beams of NIF will be available for experiments in 2003. The full 192 beam capability of NIF will be available in 2009 and ignition experiments are expected to begin shortly after that time. There is steady progress in target science and target fabrication in preparation for indirect-drive ignition experiments on NIF. Advanced target designs may lead to 5-10 times more yield than initial target designs. There has also been excellent progress on the science of ion beam and z-pinch-driven indirect-drive targets. Excellent progress on direct-drive targets has been obtained on the Omega laser at the University of Rochester. This includes improved performance of targets with a pulse shape predicted to result in reduced hydrodynamic instability. Rochester has also obtained encouraging results from initial cryogenic implosions. There is widespread interest in the science of fast ignition because of its potential for achieving higher target gain with lower driver energy and relaxed target fabrication requirements. Researchers from Osaka have achieved outstanding implosion and heating results from the Gekko XII Petawatt facility and implosions suitable for fast ignition have been tested on the Omega laser. A broad-based programme to develop lasers and ion beams for inertial fusion energy (IFE) is under way with excellent progress in drivers, chambers, target fabrication and target injection. KrF and diode pumped solid

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

Polyimide capsules may hold high pressure DT fuel without cryogenic support for the National Ignition Facility indirect-drive targets

International Nuclear Information System (INIS)

Sanchez, J.J.; Letts, S.A.

1997-01-01

New target designs for the Omega upgrade laser and ignition targets in the National Ignition Facility (NIF) require thick (80 - 100 microm) cryogenic fuel layers. The Omega upgrade target will require cryogenic handling after initial fill because of the high fill pressures and the thin capsule walls. For the NIF indirectly driven targets, a larger capsule size and new materials offer hope that they can be built, filled and stored in a manner similar to the targets used in the Nova facility without requiring cryogenic handling

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)

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.

Numerical simulation of direct-drive ICF ignition in spherical geometry

International Nuclear Information System (INIS)

Yu Xiaojin

2006-01-01

The basic condition required for achieving central ignition is producing a hot spot with 10 keV temperature and 0.3 g/cm 2 surface density. Growth of hydrodynamic instability during deceleration phase will destroy the symmetric-drive, reduce the volume of central hot spot and make a harmful effect on ignition. Based on the LARED-S code, considering the thermonuclear reaction and α-particle heating, a numerical study of direct-drive ICF in spherical geometry is made. One-dimensional results agree well with the NIF ignition target designs, and show that the α-particle heating plays an important role in marginal ignition. Two-dimensional results show that the growth of hydrodynamic instability during deceleration phase makes a harmful effect on ignition. (authors)

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

International Nuclear Information System (INIS)

Ma, T.

2012-01-01

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

National Ignition Facility frequency converter development

International Nuclear Information System (INIS)

Barker, C.E.; Auerbach, J.M.; Adams, C.H.

1996-01-01

A preliminary error budget for the third harmonic converter for the National Ignition Facility (NIF) laser driver has been developed using a root-sum-square-accumulation of error sources. Such a budget sets an upper bound on the allowable magnitude of the various effects that reduce conversion efficiency. Development efforts on crystal mounting technology and crystal quality studies are discussed

Time-resolved measurements of the hot-electron population in ignition-scale experiments on the National Ignition Facility (invited)

Energy Technology Data Exchange (ETDEWEB)

Hohenberger, M., E-mail: mhoh@lle.rochester.edu; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Albert, F.; Palmer, N. E.; Döppner, T.; Divol, L.; Dewald, E. L.; Bachmann, B.; MacPhee, A. G.; LaCaille, G.; Bradley, D. K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Lee, J. J. [National Security Technologies LLC, Livermore, California 94551 (United States)

2014-11-15

In laser-driven inertial confinement fusion, hot electrons can preheat the fuel and prevent fusion-pellet compression to ignition conditions. Measuring the hot-electron population is key to designing an optimized ignition platform. The hot electrons in these high-intensity, laser-driven experiments, created via laser-plasma interactions, can be inferred from the bremsstrahlung generated by hot electrons interacting with the target. At the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)], the filter-fluorescer x-ray (FFLEX) diagnostic–a multichannel, hard x-ray spectrometer operating in the 20–500 keV range–has been upgraded to provide fully time-resolved, absolute measurements of the bremsstrahlung spectrum with ∼300 ps resolution. Initial time-resolved data exhibited significant background and low signal-to-noise ratio, leading to a redesign of the FFLEX housing and enhanced shielding around the detector. The FFLEX x-ray sensitivity was characterized with an absolutely calibrated, energy-dispersive high-purity germanium detector using the high-energy x-ray source at NSTec Livermore Operations over a range of K-shell fluorescence energies up to 111 keV (U K{sub β}). The detectors impulse response function was measured in situ on NIF short-pulse (∼90 ps) experiments, and in off-line tests.

Construction of the NIFS campus information network, NIFS-LAN

Energy Technology Data Exchange (ETDEWEB)

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

2000-10-01

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

AXIS: An instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF

Energy Technology Data Exchange (ETDEWEB)

Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Tommasini, R.; Carpenter, A. C.; Palmer, N. E.; Zacharias, R.; Felker, B.; Holder, J. P.; Allen, F. V.; Bell, P. M.; Bradley, D.; Montesanti, R.; Landen, O. L. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

2014-11-15

Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

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.

Three-dimensional simulations of low foot and high foot implosion experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Clark, D. S.; Weber, C. R.; Milovich, J. L.; Salmonson, J. D.; Kritcher, A. L.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Hurricane, O. A.; Jones, O. S.; Marinak, M. M.; Patel, P. K.; Robey, H. F.; Sepke, S. M.; Edwards, M. J.

2016-01-01

In order to achieve the several hundred Gbar stagnation pressures necessary for inertial confinement fusion ignition, implosion experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] require the compression of deuterium-tritium fuel layers by a convergence ratio as high as forty. Such high convergence implosions are subject to degradation by a range of perturbations, including the growth of small-scale defects due to hydrodynamic instabilities, as well as longer scale modulations due to radiation flux asymmetries in the enclosing hohlraum. Due to the broad range of scales involved, and also the genuinely three-dimensional (3D) character of the flow, accurately modeling NIF implosions remains at the edge of current simulation capabilities. This paper describes the current state of progress of 3D capsule-only simulations of NIF implosions aimed at accurately describing the performance of specific NIF experiments. Current simulations include the effects of hohlraum radiation asymmetries, capsule surface defects, the capsule support tent and fill tube, and use a grid resolution shown to be converged in companion two-dimensional simulations. The results of detailed simulations of low foot implosions from the National Ignition Campaign are contrasted against results for more recent high foot implosions. While the simulations suggest that low foot performance was dominated by ablation front instability growth, especially the defect seeded by the capsule support tent, high foot implosions appear to be dominated by hohlraum flux asymmetries, although the support tent still plays a significant role. For both implosion types, the simulations show reasonable, though not perfect, agreement with the data and suggest that a reliable predictive capability is developing to guide future implosions toward ignition.

Three-dimensional simulations of low foot and high foot implosion experiments on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Clark, D. S.; Weber, C. R.; Milovich, J. L.; Salmonson, J. D.; Kritcher, A. L.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Hurricane, O. A.; Jones, O. S.; Marinak, M. M.; Patel, P. K.; Robey, H. F.; Sepke, S. M.; Edwards, M. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

2016-05-15

In order to achieve the several hundred Gbar stagnation pressures necessary for inertial confinement fusion ignition, implosion experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] require the compression of deuterium-tritium fuel layers by a convergence ratio as high as forty. Such high convergence implosions are subject to degradation by a range of perturbations, including the growth of small-scale defects due to hydrodynamic instabilities, as well as longer scale modulations due to radiation flux asymmetries in the enclosing hohlraum. Due to the broad range of scales involved, and also the genuinely three-dimensional (3D) character of the flow, accurately modeling NIF implosions remains at the edge of current simulation capabilities. This paper describes the current state of progress of 3D capsule-only simulations of NIF implosions aimed at accurately describing the performance of specific NIF experiments. Current simulations include the effects of hohlraum radiation asymmetries, capsule surface defects, the capsule support tent and fill tube, and use a grid resolution shown to be converged in companion two-dimensional simulations. The results of detailed simulations of low foot implosions from the National Ignition Campaign are contrasted against results for more recent high foot implosions. While the simulations suggest that low foot performance was dominated by ablation front instability growth, especially the defect seeded by the capsule support tent, high foot implosions appear to be dominated by hohlraum flux asymmetries, although the support tent still plays a significant role. For both implosion types, the simulations show reasonable, though not perfect, agreement with the data and suggest that a reliable predictive capability is developing to guide future implosions toward ignition.

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.

Impacts of Implosion Asymmetry And Hot Spot Shape On Ignition Capsules

Science.gov (United States)

Cheng, Baolian; Kwan, Thomas J. T.; Wang, Yi-Ming; Yi, S. Austin; Batha, Steve

2017-10-01

Implosion symmetry plays a critical role in achieving high areal density and internal energy at stagnation during hot spot formation in ICF capsules. Asymmetry causes hot spot irregularity and stagnation de-synchronization that results in lower temperatures and areal densities of the hot fuel. These degradations significantly affect the alpha heating process in the DT fuel as well as on the thermonuclear performance of the capsules. In this work, we explore the physical factors determining the shape of the hot spot late in the implosion and the effects of shape on Î+/-particle transport. We extend our ignition theory [1-4] to include the hot spot shape and quantify the effects of the implosion asymmetry on both the ignition criterion and capsule performance. We validate our theory with the NIF existing experimental data Our theory shows that the ignition criterion becomes more restrictive with the deformation of the hot spot. Through comparison with the NIF data, we demonstrate that the shape effects on the capsules' performance become more explicit as the self-heating and yield of the capsules increases. The degradation of the thermonuclear burn by the hot spot shape for high yield shots to date can be as high as 20%. Our theory is in good agreement with the NIF data. This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W-7405-ENG-36.

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.

A 1-D Study of the Ignition Space for Magnetic Indirect (X-ray) Drive Targets

Energy Technology Data Exchange (ETDEWEB)

Cobble, James Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinars, Daniel Brian [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-06-02

The ICF program today is investigating three approaches to achieving multi-MJ fusion yields and ignition: (1) laser indirect (x-ray) drive on the National Ignition Facility (NIF), (2) laser direct drive (primarily on the Omega laser facility at the University of Rochester), and (3) magnetic direct drive on the Z pulsed power facility. In this white paper we briefly consider a fourth approach, magnetic indirect drive, in which pulsedpower- driven x-ray sources are used in place of laser driven sources. We first look at some of the x-ray sources studied on Z prior to 2007 before the pulsed power ICF program shifted to magnetic direct drive. We then show results from a series of 1D Helios calculations of double-shell capsules that suggest that these sources, scaled to higher temperatures, could be a promising path to achieving multi-MJ fusion yields and ignition. We advocate here that more detailed design calculations with widely accepted 2D/3D ICF codes should be conducted for a better assessment of the prospects.

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.

National Ignition Facility TestController for automated and manual testing

Energy Technology Data Exchange (ETDEWEB)

Zielinski, Jason, E-mail: fishler2@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States)

2012-12-15

The Controls and Information Systems (CIS) organization for the National Ignition Facility (NIF) has developed controls, configuration and analysis software applications that combine for several million lines of code. The team delivers updates throughout the year, from major releases containing hundreds of changes to patch releases containing a small number of focused updates. To ensure the quality of each delivery, manual and automated tests are performed using the NIF TestController test infrastructure. The TestController system provides test inventory management, test planning, automated and manual test execution, release testing summaries and results search, all through a web browser interface. As part of the three-stage software testing strategy, the NIF TestController system helps plan, evaluate and track the readiness of each release to the NIF production environment. After several years of use in testing NIF software applications, the TestController's manual testing features have been leveraged for verifying the installation and operation of NIF Target Diagnostic hardware. The TestController recorded its first test results in 2004. Today, the system has recorded the execution of more than 160,000 tests and continues to play a central role in ensuring that NIF hardware and software meet the requirements of a high reliability facility. This paper describes the TestController system and discusses its use in assuring the quality of software delivered to the NIF.

National Ignition Facility TestController for automated and manual testing

International Nuclear Information System (INIS)

Zielinski, Jason

2012-01-01

The Controls and Information Systems (CIS) organization for the National Ignition Facility (NIF) has developed controls, configuration and analysis software applications that combine for several million lines of code. The team delivers updates throughout the year, from major releases containing hundreds of changes to patch releases containing a small number of focused updates. To ensure the quality of each delivery, manual and automated tests are performed using the NIF TestController test infrastructure. The TestController system provides test inventory management, test planning, automated and manual test execution, release testing summaries and results search, all through a web browser interface. As part of the three-stage software testing strategy, the NIF TestController system helps plan, evaluate and track the readiness of each release to the NIF production environment. After several years of use in testing NIF software applications, the TestController's manual testing features have been leveraged for verifying the installation and operation of NIF Target Diagnostic hardware. The TestController recorded its first test results in 2004. Today, the system has recorded the execution of more than 160,000 tests and continues to play a central role in ensuring that NIF hardware and software meet the requirements of a high reliability facility. This paper describes the TestController system and discusses its use in assuring the quality of software delivered to the NIF.

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

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

International Nuclear Information System (INIS)

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

2007-01-01

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

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.

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.

Gamma Bang Time/Reaction History Diagnostics for the National Ignition Facility (NIF) Using 900 Off-axis Parabolic Mirrors

International Nuclear Information System (INIS)

H.W. Herrmann; R.M. Malone; W. Stoeffl; J.M. Mack; C.S. Young

2008-01-01

Gas Cherenkov detectors (GCD) have been used to convert fusion gamma into photons to achieve gamma bang time (GBT) and reaction history measurements. The GCD designed for Omega used Cassegrain reflector optics in order to fit inside a ten-inch manipulator. A novel design for the National Ignition Facility (NIF) using 90 o Off-Axis Parabolic (OAP) mirrors will increase light collection efficiency from fusion gammas and achieve minimum time dispersion. The broadband Cherenkov light (from 200 to 800 nm) is relayed into a high-speed detector using three parabolic mirrors. Because light is collected from many source planes throughout the CO2 gas volume, the detector is positioned at the stop position rather than an image position. The stop diameter and its position are independent of the light-generation location along the gas cell. The current design collects light from a 100-mm diameter by 500-mm-long gas volume. Optical ray tracings demonstrate how light can be collected from different angled trajectories of the Compton electrons as they fly through the CO2 gas volume. A cluster of four channels will allow for increased dynamic range as well as different gamma energy threshold sensitivities

Development of a High Resolution X-ray Spectrometer on the National Ignition Facility

Science.gov (United States)

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

2017-10-01

A high-resolution x-ray spectrometer has been designed, calibrated, and deployed on the National Ignition Facility (NIF) to measure plasma parameters for a Kr-doped surrogate capsule imploded at NIF conditions. Two conical crystals, each diffracting the He α and He β complexes respectively, focus the spectra onto a steak camera photocathode for time-resolved measurements with a temporal resolution of NIF experimental results will also be discussed. This work was performed under the auspices of the U.S. Department of Energy by Princeton Plasma Physics Laboratory under contract DE-AC02-09CH11466 and by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

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

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.

NIF Ambient Vibration Measurements

International Nuclear Information System (INIS)

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

1999-01-01

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

National Ignition Facility risk management plan, rev. 1

International Nuclear Information System (INIS)

Brereton, S J; Lane, M A

1998-01-01

The initial release of the National Ignition Facility (AUF) Risk Management Plan (LLNL, 1997a) was prepared in accordance with the DOE Life Cycle Asset Management Good Practice Guide (DOE, 1996a) and supported Critical Decision 3 (CD3), Approval to Initiate Construction (DOE, 1997a). The objectives of the plan were to: (1) Identify the risks to the completion of the Project in terms of meeting technical and regulatory requirements, cost, and schedule. (2) Assess the risks in terms of likelihood of occurrence and their impact potential relative to technical performance, ES and H (environmental, safety and health), costs, and schedule. (3) Address suitable risk mitigation measures for each identified risk. This revision of the Risk Management Plan considers project risks and vulnerabilities after CD3 (DOE, 1997a) was approved by the Secretary of Energy. During the one-year period since the initial release, the vulnerabilities of greatest concern have been the litigation of the Programmatic Environmental Impact Statement (PEIS) (DOE, 1996b) by a group of environmental organizations led by the Natural Resources Defense Council; the finding and successful clean-up of polychlorinated biphenyl (PCB)-filled electrical capacitors at the NIF site excavation; the FY98 congressional budget authorization and request for the FY99 budget authorization; funding for Inertial Confinement Fusion (ICF)/NIF programmatic activities (including French and other sources of funding); and finally, progress in the core science and technology, and optics program that form the basis for the NIF design

National Ignition Facility, High-Energy-Density and Inertial Confinement Fusion, Peer-Review Panel (PRP) Final Report

Energy Technology Data Exchange (ETDEWEB)

Keane, C. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-01-28

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) is operated as a National Nuclear Security Administration (NNSA) user facility in accordance with Department of Energy (DOE) best practices, including peer-reviewed experiments, regular external reviews of performance, and the use of a management structure that facilitates user and stakeholder feedback. NIF facility time is managed using processes similar to those in other DOE science facilities and is tailored to meet the mix of missions and customers that NIF supports. The NIF Governance Plan describes the process for allocating facility time on NIF and for creating the shot schedule. It also includes the flow of responsibility from entity to entity. The plan works to ensure that NIF meets its mission goals using the principles of scientific peer review, including transparency and cooperation among the sponsor, the NIF staff, and the various user communities. The NIF Governance Plan, dated September 28, 2012, was accepted and signed by LLNL Director Parney Albright, NIF Director Ed Moses, and Don Cook and Thomas D’Agostino of NNSA. Figure 1 shows the organizational structure for NIF Governance.

A survey of pulse shape options for a revised plastic ablator ignition design

Energy Technology Data Exchange (ETDEWEB)

Clark, D. S.; Milovich, J. L.; Hinkel, D. E.; Salmonson, J. D.; Peterson, J. L.; Berzak Hopkins, L. F.; Eder, D. C.; Haan, S. W.; Jones, O. S.; Marinak, M. M.; Robey, H. F.; Smalyuk, V. A.; Weber, C. R. [Lawrence Livermore National Laboratory Livermore, California 94550 (United States)

2014-11-15

Recent experimental results using the “high foot” pulse shape for inertial confinement fusion ignition experiments on the National Ignition Facility (NIF) [Moses et al., Phys. Plasmas 16, 041006 (2009)] have shown encouraging progress compared to earlier “low foot” experiments. These results strongly suggest that controlling ablation front instability growth can significantly improve implosion performance even in the presence of persistent, large, low-mode distortions. Simultaneously, hydrodynamic growth radiography experiments have confirmed that ablation front instability growth is being modeled fairly well in NIF experiments. It is timely then to combine these two results and ask how current ignition pulse shapes could be modified to improve one-dimensional implosion performance while maintaining the stability properties demonstrated with the high foot. This paper presents such a survey of pulse shapes intermediate between the low and high foot extremes in search of an intermediate foot optimum. Of the design space surveyed, it is found that a higher picket version of the low foot pulse shape shows the most promise for improved compression without loss of stability.

Polar-direct-drive experiments on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Hohenberger, M.; Radha, P. B.; Myatt, J. F.; Marozas, J. A.; Marshall, F. J.; Michel, D. T.; Regan, S. P.; Seka, W.; Shvydky, A.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Fiksel, G.; Froula, D. H. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299 (United States); and others

2015-05-15

To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, the polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 (2004)] has been proposed. Ignition in PDD geometry requires direct-drive–specific beam smoothing, phase plates, and repointing the NIF beams toward the equator to ensure symmetric target irradiation. First experiments to study the energetics and preheat in PDD implosions at the NIF have been performed. These experiments utilize the NIF in its current configuration, including beam geometry, phase plates, and beam smoothing. Room-temperature, 2.2-mm-diam plastic shells filled with D{sub 2} gas were imploded with total drive energies ranging from ∼500 to 750 kJ with peak powers of 120 to 180 TW and peak on-target irradiances at the initial target radius from 8 × 10{sup 14} to 1.2 × 10{sup 15 }W/cm{sup 2}. Results from these initial experiments are presented, including measurements of shell trajectory, implosion symmetry, and the level of hot-electron preheat in plastic and Si ablators. Experiments are simulated with the 2-D hydrodynamics code DRACO including a full 3-D ray-trace to model oblique beams, and models for nonlocal electron transport and cross-beam energy transport (CBET). These simulations indicate that CBET affects the shell symmetry and leads to a loss of energy imparted onto the shell, consistent with the experimental data.

Observations and modeling of debris and shrapnel impacts on optics and diagnostics at the National Ignition Facility

International Nuclear Information System (INIS)

Eder, D.; Bailey, D.; Chambers, F.; Darnell, I.; Nicola, P. D.; Dixit, S.; Fisher, A.; Gururangan, G.; Kalantar, D.; Koniges, A.; Liu, W.; Marinak, M.; Masters, N.; Mlaker, V.; Prasad, R.; Sepke, S.; Whitman, P.

2013-01-01

A wide range of targets with laser energies spanning two orders of magnitude have been shot at the National Ignition Facility (NIF). The National Ignition Campaign (NIC) targets are cryogenic with Si supports and cooling rings attached to an Al Thermo-Mechanical Package (TMP) with a thin (30 micron) Au hohlraum inside. Particular attention is placed on the low-energy shots where the TMP is not completely vaporized. In addition to NIC targets, a range of other targets has also been fielded on NIF. For all targets, simulations play a critical role in determining if the risks associated with debris and shrapnel are acceptable. In a number of cases, experiments were redesigned, based on simulations, to reduce risks or to obtain data. The majority of these simulations were done using the ALE-AMR code, which provides efficient late-time (100 - 1000 X the pulse duration) 3 D calculations of complex NIF targets. (authors)

Observations and Modeling of Debris and Shrapnel Impacts on Optics and Diagnostics at the National Ignition Facility

International Nuclear Information System (INIS)

Eder, D.; Bailey, D.; Chamgers, F.; Darnell, I.; Nicola, P.D.; Dixit, S.; Fisher, A.; Gururangan, G.; Kalantar, D.; Koniges, A.; Liu, W.; Marinak, M.; Masters, N.; Mlaker, V.; Prasad, R.; Sepke, S.; Whitman, P.

2011-01-01

A wide range of targets with laser energies spanning two orders of magnitude have been shot at the National Ignition Facility (NIF). The National Ignition Campaign (NIC) targets are cryogenic with Si supports and cooling rings attached to an Al thermo-mechanical package (TMP) with a thin (30 micron) Au hohlraum inside. Particular attention is placed on the low-energy shots where the TMP is not completely vaporized. In addition to NIC targets, a range of other targets has also been fielded on NIF. For all targets, simulations play a critical role in determining if the risks associated with debris and shrapnel are acceptable. In a number of cases, experiments were redesigned, based on simulations, to reduce risks or to obtain data. The majority of these simulations were done using the ALE-AMR code, which provides efficient late-time (100-1000X the pulse duration) 3D calculations of complex NIF targets.

First hohlraum drive studies on the National Ignition Facility

International Nuclear Information System (INIS)

Dewald, E.L.; Landen, O.L.; Suter, L.J.; Schein, J.; Holder, J.; Campbell, K.; Glenzer, S.H.; McDonald, J.W.; Niemann, C.; Mackinnon, A.J.; Schneider, M.S.; Haynam, C.; Hinkel, D.; Hammel, B.A.

2006-01-01

The first hohlraum experiments on the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, 228 (2004)] using the first four laser beams have activated the indirect-drive experimental capabilities and tested radiation temperature limits imposed by hohlraum plasma filling. Vacuum hohlraums have been irradiated with laser powers up to 9 TW, 1 to 9 ns long square pulses and energies of up to 17 kJ to study the hohlraum radiation temperature scaling with the laser power and hohlraum size, and to make contact with hohlraum experiments performed previously at other laser facilities. Furthermore, for a variety of hohlraum sizes and pulse lengths, the measured x-ray flux shows signatures of plasma filling that coincide with hard x-ray emission from plasma streaming out of the hohlraum. These observations agree with hydrodynamic simulations and with analytical modeling that includes hydrodynamic and coronal radiative losses. The modeling predicts radiation temperature limits on full NIF (1.8 MJ) that are significantly greater than required for ignition hohlraums

National Ignition Facility system design requirements conventional facilities SDR001

International Nuclear Information System (INIS)

Hands, J.

1996-01-01

This System Design Requirements (SDR) document specifies the functions to be performed and the minimum design requirements for the National Ignition Facility (NIF) site infrastructure and conventional facilities. These consist of the physical site and buildings necessary to house the laser, target chamber, target preparation areas, optics support and ancillary functions

Shock timing on the National Ignition Facility: The first precision tuning series

Directory of Open Access Journals (Sweden)

Robey H.F.

2013-11-01

Full Text Available Ignition implosions on the National Ignition Facility (NIF [Lindl et al., Phys. Plasmas 11, 339 (2004] are driven with a very carefully tailored sequence of four shock waves that must be timed to very high precision in order to keep the fuel on a low adiabat. The first series of precision tuning experiments on NIF have been performed. These experiments use optical diagnostics to directly measure the strength and timing of all four shocks inside the hohlraum-driven, cryogenic deuterium-filled capsule interior. The results of these experiments are presented demonstrating a significant decrease in the fuel adiabat over previously un-tuned implosions. The impact of the improved adiabat on fuel compression is confirmed in related deuterium-tritium (DT layered capsule implosions by measurement of fuel areal density (ρR, which show the highest fuel compression (ρR ∼ 1.0 g/cm2 measured to date.

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.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Experiment archive, analysis, and visualization at the National Ignition Facility

International Nuclear Information System (INIS)

Hutton, Matthew S.; Azevedo, Stephen; Beeler, Richard; Bettenhausen, Rita; Bond, Essex; Casey, Allan; Liebman, Judith; Marsh, Amber; Pannell, Thomas; Warrick, Abbie

2012-01-01

Highlights: ► We show the computing architecture to manage scientific data from NIF experiments. ► NIF laser “shots” generate GBs of data for sub-microsec events separated by hours. ► Results are archived, analyzed and displayed with parallel and scalable code. ► Data quality and pedigree, based on calibration of each part, are tracked. ► Web-based visualization tools present data across shots and diagnostics. - Abstract: The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is the world's most energetic laser, providing a scientific research center to study inertial confinement fusion and matter at extreme energy densities and pressures. A target shot involves over 30 specialized diagnostics measuring critical x-ray, optical and nuclear phenomena to quantify ignition results for comparison with computational models. The Shot Analysis and Visualization System (SAVI) acquires and analyzes target diagnostic data for display within a time-budget of 30 min. Laser and target diagnostic data are automatically loaded into the NIF archive database through clustered software data collection agents. The SAVI Analysis Engine distributes signal and image processing tasks to a Linux cluster where computation is performed. Intermediate results are archived at each step of the analysis pipeline. Data is archived with metadata and pedigree. Experiment results are visualized through a web-based user interface in interactive dashboards tailored to single or multiple shot perspectives. The SAVI system integrates open-source software, commercial workflow tools, relational database and messaging technologies into a service-oriented and distributed software architecture that is highly parallel, scalable, and flexible. The architecture and functionality of the SAVI system will be presented along with examples.

3D Simulations of the ``Keyhole'' Hohlraum for Shock Timing on NIF

Science.gov (United States)

Robey, H. F.; Marinak, M. M.; Munro, D. H.; Jones, O. S.

2007-11-01

Ignition implosions planned for the National Ignition Facility (NIF) require a pulse shape with a carefully designed series of steps, which launch a series of shocks through the ablator and DT fuel. The relative timing of these shocks must be tuned to better than +/- 100ps to maintain the DT fuel on a sufficiently low adiabat. To meet these requirements, pre-ignition tuning experiments using a modified hohlraum geometry are being planned. This modified geometry, known as the ``keyhole'' hohlraum, adds a re-entrant gold cone, which passes through the hohlraum and capsule walls, to provide an optical line-of-sight to directly measure the shocks as they break out of the ablator. In order to assess the surrogacy of this modified geometry, 3D simulations using HYDRA [1] have been performed. The drive conditions and the resulting effect on shock timing in the keyhole hohlraum will be compared with the corresponding results for the standard ignition hohlraum. [1] M.M. Marinak, et al., Phys. Plasmas 8, 2275 (2001).

Nova Upgrade program: ignition and beyond

International Nuclear Information System (INIS)

Storm, E.; Campbell, E.M.; Hogan, W.J.; Lindl, J.D.

1993-01-01

The Lawrence Livermore National Laboratory (LLNL) Inertial Confinement Fusion (ICF) Program is addressing the critical physics and technology issues directed toward demonstrating and exploiting ignition and propagating burn to high gain with ICF targets for both defense and civilian applications. Nova is the primary U.S. facility employed in the study of the X-ray-driven (indirect drive) approach to ICF. Nova's principal objective is to demonstrate that laser-driven hohlraums can achieve the conditions of driver-target coupling efficiency, driver irradiation symmetry, driver pulseshaping, target preheat, and hydrodynamic stability required by hot-spot ignition and fuel compression to realize a fusion gain. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-05-15

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

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

The National Ignition Facility Neutron Imaging System

International Nuclear Information System (INIS)

Wilke, Mark D.; Batha, Steven H.; Bradley, Paul A.; Day, Robert D.; Clark, David D.; Fatherley, Valerie E.; Finch, Joshua P.; Gallegos, Robert A.; Garcia, Felix P.; Grim, Gary P.; Jaramillo, Steven A.; Montoya, Andrew J.; Morgan, George L.; Oertel, John A.; Ortiz, Thomas A.; Payton, Jeremy R.; Pazuchanics, Peter; Schmidt, Derek W.; Valdez, Adelaida C.; Wilde, Carl H.

2008-01-01

The National Ignition Facility (NIF) is scheduled to begin deuterium-tritium (DT) shots possibly in the next several years. One of the important diagnostics in understanding capsule behavior and to guide changes in Hohlraum illumination, capsule design, and geometry will be neutron imaging of both the primary 14 MeV neutrons and the lower-energy downscattered neutrons in the 6-13 MeV range. The neutron imaging system (NIS) described here, which we are currently building for use on NIF, uses a precisely aligned set of apertures near the target to form the neutron images on a segmented scintillator. The images are recorded on a gated, intensified charge coupled device. Although the aperture set may be as close as 20 cm to the target, the imaging camera system will be located at a distance of 28 m from the target. At 28 m the camera system is outside the NIF building. Because of the distance and shielding, the imager will be able to obtain images with little background noise. The imager will be capable of imaging downscattered neutrons from failed capsules with yields Y n >10 14 neutrons. The shielding will also permit the NIS to function at neutron yields >10 18 , which is in contrast to most other diagnostics that may not work at high neutron yields. The following describes the current NIF NIS design and compares the predicted performance with the NIF specifications that must be satisfied to generate images that can be interpreted to understand results of a particular shot. The current design, including the aperture, scintillator, camera system, and reconstruction methods, is briefly described. System modeling of the existing Omega NIS and comparison with the Omega data that guided the NIF design based on our Omega results is described. We will show NIS model calculations of the expected NIF images based on component evaluations at Omega. We will also compare the calculated NIF input images with those unfolded from the NIS images generated from our NIS numerical

A Kirkpatrick-Baez microscope for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Pickworth, L. A., E-mail: pickworth1@llnl.gov; McCarville, T.; Decker, T.; Pardini, T.; Ayers, J.; Bell, P.; Bradley, D.; Brejnholt, N. F.; Izumi, N.; Mirkarimi, P.; Pivovaroff, M.; Smalyuk, V.; Vogel, J.; Walton, C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Kilkenny, J. [General Atomics, San Diego, California 92121 (United States)

2014-11-15

Current pinhole x ray imaging at the National Ignition Facility (NIF) is limited in resolution and signal throughput to the detector for Inertial Confinement Fusion applications, due to the viable range of pinhole sizes (10–25 μm) that can be deployed. A higher resolution and throughput diagnostic is in development using a Kirkpatrick-Baez microscope system (KBM). The system will achieve <9 μm resolution over a 300 μm field of view with a multilayer coating operating at 10.2 keV. Presented here are the first images from the uncoated NIF KBM configuration demonstrating high resolution has been achieved across the full 300 μm field of view.

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

Target Visualization at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Potter, Daniel Abraham [Univ. of California, Davis, CA (United States)

2011-01-01

As the National Ignition Facility continues its campaign to achieve ignition, new methods and tools will be required to measure the quality of the targets used to achieve this goal. Techniques have been developed to measure target surface features using a phase-shifting diffraction interferometer and Leica Microsystems confocal microscope. Using these techniques we are able to produce a detailed view of the shell surface, which in turn allows us to refine target manufacturing and cleaning processes. However, the volume of data produced limits the methods by which this data can be effectively viewed by a user. This paper introduces an image-based visualization system for data exploration of target shells at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. It aims to combine multiple image sets into a single visualization to provide a method of navigating the data in ways that are not possible with existing tools.

Radiation-driven hydrodynamics of long pulse hohlraums on the National Ignition Facility

International Nuclear Information System (INIS)

Dewald, D L; Landen, O L; Suter, L J; Schein, J; Holder, J.; Campbell, K.; Glenzer, S H.; McDonald, J W.; Niemann, C.; Mackinnon, A J.; Schneider, M S.; Haynam, C.; Hinkel, D.; Hammel, B.A.

2005-01-01

The first hohlraum experiments on the National Ignition Facility (NIF) using the first four laser beams have activated the indirect drive experimental capabilities and tested radiation temperature limits imposed by hohlraum plasma filling. Vacuum hohlraums have been irradiated with laser powers up to 6 TW, 1 ns to 9 ns long square pulses and energies of up to 17 kJ to activate several diagnostics, to study the hohlraum radiation temperature scaling with the laser power and hohlraum size, and to make contact with hohlraum experiments performed at the NOVA and Omega laser facilities. Furthermore, for a variety of hohlraum sizes and pulse lengths, the measured x-ray flux shows signatures of plasma filling that coincide with hard x-ray emission from plasma streaming out of the hohlraum. These observations agree with hydrodynamic simulations and with analytical modeling that includes hydrodynamic and coronal radiative losses. The modeling predicts radiation temperature limits on full NIF (1.8 MJ) that are significantly greater than required for ignition hohlraums

Design and performance of the main amplifier system for the National Ignition Facility

International Nuclear Information System (INIS)

Beullier, J; Erlandson, A; Grebot, E; Guenet, J; Guenet, M; Horvath, J; Jancaitis, K; Larson, D; Lawson, J; LeTouze, G; Maille, X; Manes, K; Marshall, C; Mengue, T; Moor, E; Payne, S; Pedrotti, L; Rotter, M; Seznec, S; Sutton, S; Zapata, L.

1999-01-01

This paper describes the design and performance of flashlamp-pumped, Nd:glass. Brewster-angle slab amplifiers intended to be deployed in the National Ignition Facility (NIF). To verify performance, we tested a full-size, three-slab-long, NIF prototype amplifier, which we believe to be the largest flashlamp-pumped Nd:glass amplifier ever assembled. Like the NIF amplifier design, this prototype amplifier had eight 40-cm-square apertures combined in a four-aperture-high by two-aperture-wide matrix. Specially-shaped reflectors, anti-reflective coatings on the blastshields, and preionized flashlamps were used to increase storage efficiency. Cooling gas was flowed over the flashlamps to remove waste pump heat and to accelerate thermal wavefront recovery. The prototype gain results are consistent with model predictions and provide high confidence in the final engineering design of the NIF amplifiers. Although the dimensions, internal positions, and shapes of the components in the NIF amplifiers will be slightly different from the prototype, these differences are small and should produce only slight differences in amplifier performance

Recent advances in indirect drive ICF target physics

International Nuclear Information System (INIS)

Hammel, B.A.

2002-01-01

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

Switch evaluation test system for the National Ignition Facility

International Nuclear Information System (INIS)

Savage, M.E.; Simpson, W.W.; Reynolds, F.D.

1997-01-01

Flashlamp pumped lasers use pulsed power switches to commute energy stored in capacitor banks to the flashlamps. The particular application in which the authors are interested is the National Ignition Facility (NIF), being designed by Lawrence Livermore National Laboratory, Los Alamos National Laboratory, and Sandia National Laboratories (SNL). To lower the total cost of these switches, SNL has a research program to evaluate large closing switches. The target value of the energy switched by a single device is 1.6 MJ, from a 6 mF, 24kV capacitor bank. The peak current is 500 kA. The lifetime of the NIF facility is 24,000 shots. There is no switch today proven at these parameters. Several short-lived switches (100's of shots) exist that can handle the voltage and current, but would require maintenance during the facility life. Other type devices, notably ignitrons, have published lifetimes in excess of 20,000 shots, but at lower currents and shorter pulse widths. The goal of the experiments at SNL is to test switches with the full NIF wave shape, and at the correct voltage. The SNL facility can provide over 500 kA at 24 kV charge voltage. the facility has 6.4 mF total capacitance, arranged in 25 sub-modules. the modular design makes the facility more flexible (for possible testing at lower current) and safer. For pulse shaping (the NIF wave shape is critically damped) there is an inductor and resistor for each of the 25 modules. Rather than one large inductor and resistor, this lowers the current in the pulse shaping components, and raises their value to those more easily attained with lumped inductors and resistors. The authors show the design of the facility, and show results from testing conducted thus far. They also show details of the testing plan for high current switches

Early-time radiation flux symmetry optimization and its effect on gas-filled hohlraum ignition targets on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Milovich, J. L., E-mail: milovich1@llnl.gov; Dewald, E. L.; Pak, A.; Michel, P.; Town, R. P. J.; Bradley, D. K.; Landen, O.; Edwards, M. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2016-03-15

Achieving ignition on the National Ignition Facility (NIF) is tied to our ability to control and minimize deviations from sphericity of the capsule implosion. Low-mode asymmetries of the hot spot result from the combined effect of radiation drive asymmetries throughout the laser pulse and initial roughness on the capsule surface. In this paper, we report on simulations and experiments designed to assess, measure, and correct the drive asymmetries produced by the early-time (≈first 2 ns or “picket”) period of the laser pulse. The drive asymmetry during the picket is commonly thought to introduce distortions in the hot-spot shape at ignition time. However, a more subtle effect not previously considered is that it also leads to an asymmetry in shock velocity and timing, thereby increasing the fuel adiabat and reducing the margin for ignition. It is shown via hydrodynamic simulations that minimizing this effect requires that the early-time asymmetry be kept below 7.5% in the second Legendre mode (P{sub 2}), thus keeping the loss of performance margin below ≈10% for a layered implosion. Asymmetries during the picket of the laser pulse are measured using the instantaneous self-emission of a high-Z re-emission sphere in place of an ignition capsule in a hohlraum with large azimuthal diagnostic windows. Three dimensional simulations using the code HYDRA (to capture the effect of non-azimuthal hohlraum features) coupled to a cross-beam energy transfer model [Michel et al., Phys. Plasmas 17, 056305 (2010)] are used to establish the surrogacy of the re-emit target and to assess the early-time drive symmetry. Calculations using this model exhibit the same sensitivity to variations in the relative input powers between the different cones of NIF beams as measured for the “Rev5” CH target [Haan et al., Phys Plasmas 18, 051001 (2011)] and reported by Dewald et al. [Phys. Rev. Lett. 111, 235001 (2013)]. The same methodology applied to recently improved implosions

Early-time radiation flux symmetry optimization and its effect on gas-filled hohlraum ignition targets on the National Ignition Facility

International Nuclear Information System (INIS)

Milovich, J. L.; Dewald, E. L.; Pak, A.; Michel, P.; Town, R. P. J.; Bradley, D. K.; Landen, O.; Edwards, M. J.

2016-01-01

Achieving ignition on the National Ignition Facility (NIF) is tied to our ability to control and minimize deviations from sphericity of the capsule implosion. Low-mode asymmetries of the hot spot result from the combined effect of radiation drive asymmetries throughout the laser pulse and initial roughness on the capsule surface. In this paper, we report on simulations and experiments designed to assess, measure, and correct the drive asymmetries produced by the early-time (≈first 2 ns or “picket”) period of the laser pulse. The drive asymmetry during the picket is commonly thought to introduce distortions in the hot-spot shape at ignition time. However, a more subtle effect not previously considered is that it also leads to an asymmetry in shock velocity and timing, thereby increasing the fuel adiabat and reducing the margin for ignition. It is shown via hydrodynamic simulations that minimizing this effect requires that the early-time asymmetry be kept below 7.5% in the second Legendre mode (P_2), thus keeping the loss of performance margin below ≈10% for a layered implosion. Asymmetries during the picket of the laser pulse are measured using the instantaneous self-emission of a high-Z re-emission sphere in place of an ignition capsule in a hohlraum with large azimuthal diagnostic windows. Three dimensional simulations using the code HYDRA (to capture the effect of non-azimuthal hohlraum features) coupled to a cross-beam energy transfer model [Michel et al., Phys. Plasmas 17, 056305 (2010)] are used to establish the surrogacy of the re-emit target and to assess the early-time drive symmetry. Calculations using this model exhibit the same sensitivity to variations in the relative input powers between the different cones of NIF beams as measured for the “Rev5” CH target [Haan et al., Phys Plasmas 18, 051001 (2011)] and reported by Dewald et al. [Phys. Rev. Lett. 111, 235001 (2013)]. The same methodology applied to recently improved implosions using

Early-time radiation flux symmetry optimization and its effect on gas-filled hohlraum ignition targets on the National Ignition Facility

Science.gov (United States)

Milovich, J. L.; Dewald, E. L.; Pak, A.; Michel, P.; Town, R. P. J.; Bradley, D. K.; Landen, O.; Edwards, M. J.

2016-03-01

Achieving ignition on the National Ignition Facility (NIF) is tied to our ability to control and minimize deviations from sphericity of the capsule implosion. Low-mode asymmetries of the hot spot result from the combined effect of radiation drive asymmetries throughout the laser pulse and initial roughness on the capsule surface. In this paper, we report on simulations and experiments designed to assess, measure, and correct the drive asymmetries produced by the early-time (≈first 2 ns or "picket") period of the laser pulse. The drive asymmetry during the picket is commonly thought to introduce distortions in the hot-spot shape at ignition time. However, a more subtle effect not previously considered is that it also leads to an asymmetry in shock velocity and timing, thereby increasing the fuel adiabat and reducing the margin for ignition. It is shown via hydrodynamic simulations that minimizing this effect requires that the early-time asymmetry be kept below 7.5% in the second Legendre mode (P2), thus keeping the loss of performance margin below ≈10% for a layered implosion. Asymmetries during the picket of the laser pulse are measured using the instantaneous self-emission of a high-Z re-emission sphere in place of an ignition capsule in a hohlraum with large azimuthal diagnostic windows. Three dimensional simulations using the code HYDRA (to capture the effect of non-azimuthal hohlraum features) coupled to a cross-beam energy transfer model [Michel et al., Phys. Plasmas 17, 056305 (2010)] are used to establish the surrogacy of the re-emit target and to assess the early-time drive symmetry. Calculations using this model exhibit the same sensitivity to variations in the relative input powers between the different cones of NIF beams as measured for the "Rev5" CH target [Haan et al., Phys Plasmas 18, 051001 (2011)] and reported by Dewald et al. [Phys. Rev. Lett. 111, 235001 (2013)]. The same methodology applied to recently improved implosions using different

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

International Nuclear Information System (INIS)

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

2006-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-06-15

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

Thinshell symmetry surrogates for the National Ignition Facility: A rocket equation analysis

Science.gov (United States)

Amendt, Peter; Shestakov, A. I.; Landen, O. L.; Bradley, D. K.; Pollaine, S. M.; Suter, L. J.; Turner, R. E.

2001-06-01

Several techniques for inferring the degree of flux symmetry in indirectly driven cylindrical hohlraums have been developed over the past several years for eventual application to the National Ignition Facility (NIF) [Paisner et al., Laser Focus World 30, 75 (1994)]. These methods use various ignition capsule surrogates, including non-cryogenic imploded capsules [Hauer et al., Phys. Plasmas 2, 2488 (1995)], backlit aerogel foamballs [Amendt et al., Rev. Sci. Instrum. 66, 785 (1995)], reemission balls [Delamater, Magelssen, and Hauer, Phys. Rev. E 53, 5240 (1996)], and backlit thinshells [Pollaine et al., Phys. Plasmas 8, 2357 (2001)]. Recent attention has focussed on the backlit thinshells as a promising means for detecting higher-order Legendre flux asymmetries, e.g., P6 and P8, which are predicted to be important sources of target performance degradation on the NIF for levels greater than 1% [Haan et al., Phys. Plasmas 2, 2490 (1995)]. A key property of backlit thinshells is the strong amplification of modal flux asymmetry imprinting with shell convergence. A simple single-parameter analytic description based on a rocket model is presented which explores the degree of linearity of the shell response to an imposed flux asymmetry. Convergence and mass ablation effects introduce a modest level of nonlinearity in the shell response. The effect of target fabrication irregularities on shell distortion is assessed with the rocket model and particular sensitivity to shell thickness variations is shown. The model can be used to relate an observed or simulated backlit implosion trajectory to an ablation pressure asymmetry history. Ascertaining this history is an important element for readily establishing the degree of surrogacy of a symmetry target for a NIF ignition capsule.

Thinshell symmetry surrogates for the National Ignition Facility: A rocket equation analysis

International Nuclear Information System (INIS)

Amendt, Peter; Shestakov, A.I.; Landen, O.L.; Bradley, D.K.; Pollaine, S.M.; Suter, L.J.; Turner, R.E.

2001-01-01

Several techniques for inferring the degree of flux symmetry in indirectly driven cylindrical hohlraums have been developed over the past several years for eventual application to the National Ignition Facility (NIF) [Paisner et al., Laser Focus World 30, 75 (1994)]. These methods use various ignition capsule surrogates, including non-cryogenic imploded capsules [Hauer et al., Phys. Plasmas 2, 2488 (1995)], backlit aerogel foamballs [Amendt et al., Rev. Sci. Instrum. 66, 785 (1995)], reemission balls [Delamater, Magelssen, and Hauer, Phys. Rev. E 53, 5240 (1996)], and backlit thinshells [Pollaine et al., Phys. Plasmas 8, 2357 (2001)]. Recent attention has focussed on the backlit thinshells as a promising means for detecting higher-order Legendre flux asymmetries, e.g., P6 and P8, which are predicted to be important sources of target performance degradation on the NIF for levels greater than 1% [Haan et al., Phys. Plasmas 2, 2490 (1995)]. A key property of backlit thinshells is the strong amplification of modal flux asymmetry imprinting with shell convergence. A simple single-parameter analytic description based on a rocket model is presented which explores the degree of linearity of the shell response to an imposed flux asymmetry. Convergence and mass ablation effects introduce a modest level of nonlinearity in the shell response. The effect of target fabrication irregularities on shell distortion is assessed with the rocket model and particular sensitivity to shell thickness variations is shown. The model can be used to relate an observed or simulated backlit implosion trajectory to an ablation pressure asymmetry history. Ascertaining this history is an important element for readily establishing the degree of surrogacy of a symmetry target for a NIF ignition capsule

National Ignition Facility Configuration Management Plan

International Nuclear Information System (INIS)

Cabral, S G; Moore, T L

2002-01-01

This Configuration Management Plan (CMP) describes the technical and administrative management process for controlling the National Ignition Facility (NIF) Project configuration. The complexity of the NIF Project (i.e., participation by multiple national laboratories and subcontractors involved in the development, fabrication, installation, and testing of NIF hardware and software, as well as construction and testing of Project facilities) requires implementation of the comprehensive configuration management program defined in this plan. A logical schematic illustrating how the plan functions is provided in Figure 1. A summary of the process is provided in Section 4.0, Configuration Change Control. Detailed procedures that make up the overall process are referenced. This CMP is consistent with guidance for managing a project's configuration provided in Department of Energy (DOE) Order 430.1, Guide PMG 10, ''Project Execution and Engineering Management Planning''. Configuration management is a formal discipline comprised of the following four elements: (1) Identification--defines the functional and physical characteristics of a Project and uniquely identifies the defining requirements. This includes selection of components of the end product(s) subject to control and selection of the documents that define the project and components. (2) Change management--provides a systematic method for managing changes to the project and its physical and functional configuration to ensure that all changes are properly identified, assessed, reviewed, approved, implemented, tested, and documented. (3) Data management--ensures that necessary information on the project and its end product(s) is systematically recorded and disseminated for decision-making and other uses. Identifies, stores and controls, tracks status, retrieves, and distributes documents. (4) Assessments and validation--ensures that the planned configuration requirements match actual physical configurations and

Laser Science and Technology Program Update 2001

International Nuclear Information System (INIS)

Chen, H L; Hackel, L A

2002-01-01

The Laser Science and Technology (LSandT) Program's mission is to develop advanced solid-state lasers, optics, materials technologies, and applications to solve problems and create new capabilities of importance to the Nation and the Laboratory. A top, near-term priority is to provide technical support to the National Ignition Facility (NIF) to ensure activation success. LSandT provides the NIF Programs with core competencies and supports its economic viability. The primary objectives of LSandT activities in fiscal year (FY) 2001 have been threefold: (1) to support deployment of hardware and to enhance lasers and optics performance for NIF, (2) to develop advanced solid-state laser systems and optical components for the Department of Energy (DOE) and the Department of Defense (DoD), and (3) to invent, develop, and deliver improved concepts and hardware for other government agencies and U.S. industry. Special efforts have also been devoted to building and maintaining our capabilities in three technology areas: high-power solid-state lasers, high-power optical materials, and applications of advanced lasers

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.

Reproducibility of hohlraum-driven implosion symmetry on the National Ignition Facility

Directory of Open Access Journals (Sweden)

Kyrala G.A.

2013-11-01

Full Text Available Indirectly driven Symcap capsules are used at the NIF to obtain information about ignition capsule implosion performance, in particular shape. Symcaps replace the cryogenic fuel layer with an equivalent ablator mass and can be similarly diagnosed. Symcaps are good symmetry surrogates to an ignition capsule after the peak of the drive, radiation-hydrodynamics simulations predict that doping of the symcaps vary the behavior of the implosion. We compare the equatorial shapes of a symcap doped with Si or Ge, as well as examine the reproducibility of the shape measurement using two symcaps with the same hohlraum and laser conditions.

Inertial confinement fusion target insertion concepts for the National Ignition Facility

International Nuclear Information System (INIS)

Laughon, G.J.; Schultz, K.R.

1996-01-01

The National Ignition Facility (NIF) will be used to demonstrate fusion ignition in a laboratory environment in order to support development of inertial fusion as a potential fusion energy source for civilian use. However, target insertion must first be addressed before inertial fusion can become a practical energy source. Since target insertion systems currently utilized are not suitable for multiple shots in quick succession, insertion concepts involving free-falling and artificially accelerated targets are developed and evaluated against a set of predetermined guidelines. It is shown that a system involving a fast retraction positioner would be suitable. 5 refs., 4 figs

Laser beam smoothing and backscatter saturation processes in plasmas relevant to national ignition facility hohlraums

International Nuclear Information System (INIS)

MacGowan, B.J.; Berger, R.L.; Cohen, B.I.

2001-01-01

We have used gas-filled targets irradiated by the Nova laser to simulate National Ignition Facility (NIF) hohlraum plasmas and to study the dependence of Stimulated Raman (SRS) and Brillouin (SBS) Scattering on beam smoothing at a range of laser intensities (3ω, 2-410 15 Wcm -2 ) and plasma conditions. We have demonstrated the effectiveness of polarization smoothing as a potential upgrade to the NIF. Experiments with higher intensities and higher densities characteristic of 350eV hohlraum designs indicate that with appropriate beam smoothing the backscatter from such hohlraums may be tolerable. (author)

1996 ICF program overview

International Nuclear Information System (INIS)

Correll, D

1996-01-01

The continuing objective of the Inertial Confinement Fusion (ICF) Program is the demonstration of thermonuclear fusion ignition and energy gain in the laboratory. The underlying theme of all ICF activities as a science research and development program is the Department of Energy's (DOE's) Defense Programs (DP) science-based Stockpile Stewardship and Management (SSM) Program. The extension of current program research capabilities in the National Ignition Facility (NIF) is necessary for the ICF Program to satisfy its stewardship responsibilities. ICF resources (people and facilities) are increasingly being redirected in support of the performance, schedule, and cost goals of the NIF. One of the more important aspects of ICF research is the national nature of the program. Lawrence Livermore National Laboratory's (LLNL's) ICF Program falls within DOE's national ICF Program, which includes the Nova and Beamlet laser facilities at LLNL and the OMEGA, Nike, and Trident laser facilities at the University of Rochester (Laboratory for Laser Energetics, UR/LLE), the Naval Research Laboratory (NRL), and Los Alamos National Laboratory (LANL), respectively. The Particle Beam Fusion Accelerator (PBFA) and Saturn pulsed-power facilities are at Sandia National Laboratories (SNL). General Atomics, Inc. (GA) develops and provides many of the targets for the above experimental facilities. LLNL's ICF Program supports activities in two major interrelated areas: (1) target physics and technology (experimental, theoretical, and computational research); and (2) laser science and optics technology development. Experiments on LLNL's Nova laser primarily support ignition and weapons physics research. Experiments on LLNL's Beamlet laser support laser science and optics technology development. In addition, ICF sciences and technologies, developed as part of the DP mission goals, continue to support additional DOE objectives. These objectives are (1) to achieve diversity in energy sources

National Ignition Facility and managing location, component, and state

International Nuclear Information System (INIS)

Foxworthy, Cemil; Fung, Tracy; Beeler, Rich; Li, Joyce; Dugorepec, Jasna; Chang, Cathy

2012-01-01

Highlights: ► NIF in comprised of over 100k serialized parts that must be tracked and maintained. ► We discuss a web-based integrated parts management system designed for NIF. ► The parts database stores associated calibration data with effective dates. ► The system interfaces with the NIF control system and performance models. ► Work activity (Permits, Problem Logs, Work Orders) are managed by the system. - Abstract: The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that contains a 192-beam, 1.8-MJ, 500-TW, ultraviolet laser system coupled with a 10-m diameter target chamber. There are over 6200 Line Replaceable Units (LRUs) comprised of more than 104,000 serialized parts that make up the NIF. Each LRU is a modular unit typically composed of a mechanical housing, laser optics (glass, lenses, or mirrors), and utilities. To date, there are more than 120,000 data sets created to characterize the attributes of these parts. Greater than 51,000 Work Permits have been issued to install, maintain, and troubleshoot the components. One integrated system is used to manage these data, and more. The Location Component and State (LoCoS) system is a web application built using Java Enterprise Edition technologies and is accessed by over 1200 users. It is either directly or indirectly involved with each aspect of NIF work activity, and interfaces with ten external systems including the Integrated Computer Control System (ICCS) and the Laser Performance Operations Model (LPOM). Besides providing business functionality, LoCoS also acts as the NIF enterprise service bus. In this role, numerous integration approaches had to be adopted including: file exchange, database sharing, queuing, and web services in order to accommodate various business, technical, and security requirements. Architecture and implementation decisions are discussed.

Fast ignition: Physics progress in the US fusion energy program and prospects for achieving ignition

International Nuclear Information System (INIS)

Key, M.; Andersen, C.; Cowan, T.

2003-01-01

Fast ignition (FI) has significant potential advantages for inertial fusion energy and it is therefore being studied as an exploratory concept in the US fusion energy program. FI is based on short pulse isochoric heating of pre-compressed DT by intense beams of laser accelerated MeV electrons or protons. Recent experimental progress in the study of these two heating processes is discussed. The goal is to benchmark new models in order to predict accurately the requirements for full-scale fast ignition. An overview is presented of the design and experimental testing of a cone target implosion concept for fast ignition. Future prospects and conceptual designs for larger scale FI experiments using planned high energy petawatt upgrades of major lasers in the US are outlined. A long-term road map for FI is defined. (author)

PROMPT DOSE ANALYSIS FOR THE NATIONAL IGNITION FACILITY

International Nuclear Information System (INIS)

Khater, H.; Dauffy, L.; Sitaraman, S.; Brereton, S.

2008-01-01

Detailed 3-D modeling of the NIF facility is developed to accurately understand the prompt radiation environment within NIF. Prompt dose values are calculated for different phases of NIF operation. Results of the analysis were used to determine the final thicknesses of the Target Bay (TB) and secondary doors as well as the required shield thicknesses for all unused penetrations. Integrated dose values at different locations within the facility are needed to formulate the personnel access requirements within different parts of the facility. The conclusions of this presentation are: (1) The current NIF facility model includes all important features of the Target Chamber, shielding system, and building configuration; (2) All shielding requirements for Phase I operation are met; (3) Negligible dose values (a fraction of mrem) are expected in normally occupied areas during Phase I; (4) In preparation for the Ignition Campaign and Phase IV of operation, all primary and secondary shield doors will be installed; (5) Unused utility penetrations in the Target Bay and Switchyard walls (∼50%) will be shielded by 1 foot thick concrete to reduce prompt dose inside and outside the NIF facility; (6) During Phase IV, a 20 MJ shot will produce acceptable dose levels in the occupied areas as well as at the nearest site boundary; (7) A comprehensive radiation monitoring plan will be put in place to monitor dose values at large number of locations; and (8) Results of the dose monitoring will be used to modify personnel access requirements if needed

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.

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.

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

Energy Technology Data Exchange (ETDEWEB)

Ma, T.; Izumi, N.; Tommasini, R.; Bradley, D. K.; Bell, P.; Cerjan, C. J.; Dixit, S.; Doeppner, T.; Jones, O.; Landen, O. L.; LePape, S.; Mackinnon, A. J.; Park, H.-S.; Patel, P. K.; Prasad, R. R.; Ralph, J.; Smalyuk, V. A.; Springer, P. T.; Suter, L.; Town, R. P. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-10-15

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-11-02

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

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Filter-fluorescer diagnostic system for the National Ignition Facility

International Nuclear Information System (INIS)

McDonald, J.W.; Kauffman, R.L.; Celeste, J.R.; Rhodes, M.A.; Lee, F.D.; Suter, L.J.; Lee, A.P.; Foster, J.M.; Slark, G.

2004-01-01

An early filter-fluorescer diagnostic system is being fielded at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) to measure the amount of hard x rays (20< hν<150 keV) generated in laser fusion experiments. From these measurements we hope to quantify the number of hot electrons produced in laser fusion experiments. The measurement of hot electron production is important for ignition experiments because these electrons can preheat the fuel capsule. Hot electrons can also be employed in experimentation by preheating hydrodynamic packages or by driving plasmas out of equilibrium. The experimental apparatus, data collection, analysis and calibration issues are discussed. Expected data signal levels are predicted and discussed

Exploring the limits of case-to-capsule ratio, pulse length, and picket energy for symmetric hohlraum drive on the National Ignition Facility Laser

Science.gov (United States)

Callahan, D. A.; Hurricane, O. A.; Ralph, J. E.; Thomas, C. A.; Baker, K. L.; Benedetti, L. R.; Berzak Hopkins, L. F.; Casey, D. T.; Chapman, T.; Czajka, C. E.; Dewald, E. L.; Divol, L.; Döppner, T.; Hinkel, D. E.; Hohenberger, M.; Jarrott, L. C.; Khan, S. F.; Kritcher, A. L.; Landen, O. L.; LePape, S.; MacLaren, S. A.; Masse, L. P.; Meezan, N. B.; Pak, A. E.; Salmonson, J. D.; Woods, D. T.; Izumi, N.; Ma, T.; Mariscal, D. A.; Nagel, S. R.; Kline, J. L.; Kyrala, G. A.; Loomis, E. N.; Yi, S. A.; Zylstra, A. B.; Batha, S. H.

2018-05-01

We present a data-based model for low mode asymmetry in low gas-fill hohlraum experiments on the National Ignition Facility {NIF [Moses et al., Fusion Sci. Technol. 69, 1 (2016)]} laser. This model is based on the hypothesis that the asymmetry in these low fill hohlraums is dominated by the hydrodynamics of the expanding, low density, high-Z (gold or uranium) "bubble," which occurs where the intense outer cone laser beams hit the high-Z hohlraum wall. We developed a simple model which states that the implosion symmetry becomes more oblate as the high-Z bubble size becomes large compared to the hohlraum radius or the capsule size becomes large compared to the hohlraum radius. This simple model captures the trends that we see in data that span much of the parameter space of interest for NIF ignition experiments. We are now using this model as a constraint on new designs for experiments on the NIF.

Software solutions manage the definition, operation, maintenance and configuration control of the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Dobson, D; Churby, A; Krieger, E; Maloy, D; White, K

2011-07-25

The National Ignition Facility (NIF) is the world's largest laser composed of millions of individual parts brought together to form one massive assembly. Maintaining control of the physical definition, status and configuration of this structure is a monumental undertaking yet critical to the validity of the shot experiment data and the safe operation of the facility. The NIF business application suite of software provides the means to effectively manage the definition, build, operation, maintenance and configuration control of all components of the National Ignition Facility. State of the art Computer Aided Design software applications are used to generate a virtual model and assemblies. Engineering bills of material are controlled through the Enterprise Configuration Management System. This data structure is passed to the Enterprise Resource Planning system to create a manufacturing bill of material. Specific parts are serialized then tracked along their entire lifecycle providing visibility to the location and status of optical, target and diagnostic components that are key to assessing pre-shot machine readiness. Nearly forty thousand items requiring preventive, reactive and calibration maintenance are tracked through the System Maintenance & Reliability Tracking application to ensure proper operation. Radiological tracking applications ensure proper stewardship of radiological and hazardous materials and help provide a safe working environment for NIF personnel.

Software solutions manage the definition, operation, maintenance and configuration control of the National Ignition Facility

International Nuclear Information System (INIS)

Dobson, D.; Churby, A.; Krieger, E.; Maloy, D.; White, K.

2011-01-01

The National Ignition Facility (NIF) is the world's largest laser composed of millions of individual parts brought together to form one massive assembly. Maintaining control of the physical definition, status and configuration of this structure is a monumental undertaking yet critical to the validity of the shot experiment data and the safe operation of the facility. The NIF business application suite of software provides the means to effectively manage the definition, build, operation, maintenance and configuration control of all components of the National Ignition Facility. State of the art Computer Aided Design software applications are used to generate a virtual model and assemblies. Engineering bills of material are controlled through the Enterprise Configuration Management System. This data structure is passed to the Enterprise Resource Planning system to create a manufacturing bill of material. Specific parts are serialized then tracked along their entire lifecycle providing visibility to the location and status of optical, target and diagnostic components that are key to assessing pre-shot machine readiness. Nearly forty thousand items requiring preventive, reactive and calibration maintenance are tracked through the System Maintenance and Reliability Tracking application to ensure proper operation. Radiological tracking applications ensure proper stewardship of radiological and hazardous materials and help provide a safe working environment for NIF personnel.

Design and implementation plan for indirect-drive highly nonlinear ablative Rayleigh-Taylor instability experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Casner, A.; Masse, L.; Delorme, B.; Jacquet, L.; Liberatore, S.; Smalyuk, V.; Martinez, D.; Seugling, R.; Park, H.S.; Remington, B.A.; Moore, A.; Igumenshev, I.; Chicanne, C.

2013-01-01

In the context of National Ignition Facility Basic Science program we propose to study on the NIF ablative Rayleigh-Taylor (RT) instability in transition from weakly nonlinear to highly nonlinear regimes. Based on the analogy between flame front and ablation front, highly nonlinear RT instability measurements at the ablation front can provide important insights into the initial deflagration stage of thermonuclear supernovae of type Ia. NIF provides a unique platform to study the rich physics of nonlinear and turbulent mixing flows in High Energy Density plasmas because it can accelerate targets over much larger distances and longer time periods than previously achieved on the NOVA and OMEGA lasers. In one shot, growth of RT modulations can be measured from the weakly nonlinear stage near nonlinear saturation levels to the highly nonlinear bubble-competition, bubble-merger regimes and perhaps into a turbulent-like regime. The role of ablation on highly-nonlinear RT instability evolution will be comprehensively studied by varying ablation velocity using indirect and direct-drive platforms. We present a detailed hydro-code design of the indirect-drive platform and discuss the implementation plan for these experiments which only use NIF diagnostics already qualified. (authors)

X-ray emission from National Ignition Facility indirect drive targets

International Nuclear Information System (INIS)

Anderson, A.T.; Managan, R.A.; Tobin, M.T.; Peterson, P.F.

1996-01-01

We have performed a series of 1-D numerical simulations of the x-ray emission from National Ignition Facility (NIF) targets. Results are presented in terms of total x-ray energy, pulse length, and spectrum. Scaling of x-ray emissions is presented for variations in both target yield and hohlraum thickness. Experiments conducted on the Nova facility provide some validation of the computational tools and methods

High-energy x-ray microscopy of laser-fusion plasmas at the National Ignition Facility

International Nuclear Information System (INIS)

Koch, J.A.; Landen, O.L.; Hammel, B.A.

1997-01-01

Multi-keV x-ray microscopy will be an important laser-produced plasma diagnostic at future megajoule facilities such as the National Ignition Facility (NIF).In preparation for the construction of this facility, we have investigated several instrumentation options in detail, and we conclude that near normal incidence single spherical or toroidal crystals may offer the best general solution for high-energy x-raymicroscopy at NIF and at similar large facilities. Kirkpatrick-Baez microscopes using multi-layer mirrors may also be good secondary options, particularly if apertures are used to increase the band-width limited field of view

A recoverable gas-cell diagnostic for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Ratkiewicz, A., E-mail: ratkiewicz1@llnl.gov; Berzak Hopkins, L.; Bleuel, D. L.; Cassata, W. S.; Velsko, C. A.; Yeamans, C. B. [Lawrence Livermore National Laboratory, Livermore, California 95440 (United States); Bernstein, L. A.; Bibber, K. van; Goldblum, B. L. [University of California, Berkeley, California 94720 (United States); Siem, S. [University of Oslo, N-0316 Oslo (Norway); Wiedeking, M. [iThemba LABS, Somerset West 7129 (South Africa)

2016-11-15

The high-fluence neutron spectrum produced by the National Ignition Facility (NIF) provides an opportunity to measure the activation of materials by fast-spectrum neutrons. A new large-volume gas-cell diagnostic has been designed and qualified to measure the activation of gaseous substances at the NIF. This in-chamber diagnostic is recoverable, reusable and has been successfully fielded. Data from the qualification of the diagnostic have been used to benchmark an Monte Carlo N-Particle Transport Code simulation describing the downscattered neutron spectrum seen by the gas cell. We present early results from the use of this diagnostic to measure the activation of {sup nat}Xe and discuss future work to study the strength of interactions between plasma and nuclei.

A recoverable gas-cell diagnostic for the National Ignition Facility.

Science.gov (United States)

Ratkiewicz, A; Berzak Hopkins, L; Bleuel, D L; Bernstein, L A; van Bibber, K; Cassata, W S; Goldblum, B L; Siem, S; Velsko, C A; Wiedeking, M; Yeamans, C B

2016-11-01

The high-fluence neutron spectrum produced by the National Ignition Facility (NIF) provides an opportunity to measure the activation of materials by fast-spectrum neutrons. A new large-volume gas-cell diagnostic has been designed and qualified to measure the activation of gaseous substances at the NIF. This in-chamber diagnostic is recoverable, reusable and has been successfully fielded. Data from the qualification of the diagnostic have been used to benchmark an Monte Carlo N-Particle Transport Code simulation describing the downscattered neutron spectrum seen by the gas cell. We present early results from the use of this diagnostic to measure the activation of nat Xe and discuss future work to study the strength of interactions between plasma and nuclei.

National ignition facility environment, safety, and health management plan

International Nuclear Information System (INIS)

1995-11-01

The ES ampersand H Management Plan describes all of the environmental, safety, and health evaluations and reviews that must be carried out in support of the implementation of the National Ignition Facility (NIF) Project. It describes the policy, organizational responsibilities and interfaces, activities, and ES ampersand H documents that will be prepared by the Laboratory Project Office for the DOE. The only activity not described is the preparation of the NIF Project Specific Assessment (PSA), which is to be incorporated into the Programmatic Environmental Impact Statement for Stockpile Stewardship and Management (PEIS). This PSA is being prepared by Argonne National Laboratory (ANL) with input from the Laboratory participants. As the independent NEPA document preparers ANL is directly contracted by the DOE, and its deliverables and schedule are agreed to separately with DOE/OAK

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)

The Shock/Shear platform for planar radiation-hydrodynamics experiments on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Doss, F. W., E-mail: fdoss@lanl.gov; Kline, J. L.; Flippo, K. A.; Perry, T. S.; DeVolder, B. G.; Tregillis, I.; Loomis, E. N.; Merritt, E. C.; Murphy, T. J.; Welser-Sherrill, L.; Fincke, J. R. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2015-05-15

An indirectly-driven shock tube experiment fielded on the National Ignition Facility (NIF) was used to create a high-energy-density hydrodynamics platform at unprecedented scale. Scaling up a shear-induced mixing experiment previously fielded at OMEGA, the NIF shear platform drives 130 μm/ns shocks into a CH foam-filled shock tube (∼ 60 mg/cc) with interior dimensions of 1.5 mm diameter and 5 mm length. The pulse-shaping capabilities of the NIF are used to extend the drive for >10 ns, and the large interior tube volumes are used to isolate physics-altering edge effects from the region of interest. The scaling of the experiment to the NIF allows for considerable improvement in maximum driving time of hydrodynamics, in fidelity of physics under examination, and in diagnostic clarity. Details of the experimental platform and post-shot simulations used in the analysis of the platform-qualifying data are presented. Hydrodynamic scaling is used to compare shear data from OMEGA with that from NIF, suggesting a possible change in the dimensionality of the instability at late times from one platform to the other.

Origins and Scaling of Hot-Electron Preheat in Ignition-Scale Direct-Drive Inertial Confinement Fusion Experiments

Science.gov (United States)

Rosenberg, M. J.; Solodov, A. A.; Myatt, J. F.; Seka, W.; Michel, P.; Hohenberger, M.; Short, R. W.; Epstein, R.; Regan, S. P.; Campbell, E. M.; Chapman, T.; Goyon, C.; Ralph, J. E.; Barrios, M. A.; Moody, J. D.; Bates, J. W.

2018-01-01

Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for the first time to regimes of electron density scale length (˜500 to 700 μ m ), electron temperature (˜3 to 5 keV), and laser intensity (6 to 16 ×1014 W /cm2 ) that are relevant to direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data on the NIF show that the near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than by two-plasmon decay (TPD). This difference in regime is explained based on absolute SRS and TPD threshold considerations. SRS sidescatter tangential to density contours and other SRS mechanisms are observed. The fraction of laser energy converted to hot electrons is ˜0.7 % to 2.9%, consistent with observed levels of SRS. The intensity threshold for hot-electron production is assessed, and the use of a Si ablator slightly increases this threshold from ˜4×10 14 to ˜6 ×1014 W /cm2 . These results have significant implications for mitigation of LPI hot-electron preheat in direct-drive ignition designs.

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

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.

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.

Use of d-3He proton spectroscopy as a diagnostic of shell rho r in capsule implosion experiments with approximately 0.2 NIF scale high temperature Hohlraums at Omega.

Science.gov (United States)

Delamater, N D; Wilson, D C; Kyrala, G A; Seifter, A; Hoffman, N M; Dodd, E; Singleton, R; Glebov, V; Stoeckl, C; Li, C K; Petrasso, R; Frenje, J

2008-10-01

We present the calculations and preliminary results from experiments on the Omega laser facility using d-(3)He filled plastic capsule implosions in gold Hohlraums. These experiments aim to develop a technique to measure shell rho r and capsule unablated mass with proton spectroscopy and will be applied to future National Ignition Facility (NIF) experiments with ignition scale capsules. The Omega Hohlraums are 1900 microm length x 1200 microm diameter and have a 70% laser entrance hole. This is approximately a 0.2 NIF scale ignition Hohlraum and reaches temperatures of 265-275 eV similar to those during the peak of the NIF drive. These capsules can be used as a diagnostic of shell rho r, since the d-(3)He gas fill produces 14.7 MeV protons in the implosion, which escape through the shell and produce a proton spectrum that depends on the integrated rho r of the remaining shell mass. The neutron yield, proton yield, and spectra change with capsule shell thickness as the unablated mass or remaining capsule rho r changes. Proton stopping models are used to infer shell unablated mass and shell rho r from the proton spectra measured with different filter thicknesses. The experiment is well modeled with respect to Hohlraum energetics, neutron yields, and x-ray imploded core image size, but there are discrepancies between the observed and simulated proton spectra.

The ICF status and plans in the United States

International Nuclear Information System (INIS)

Moses, E.I.; Miller, G.H.; Kauffman, R.L.

2006-01-01

The United States continues to maintain its leadership in inertial confinement fusion as it moves toward the goal of ignition. The flagship of the program is the National Ignition Facility (NIF) presently under construction at Lawrence Livermore National Laboratory. Experiments had begun on the first four beams of the National Ignition Facility just at the time of the last IFSA Conference. Several new successful campaigns have been conducted since then in planar hydrodynamics and hohlraums as well as activating the VISAR diagnostic for equation of state experiments. Highlights of these results will be reviewed. Presently, the four beam experimental capability has been suspended while the first eight beams are being installed as the first step in building out the project. Meanwhile, much progress has been made in developing ignition designs for using NIF. An array of designs having several ablator materials have been shown computationally to ignite with energies ranging from the design energy to as low as 1 MJ of laser energy. Alternative direct drive designs in the NIF indirect drive configuration have been developed by LLE. This wide array of design choices has increased the chance of achieving ignition sooner on the facility. Plans are now being developed to begin an ignition experimental campaign on NIF in 2010, a little over a year after completion of the facility. Other US facilities are also implementing improved capabilities. Peta-watt lasers are now under construction at the University of Rochester and Sandia National Laboratory. The Z pulsed power machine at Sandia National Laboratory is being refurbished to improve its performance. The ongoing research program at the OMEGA laser at the University of Rochester and the Z machine at Sandia National Laboratory as well as at the Nike, Trident and Janus lasers remain strong, performing experiments supporting the NIF ignition plan and direct drive ignition. There also is an active program in the broader field of

The ICF status and plans in the United States

Energy Technology Data Exchange (ETDEWEB)

Moses, E.I.; Miller, G.H.; Kauffman, R.L. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

2006-06-15

The United States continues to maintain its leadership in inertial confinement fusion as it moves toward the goal of ignition. The flagship of the program is the National Ignition Facility (NIF) presently under construction at Lawrence Livermore National Laboratory. Experiments had begun on the first four beams of the National Ignition Facility just at the time of the last IFSA Conference. Several new successful campaigns have been conducted since then in planar hydrodynamics and hohlraums as well as activating the VISAR diagnostic for equation of state experiments. Highlights of these results will be reviewed. Presently, the four beam experimental capability has been suspended while the first eight beams are being installed as the first step in building out the project. Meanwhile, much progress has been made in developing ignition designs for using NIF. An array of designs having several ablator materials have been shown computationally to ignite with energies ranging from the design energy to as low as 1 MJ of laser energy. Alternative direct drive designs in the NIF indirect drive configuration have been developed by LLE. This wide array of design choices has increased the chance of achieving ignition sooner on the facility. Plans are now being developed to begin an ignition experimental campaign on NIF in 2010, a little over a year after completion of the facility. Other US facilities are also implementing improved capabilities. Peta-watt lasers are now under construction at the University of Rochester and Sandia National Laboratory. The Z pulsed power machine at Sandia National Laboratory is being refurbished to improve its performance. The ongoing research program at the OMEGA laser at the University of Rochester and the Z machine at Sandia National Laboratory as well as at the Nike, Trident and Janus lasers remain strong, performing experiments supporting the NIF ignition plan and direct drive ignition. There also is an active program in the broader field of

The ICF Status and Plans in the United States

International Nuclear Information System (INIS)

Moses, E; Miller, G; Kauffman, R

2005-01-01

The United States continues to maintain its leadership in ICF as it moves toward the goal of ignition. The flagship of the program is the National Ignition Facility (NIF) presently under construction at LLNL. Experiments had begun on the first four beams of the National Ignition Facility just at the time of the last IFSA Conference. Several new successful campaigns have been conducted since then in planar hydrodynamics and hohlraums as well as activating the VISAR diagnostic for equation of state experiments. Highlights of these results will be reviewed. Presently, the four beam experimental capability has been suspended while the first eight beams are being installed as the first step in building out the project. Meanwhile, much progress has been made in developing ignition designs for using NIF. An array of designs having several ablator materials have been shown computationally to ignite with energies ranging from the design energy to as low as 1 MJ of laser energy. Alternative direct drive designs in the NIF indirect drive configuration have been developed by LLE. This wide array of design choices has increased the chance of achieving ignition sooner on the facility. Plans are now being developed to begin an ignition experimental campaign on NIF in 2010, a little over a year after completion of the facility. Other US facilities are also implementing improved capabilities. Petawatt lasers are now under construction at the University of Rochester and Sandia National Laboratory. The Z pulsed power machine at Sandia National Laboratory is being refurbished to improve its performance. The ongoing research program at the OMEGA laser at the University of Rochester and the Z machine at Sandia National Laboratory as well as at the Nike, Trident and Janus lasers remain strong, performing experiments supporting the NIF ignition plan and direct drive ignition. There also is an active program in the broader field of high energy density science on these facilities. These

Evaulation of B4C as an ablator material for NIF capsules. Revision 1

International Nuclear Information System (INIS)

Burnham, A.K.; Alford, C.S.; Makowiecki, D.M.; Dittrich, T.R.; Wallace, R.J.; Honea, E.C.; King, C.M.; Steinman, D.

1997-01-01

Boron carbide (B 4 C) is examined as a potential fuel container and ablator for implosion capsules on the National Ignition Facility (NIF). A capsule of pure B 4 C encasing a layer of solid DT implodes stably and ignites with anticipated NIF x-ray drives, producing 18 MJ of energy. Thin films of B 4 C were found to be resistant to oxidation and modestly transmitting in the infrared (IR), possibly enabling IR fuel characterization and enhancement for thin permeation barriers but not for full-thickness capsules. Polystyrene mandrels 0.5 mm in diameter were successfully coated with 0.15-2.0 micrometers of B 4 C. Thickness estimated from optical density agreed well with those measured by scanning electron microscopy (SEM). The B 4 C microstructure was columnar but finer than for Be made at the same conditions. B 4 C is a very strong material, with a fiber tensile strength capable of holding NIF fill pressures at room temperature, but it is also very brittle, and microscopic flaws or grain structure may limit the noncryogenic fill pressure. Argon (Ar) permeation rates were measured for a few capsules that had been further coated with 5 micrometers of plasma polymer. The B 4 C coatings tended to crack under tensile load. Some shells filled more slowly than they leaked, suggesting that the cracks open and close under opposite pressure loading. As observed earlier for Ti coatings, 0.15-micrometer layers of B 4 C had better gas retention properties than 2-micrometer layers, possibly because of fewer cracks. Permeation and fill strength issues for capsules with a full ablator thickness of B 4 C are unresolved. 21 refs., 6 figs

Status of Indirect Drive ICF Experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Dewald, E.

2016-01-01

In the quest to demonstrate Inertial Confinement Fusion (ICF) ignition of deuterium-tritium (DT) filled capsules and propagating thermonuclear burn with net energy gain (fusion energy/laser energy >1), recent experiments on the National Ignition Facility (NIF) have shown progress towards increasing capsule hot spot temperature (T ion >5 keV) and fusion neutron yield (~10 16 ), while achieving ~2x yield amplification by alpha particle deposition. At the same time a performance cliff was reached, resulting in lower fusion yields than expected as the implosion velocity was increased. Ongoing studies of the hohlraum and capsule physics are attempting to disseminate possible causes for this performance ceiling.

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

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

Science.gov (United States)

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

2006-12-01

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

Recent progress on the National Ignition Facility advanced radiographic capability

Energy Technology Data Exchange (ETDEWEB)

Wegner, P.; Bowers, M.; Chen, H.; Heebner, J.; Hermann, M.; Kalantar, D.; Martinez, D.

2016-01-08

The National Ignition Facility (NIF) is a megajoule (million-joule)-class laser and experimental facility built for Stockpile Stewardship and High Energy Density (HED) science research [1]. Up to several times a day, 192 laser pulses from NIF's 192 laser beamlines converge on a millimeter-scale target located at the center of the facility's 10-meter diameter target chamber. The carefully synchronized pulses, typically a few nanoseconds (billionths of a second) in duration and co-times to better than 20 picoseconds (trillionths of a second), a deliver a combined energy of up to 1.8 megajoules and a peak power of 500 terawatts (trillion watts). Furthermore, this drives temperatures inside the target to tens of millions of degrees and pressures to many billion times greater than Earth's atmosphere.

Sensitivity of chemical vapor deposition diamonds to DD and DT neutrons at OMEGA and the National Ignition Facility

Science.gov (United States)

Kabadi, N. V.; Sio, H.; Glebov, V.; Gatu Johnson, M.; MacPhee, A.; Frenje, J. A.; Li, C. K.; Seguin, F.; Petrasso, R.; Forrest, C.; Knauer, J.; Rinderknecht, H. G.

2016-11-01

The particle-time-of-flight (pTOF) detector at the National Ignition Facility (NIF) is used routinely to measure nuclear bang-times in inertial confinement fusion implosions. The active detector medium in pTOF is a chemical vapor deposition diamond. Calibration of the detectors sensitivity to neutrons and protons would allow measurement of nuclear bang times and hot spot areal density (ρR) on a single diagnostic. This study utilizes data collected at both NIF and Omega in an attempt to determine pTOF's absolute sensitivity to neutrons. At Omega pTOF's sensitivity to DT-n is found to be stable to within 8% at different bias voltages. At the NIF pTOF's sensitivity to DD-n varies by up to 59%. This variability must be decreased substantially for pTOF to function as a neutron yield detector at the NIF. Some possible causes of this variability are ruled out.

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...

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

Science.gov (United States)

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

2009-04-08

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

National Ignition Facility and managing location, component, and state

Energy Technology Data Exchange (ETDEWEB)

Foxworthy, Cemil, E-mail: foxworthy3@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA (United States); Fung, Tracy; Beeler, Rich; Li, Joyce; Dugorepec, Jasna; Chang, Cathy [Lawrence Livermore National Laboratory, Livermore, CA (United States)

2012-12-15

Highlights: Black-Right-Pointing-Pointer NIF in comprised of over 100k serialized parts that must be tracked and maintained. Black-Right-Pointing-Pointer We discuss a web-based integrated parts management system designed for NIF. Black-Right-Pointing-Pointer The parts database stores associated calibration data with effective dates. Black-Right-Pointing-Pointer The system interfaces with the NIF control system and performance models. Black-Right-Pointing-Pointer Work activity (Permits, Problem Logs, Work Orders) are managed by the system. - Abstract: The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that contains a 192-beam, 1.8-MJ, 500-TW, ultraviolet laser system coupled with a 10-m diameter target chamber. There are over 6200 Line Replaceable Units (LRUs) comprised of more than 104,000 serialized parts that make up the NIF. Each LRU is a modular unit typically composed of a mechanical housing, laser optics (glass, lenses, or mirrors), and utilities. To date, there are more than 120,000 data sets created to characterize the attributes of these parts. Greater than 51,000 Work Permits have been issued to install, maintain, and troubleshoot the components. One integrated system is used to manage these data, and more. The Location Component and State (LoCoS) system is a web application built using Java Enterprise Edition technologies and is accessed by over 1200 users. It is either directly or indirectly involved with each aspect of NIF work activity, and interfaces with ten external systems including the Integrated Computer Control System (ICCS) and the Laser Performance Operations Model (LPOM). Besides providing business functionality, LoCoS also acts as the NIF enterprise service bus. In this role, numerous integration approaches had to be adopted including: file exchange, database sharing, queuing, and web services in order to accommodate various business, technical, and security requirements

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.

An in-flight radiography platform to measure hydrodynamic instability growth in inertial confinement fusion capsules at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Raman, K. S.; Smalyuk, V. A.; Casey, D. T.; Haan, S. W.; Hurricane, O. A.; Kroll, J. J.; Peterson, J. L.; Remington, B. A.; Robey, H. F.; Clark, D. S.; Hammel, B. A.; Landen, O. L.; Marinak, M. M.; Munro, D. H.; Salmonson, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hoover, D. E.; Nikroo, A. [General Atomics, San Diego, California 92121 (United States); Peterson, K. J. [Sandia National Laboratory, Albuquerque, New Mexico 87125 (United States)

2014-07-15

A new in-flight radiography platform has been established at the National Ignition Facility (NIF) to measure Rayleigh–Taylor and Richtmyer–Meshkov instability growth in inertial confinement fusion capsules. The platform has been tested up to a convergence ratio of 4. An experimental campaign is underway to measure the growth of pre-imposed sinusoidal modulations of the capsule surface, as a function of wavelength, for a pair of ignition-relevant laser drives: a “low-foot” drive representative of what was fielded during the National Ignition Campaign (NIC) [Edwards et al., Phys. Plasmas 20, 070501 (2013)] and the new high-foot [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014)] pulse shape, for which the predicted instability growth is much lower. We present measurements of Legendre modes 30, 60, and 90 for the NIC-type, low-foot, drive, and modes 60 and 90 for the high-foot drive. The measured growth is consistent with model predictions, including much less growth for the high-foot drive, demonstrating the instability mitigation aspect of this new pulse shape. We present the design of the platform in detail and discuss the implications of the data it generates for the on-going ignition effort at NIF.

An in-flight radiography platform to measure hydrodynamic instability growth in inertial confinement fusion capsules at the National Ignition Facility

International Nuclear Information System (INIS)

Raman, K. S.; Smalyuk, V. A.; Casey, D. T.; Haan, S. W.; Hurricane, O. A.; Kroll, J. J.; Peterson, J. L.; Remington, B. A.; Robey, H. F.; Clark, D. S.; Hammel, B. A.; Landen, O. L.; Marinak, M. M.; Munro, D. H.; Salmonson, J.; Hoover, D. E.; Nikroo, A.; Peterson, K. J.

2014-01-01

A new in-flight radiography platform has been established at the National Ignition Facility (NIF) to measure Rayleigh–Taylor and Richtmyer–Meshkov instability growth in inertial confinement fusion capsules. The platform has been tested up to a convergence ratio of 4. An experimental campaign is underway to measure the growth of pre-imposed sinusoidal modulations of the capsule surface, as a function of wavelength, for a pair of ignition-relevant laser drives: a “low-foot” drive representative of what was fielded during the National Ignition Campaign (NIC) [Edwards et al., Phys. Plasmas 20, 070501 (2013)] and the new high-foot [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014)] pulse shape, for which the predicted instability growth is much lower. We present measurements of Legendre modes 30, 60, and 90 for the NIC-type, low-foot, drive, and modes 60 and 90 for the high-foot drive. The measured growth is consistent with model predictions, including much less growth for the high-foot drive, demonstrating the instability mitigation aspect of this new pulse shape. We present the design of the platform in detail and discuss the implications of the data it generates for the on-going ignition effort at NIF

Development of the CD Symcap platform to study gas-shell mix in implosions at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Casey, D. T.; Smalyuk, V. A.; Tipton, R. E.; Pino, J. E.; Remington, B. A.; Rowley, D. P.; Weber, S. V.; Barrios, M.; Benedetti, L. R.; Bleuel, D. L.; Bond, E. J.; Bradley, D. K.; Caggiano, J. A.; Callahan, D. A.; Cerjan, C. J.; Edwards, M. J.; Fittinghoff, D.; Glenn, S.; Haan, S. W.; Hamza, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2014-09-15

Surrogate implosions play an important role at the National Ignition Facility (NIF) for isolating aspects of the complex physical processes associated with fully integrated ignition experiments. The newly developed CD Symcap platform has been designed to study gas-shell mix in indirectly driven, pure T{sub 2}-gas filled CH-shell implosions equipped with 4 μm thick CD layers. This configuration provides a direct nuclear signature of mix as the DT yield (above a characterized D contamination background) is produced by D from the CD layer in the shell, mixing into the T-gas core. The CD layer can be placed at different locations within the CH shell to probe the depth and extent of mix. CD layers placed flush with the gas-shell interface and recessed up to 8 μm have shown that most of the mix occurs at the inner-shell surface. In addition, time-gated x-ray images of the hotspot show large brightly radiating objects traversing through the hotspot around bang-time, which are likely chunks of CH/CD plastic. This platform is a powerful new capability at the NIF for understanding mix, one of the key performance issues for ignition experiments.

Origins and Scaling of Hot-Electron Preheat in Ignition-Scale Direct-Drive Inertial Confinement Fusion Experiments.

Science.gov (United States)

Rosenberg, M J; Solodov, A A; Myatt, J F; Seka, W; Michel, P; Hohenberger, M; Short, R W; Epstein, R; Regan, S P; Campbell, E M; Chapman, T; Goyon, C; Ralph, J E; Barrios, M A; Moody, J D; Bates, J W

2018-02-02

Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for the first time to regimes of electron density scale length (∼500 to 700  μm), electron temperature (∼3 to 5 keV), and laser intensity (6 to 16×10^{14}  W/cm^{2}) that are relevant to direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data on the NIF show that the near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than by two-plasmon decay (TPD). This difference in regime is explained based on absolute SRS and TPD threshold considerations. SRS sidescatter tangential to density contours and other SRS mechanisms are observed. The fraction of laser energy converted to hot electrons is ∼0.7% to 2.9%, consistent with observed levels of SRS. The intensity threshold for hot-electron production is assessed, and the use of a Si ablator slightly increases this threshold from ∼4×10^{14} to ∼6×10^{14}  W/cm^{2}. These results have significant implications for mitigation of LPI hot-electron preheat in direct-drive ignition designs.

Construction safety program for the National Ignition Facility, July 30, 1999 (NIF-0001374-OC)

International Nuclear Information System (INIS)

Benjamin, D. W.

1999-01-01

These rules apply to all LLNL employees, non-LLNL employees (including contract labor, supplemental labor, vendors, personnel matrixed/assigned from other National Laboratories, participating guests, visitors and students) and contractors/subcontractors. The General Rules-Code of Safe Practices shall be used by management to promote accident prevention through indoctrination, safety and health training and on-the-job application. As a condition for contracts award, all contractors and subcontractors and their employees must certify on Form S and H A-l that they have read and understand, or have been briefed and understand, the National Ignition Facility OCIP Project General Rules-Code of Safe Practices. (An interpreter must brief those employees who do not speak or read English fluently.) In addition, all contractors and subcontractors shall adopt a written General Rules-Code of Safe Practices that relates to their operations. The General Rules-Code of Safe Practices must be posted at a conspicuous location at the job site office or be provided to each supervisory employee who shall have it readily available. Copies of the General Rules-Code of Safe Practices can also be included in employee safety pamphlets

Effect of amplifier component maintenance on laser system availability and reliability for the US National Ignition Facility

International Nuclear Information System (INIS)

Erlandson, A.C.; Lambert, H.; Zapata, L.E.

1996-12-01

We have analyzed the availability and reliability of the flashlamp-pumped, Nd:glass amplifiers that, as a part of a laser now being designed for future experiments, in inertial confinement fusion (ICF), will be used in the National Ignition Facility (NIF). Clearly , in order for large ICF systems such as the NIF to operate effectively as a whole, all components must meet demanding availability and reliability requirements. Accordingly, the NIF amplifiers can achieve high reliability and availability by using reliable parts, and by using a cassette-based maintenance design that allows most key amplifier parts to be 1744 replaced within a few hours. In this way, parts that degrade slowly, as the laser slabs, silver reflectors, and blastshields can be expected to do, based on previous experience, can be replaced either between shots or during scheduled maintenance periods, with no effect on availability or reliability. In contrast, parts that fail rapidly, such as the flashlamps, can and do cause unavailability or unreliability. Our analysis demonstrates that the amplifiers for the NIF will meet availability and reliability goals, respectively, of 99.8% and 99.4%, provided that the 7680 NIF flashlamps in NIF have failure rates of less than, or equal to, those experienced on Nova, a 5000-lamp laser at Lawrence Livermore National Laboratory (LLNL)

Using penumbral imaging to measure micrometer size plasma hot spots in Gbar equation of state experiments on the National Ignition Facility.

Science.gov (United States)

Bachmann, B; Kritcher, A L; Benedetti, L R; Falcone, R W; Glenn, S; Hawreliak, J; Izumi, N; Kraus, D; Landen, O L; Le Pape, S; Ma, T; Pérez, F; Swift, D; Döppner, T

2014-11-01

We have developed an experimental platform for absolute equation of state measurements up to Gbar pressures on the National Ignition Facility (NIF) within the Fundamental Science Program. We use a symmetry-tuned hohlraum drive to launch a spherical shock wave into a solid CH sphere. Streaked radiography is the primary diagnostic to measure the density change at the shock front as the pressure increases towards smaller radii. At shock stagnation in the center of the capsule, we observe a short and bright x-ray self emission from high density (∼50 g/cm(3)) plasma at ∼1 keV. Here, we present results obtained with penumbral imaging which has been carried out to characterize the size of the hot spot emission. This allows extending existing NIF diagnostic capabilities for spatial resolution (currently ∼10 μm) at higher sensitivity. At peak emission we find the hot spot radius to be as small as 5.8 +/- 1 μm, corresponding to a convergence ratio of 200.

Using penumbral imaging to measure micrometer size plasma hot spots in Gbar equation of state experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Bachmann, B.; Kritcher, A. L.; Benedetti, L. R.; Glenn, S.; Hawreliak, J.; Izumi, N.; Landen, O. L.; Le Pape, S.; Ma, T.; Pérez, F.; Swift, D.; Döppner, T.; Falcone, R. W.; Kraus, D.

2014-01-01

We have developed an experimental platform for absolute equation of state measurements up to Gbar pressures on the National Ignition Facility (NIF) within the Fundamental Science Program. We use a symmetry-tuned hohlraum drive to launch a spherical shock wave into a solid CH sphere. Streaked radiography is the primary diagnostic to measure the density change at the shock front as the pressure increases towards smaller radii. At shock stagnation in the center of the capsule, we observe a short and bright x-ray self emission from high density (∼50 g/cm 3 ) plasma at ∼1 keV. Here, we present results obtained with penumbral imaging which has been carried out to characterize the size of the hot spot emission. This allows extending existing NIF diagnostic capabilities for spatial resolution (currently ∼10 μm) at higher sensitivity. At peak emission we find the hot spot radius to be as small as 5.8 +/− 1 μm, corresponding to a convergence ratio of 200

National Ignition Facility and Managing Location, Component, and State

Energy Technology Data Exchange (ETDEWEB)

Foxworthy, C; Fung, T; Beeler, R; Li, J; Dugorepec, J; Chang, C

2011-07-25

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that contains a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system coupled with a 10-meter diameter target chamber. There are over 6,200 Line Replaceable Units (LRUs) comprised of more than 104,000 serialized parts that make up the NIF. Each LRU is a modular unit typically composed of a mechanical housing, laser optics (glass, lenses, or mirrors), and utilities. To date, there are more than 120,000 data sets created to characterize the attributes of these parts. Greater than 51,000 Work Permits have been issued to install, maintain, and troubleshoot the components. One integrated system is used to manage these data, and more. The Location Component and State (LoCoS) system is a web application built using Java Enterprise Edition technologies and is accessed by over 1,200 users. It is either directly or indirectly involved with each aspect of NIF work activity, and interfaces with ten external systems including the Integrated Computer Control System (ICCS) and the Laser Performance Operations Model (LPOM). Besides providing business functionality, LoCoS also acts as the NIF enterprise service bus. In this role, numerous integration approaches had to be adopted including: file exchange, database sharing, queuing, and web services in order to accommodate various business, technical, and security requirements. Architecture and implementation decisions are discussed.

National Ignition Facility and Managing Location, Component, and State

International Nuclear Information System (INIS)

Foxworthy, C.; Fung, T.; Beeler, R.; Li, J.; Dugorepec, J.; Chang, C.

2011-01-01

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that contains a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system coupled with a 10-meter diameter target chamber. There are over 6,200 Line Replaceable Units (LRUs) comprised of more than 104,000 serialized parts that make up the NIF. Each LRU is a modular unit typically composed of a mechanical housing, laser optics (glass, lenses, or mirrors), and utilities. To date, there are more than 120,000 data sets created to characterize the attributes of these parts. Greater than 51,000 Work Permits have been issued to install, maintain, and troubleshoot the components. One integrated system is used to manage these data, and more. The Location Component and State (LoCoS) system is a web application built using Java Enterprise Edition technologies and is accessed by over 1,200 users. It is either directly or indirectly involved with each aspect of NIF work activity, and interfaces with ten external systems including the Integrated Computer Control System (ICCS) and the Laser Performance Operations Model (LPOM). Besides providing business functionality, LoCoS also acts as the NIF enterprise service bus. In this role, numerous integration approaches had to be adopted including: file exchange, database sharing, queuing, and web services in order to accommodate various business, technical, and security requirements. Architecture and implementation decisions are discussed.

Physics issues related to the confinement of ICF experiments in the US National Ignition Facility

International Nuclear Information System (INIS)

Tobin, M.; Anderson, A.; Latkowski, J.

1995-04-01

ICF experiments planned for the proposed US National Ignition Facility (NIF) will produce emissions of neutrons, x rays, debris, and shrapnel. The NIF Target Area (TA) must acceptably confine these emissions and respond to their effects to allow an efficient rate of experiments, from 600 to possibly 1500 per year, and minimal down time for maintenance. Detailed computer code predictions of emissions are necessary to study their effects and impacts on Target Area operations. Preliminary results show that the rate of debris shield transmission loss (and subsequent periodicity of change-out) due to ablated material deposition is acceptable, neutron effects on optics are manageable, and preliminary safety analyses show a facility rating of low hazard, non-nuclear. Therefore, NIF Target Area design features such as fused silica debris shields, refractory first wall coating, and concrete shielding are effective solutions to confinement of ICF experiment emissions

Symmetry tuning with megajoule laser pulses at the National Ignition Facility

Directory of Open Access Journals (Sweden)

Kline J.L.

2013-11-01

Full Text Available Experiments conducted at the National Ignition Facility using shaped laser pulses with more than 1 MJ of energy have demonstrated the ability to control the implosion symmetry under ignition conditions. To achieve thermonuclear ignition, the low mode asymmetries must be small to minimize the size of the hotspot. The symmetry tuning experiments use symmetry capsules, “symcaps”, which replace the DT fuel with an equivalent mass of CH to emulate the hydrodynamic behavior of an ignition capsule. The x-ray self-emission signature from gas inside the capsule during the peak compression correlates with the surrounding hotspot shape. By tuning the shape of the self-emission, the capsule implosion symmetry can be made to be “round.” In the experimental results presented here, we utilized crossbeam energy transfer [S. H. Glenzer, et al., Science 327, 1228 (2010] to change the ratio of the inner to outer cone power inside the hohlraum targets on the NIF. Variations in the ratio of the inner cone to outer cone power affect the radiation pattern incident on the capsule modifying the implosion symmetry.

Spatial filter lens design for the main laser of the National Ignition Facility

International Nuclear Information System (INIS)

Korniski, R.J.

1998-01-01

The National Ignition Facility (NIF), being designed and constructed at Lawrence Livermore National Laboratory (LLNL), comprises 192 laser beams The lasing medium is neodymium in phosphate glass with a fundamental frequency (1ω) of 1 053microm Sum frequency generation in a pair of conversion crystals (KDP/KD*P) will produce 1 8 megajoules of the third harmonic light (3ω or λ=351microm) at the target The purpose of this paper is to provide the lens design community with the current lens design details of the large optics in the Main Laser This paper describes the lens design configuration and design considerations of the Main Laser The Main Laser is 123 meters long and includes two spatial filters one 13 5 meters and one 60 meters These spatial filters perform crucial beam filtering and relaying functions We shall describe the significant lens design aspects of these spatial filter lenses which allow them to successfully deliver the appropriate beam characteristic onto the target For an overview of NIF please see ''Optical system design of the National Ignition Facility,'' by R Edward English. et al also found in this volume

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

Mode 1 drive asymmetry in inertial confinement fusion implosions on the National Ignition Facility

International Nuclear Information System (INIS)

Spears, Brian K.; Edwards, M. J.; Hatchett, S.; Kritcher, A.; Lindl, J.; Munro, D.; Patel, P.; Robey, H. F.; Town, R. P. J.; Kilkenny, J.; Knauer, J.

2014-01-01

Mode 1 radiation drive asymmetry (pole-to-pole imbalance) at significant levels can have a large impact on inertial confinement fusion implosions at the National Ignition Facility (NIF). This asymmetry distorts the cold confining shell and drives a high-speed jet through the hot spot. The perturbed hot spot shows increased residual kinetic energy and reduced internal energy, and it achieves reduced pressure and neutron yield. The altered implosion physics manifests itself in observable diagnostic signatures, especially the neutron spectrum which can be used to measure the neutron-weighted flow velocity, apparent ion temperature, and neutron downscattering. Numerical simulations of implosions with mode 1 asymmetry show that the resultant simulated diagnostic signatures are moved toward the values observed in many NIF experiments. The diagnostic output can also be used to build a set of integrated implosion performance metrics. The metrics indicate that P 1 has a significant impact on implosion performance and must be carefully controlled in NIF implosions

Mode 1 drive asymmetry in inertial confinement fusion implosions on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Spears, Brian K., E-mail: spears9@llnl.gov; Edwards, M. J.; Hatchett, S.; Kritcher, A.; Lindl, J.; Munro, D.; Patel, P.; Robey, H. F.; Town, R. P. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); Kilkenny, J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Knauer, J. [Laboratory for Laser Energetics, 250 E. River Road Rochester, New York 14623-1212 (United States)

2014-04-15

Mode 1 radiation drive asymmetry (pole-to-pole imbalance) at significant levels can have a large impact on inertial confinement fusion implosions at the National Ignition Facility (NIF). This asymmetry distorts the cold confining shell and drives a high-speed jet through the hot spot. The perturbed hot spot shows increased residual kinetic energy and reduced internal energy, and it achieves reduced pressure and neutron yield. The altered implosion physics manifests itself in observable diagnostic signatures, especially the neutron spectrum which can be used to measure the neutron-weighted flow velocity, apparent ion temperature, and neutron downscattering. Numerical simulations of implosions with mode 1 asymmetry show that the resultant simulated diagnostic signatures are moved toward the values observed in many NIF experiments. The diagnostic output can also be used to build a set of integrated implosion performance metrics. The metrics indicate that P{sub 1} has a significant impact on implosion performance and must be carefully controlled in NIF implosions.

The First Experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Landen, O L; Glenzer, S; Froula, D; Dewald, E; Suter, L J; Schneider, M; Hinkel, D; Fernandez, J; Kline, J; Goldman, S; Braun, D; Celliers, P; Moon, S; Robey, H; Lanier, N; Glendinning, G; Blue, B; Wilde, B; Jones, O; Schein, J; Divol, L; Kalantar, D; Campbell, K; Holder, J; MacDonald, J; Niemann, C; Mackinnon, A; Collins, R; Bradley, D; Eggert, J; Hicks, D; Gregori, G; Kirkwood, R; Young, B; Foster, J; Hansen, F; Perry, T; Munro, D; Baldis, H; Grim, G; Heeter, R; Hegelich, B; Montgomery, D; Rochau, G; Olson, R; Turner, R; Workman, J; Berger, R; Cohen, B; Kruer, W; Langdon, B; Langer, S; Meezan, N; Rose, H; Still, B; Williams, E; Dodd, E; Edwards, J; Monteil, M; Stevenson, M; Thomas, B; Coker, R; Magelssen, G; Rosen, P; Stry, P; Woods, D; Weber, S; Alvarez, S; Armstrong, G; Bahr, R; Bourgade, J; Bower, D; Celeste, J; Chrisp, M; Compton, S; Cox, J; Constantin, C; Costa, R; Duncan, J; Ellis, A; Emig, J; Gautier, C; Greenwood, A; Griffith, R; Holdner, F; Holtmeier, G; Hargrove, D; James, T; Kamperschroer, J; Kimbrough, J; Landon, M; Lee, D; Malone, R; May, M; Montelongo, S; Moody, J; Ng, E; Nikitin, A; Pellinen, D; Piston, K; Poole, M; Rekow, V; Rhodes, M; Shepherd, R; Shiromizu, S; Voloshin, D; Warrick, A; Watts, P; Weber, F; Young, P; Arnold, P; Atherton, L J; Bardsley, G; Bonanno, R; Borger, T; Bowers, M; Bryant, R; Buckman, S; Burkhart, S; Cooper, F; Dixit, S; Erbert, G; Eder, D; Ehrlich, B; Felker, B; Fornes, J; Frieders, G; Gardner, S; Gates, C; Gonzalez, M; Grace, S; Hall, T; Haynam, C; Heestand, G; Henesian, M; Hermann, M; Hermes, G; Huber, S; Jancaitis, K; Johnson, S; Kauffman, B; Kelleher, T; Kohut, T; Koniges, A E; Labiak, T; Latray, D; Lee, A; Lund, D; Mahavandi, S; Manes, K R; Marshall, C; McBride, J; McCarville, T; McGrew, L; Menapace, J.

2005-01-01

A first set of laser-plasma interaction, hohlraum energetics and hydrodynamic experiments have been performed using the first 4 beams of the National Ignition Facility (NIF), in support of indirect drive Inertial Confinement Fusion (ICF) and High Energy Density Physics (HEDP). In parallel, a robust set of optical and x-ray spectrometers, interferometer, calorimeters and imagers have been activated. The experiments have been undertaken with laser powers and energies of up to 8 TW and 17 kJ in flattop and shaped 1-9 ns pulses focused with various beam smoothing options

2x1 prototype plasma-electrode pockels cell (PEPC) for the National Ignition Facility

International Nuclear Information System (INIS)

Rhodes, M. A.

1996-10-01

A large aperture optical switch based on plasma electrode Pockels cell (PEPC) technology is an integral part of the National Ignition Facility (NIP) laser design. This optical switch will trap the input optical pulse in the NIF amplifier cavity for four gain passes and then switch the high-energy output optical pulse out of the cavity. The switch will consist of arrays of plasma electrode Pockels cells working in conjunction with thin-film, Brewster's angle polarizes. The 192 beams in the NIF will be arranged in 4x2 bundles. To meet the required beam-to-beam spacing within each bundle, we have proposed a NIF PEPC design based on a 4x1 mechanical module (column) which is in turn comprised of two electrically independent 2x1 PEPC units. In this paper, we report on the design a single 2x1 prototype module and experimental tests of important design issues using our single, 32 cm aperture PEPC prototype. The purpose the 2x1 prototype is to prove the viability of a 2x1 PEPC and to act, as an engineering test bed for the NIF PEPC design

Building a World-Class Safety Culture: The National Ignition Facility and the Control of Human and Organizational Error

International Nuclear Information System (INIS)

Bennett, C T; Stalnaker, G

2002-01-01

Accidents in complex systems send us signals. They may be harbingers of a catastrophe. Some even argue that a ''normal'' consequence of operations in a complex organization may not only be the goods it produces, but also accidents and--inevitably--catastrophes. We would like to tell you the story of a large, complex organization, whose history questions the argument ''that accidents just happen.'' Starting from a less than enviable safety record, the National Ignition Facility (NIF) has accumulated over 2.5 million safe hours. The story of NIF is still unfolding. The facility is still being constructed and commissioned. But the steps NIF has taken in achieving its safety record provide a principled blueprint that may be of value to others. Describing that principled blueprint is the purpose of this paper. The first part of this paper is a case study of NIF and its effort to achieve a world-class safety record. This case study will include a description of (1) NIF's complex systems, (2) NIF's early safety history, (3) factors that may have initiated its safety culture change, and (4) the evolution of its safety blueprint. In the last part of the paper, we will compare NIF's safety culture to what safety industry experts, psychologists, and sociologists say about how to shape a culture and control organizational error

Hot spot mix in ICF implosions on the NIF

Science.gov (United States)

Ma, Tammy

2016-10-01

In the quest to achieve ignition through the inertial confinement fusion scheme, one of the critical challenges is to drive a symmetric implosion at high velocity without hydrodynamic instabilities becoming detrimental. These instabilities, primarily at the ablation front and the fuel-ablator interface, can cause mix of the higher-Z shell into the hot spot, resulting in increased radiation loss and thus reduced temperature and neutron yield. To quantify the level of mix, we developed a model that infers the level of hot spot contamination using the ratio of the enhanced x-ray production relative to the neutron yield. Applying this methodology to the full ensemble of indirect-drive National Ignition Facility (NIF) cryogenically layered DT implosions provides insight on the sensitivity of performance to the level of ablator-hot spot mix. In particular, the improvement seen with the High Foot design can be primarily attributed to a reduction in ablation-front instability mix that enabled the implosions to be pushed to higher velocity and performance. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, Lawrence Livermore National Security, LLC.

First Laser-Plasma Interaction and Hohlraum Experiments on NIF

International Nuclear Information System (INIS)

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

2005-01-01

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

Radiochemical determination of Inertial Confinement Fusion capsule compression at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Shaughnessy, D. A., E-mail: shaughnessy2@llnl.gov; Moody, K. J.; Gharibyan, N.; Grant, P. M.; Gostic, J. M.; Torretto, P. C.; Wooddy, P. T.; Bandong, B. B.; Cerjan, C. J.; Hagmann, C. A.; Caggiano, J. A.; Yeamans, C. B.; Bernstein, L. A.; Schneider, D. H. G.; Henry, E. A.; Fortner, R. J. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States); Despotopulos, J. D. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States); Radiochemistry Program, University of Nevada Las Vegas, Las Vegas, Nevada 89154 (United States)

2014-06-15

We describe a radiochemical measurement of the ratio of isotope concentrations produced in a gold hohlraum surrounding an Inertial Confinement Fusion capsule at the National Ignition Facility (NIF). We relate the ratio of the concentrations of (n,γ) and (n,2n) products in the gold hohlraum matrix to the down-scatter of neutrons in the compressed fuel and, consequently, to the fuel's areal density. The observed ratio of the concentrations of {sup 198m+g}Au and {sup 196g}Au is a performance signature of ablator areal density and the fuel assembly confinement time. We identify the measurement of nuclear cross sections of astrophysical importance as a potential application of the neutrons generated at the NIF.

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

Science.gov (United States)

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

2015-09-01

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

Modeling NIF experimental designs with adaptive mesh refinement and Lagrangian hydrodynamics

Science.gov (United States)

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

2006-06-01

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

Modeling NIF Experimental Designs with Adaptive Mesh Refinement and Lagrangian Hydrodynamics

International Nuclear Information System (INIS)

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

2005-01-01

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

Modeling Nif experimental designs with adaptive mesh refinement and Lagrangian hydrodynamics

International Nuclear Information System (INIS)

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

2006-01-01

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

Analysis of thermal issues associated with the pre-amplifier modules in the National Ignition Facility

International Nuclear Information System (INIS)

Lam, K.L.

1998-01-01

The design of the National Ignition Facility (NIF) calls for a desired temperature field of 20.00 ± 0.28 C throughout the facility. This design requirement is needed to prevent degradation of the operating performance and net yield of the NIF by heat loads generated within the facility. In particular, the potential interference of waste heat from the lighting fixtures and equipment such as the electronics racks, and pre-amplifier modules (PAMs), and its impact on the operational performance of the laser beam transport tubes and optical alignment components must be evaluated. This report describes the thermal analyses associated with the PAMs. Evaluation of thermal issues for the other equipment is discussed elsewhere

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

ICF quarterly report January - March 1997 volume 7, number 3; TOPICAL

International Nuclear Information System (INIS)

Murray, J

1998-01-01

The National Ignition Facility Project The mission of the National Ignition Facility (NIF) is to produce ignition and modest energy gain in inertial confinement fusion (ICF) targets. Achieving these goals will maintain U.S. world leadership in ICF and will directly benefit the U.S. Department of Energy (DOE) missions in national security, science and technology, energy resources, and industrial competitiveness. Development and operation of the NIF are consistent with DOE goals for environmental quality, openness to the community, and nuclear nonproliferation and arms control. Although the primary mission of inertial fusion is for defense applications, inertial fusion research will provide critical information for the development of inertial fusion energy. The NIF, under construction at Lawrence Livermore National Laboratory (LLNL), is a cornerstone of the DOE's science-based Stockpile Stewardship Program for addressing high-energy-density physics issues in the absence of nuclear weapons testing. In pursuit of this mission, the DOE's Defense Programs has developed a state-of-the-art capability with the NIF to investigate high-energy-density physics in the laboratory with a microfusion capability for defense and energy applications. As a Strategic System Acquisition, the NIF Project has a separate and disciplined reporting chain to DOE as shown below

Radiation effects on active camera electronics in the target chamber at the National Ignition Facility

Science.gov (United States)

Dayton, M.; Datte, P.; Carpenter, A.; Eckart, M.; Manuel, A.; Khater, H.; Hargrove, D.; Bell, P.

2017-08-01

The National Ignition Facility's (NIF) harsh radiation environment can cause electronics to malfunction during high-yield DT shots. Until now there has been little experience fielding electronic-based cameras in the target chamber under these conditions; hence, the performance of electronic components in NIF's radiation environment was unknown. It is possible to purchase radiation tolerant devices, however, they are usually qualified for radiation environments different to NIF, such as space flight or nuclear reactors. This paper presents the results from a series of online experiments that used two different prototype camera systems built from non-radiation hardened components and one commercially available camera that permanently failed at relatively low total integrated dose. The custom design built in Livermore endured a 5 × 1015 neutron shot without upset, while the other custom design upset at 2 × 1014 neutrons. These results agreed with offline testing done with a flash x-ray source and a 14 MeV neutron source, which suggested a methodology for developing and qualifying electronic systems for NIF. Further work will likely lead to the use of embedded electronic systems in the target chamber during high-yield shots.

Science of NIF scale capsule development (activities for FY97)

International Nuclear Information System (INIS)

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

1997-01-01

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

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.

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.

The National Ignition Facility: Ushering in a new age for high energy density science

International Nuclear Information System (INIS)

Moses, E. I.; Boyd, R. N.; Remington, B. A.; Keane, C. J.; Al-Ayat, R.

2009-01-01

The National Ignition Facility (NIF) [E. I. Moses, J. Phys.: Conf. Ser. 112, 012003 (2008); https://lasers.llnl.gov/], completed in March 2009, is the highest energy laser ever constructed. The high temperatures and densities achievable at NIF will enable a number of experiments in inertial confinement fusion and stockpile stewardship, as well as access to new regimes in a variety of experiments relevant to x-ray astronomy, laser-plasma interactions, hydrodynamic instabilities, nuclear astrophysics, and planetary science. The experiments will impact research on black holes and other accreting objects, the understanding of stellar evolution and explosions, nuclear reactions in dense plasmas relevant to stellar nucleosynthesis, properties of warm dense matter in planetary interiors, molecular cloud dynamics and star formation, and fusion energy generation.

Management Of Experiments And Data At The National Ignition Facility

International Nuclear Information System (INIS)

Azevedo, S.; Casey, A.; Beeler, R.; Bettenhausen, R.; Bond, E.; Chandrasekaran, H.; Foxworthy, C.; Hutton, M.; Krammen, J.; Liebman, J.; Marsh, A.; Pannell, T.; Rhodes, J.; Tappero, J.; Warrick, A.

2011-01-01

Experiments, or 'shots', conducted at the National Ignition Facility (NIF) are discrete events that occur over a very short time frame (tens of nanoseconds) separated by many hours. Each shot is part of a larger campaign of shots to advance scientific understanding in high-energy-density physics. In one campaign, scientists use energy from the 192-beam, 1.8-Megajoule pulsed laser in the NIF system to symmetrically implode a hydrogen-filled target, thereby creating conditions similar to the interior of stars in a demonstration of controlled fusion. Each NIF shot generates gigabytes of data from over 30 diagnostics that measure optical, x-ray, and nuclear phenomena from the imploding target. We have developed systems to manage all aspects of the shot cycle. Other papers will discuss the control of the lasers and targets, while this paper focuses on the setup and management of campaigns and diagnostics. Because of the low duty cycle of shots, and the thousands of adjustments for each shot (target type, composition, shape; laser beams used, their power profiles, pointing; diagnostic systems used, their configuration, calibration, settings) it is imperative that we accurately define all equipment prior to the shot. Following the shot, and capture of the data by the automatic control system, it is equally imperative that we archive, analyze and visualize the results within the required 30 minutes post-shot. Results must be securely archived, approved, web-visible and downloadable in order to facilitate subsequent publication. To-date NIF has successfully fired over 2,500 system shots, as well as thousands of test firings and dry-runs. We will present an overview of the highly-flexible and scalable campaign management systems and tools employed at NIF that control experiment configuration of the facility all the way through presentation of analyzed results.

Damage sources for the NIF Grating Debris Shield (GDS) and methods for their mitigation

Science.gov (United States)

Carr, C. W.; Bude, J.; Miller, P. E.; Parham, T.; Whitman, P.; Monticelli, M.; Raman, R.; Cross, D.; Welday, B.; Ravizza, F.; Suratwala, T.; Davis, J.; Fischer, M.; Hawley, R.; Lee, H.; Matthews, M.; Norton, M.; Nostrand, M.; Vanblarcom, D.; Sommer, S.

2017-11-01

The primary sources of damage on the National Ignition Facility (NIF) Grating Debris Shield (GDS) are attributed to two independent types of laser-induced particulates. The first comes from the eruptions of bulk damage in a disposable debris shield downstream of the GDS. The second particle source comes from stray light focusing on absorbing glass armor at higher than expected fluences. We show that the composition of the particles is secondary to the energetics of their delivery, such that particles from either source are essentially benign if they arrive at the GDS with low temperatures and velocities.

Measurements of fuel and ablator ρR in Symmetry-Capsule implosions with the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Gatu Johnson, M., E-mail: gatu@psfc.mit.edu; Frenje, J. A.; Li, C. K.; Séguin, F. H.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Bionta, R. M.; Casey, D. T.; Caggiano, J. A.; Hatarik, R.; Khater, H. Y.; Sayre, D. B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Knauer, J. P.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Herrmann, H. W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kilkenny, J. D. [General Atomics, San Diego, California 92186 (United States)

2014-11-15

The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility (NIF) measures the neutron spectrum in the energy range of 4–20 MeV. This paper describes MRS measurements of DT-fuel and CH-ablator ρR in DT gas-filled symmetry-capsule implosions at the NIF. DT-fuel ρR's of 80–140 mg/cm{sup 2} and CH-ablator ρR's of 400–680 mg/cm{sup 2} are inferred from MRS data. The measurements were facilitated by an improved correction of neutron-induced background in the low-energy part of the MRS spectrum. This work demonstrates the accurate utilization of the complete MRS-measured neutron spectrum for diagnosing NIF DT implosions.

Probing the deep nonlinear stage of the ablative Rayleigh-Taylor instability in indirect drive experiments on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Casner, A., E-mail: alexis.casner@cea.fr; Masse, L.; Liberatore, S.; Loiseau, P.; Masson-Laborde, P. E.; Jacquet, L. [CEA, DAM, DIF, F-91297 Arpajon (France); Martinez, D.; Moore, A. S.; Seugling, R.; Felker, S.; Haan, S. W.; Remington, B. A.; Smalyuk, V. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Farrell, M.; Giraldez, E.; Nikroo, A. [General Atomics, San Diego, California 92121 (United States)

2015-05-15

Academic tests in physical regimes not encountered in Inertial Confinement Fusion will help to build a better understanding of hydrodynamic instabilities and constitute the scientifically grounded validation complementary to fully integrated experiments. Under the National Ignition Facility (NIF) Discovery Science program, recent indirect drive experiments have been carried out to study the ablative Rayleigh-Taylor Instability (RTI) in transition from weakly nonlinear to highly nonlinear regime [A. Casner et al., Phys. Plasmas 19, 082708 (2012)]. In these experiments, a modulated package is accelerated by a 175 eV radiative temperature plateau created by a room temperature gas-filled platform irradiated by 60 NIF laser beams. The unique capabilities of the NIF are harnessed to accelerate this planar sample over much larger distances (≃1.4 mm) and longer time periods (≃12 ns) than previously achieved. This extended acceleration could eventually allow entering into a turbulent-like regime not precluded by the theory for the RTI at the ablation front. Simultaneous measurements of the foil trajectory and the subsequent RTI growth are performed and compared with radiative hydrodynamics simulations. We present RTI growth measurements for two-dimensional single-mode and broadband multimode modulations. The dependence of RTI growth on initial conditions and ablative stabilization is emphasized, and we demonstrate for the first time in indirect-drive a bubble-competition, bubble-merger regime for the RTI at ablation front.

National Ignition Facility monthly status report--February 2000

International Nuclear Information System (INIS)

Moses, E

2000-01-01

The Project provides for the design, procurement, construction, assembly, installation, and acceptance testing of the National Ignition Facility (NIF), an experimental inertial confinement fusion facility intended to achieve controlled thermonuclear fusion in the laboratory by imploding a small capsule containing a mixture of the hydrogen isotopes deuterium and tritium. The NIF will be constructed at the Lawrence Livermore National Laboratory (LLNL), Livermore, California as determined by the Record of Decision made on December 19, 1996, as a part of the Stockpile Stewardship and Management Programmatic Environmental Impact Statement. Safety: The Incident Analysis and Construction Management Safety Review Teams were formed to review the January 13, 2000, accident in which a worker received a back injury when a 42-in.-diameter duct fell during installation. One action is to contract DuPont to review the Safety Program. Technical Status: The general status of the technologies underlying the NIF Project remains satisfactory. The issues currently being addressed are (1) cleanliness for installation, assembly, and activation of the laser system by Systems Engineering; (2) laser glass--a second pilot run at one of the two commercial suppliers is ongoing successfully; and (3) operational costs associated with final optics assembly (FOA) optics components--methods are being developed to mitigate 3ω damage and to resolve beam rotation issues. Schedule: The completion of the Title II design of laser equipment is now approximately 83% complete. The Beampath Infrastructure System is on the critical schedule path. The procurement strategy was evaluated by commercial construction management and Architectural/Engineering (A/E) contractors with a panel of independent experts, the Beampath Infrastructure System (BIS) Implementation Review Committee Advisory Group. The BIS Integration Management and Installation Services (IMI) Subcontractor solicitation package and approach were

Using penumbral imaging to measure micrometer size plasma hot spots in Gbar equation of state experiments on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Bachmann, B., E-mail: bachmann2@llnl.gov; Kritcher, A. L.; Benedetti, L. R.; Glenn, S.; Hawreliak, J.; Izumi, N.; Landen, O. L.; Le Pape, S.; Ma, T.; Pérez, F.; Swift, D.; Döppner, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Falcone, R. W. [Department of Physics, University of California, Berkeley, California 94720 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Kraus, D. [Department of Physics, University of California, Berkeley, California 94720 (United States)

2014-11-15

We have developed an experimental platform for absolute equation of state measurements up to Gbar pressures on the National Ignition Facility (NIF) within the Fundamental Science Program. We use a symmetry-tuned hohlraum drive to launch a spherical shock wave into a solid CH sphere. Streaked radiography is the primary diagnostic to measure the density change at the shock front as the pressure increases towards smaller radii. At shock stagnation in the center of the capsule, we observe a short and bright x-ray self emission from high density (∼50 g/cm{sup 3}) plasma at ∼1 keV. Here, we present results obtained with penumbral imaging which has been carried out to characterize the size of the hot spot emission. This allows extending existing NIF diagnostic capabilities for spatial resolution (currently ∼10 μm) at higher sensitivity. At peak emission we find the hot spot radius to be as small as 5.8 +/− 1 μm, corresponding to a convergence ratio of 200.

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.

Radiation transport and energetics of laser-driven half-hohlraums at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Moore, A. S. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Cooper, A. B.R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); MacLaren, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Graham, P. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Lu, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seugling, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Satcher, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Klingmann, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Comley, A. J. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Marrs, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); May, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Widmann, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glendinning, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Castor, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sain, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Back, C. A. [General Atomics, San Diego, CA (United States); Hund, J. [General Atomics, San Diego, CA (United States); Baker, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hsing, W. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Foster, J. [Directorate Science and Technology, AWE Aldermaston, Reading (United Kingdom); Young, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Young, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-06-01

Experiments that characterize and develop a high energy-density half-hohlraum platform for use in bench-marking radiation hydrodynamics models have been conducted at the National Ignition Facility (NIF). Results from the experiments are used to quantitatively compare with simulations of the radiation transported through an evolving plasma density structure, colloquially known as an N-wave. A half-hohlraum is heated by 80 NIF beams to a temperature of 240 eV. This creates a subsonic di usive Marshak wave which propagates into a high atomic number Ta₂O₅ aerogel. The subsequent radiation transport through the aerogel and through slots cut into the aerogel layer is investigated. We describe a set of experiments that test the hohlraum performance and report on a range

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.

Laser Science and Technology Program Update 2002

International Nuclear Information System (INIS)

Hackel, L A; Chen, H L

2003-01-01

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

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.

Shot Automation for the National Ignition Facility

International Nuclear Information System (INIS)

Lagin, L J; Bettenhausen, R C; Beeler, R G; Bowers, G A; Carey, R.; Casavant, D.D.; Cline, B.D.; Demaret, R.D.; Domyancic, D.M.; Elko, S.D.; Fisher, J.M.; Hermann, M.R.; Krammen, J.E.; Kohut, T.R.; Marshall, C.D.; Mathisen, D.G.; Ludwigsen, A.P.; Patterson, Jr. R.W.; Sanchez, R.J.; Stout, E.A.; Van Arsdall, P.J.; Van Wonterghem, B.M.

2005-01-01

A shot automation framework has been developed and deployed during the past year to automate shots performed on the National Ignition Facility (NIF) using the Integrated Computer Control System This framework automates a 4-8 hour shot sequence, that includes inputting shot goals from a physics model, set up of the laser and diagnostics, automatic alignment of laser beams and verification of status. This sequence consists of set of preparatory verification shots, leading to amplified system shots using a 4-minute countdown, triggering during the last 2 seconds using a high-precision timing system, followed by post-shot analysis and archiving. The framework provides for a flexible, model-based execution driven of scriptable automation called macro steps. The framework is driven by high-level shot director software that provides a restricted set of shot life cycle state transitions to 25 collaboration supervisors that automate 8-laser beams (bundles) and a common set of shared resources. Each collaboration supervisor commands approximately 10 subsystem shot supervisors that perform automated control and status verification. Collaboration supervisors translate shot life cycle state commands from the shot director into sequences of ''macro steps'' to be distributed to each of its shot supervisors. Each Shot supervisor maintains order of macro steps for each subsystem and supports collaboration between macro steps. They also manage failure, restarts and rejoining into the shot cycle (if necessary) and manage auto/manual macro step execution and collaborations between other collaboration supervisors. Shot supervisors execute macro step shot functions commanded by collaboration supervisors. Each macro step has database-driven verification phases and a scripted perform phase. This provides for a highly flexible methodology for performing a variety of NIF shot types. Database tables define the order of work and dependencies (workflow) of macro steps to be performed for a

8. High power laser and ignition facilities

International Nuclear Information System (INIS)

Bayramian, A.J.; Beach, R.J.; Bibeau, C.

2002-01-01

This document gives a review of the various high power laser projects and ignition facilities in the world: the Mercury laser system and Electra (Usa), the krypton fluoride (KrF) laser and the HALNA (high average power laser for nuclear-fusion application) project (Japan), the Shenguang series, the Xingguang facility and the TIL (technical integration line) facility (China), the Vulcan peta-watt interaction facility (UK), the Megajoule project and its feasibility phase: the LIL (laser integration line) facility (France), the Asterix IV/PALS high power laser facility (Czech Republic), and the Phelix project (Germany). In Japan the 100 TW Petawatt Module Laser, constructed in 1997, is being upgraded to the world biggest peta-watt laser. Experiments have been performed with single-pulse large aperture e-beam-pumped Garpun (Russia) and with high-current-density El-1 KrF laser installation (Russia) to investigate Al-Be foil transmittance and stability to multiple e-beam irradiations. An article is dedicated to a comparison of debris shield impacts for 2 experiments at NIF (national ignition facility). (A.C.)

Drive development for an 10 Mbar Rayleigh-Taylor strength experiment on the National Ignition Facility

Science.gov (United States)

Prisbrey, Shon; Park, Hye-Sook; Huntington, Channing; McNaney, James; Smith, Raym; Wehrenberg, Christopher; Swift, Damian; Panas, Cynthia; Lord, Dawn; Arsenlis, Athanasios

2017-10-01

Strength can be inferred by the amount a Rayleigh-Taylor surface deviates from classical growth when subjected to acceleration. If the acceleration is great enough, even materials highly resistant to deformation will flow. We use the National Ignition Facility (NIF) to create an acceleration profile that will cause sample metals, such as Mo or Cu, to reach peak pressures of 10 Mbar without inducing shock melt. To create such a profile we shock release a stepped density reservoir across a large gap with the stagnation of the reservoir on the far side of the gap resulting in the desired pressure drive history. Low density steps (foams) are a necessary part of this design and have been studied in the last several years on the Omega and NIF facilities. We will present computational and experimental progress that has been made on the 10 Mbar drive designs - including recent drive shots carried out at the NIF. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344. LLNL-ABS-734781.

Gas-filled hohlraum experiments at the national ignition facility.

Energy Technology Data Exchange (ETDEWEB)

Fernández, J. C. (Juan C.); Gautier, D. C. (Donald Cort); Goldman, S. R. (Sanford R.); Grimm, B. M.; Hegelich, B. M. (Bjorn M.); Kline, J. L. (John L.); Montgomery, D. S. (David S.); Lanier, N. E. (Nicholas E.); Rose, H. A. (Harvey A.); Schmidt, D. M. (David M.); Swift, D. C.; Workman, J. B. (Jonathan B.); Alvarez, Sharon; Bower, Dan.; Braun, Dave.; Campbell, K. (Katherine); DeWald, E.; Glenzer, S. (Siegfried); Holder, J. (Joe P.); Kamperschroer, J. H. (James H.); Kimbrough, Joe (Joseph R.); Kirkwood, Robert (Bob); Landen, O. L. (Otto L.); Mccarville, Tom (Tomas J.); Macgowan, B.; Mackinnon, A.; Niemann, C.; Schein, J.; Schneider, M; Watts, Phil; Young, Ben-li [number : znumber] 194154; Young B.

2004-01-01

The summary of this paper is: (1) We have fielded on NIF a gas-filled hohlraum designed for future ignition experiments; (2) Wall-motion measurements are consistent with LASNEX simulations; (3) LPI back-scattering results have confounded expectations - (a) Stimulated Brillouin (SBS) dominates Raman (SRS) for any gas-fill species, (b) Measured SBS time-averaged reflectivity values are high, peak values are even higher, (c) SRS and SBS peak while laser-pulse is rising; and (4) Plasma conditions at the onset of high back-scattering yield high SBS convective linear gain - Wavelengths of the back-scattered light is predicted by linear theory.

Gas-filled hohlraum experiments at the national ignition facility

International Nuclear Information System (INIS)

Fernandez, J.C.; Gautier, D.C.; Goldman, S.R.; Grimm, B.M.; Hegelich, B.M.; Kline, J.L.; Montgomery, D.S.; Lanier, N.E.; Rose, H.A.; Schmidt, D.M.; Swift, D.C.; Workman, J.B.; Alvarez, Sharon; Bower, Dan; Braun, Dave; Campbell, K.; DeWald, E.; Glenzer, S.; Holder, J.; Kamperschroer, J.H.; Kimbrough, Joe; Kirkwood, Robert; Landen, O.L.; Mccarville, Tom; Macgowan, B.; Mackinnon, A.; Niemann, C.; Schein, J.; Schneider, M.; Watts, Phil; Young, Ben-li; Young B.

2004-01-01

The summary of this paper is: (1) We have fielded on NIF a gas-filled hohlraum designed for future ignition experiments; (2) Wall-motion measurements are consistent with LASNEX simulations; (3) LPI back-scattering results have confounded expectations - (a) Stimulated Brillouin (SBS) dominates Raman (SRS) for any gas-fill species, (b) Measured SBS time-averaged reflectivity values are high, peak values are even higher, (c) SRS and SBS peak while laser-pulse is rising; and (4) Plasma conditions at the onset of high back-scattering yield high SBS convective linear gain - Wavelengths of the back-scattered light is predicted by linear theory.

X-ray penumbral imaging diagnostic developments at the National Ignition Facility

Science.gov (United States)

Bachmann, B.; Abu-Shawareb, H.; Alexander, N.; Ayers, J.; Bailey, C. G.; Bell, P.; Benedetti, L. R.; Bradley, D.; Collins, G.; Divol, L.; Döppner, T.; Felker, S.; Field, J.; Forsman, A.; Galbraith, J. D.; Hardy, C. M.; Hilsabeck, T.; Izumi, N.; Jarrot, C.; Kilkenny, J.; Kramer, S.; Landen, O. L.; Ma, T.; MacPhee, A.; Masters, N.; Nagel, S. R.; Pak, A.; Patel, P.; Pickworth, L. A.; Ralph, J. E.; Reed, C.; Rygg, J. R.; Thorn, D. B.

2017-08-01

X-ray penumbral imaging has been successfully fielded on a variety of inertial confinement fusion (ICF) capsule implosion experiments on the National Ignition Facility (NIF). We have demonstrated sub-5 μm resolution imaging of stagnated plasma cores (hot spots) at x-ray energies from 6 to 30 keV. These measurements are crucial for improving our understanding of the hot deuterium-tritium fuel assembly, which can be affected by various mechanisms, including complex 3-D perturbations caused by the support tent, fill tube or capsule surface roughness. Here we present the progress on several approaches to improve x-ray penumbral imaging experiments on the NIF. We will discuss experimental setups that include penumbral imaging from multiple lines-of-sight, target mounted penumbral apertures and variably filtered penumbral images. Such setups will improve the signal-to-noise ratio and the spatial imaging resolution, with the goal of enabling spatially resolved measurements of the hot spot electron temperature and material mix in ICF implosions.

PLASMA ELECTRODE POCKELS CELL SUBSYSTEM PERFORMANCE IN THE NATIONAL IGNITION FACILITY

International Nuclear Information System (INIS)

Barbosa, F; Arnold, P; Hinz, A; Zacharias, R; Ollis, C; Fulkerson, E; Mchale, B; Runtal, A; Bishop, C

2007-01-01

The Plasma Electrode Pockels Cell (PEPC) subsystem is a key component of the National Ignition Facility, enabling the laser to employ an efficient four-pass main amplifier architecture. PEPC relies on a pulsed power technology to initiate and maintain plasma within the cells and to provide the necessary high voltage bias to the cells nonlinear crystals. Ultimately, nearly 300 high-voltage, high-current pulse generators will be deployed in the NIF in support of PEPC. Production of solid-state plasma pulse generators and thyratron-switched pulse generators is now complete, with the majority of the hardware deployed in the facility. An entire cluster (one-fourth of a complete NIF) has been commissioned and is operating on a routine basis, supporting laser shot operations. Another cluster has been deployed, awaiting final commissioning. Activation and commissioning of new hardware continues to progress in parallel, driving toward a goal of completing the PEPC subsystem in late 2007

Planning Tools For Estimating Radiation Exposure At The National Ignition Facility

International Nuclear Information System (INIS)

Verbeke, J.; Young, M.; Brereton, S.; Dauffy, L.; Hall, J.; Hansen, L.; Khater, H.; Kim, S.; Pohl, B.; Sitaraman, S.

2010-01-01

A set of computational tools was developed to help estimate and minimize potential radiation exposure to workers from material activation in the National Ignition Facility (NIF). AAMI (Automated ALARA-MCNP Interface) provides an efficient, automated mechanism to perform the series of calculations required to create dose rate maps for the entire facility with minimal manual user input. NEET (NIF Exposure Estimation Tool) is a web application that combines the information computed by AAMI with a given shot schedule to compute and display the dose rate maps as a function of time. AAMI and NEET are currently used as work planning tools to determine stay-out times for workers following a given shot or set of shots, and to help in estimating integrated doses associated with performing various maintenance activities inside the target bay. Dose rate maps of the target bay were generated following a low-yield 10 16 D-T shot and will be presented in this paper.

Simulations of a phase corrector plate for the National Ignition Facility

International Nuclear Information System (INIS)

Williams, W. H. LLNL

1998-01-01

Simulations are presented on the effect of placing a static phase corrector plate in each beamline of the National Ignition Facility (NIF) to assist the adaptive optic in correcting beam phase aberrations. Results indicate such a plate could significantly improve the focal spot, reducing a 3ω, 80% spot half-angle from 21 to 8 microrad for poorer-qualtiy optics, and 17 to 7 for better optics. Such a plate appears to be within the range of current fabrication technologies. It would have an alignment requiremnt of ±0.5 mm, if placed in the front end. In NIF operation, the occasional replacement of laser slabs would slowly degrade the beam quality for a fixed corrector plate, with the spot size increasing from 8 to 15 microrad after four new slabs for poorer optics, and 7 to 12 microrad for better optics. The energy fraciton clipped on the injection pinhole (±100 microrad) would be <0.5% due to this pre-correction

Wildfire ignition resistant home design(WIRHD) program: Full-scale testing and demonstration final report.

Energy Technology Data Exchange (ETDEWEB)

Quarles, Stephen, L.; Sindelar, Melissa

2011-12-13

The primary goal of the Wildfire ignition resistant home design(WIRHD) program was to develop a home evaluation tool that could assess the ignition potential of a structure subjected to wildfire exposures. This report describes the tests that were conducted, summarizes the results, and discusses the implications of these results with regard to the vulnerabilities to homes and buildings.

Final report for NIF chamber dynamics studies

International Nuclear Information System (INIS)

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

1998-01-01

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

Target experimental area and systems of the Us national ignition facility

International Nuclear Information System (INIS)

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

2000-01-01

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

Simulations of laser imprint for Nova experiments and for ignition capsules. Revision 1

International Nuclear Information System (INIS)

Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Key, M.H.; Remington, B.A.; Rothenberg, J.L.; Wolfrum, E.; Verdon, C.P.; Knauer, J.P.

1996-12-01

In direct drive ICF, nonuniformities in laser illumination seed ripples at the ablation front in a process called ''imprint''. These nonuniformities grow during the capsule implosion and, if initially large enough, can penetrate the capsule shell, impede ignition, or degrade burn. Imprint has been simulated for recent experiments performed on the Nova laser at LLNL examining a variety of beam smoothing conditions. Most used laser intensities similar to the early part of an ignition capsule pulse shape, 1 ≅ 10 13 W/cm 2 . The simulations matched most of the measurements of imprint modulation. The effect of imprint upon National Ignition Facility (NIF) direct drive ignition capsules has also been simulated. Imprint is predicted to give modulation comparable to an intrinsic surface finish of ∼10 nm RMS. Modulation growth was examined using the Haan [Phys. Rev. A 39, 5812 (1989)] model, with linear growth factors as a function of spherical harmonic mode number obtained from an analytic dispersion relation. Ablation front amplitudes are predicted to become substantially nonlinear, so that saturation corrections are large. Direct numerical simulations of two-dimensional multimode growth were also performed. The capsule shell is predicted to remain intact, which gives a basis for believing that ignition can be achieved. 27 refs., 10 figs

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.

Progress in detailed modelling of low foot and high foot implosion experiments on the National Ignition Facility

Science.gov (United States)

Clark, D. S.; Weber, C. R.; Eder, D. C.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Jones, O. S.; Kritcher, A. L.; Marinak, M. M.; Milovich, J. L.; Patel, P. K.; Robey, H. F.; Salmonson, J. D.; Sepke, S. M.

2016-05-01

Several dozen high convergence inertial confinement fusion ignition experiments have now been completed on the National Ignition Facility (NIF). These include both “low foot” experiments from the National Ignition Campaign (NIC) and more recent “high foot” experiments. At the time of the NIC, there were large discrepancies between simulated implosion performance and experimental data. In particular, simulations over predicted neutron yields by up to an order of magnitude, and some experiments showed clear evidence of mixing of ablator material deep into the hot spot that could not be explained at the time. While the agreement between data and simulation improved for high foot implosion experiments, discrepancies nevertheless remain. This paper describes the state of detailed modelling of both low foot and high foot implosions using 1-D, 2-D, and 3-D radiation hydrodynamics simulations with HYDRA. The simulations include a range of effects, in particular, the impact of the plastic membrane used to support the capsule in the hohlraum, as well as low-mode radiation asymmetries tuned to match radiography measurements. The same simulation methodology is applied to low foot NIC implosion experiments and high foot implosions, and shows a qualitatively similar level of agreement for both types of implosions. While comparison with the experimental data remains imperfect, a reasonable level of agreement is emerging and shows a growing understanding of the high-convergence implosions being performed on NIF.

Progress in detailed modelling of low foot and high foot implosion experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Clark, D S; Weber, C R; Eder, D C; Haan, S W; Hammel, B A; Hinkel, D E; Jones, O S; Kritcher, A L; Marinak, M M; Milovich, J L; Patel, P K; Robey, H F; Salmonson, J D; Sepke, S M

2016-01-01

Several dozen high convergence inertial confinement fusion ignition experiments have now been completed on the National Ignition Facility (NIF). These include both “low foot” experiments from the National Ignition Campaign (NIC) and more recent “high foot” experiments. At the time of the NIC, there were large discrepancies between simulated implosion performance and experimental data. In particular, simulations over predicted neutron yields by up to an order of magnitude, and some experiments showed clear evidence of mixing of ablator material deep into the hot spot that could not be explained at the time. While the agreement between data and simulation improved for high foot implosion experiments, discrepancies nevertheless remain. This paper describes the state of detailed modelling of both low foot and high foot implosions using 1-D, 2-D, and 3-D radiation hydrodynamics simulations with HYDRA. The simulations include a range of effects, in particular, the impact of the plastic membrane used to support the capsule in the hohlraum, as well as low-mode radiation asymmetries tuned to match radiography measurements. The same simulation methodology is applied to low foot NIC implosion experiments and high foot implosions, and shows a qualitatively similar level of agreement for both types of implosions. While comparison with the experimental data remains imperfect, a reasonable level of agreement is emerging and shows a growing understanding of the high-convergence implosions being performed on NIF. (paper)

Inertial confinement fusion. 1995 ICF annual report, October 1994--September 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-06-01

Lawrence Livermore National Laboratory`s (LLNL`s) Inertial Confinement Fusion (ICF) Program is a Department of Energy (DOE) Defense Program research and advanced technology development program focused on the goal of demonstrating thermonuclear fusion ignition and energy gain in the laboratory. During FY 1995, the ICF Program continued to conduct ignition target physics optimization studies and weapons physics experiments in support of the Defense Program`s stockpile stewardship goals. It also continued to develop technologies in support of the performance, cost, and schedule goals of the National Ignition Facility (NIF) Project. The NIF is a key element of the DOE`s Stockpile Stewardship and Management Program. In addition to its primary Defense Program goals, the ICF Program provides research and development opportunities in fundamental high-energy-density physics and supports the necessary research base for the possible long-term application to inertial fusion energy (IFE). Also, ICF technologies have had spin-off applications for industrial and governmental use. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

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...

Radiation transport and energetics of laser-driven half-hohlraums at the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Moore, A. S., E-mail: alastair.moore@physics.org; Graham, P.; Comley, A. J.; Foster, J. [Directorate Science and Technology, AWE Aldermaston, Reading RG7 4PR (United Kingdom); Cooper, A. B. R.; Schneider, M. B.; MacLaren, S.; Lu, K.; Seugling, R.; Satcher, J.; Klingmann, J.; Marrs, R.; May, M.; Widmann, K.; Glendinning, G.; Castor, J.; Sain, J.; Baker, K.; Hsing, W. W.; Young, B. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

2014-06-15

Experiments that characterize and develop a high energy-density half-hohlraum platform for use in benchmarking radiation hydrodynamics models have been conducted at the National Ignition Facility (NIF). Results from the experiments are used to quantitatively compare with simulations of the radiation transported through an evolving plasma density structure, colloquially known as an N-wave. A half-hohlraum is heated by 80 NIF beams to a temperature of 240 eV. This creates a subsonic diffusive Marshak wave, which propagates into a high atomic number Ta{sub 2}O{sub 5} aerogel. The subsequent radiation transport through the aerogel and through slots cut into the aerogel layer is investigated. We describe a set of experiments that test the hohlraum performance and report on a range of x-ray measurements that absolutely quantify the energetics and radiation partition inside the target.

The effect of laser spot shapes on polar-direct-drive implosions on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Weilacher, F.; Radha, P. B., E-mail: rbah@lle.rochester.edu; Collins, T. J. B.; Marozas, J. A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2015-03-15

Ongoing polar-direct-drive (PDD) implosions on the National Ignition Facility (NIF) [J. D. Lindl and E. I. Moses, Phys. Plasmas 18, 050901 (2011)] use existing NIF hardware, including indirect-drive phase plates. This limits the performance achievable in these implosions. Spot shapes are identified that significantly improve the uniformity of PDD NIF implosions; outer surface deviation is reduced by a factor of 7 at the end of the laser pulse and hot-spot distortion is reduced by a factor of 2 when the shell has converged by a factor of ∼10. As a result, the neutron yield increases by approximately a factor of 2. This set of laser spot shapes is a combination of circular and elliptical spots, along with elliptical spot shapes modulated by an additional higher-intensity ellipse offset from the center of the beam. This combination is motivated in this paper. It is also found that this improved implosion uniformity is obtained independent of the heat conduction model. This work indicates that significant improvement in performance can be obtained robustly with the proposed spot shapes.

The effect of laser spot shapes on polar-direct-drive implosions on the National Ignition Facility

International Nuclear Information System (INIS)

Weilacher, F.; Radha, P. B.; Collins, T. J. B.; Marozas, J. A.

2015-01-01

Ongoing polar-direct-drive (PDD) implosions on the National Ignition Facility (NIF) [J. D. Lindl and E. I. Moses, Phys. Plasmas 18, 050901 (2011)] use existing NIF hardware, including indirect-drive phase plates. This limits the performance achievable in these implosions. Spot shapes are identified that significantly improve the uniformity of PDD NIF implosions; outer surface deviation is reduced by a factor of 7 at the end of the laser pulse and hot-spot distortion is reduced by a factor of 2 when the shell has converged by a factor of ∼10. As a result, the neutron yield increases by approximately a factor of 2. This set of laser spot shapes is a combination of circular and elliptical spots, along with elliptical spot shapes modulated by an additional higher-intensity ellipse offset from the center of the beam. This combination is motivated in this paper. It is also found that this improved implosion uniformity is obtained independent of the heat conduction model. This work indicates that significant improvement in performance can be obtained robustly with the proposed spot shapes

Beam Diagnostics Systems for the National Ignition Facility

International Nuclear Information System (INIS)

Demaret, R D; Boyd, R D; Bliss, E S; Gates, A J; Severyn, J R

2001-01-01

The National Ignition Facility (NIF) laser focuses 1.8 megajoules of ultraviolet light (wavelength 351 nanometers) from 192 beams into a 600-micrometer-diameter volume. Effective use of this output in target experiments requires that the power output from all of the beams match within 8% over their entire 20-nanosecond waveform. The scope of NIF beam diagnostics systems necessary to accomplish this task is unprecedented for laser facilities. Each beamline contains 110 major optical components distributed over a 510-meter path, and diagnostic tolerances for beam measurement are demanding. Total laser pulse energy is measured with 2.8% precision, and the interbeam temporal variation of pulse power is measured with 4% precision. These measurement goals are achieved through use of approximately 160 sensor packages that measure the energy at five locations and power at three locations along each beamline using 335 photodiodes, 215 calorimeters, and 36 digitizers. Successful operation of such a system requires a high level of automation of the widely distributed sensors. Computer control systems provide the basis for operating the shot diagnostics with repeatable accuracy, assisted by operators who oversee system activities and setup, respond to performance exceptions, and complete calibration and maintenance tasks

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.

Development on the National Ignition Facility of a High Energy Density Opacity Platform

Energy Technology Data Exchange (ETDEWEB)

Perry, Theodore Sonne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dodd, Evan S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); DeVolder, Barbara Gloria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Johns, Heather Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cardenas, Tana [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Archuleta, Thomas Nick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kline, John L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Flippo, Kirk Adler [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vinyard, Natalia Sergeevna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sherrill, Manolo Edgar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilde, Bernhard Heinz [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tregillis, Ian Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Douglas, Melissa Rae [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Heeter, R. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Liedahl, D. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wilson, B. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Iglesias, C. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schneider, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Martin, M. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); London, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ahmed, M. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thompson, N. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Emig, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zika, M. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Opachich, Y. P. [Nevada National Security Site (NNSS), NV (United States); King, J. A. [Nevada National Security Site (NNSS), NV (United States); Ross, P. W. [Nevada National Security Site (NNSS), NV (United States); Huffman, E. J. [Nevada National Security Site (NNSS), NV (United States); Knight, R. A. [Nevada National Security Site (NNSS), NV (United States); Koch, J. A. [Nevada National Security Site (NNSS), NV (United States); Pond, T. D. [Nevada National Security Site (NNSS), NV (United States); Craxton, R. S. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Zhang, R. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; McKenty, P. W. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Garcia, E. M. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Bailey, J. E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rochau, G. A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hansen, S. B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-02

X-ray opacity is a crucial factor in all radiation-hydrodynamics calculations, yet it is one of the least validated of the material properties in simulation codes for high-energy-density plasmas. Recent opacity experiments at the Sandia Z-machine have shown up to factors of two discrepancies between theory and experiment for various mid-Z elements (Fe, Cr, Ni). These discrepancies raise doubts regarding the accuracy of the opacity models which are used in ICF and stewardship as well as in astrophysics. Therefore, a new experimental opacity platform has been developed on the National Ignition Facility (NIF), not only to verify the Z-machine experimental results, but also to extend the experiments to other temperatures and densities. Within the context of the national opacity strategy, the first NIF experiments were directed towards measuring the opacity of iron at a temperature of ~160 eV and an electron density of ~7xl021 cm-3(Anchor 1). The Z data agree with theory at these conditions, providing a reference point for validation of the NIF platform. Development shots on NIF have demonstrated the ability to create a sufficiently bright point backlighter using an imploding plastic capsule, and also a combined hohlraum, sample and laser drive able to produce iron plasmas at the desired conditions. Spectrometer qualification has been completed, albeit with additional improvements planned, and the first iron absorption spectra have now been obtained.

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.

Applications and results of X-ray spectroscopy in implosion experiments on the National Ignition Facility

Science.gov (United States)

Epstein, R.; Regan, S. P.; Hammel, B. A.; Suter, L. J.; Scott, H. A.; Barrios, M. A.; Bradley, D. K.; Callahan, D. A.; Cerjan, C.; Collins, G. W.; Dixit, S. N.; Döppner, T.; Edwards, M. J.; Farley, D. R.; Fournier, K. B.; Glenn, S.; Glenzer, S. H.; Golovkin, I. E.; Hamza, A.; Hicks, D. G.; Izumi, N.; Jones, O. S.; Key, M. H.; Kilkenny, J. D.; Kline, J. L.; Kyrala, G. A.; Landen, O. L.; Ma, T.; MacFarlane, J. J.; Mackinnon, A. J.; Mancini, R. C.; McCrory, R. L.; Meyerhofer, D. D.; Meezan, N. B.; Nikroo, A.; Park, H.-S.; Patel, P. K.; Ralph, J. E.; Remington, B. A.; Sangster, T. C.; Smalyuk, V. A.; Springer, P. T.; Town, R. P. J.; Tucker, J. L.

2017-03-01

Current inertial confinement fusion experiments on the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] are attempting to demonstrate thermonuclear ignition using x-ray drive by imploding spherical targets containing hydrogen-isotope fuel in the form of a thin cryogenic layer surrounding a central volume of fuel vapor [J. Lindl, Phys. Plasmas 2, 3933 (1995)]. The fuel is contained within a plastic ablator layer with small concentrations of one or more mid-Z elements, e.g., Ge or Cu. The capsule implodes, driven by intense x-ray emission from the inner surface of a hohlraum enclosure irradiated by the NIF laser, and fusion reactions occur in the central hot spot near the time of peak compression. Ignition will occur if the hot spot within the compressed fuel layer attains a high-enough areal density to retain enough of the reaction product energy to reach nuclear reaction temperatures within the inertial hydrodynamic disassembly time of the fuel mass [J. Lindl, Phys. Plasmas 2, 3933 (1995)]. The primary purpose of the ablator dopants is to shield the ablator surface adjacent to the DT ice from heating by the hohlraum x-ray drive [S. W. Haan et al., Phys. Plasmas 18, 051001 (2011)]. Simulations predicted that these dopants would produce characteristic K-shell emission if ablator material mixed into the hot spot [B. A. Hammel et al., High Energy Density Phys. 6, 171 (2010)]. In NIF ignition experiments, emission and absorption features from these dopants appear in x-ray spectra measured with the hot-spot x-ray spectrometer in Supersnout II [S. P. Regan et al., "Hot-Spot X-Ray Spectrometer for the National Ignition Facility," to be submitted to Review of Scientific Instruments]. These include K-shell emission lines from the hot spot (driven primarily by inner-shell collisional ionization and dielectronic recombination) and photoionization edges, fluorescence, and absorption lines caused by the absorption of the

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.

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.

Laser coupling to reduced-scale targets at NIF Early Light

International Nuclear Information System (INIS)

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

2005-01-01

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

Plasma physics study and laser development for the fast ignition realization experiment (FIREX) project

International Nuclear Information System (INIS)

Azechi, H.; Mima, K.; Fujimoto, Y.

2008-10-01

Since the approval of the first phase of Fast Ignition Realization Experiment (FIREX-I), we have devoted our efforts on designing advanced targets and constructing the world highest-energy Peta Watt laser. The new target design has the following features. The coupling efficiency from the heating laser to the thermal energy of the compressed core plasma can be increased by the two ways:1) Low-Z foam layer on the inner surface of the cone for optimum absorption. 2) Double cone. Electrons generated in the inner surface of the double cone will return by sheathe potential generated between two cones. The implosion performance can be improved by three ways: 3) Low-Z plastic layer on the outer surface of the cone may suppress the expansion of the Au cone that flows into the interior of the compressed core. 4) Br doped plastic ablator may significantly moderate the Rayleigh-Taylor instability, making implosion more stable. 5) Evacuation of the target center to prevent gas jets from destroying the cone tip. For project robustness, we also explore 6) impact ignition scheme that eliminates complexity of laser-plasma interaction while keeping the compactness advantage of fast ignition. The fully integrated fast ignition experiment is scheduled on 2009. If subsequent FIREX-II will start as proposed, the ignition and burn will be demonstrated shortly after the ignition at NIF and LMJ, providing a scientific database of both central and fast ignition. (author)

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

International Nuclear Information System (INIS)

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

1999-01-01

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

Recent advances in indirect drive ICF target physics at LLNL

International Nuclear Information System (INIS)

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

1999-01-01

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

Report from the Integrated Modeling Panel at the Workshop on the Science of Ignition on NIF

Energy Technology Data Exchange (ETDEWEB)

Marinak, M; Lamb, D

2012-07-03

This section deals with multiphysics radiation hydrodynamics codes used to design and simulate targets in the ignition campaign. These topics encompass all the physical processes they model, and include consideration of any approximations necessary due to finite computer resources. The section focuses on what developments would have the highest impact on reducing uncertainties in modeling most relevant to experimental observations. It considers how the ICF codes should be employed in the ignition campaign. This includes a consideration of how the experiments can be best structured to test the physical models the codes employ.

Producing National Ignition Facility (NIF)-quality beams on the Nova and Beamlet lasers

International Nuclear Information System (INIS)

Widmayer, C.C.; Auerbach, J.M.; Ehrlich, R.B.

1996-08-01

The Nova and Beamlet lasers were used to simulate the beam propagation conditions that will be encountered during the National Ignition Facility operation. Perturbation theory predicts that there is a 5mm scale length propagation mode that experiences large nonlinear power growth. This mode was observed in the tests. Further tests have confirmed that this mode can be suppressed with improved spatial filtering

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.

Characterization of third-harmonic target plan irradiance on the National Ignition Facility Beamlet demonstration project

International Nuclear Information System (INIS)

Wegner, P.J.; Van Wonterghem, B.M.; Dixit, S.N.; Henesian, M.A.; Barker, C.E.; Thompson, C.E.; Seppala, L.G.; Caird, J.A.

1997-01-01

The Beamlet laser is a single-aperture prototype for the National Ignition Facility (NIF). We have recently installed and activated a 55 m 3 vacuum vessel and associated diagnostic package at the output of the Beamlet that we are using to characterize target plane irradiance at high power. Measurements obtained both with and without a kinoform diffractive optic are reported. Dependences on critical laser parameters including output power, spatial filtering, and wavefront correction are discussed and compared with simulations

Software solutions manage the definition, operation, maintenance and configuration control of the National Ignition Facility

International Nuclear Information System (INIS)

Dobson, Darwin; Churby, Al; Krieger, Ed; Maloy, Donna; White, Kevin

2012-01-01

Highlights: ► NIF is a complex experimental facility composed of ∼4 million components. ► We describe business tools to define, build, operate, and maintain all components. ► CAD tools generate virtual models and assemblies under configuration control. ► Items requiring preventive, reactive, and/or calibration maintenance are tracked. ► Radiological or hazardous materials undergo additional controls. - Abstract: The National Ignition Facility (NIF) is the world's largest laser composed of millions of individual parts brought together to form one massive assembly. Maintaining control of the physical definition, status and configuration of this structure is a monumental undertaking yet critical to the validity of experimental data and the safe operation of the facility. A major programmatic challenge is to deploy software solutions to effectively manage the definition, build, operation, and maintenance, and configuration control of all components of NIF. The strategy for meeting this challenge involves deploying and integrating an enterprise application suite of solutions consisting of both Commercial-Off-The-Shelf (COTS) products and custom developed software.This paper describes how this strategy has been implemented along with a discussion on the successes realized and the ongoing challenges associated with this approach.

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)].

Capsule Performance Optimization for the National Ignition Facility

Science.gov (United States)

Landen, Otto

2009-11-01

The overall goal of the capsule performance optimization campaign is to maximize the probability of ignition by experimentally correcting for likely residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. This will be accomplished using a variety of targets that will set key laser, hohlraum and capsule parameters to maximize ignition capsule implosion velocity, while minimizing fuel adiabat, core shape asymmetry and ablator-fuel mix. The targets include high Z re-emission spheres setting foot symmetry through foot cone power balance [1], liquid Deuterium-filled ``keyhole'' targets setting shock speed and timing through the laser power profile [2], symmetry capsules setting peak cone power balance and hohlraum length [3], and streaked x-ray backlit imploding capsules setting ablator thickness [4]. We will show how results from successful tuning technique demonstration shots performed at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design meet the required sensitivity and accuracy. We will also present estimates of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors, and show that these get reduced after a number of shots and iterations to meet an acceptable level of residual uncertainty. Finally, we will present results from upcoming tuning technique validation shots performed at NIF at near full-scale. Prepared by LLNL under Contract DE-AC52-07NA27344. [4pt] [1] E. Dewald, et. al. Rev. Sci. Instrum. 79 (2008) 10E903. [0pt] [2] T.R. Boehly, et. al., Phys. Plasmas 16 (2009) 056302. [0pt] [3] G. Kyrala, et. al., BAPS 53 (2008) 247. [0pt] [4] D. Hicks, et. al., BAPS 53 (2008) 2.

A magnetic particle time-of-flight (MagPTOF) diagnostic for measurements of shock- and compression-bang time at the NIF (invited)

Energy Technology Data Exchange (ETDEWEB)

Rinderknecht, H. G., E-mail: hgr@mit.edu; Sio, H.; Frenje, J. A.; Gatu Johnson, M.; Zylstra, A. B.; Sinenian, N.; Rosenberg, M. J.; Li, C. K.; Sèguin, F. H.; Petrasso, R. D. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Magoon, J.; Agliata, A.; Shoup, M.; Glebov, V. U.; Hohenberger, M.; Stoeckl, C.; Sangster, T. C. [Laboratory for Laser Energetics, Rochester, New York 14623 (United States); Ayers, S.; Bailey, C. G.; Rygg, J. R. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2014-11-15

A magnetic particle time-of-flight (MagPTOF) diagnostic has been designed to measure shock- and compression-bang time using D{sup 3}He-fusion protons and DD-fusion neutrons, respectively, at the National Ignition Facility (NIF). This capability, in combination with shock-burn weighted areal density measurements, will significantly constrain the modeling of the implosion dynamics. This design is an upgrade to the existing particle time-of-flight (pTOF) diagnostic, which records bang times using DD or DT neutrons with an accuracy better than ±70 ps [H. G. Rinderknecht et al., Rev. Sci. Instrum. 83, 10D902 (2012)]. The inclusion of a deflecting magnet will increase D{sup 3}He-proton signal-to-background by a factor of 1000, allowing for the first time simultaneous measurements of shock- and compression-bang times in D{sup 3}He-filled surrogate implosions at the NIF.

A magnetic particle time-of-flight (MagPTOF) diagnostic for measurements of shock- and compression-bang time at the NIF (invited).

Science.gov (United States)

Rinderknecht, H G; Sio, H; Frenje, J A; Magoon, J; Agliata, A; Shoup, M; Ayers, S; Bailey, C G; Gatu Johnson, M; Zylstra, A B; Sinenian, N; Rosenberg, M J; Li, C K; Sèguin, F H; Petrasso, R D; Rygg, J R; Kimbrough, J R; Mackinnon, A; Bell, P; Bionta, R; Clancy, T; Zacharias, R; House, A; Döppner, T; Park, H S; LePape, S; Landen, O; Meezan, N; Robey, H; Glebov, V U; Hohenberger, M; Stoeckl, C; Sangster, T C; Li, C; Parat, J; Olson, R; Kline, J; Kilkenny, J

2014-11-01

A magnetic particle time-of-flight (MagPTOF) diagnostic has been designed to measure shock- and compression-bang time using D(3)He-fusion protons and DD-fusion neutrons, respectively, at the National Ignition Facility (NIF). This capability, in combination with shock-burn weighted areal density measurements, will significantly constrain the modeling of the implosion dynamics. This design is an upgrade to the existing particle time-of-flight (pTOF) diagnostic, which records bang times using DD or DT neutrons with an accuracy better than ±70 ps [H. G. Rinderknecht et al., Rev. Sci. Instrum. 83, 10D902 (2012)]. The inclusion of a deflecting magnet will increase D(3)He-proton signal-to-background by a factor of 1000, allowing for the first time simultaneous measurements of shock- and compression-bang times in D(3)He-filled surrogate implosions at the NIF.

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.

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

Laser Performance Operations Model (LPOM): A Tool to Automate the Setup and Diagnosis of the National Ignition Facility

International Nuclear Information System (INIS)

Shaw, M; House, R; Haynam, C; Williams, W

2005-01-01

The National Ignition Facility (NIF), currently under construction at the University of California's Lawrence Livermore National Laboratory (LLNL) is a stadium-sized facility containing a 192-beam, 1.8 MJ, 500-TW, 351-nm laser system together with a 10-m diameter target chamber with room for nearly 100 experimental diagnostics. When completed, NIF will be the world's largest laser experimental system, providing a national center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. The first four beamlines (a quad) have recently been commissioned, and operations on the first bundle (units of eight beamlines) will begin in Summer 2005. A computational system, the Laser Performance Operations Model (LPOM) has been developed and deployed to automate the laser setup process, and accurately predict laser energetics. For each shot on NIF, the LPOM determines the characteristics of the injection laser system required to achieve the desired main laser output, provides parameter checking for equipment protection, determines the required diagnostic setup, and supplies post-shot data analysis and reporting

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

Science.gov (United States)

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

2016-10-01

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

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

International Nuclear Information System (INIS)

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

1995-05-01

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

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

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.

Dynamic symmetry of indirectly driven inertial confinement fusion capsules on the National Ignition Facility

International Nuclear Information System (INIS)

Town, R. P. J.; Bradley, D. K.; Kritcher, A.; Jones, O. S.; Rygg, J. R.; Tommasini, R.; Barrios, M.; Benedetti, L. R.; Berzak Hopkins, L. F.; Celliers, P. M.; Döppner, T.; Dewald, E. L.; Eder, D. C.; Field, J. E.; Glenn, S. M.; Izumi, N.; Haan, S. W.; Khan, S. F.; Ma, T.; Milovich, J. L.

2014-01-01

In order to achieve ignition using inertial confinement fusion it is important to control the growth of low-mode asymmetries as the capsule is compressed. Understanding the time-dependent evolution of the shape of the hot spot and surrounding fuel layer is crucial to optimizing implosion performance. A design and experimental campaign to examine sources of asymmetry and to quantify symmetry throughout the implosion has been developed and executed on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. We have constructed a large simulation database of asymmetries applied during different time intervals. Analysis of the database has shown the need to measure and control the hot-spot shape, areal density distribution, and symmetry swings during the implosion. The shape of the hot spot during final stagnation is measured using time-resolved imaging of the self-emission, and information on the shape of the fuel at stagnation can be obtained from Compton radiography [R. Tommasini et al., Phys. Plasmas 18, 056309 (2011)]. For the first time on NIF, two-dimensional inflight radiographs of gas-filled and cryogenic fuel layered capsules have been measured to infer the symmetry of the radiation drive on the capsule. These results have been used to modify the hohlraum geometry and the wavelength tuning to improve the inflight implosion symmetry. We have also expanded our shock timing capabilities by the addition of extra mirrors inside the re-entrant cone to allow the simultaneous measurement of shock symmetry in three locations on a single shot, providing asymmetry information up to Legendre mode 4. By diagnosing the shape at nearly every step of the implosion, we estimate that shape has typically reduced fusion yield by about 50% in ignition experiments

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.

Laser scattering in large-scale-length plasmas relevant to National Ignition Facility hohlraums

International Nuclear Information System (INIS)

MacGowan, B.J.; Berger, R.L.; Afeyan, B.B.

1996-10-01

We have used homogeneous plasmas of high density (up to 1.3 X 10 21 electrons per cm 3 ) and temperature (∼ 3 keV) with large density scale lengths (∼2 mm) to approximate conditions within National Ignition Facility (NIF) hohlraums. Within these plasmas we have studied the dependence of stimulated Raman (SRS) and Brillouin (SBS) scattering on beam smoothing and plasma conditions at the relevant laser intensity (3ω, 2 X 10 15 Wcm 2 ). Both SBS and SRS are reduced by the use of smoothing by spectral dispersion (SSD)

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...

Expression of the nifA gene of Herbaspirillum seropedicae: role of the NtrC and NifA binding sites and of the -24/-12 promoter element.

Science.gov (United States)

Souza, E M; Pedrosa, F O; Rigo, L U; Machado, H B; Yates, M G

2000-06-01

The nifA promoter of Herbaspirillum seropedicae contains potential NtrC, NifA and IHF binding sites together with a -12/-24 sigma(N)-dependent promoter. This region has now been investigated by deletion mutagenesis for the effect of NtrC and NifA on the expression of a nifA::lacZ fusion. A 5' end to the RNA was identified at position 641, 12 bp downstream from the -12/-24 promoter. Footprinting experiments showed that the G residues at positions -26 and -9 are hypermethylated, and that the region from -10 to +10 is partially melted under nitrogen-fixing conditions, confirming that this is the active nifA promoter. In H. seropedicae nifA expression from the sigma(N)-dependent promoter is repressed by fixed nitrogen but not by oxygen and is probably activated by the NtrC protein. NifA protein is apparently not essential for nifA expression but it can still bind the NifA upstream activating sequence.

Supplement analysis for paleontological excavation at the National Ignition Facility at Lawrence Livermore National Laboratory

International Nuclear Information System (INIS)

1997-01-01

On December 15, 1997, contractor workers supporting the National Ignition Facility (NIF) construction uncovered bones suspected to be of paleontological importance. The NIF workers were excavating a utility trench near the southwest corner of the NIF footprint area, located at the northeast corner of the Lawrence Livermore National Laboratory (LLNL) Livermore Site, and were excavating at a depth of approximately 30 feet. Upon the discovery of bone fragments, the excavation in the immediate vicinity was halted and the LLNL archaeologist was notified. The archaeologist determined that there was no indication of cultural resources. Mark Goodwin, Senior Curator for the University of California Museum of Paleontology at the University of California, Berkeley, was then contacted. Mr. Goodwin visited the site on December 16th and confirmed that the bones consisted of a section of the skull, a portion of the mandible, several teeth, upper palate, and possibly the vertebrae of a mammoth, genus Mammuthus columbi. This supplement analysis evaluates the potential for adverse impacts of excavating skeletal remains, an activity that was only generally assessed by the NIF Project-Specific Analysis in the Final Programmatic Environmental impact Statement for Stockpile Stewardship and Management (SS and M PEIS) published in September 1996 (DOE/EIS-0236) and its Record of Decision published on December 19, 1996. This supplement analysis has been prepared pursuant to the DOE regulations implementing the National Environmental Policy Act (10 CFR 1021.314)

Laser performance operations model (LPOM): a computational system that automates the setup and performance analysis of the national ignition facility

Energy Technology Data Exchange (ETDEWEB)

Shaw, M; House, R; Williams, W; Haynam, C; White, R; Orth, C; Sacks, R [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA, 94550 (United States)], E-mail: shaw7@llnl.gov

2008-05-15

The National Ignition Facility (NIF) is a stadium-sized facility containing a 192-beam, 1.8 MJ, 500-TW, 351-nm laser system together with a 10-m diameter target chamber with room for many target diagnostics. NIF will be the world's largest laser experimental system, providing a national center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. A computational system, the Laser Performance Operations Model (LPOM) has been developed and deployed that automates the laser setup process, and accurately predict laser energetics. LPOM determines the settings of the injection laser system required to achieve the desired main laser output, provides equipment protection, determines the diagnostic setup, and supplies post shot data analysis and reporting.

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