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Sample records for icf ignition revision

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

    SciTech Connect

    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.

  2. ICF diagnostics. Revision 1

    SciTech Connect

    Coleman, L.W.

    1982-12-17

    In the past several years there have been significant advances and accomplishments in the field of Inertial Confinement Fusion (ICF) research which are directly attributable to an active experimental program supported by the development and applications of sophisticated and specialized diagnostics instruments and techniques. The continued development of high temporal-and spatial-resolution diagnostics, although with a somewhat different technical emphasis than previously, is essential for maintaining progress in ICF. With the generation of inertial fusion drivers now becoming available progress toward higher density compression of fusion fuel will be attained at the expense of temperature, and consequently emissions from the targets will be limited. At the same time since the targets are being driven to higher density they are more opaque to the low-to-moderate energy x-rays (up to a few keV) and particles (alpha particles, protons, and knock-on charged particles) that have been utilized for diagnosing target performance.

  3. The US ICF Ignition Program and the Inertial Fusion Program

    SciTech Connect

    Lindl, J D; Hammel, B A; Logan, B G; Meyerhofer, D D; Payne, S A; Stehian, J D

    2003-07-02

    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 programs to develop fusion energy using lasers, ion beams and z-pinches. Two ignition facilities are under construction (NIF in the U.S. and LMJ in France) and both projects are progressing toward an initial experimental capability. The LIL prototype beamline for LMJ and the first 4 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 the 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 program to develop lasers and ions beams for IFE is under way with excellent progress in drivers, chambers, target fabrication and target injection. KrF and Diode Pumped Solid-State lasers (DPSSL) are being developed in conjunction with drywall chambers and direct drive targets

  4. Effect of High-Z Doping on ICF TN Performance and Ignition

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Ming

    2013-10-01

    One of the challenges of ICF ignition is to achieve desired areal density ρR of the hot-spot region so that a self-sustained TN burn could be initiated and maintained. The recent study of the NIC data indicated that the areal density ρR of the hot-spot inferred by the DSR was lower than the ignition requirement set by ITF. In this work, we will study the effect of Hi-Z doping in the DT gas on the ICF TN performance. The mechanism of the high-Z doping is to utilize additional radiative cooling of high-Z doping during the implosion phase of the evolution so that the gas cavity will follow a lower adiabatic path. This allows a more isothermal compression of the gas to a high density and ρR at the center of the target. The radiative cooling caused by mixing of high Z material into the gas region was considered to degrade to the performance of ICF capsule. However, a trace of high-Z doping enhances both the TN performance as well as the hot-spot ρR. Overall, for a transparent pusher design, over 38% of improvement of gas (hot-spot) ρR and over 200% increase of the yield rate compared to the baseline design have been achieved using this. For an opaque pusher design, no TN performance improvement had been observed in calculation. Work supported by the Department of Energy.

  5. Thermonuclear Burn in Ignition-Scale ICF Targets under Highly Compressed Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Perkins, L. John; Logan, B. Grant; Zimmerman, George; Moody, John; Ho, Darwin; Strozzi, David; Rhodes, Mark; Caporaso, George; Werner, Christopher

    2013-10-01

    We report for the first time on full 2-D radiation-hydrodynamic implosion simulations that demonstrate the impact of highly compressed magnetic fields on the ignition and burn of spherically-converging ICF targets with application to the National Ignition Facility indirect-drive ignition capsule [L.J.Perkins et al., Phys. Plasmas, to be published Aug 2013]. Initial seed fields of 20-100T (potentially attainable using present experimental methods) that compress to greater than 104 T (100 MG) under implosion can relax hotspot areal densities and pressures required for ignition and propagating burn by ~50% in targets degraded by lower-mode perturbations compared to those with no applied field. This accrues from range shortening and magnetic mirror trapping of fusion alpha particles, suppression of electron heat conduction and potential reduction of hydrodynamic instability growth. This may permit the recovery of ignition, or at least significant alpha particle heating, in submarginal capsules that would otherwise fail because of adverse hydrodynamic instabilities. The field may also ameliorate adverse hohlraum plasma conditions such as stimulated Raman scattering. We also discuss experimental concepts for a potential NIF hohlraum coil driven by a co-located pulsed power supply that may be capable of detectable alpha particle heating and fusion yield through magnetized volumetric burn in a high pressure DT gas capsule.

  6. Status of Indirect Drive ICF Experiments on the National Ignition Facility

    SciTech Connect

    Dewald, E.

    2016-03-21

    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 (Tion>5 keV) and fusion neutron yield (~1016), 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.

  7. ICStatus and progress of the National Ignition Facility as ICF and HED user facility

    NASA Astrophysics Data System (ADS)

    Van Wonterghem, B. M.; Kauffman, R. L.; Larson, D. W.; Herrmann, M. C.

    2016-05-01

    Since its completion in 2009, the National Ignition Facility has been operated in support of NNSA's Stockpile Stewardship mission, providing unique experimental data in the high energy density regime. We will describe the progress made by the National Ignition facility in the user office and management, facility capabilities, target diagnostics and diagnostics development. We will also discuss the results of a major effort to increase the shot rate on NIF. An extensive set of projects, developed in conjunction with the HED community and drawing on best practices at other facilities, improved shot rate by over 80% and recently enabled us to deliver 356 target experiments in FY15 in support of the users. Through an updated experimental set-up and review process, computer controlled set-up of the laser and diagnostics and disciplined operations, NIF also continued to deliver experimental reliability, precision and repeatability. New and complex platforms are introduced with a high success rate. Finally we discuss how new capabilities and further efficiency improvements will enable the successful execution of ICF and HED experimental programs required to support the quest for Ignition and the broader Science Based Stockpile Stewardship mission

  8. SRS analyses of direct-drive ICF experiments at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Michel, P.; Rosenberg, M.; Myatt, J.; Solodov, A.; Seka, W.; Chapman, T.; Hohenberger, M.; Masse, L.; Goyon, C.; Turnbull, D.; Regan, S.; Moody, J. D.

    2016-10-01

    A series of planar target experiments was recently conducted at the National Ignition Facility (NIF) to study the laser-plasma interactions processes responsible for the production of suprathermal electrons, and their scaling from experiments at the Omega facility to full-scale ICF experiments at the MJ level on the NIF. We will present experimental analyses and simulations of Stimulated Raman Scattering (SRS) in these planar target experiments. Our work indicates the presence of purely backscattered SRS refracted off nearly one-dimensional density gradients, as well as more complicated features such as side-scatter and scattering from non-1D features (e.g. edges) in the target. Simulations using ray- and paraxial-wave- based simulation codes are used to extrapolate the hot electron fraction from the SRS measurements, and point to SRS being the primary mechanism for the generation of suprathermal electrons in these experiments. We will also present analyses of spherical implosions experiments and provide extrapolations and implications for future full-scale direct-drive experiments at NIF. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  9. Physics issues related to the confinement of ICF experiments in the U.S. National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Tobin, M.; Anderson, A.; Latkowski, J.; Singh, M.; Marshall, C.; Bernat, T.

    1996-05-01

    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.

  10. National Ignition Facility Quality Assurance Program Plan. Revision 1

    SciTech Connect

    Wolfe, C.R.; Yatabe, J.

    1996-09-01

    The National Ignition Facility (NIF) is a key constituent of the Department of Energy`s Stockpile Stewardship Program. The NIF will use inertial confinement fusion (ICF) to produce ignition and energy gain in ICF targets, and will perform weapons physics and high-energy- density experiments in support of national security and civilian objectives. The NIF Project is a national facility involving the collaboration of several DOE laboratories and subcontractors, including Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), and the University of Rochester Laboratory for Laser Energetics (UR/LLE). The primary mission of the NIF Project is the construction and start-up operation of laser-based facilities that will demonstrate fusion ignition in the laboratory to provide nuclear-weapons-related physics data, and secondarily, to propagate fusion burn aimed at developing a potential source of civilian energy. To support the accomplishment of this very important mission, the LLNL Laser Directorate created the NIF Project Office to organize and bring about the Project. The NIF Project Office has established this Quality Assurance Program to ensure its success. This issue of the Quality Assurance Program Plan (QAPP) adds the requirements for the conduct of Title 11 design, construction, procurement, and Title III engineering. This QAPP defines and describes the program-the management system-for specifying, achieving, and assuring the quality of all NIF Project work consistent with the policies of the Laboratory and the Laser Directorate.

  11. Block Ignition Inertial Confinement Fusion (ICF) with Condensed Matter Cluster Type Targets for p-B11 Powered Space Propulsion

    SciTech Connect

    Miley, George H.; Hora, H.; Badziak, J.; Wolowski, J.; Sheng Zhengming; Zhang Jie; Osman, F.; Zhang Weiyan; Tuhe Xia

    2009-03-16

    The use of laser-driven Inertial Confinement Fusion (ICF) for space propulsion has been the subject of several earlier conceptual design studies, (see: Orth, 1998; and other references therein). However, these studies were based on older ICF technology using either 'direct' or 'in-direct x-ray driven' type target irradiation. Important new directions have opened for laser ICF in recent years following the development of 'chirped' lasers capable of ultra short pulses with powers of TW up to few PW which leads to the concept of 'fast ignition (FI)' to achieve higher energy gains from target implosions. In a recent publication the authors showed that use of a modified type of FI, termed 'block ignition' (Miley et al., 2008), could meet many of the requirements anticipated (but not then available) by the designs of the Vehicle for Interplanetary Space Transport Applications (VISTA) ICF fusion propulsion ship (Orth, 2008) for deep space missions. Subsequently the first author devised and presented concepts for imbedding high density condensed matter 'clusters' of deuterium into the target to obtain ultra high local fusion reaction rates (Miley, 2008). Such rates are possible due to the high density of the clusters (over an order of magnitude above cryogenic deuterium). Once compressed by the implosion, the yet higher density gives an ultra high reaction rate over the cluster volume since the fusion rate is proportional to the square of the fuel density. Most recently, a new discovery discussed here indicates that the target matrix could be composed of B{sup 11} with proton clusters imbedded. This then makes p-B{sup 11} fusion practical, assuming all of the physics issues such as stability of the clusters during compression are resolved. Indeed, p-B{sup 11} power is ideal for fusion propulsion since it has a minimum of unwanted side products while giving most of the reaction energy to energetic alpha particles which can be directed into an exhaust (propulsion) nozzle

  12. Early time hot electron generation and deposition at the capsule in indirect drive ICF implosions on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Dewald, Eduard; Pak, Arthur; Milovich, Jose; Bachmann, Benjamin; Hohenberger, Matthias; Albert, Felicie; Robey, Harry; Thomas, Cliff; Divol, Laurent; Doeppner, Tilo; MacKinnon, Andrew; Meezan, Nathan; Callahan, Debbie; Hinkel, Denise; Hurricane, Omar; Landen, Otto; Edwards, John

    2014-10-01

    In indirect drive ICF experiments on the National Ignition Facility (NIF), hot electrons generated by laser plasma instabilities can preheat the deuterium-tritium (DT) capsule, compromising ignition. While below detection limit, the early time (picket) allowable hot electrons in low adiabat implosions are ~1 J in electrons with >170 keV energy compared to 1000 J during the late time peak laser power. At the same time, High Foot implosions that demonstrated fuel-ablator mix mitigation and improved yield, have also shown picket hot electrons that can be comparable to allowable threshold. High Foot Re-emit experiments for tuning the picket radiation symmetry also infer the fraction and uniformity of hot electrons reaching the capsule by hard x-ray (50 keV) imaging combined with 40--300 keV spectra. Their scalings with laser and plasma conditions are discussed. This work performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

  13. ICF ignition capsule neutron, gamma ray, and high energy x-ray images

    NASA Astrophysics Data System (ADS)

    Bradley, P. A.; Wilson, D. C.; Swenson, F. J.; Morgan, G. L.

    2003-03-01

    Post-processed total neutron, RIF neutron, gamma-ray, and x-ray images from 2D LASNEX calculations of burning ignition capsules are presented. The capsules have yields ranging from tens of kilojoules (failures) to over 16 MJ (ignition), and their implosion symmetry ranges from prolate (flattest at the hohlraum equator) to oblate (flattest towards the laser entrance hole). The simulated total neutron images emphasize regions of high DT density and temperature; the reaction-in-flight neutrons emphasize regions of high DT density; the gamma rays emphasize regions of high shell density; and the high energy x rays (>10 keV) emphasize regions of high temperature.

  14. Electron Generation and Transport in Intense Relativistic Laser-Plasma Interactions Relevant to Fast Ignition ICF

    SciTech Connect

    Ma, Tammy Yee Wing

    2010-01-01

    The reentrant cone approach to Fast Ignition, an advanced Inertial Confinement Fusion scheme, remains one of the most attractive because of the potential to efficiently collect and guide the laser light into the cone tip and direct energetic electrons into the high density core of the fuel. However, in the presence of a preformed plasma, the laser energy is largely absorbed before it can reach the cone tip. Full scale fast ignition laser systems are envisioned to have prepulses ranging between 100 mJ to 1 J. A few of the imperative issues facing fast ignition, then, are the conversion efficiency with which the laser light is converted to hot electrons, the subsequent transport characteristics of those electrons, and requirements for maximum allowable prepulse this may put on the laser system. This dissertation examines the laser-to-fast electron conversion efficiency scaling with prepulse for cone-guided fast ignition. Work in developing an extreme ultraviolet imager diagnostic for the temperature measurements of electron-heated targets, as well as the validation of the use of a thin wire for simultaneous determination of electron number density and electron temperature will be discussed.

  15. The effects of 3D asymmetries in ICF capsule implosions on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Chittenden, Jeremy; Taylor, Shaun; Appelbe, Brian; Niasse, Nicholas

    2013-10-01

    We report on investigations into the effect of asymmetry on thermonuclear yield in ICF implosions on the NIF. 3D radiation hydrodynamics calculations of the entire capsule volume are presented which attempt to predict the structural form of the perturbations at the stagnation phase, based upon initial capsule defects, dust particles, radiation drive asymmetries, etc. Asymmetries arising at the interface between the hotspot and the cold dense fuel layer are further amplified by the Rayleigh-Taylor instability during the deceleration phase. Where multi-mode asymmetries interact in three dimensions, not all of kinetic energy is dissipated effectively. Low mode asymmetries which change the overall shape of the hotspot increase the surface area leading to increased thermal conduction. Higher mode asymmetries promote mixing of the cold fuel layer into the hotspot at stagnation. This essentially acts as an increased rate of ablation of the dense fuel at the hotspot surface, pulling material with low specific enthalpy into the hotpot, lowering the average hotspot temperature and quenching the burn. Signatures of the form of the perturbations are revealed in synthetic neutron spectra, X-ray images and radiography data.

  16. Limitation on Pre-pulse Level for Cone-Guided Fast-Ignition ICF

    SciTech Connect

    MacPhee, A G; Akli, K U; Beg, F N; Chen, C D; Chen, H; Divol, L; Hey, D S; Freeman, R R; Henesian, M; Kemp, A J; Key, M H; Pape, S L; Link, A; Ma, T; Mackinnon, A J; Ovchinnikov, V M; Patel, P K; Phillips, T W; Stephens, R B; Tabak, M; Town, R; Van Woerkom, L D; Wei, M S; Wilks, S C

    2009-09-01

    The viability of fast-ignition (FI) inertial confinement fusion hinges on the efficient transfer of laser energy to the compressed fuel via multi-MeV electrons. Pre-formed plasma due to laser pre-pulse strongly influences ultra-intense laser plasma interactions and hot electron generation in the hollow cone of an FI target. We induced a prepulse and consequent preplasma in copper cone targets and measured the energy deposition zone of the main pulse by imaging the emitted K{sub {alpha}} radiation. An integrated simulation of radiation hydrodynamics for the pre-plasma and particle in cell for the main pulse interactions agree well with the measured deposition zones and provide an insight into the enrgy deposition mechanism and electron distribution. It was demonstrated that a under these conditions a 100mJ pre-pulse completely eliminates the forward going component of {approx}2-4MeV electrons. Consequences for cone-guided fast-ignition are discussed.

  17. Suprathermal Ion Populations in ICF Plasmas - Implications for Diagnostics and Ignition

    NASA Astrophysics Data System (ADS)

    Knapp, Patrick; Schmit, Paul; Sinars, Daniel

    2013-10-01

    We report on investigations into the effects of suprathermal ion populations on neutron production in Inertial Confinement and Magneto-Inertial Fusion plasmas. In a recent article we showed that a suprathermal population taking the form of a power-law in energy will significantly modify the shape and width of the neutron spectrum and can dramatically increase the fusion reactivity compared to the Maxwellian case. Specific diagnostic signatures are discussed in detail. We build on this work to include the effect of an applied magnetic field on the neutron spectra, isotropy and production rate. Finally, the impact that these modifications have on the ability to reach high fusion yields and ignition is discussed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration.

  18. Early hot electrons generation and beaming in ICF gas filled hohlraums at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Dewald, Eduard; Michel, Pierre; Hartemann, Fred; Milovich, Jose; Hohenberger, Matthias; Divol, Laurent; Landen, Otto; Pak, Arthur; Thomas, Cliff; Doeppner, Tilo; Bachmann, Benjamin; Meezan, Nathan; MacKinnon, Andrew; Hurricane, Omar; Callahan, Debbie; Hinkel, Denise; Edwards, John

    2015-11-01

    In laser driven hohlraum capsule implosions on the National Ignition Facility, supra-thermal hot electrons generated by laser plasma instabilities can preheat the capsule. Time resolved hot electron Bremsstrahlung spectra combined with 30 keV x-ray imaging uncover for the first time the directionality of hot electrons onto a high-Z surrogate capsule located at the hohlraum center. In the most extreme case, we observed a collimated beaming of hot electrons onto the capsule poles, reaching 50x higher localized energy deposition than for isotropic electrons. A collective SRS model where all laser beams in a cone drive a common plasma wave provides a physical interpretation for the observed beaming. Imaging data are used to distinguish between this mechanism and 2ωp instability. The amount of hot electrons generated can be controlled by the laser pulse shape and hohlraum plasma conditions. This work performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

  19. Design of a High-Foot High-Adiabat ICF Capsule for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Dittrich, T. R.; Hurricane, O. A.; Callahan, D. A.; Dewald, E. L.; Döppner, T.; Hinkel, D. E.; Berzak Hopkins, L. F.; Le Pape, S.; Ma, T.; Milovich, J. L.; Moreno, J. C.; Patel, P. K.; Park, H.-S.; Remington, B. A.; Salmonson, J. D.; Kline, J. L.

    2014-02-01

    The National Ignition Campaign's [M. J. Edwards et al., Phys. Plasmas 20, 070501 (2013), 10.1063/1.4816115] point design implosion has achieved DT neutron yields of 7.5×1014 neutrons, inferred stagnation pressures of 103 Gbar, and inferred areal densities (ρR) of 0.90 g/cm2 (shot N111215), values that are lower than 1D expectations by factors of 10×, 3.3×, and 1.5×, respectively. In this Letter, we present the design basis for an inertial confinement fusion capsule using an alternate indirect-drive pulse shape that is less sensitive to issues that may be responsible for this lower than expected performance. This new implosion features a higher radiation temperature in the "foot" of the pulse, three-shock pulse shape resulting in an implosion that has less sensitivity to the predicted ionization state of carbon, modestly lower convergence ratio, and significantly lower ablation Rayleigh-Taylor instability growth than that of the NIC point design capsule. The trade-off with this new design is a higher fuel adiabat that limits both fuel compression and theoretical capsule yield. The purpose of designing this capsule is to recover a more ideal one-dimensional implosion that is in closer agreement to simulation predictions. Early experimental results support our assertions since as of this Letter, a high-foot implosion has obtained a record DT yield of 2.4×1015 neutrons (within ˜70% of 1D simulation) with fuel ρR =0.84 g/cm2 and an estimated ˜1/3 of the yield coming from α-particle self-heating.

  20. Site support program plan for ICF Kaiser Hanford Company, Revision 1

    SciTech Connect

    1995-10-01

    This document is the general administrative plan implemented by the Hanford Site contractor, ICF Kaiser Hanford Company. It describes the mission, administrative structure, projected staffing, to be provided by the contractor. The report breaks out the work responsibilities within the different units of the company, a baseline schedule for the different groups, and a cost summary for the different operating units.

  1. The Edward Teller Medal Lecture: the Evolution Toward Indirect Drive and Two Decades of Progress Toward Icf Ignition and Burn

    NASA Astrophysics Data System (ADS)

    Lindl, John D.

    In 1972, I joined the Livermore ICF Theory and Target Design group led by John Nuckolls, shortly after publication of John's seminal Nature article on ICF. My primary role, working with others in the target design program including Mordy Rosen, Steve Haan, and Larry Suter, has been as a target designer and theorist who utilized the LASNEX code to perform numerical experiments, which along with analysis of laboratory and underground thermonuclear experiments allowed me to develop a series of models and physical insights which have been used to set the direction and priorities of the Livermore program.

  2. National Ignition Facility project acquisition plan revision 1

    SciTech Connect

    Clobes, A.R.

    1996-10-01

    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.

  3. The Edward Teller medal lecture: The evolution toward Indirect Drive and two decades of progress toward ICF ignition and burn

    SciTech Connect

    Lindl, J.D.

    1993-12-01

    In 1972, I joined the Livermore ICF Theory and Target Design group led by John Nuckolls, shortly after publication of John`s seminal Nature article on ICF. My primary role, working with others in the target design program including Mordy Rosen, Steve Haan, and Larry Suter, has been as a target designer and theorist who utilized the LASNEX code to perform numerical experiments, which along with analysis of laboratory and underground thermonuclear experiments allowed me to develop a series of models and physical insights which have been used to set the direction and priorities of the Livermore program. I have had the good fortune of working with an outstanding team of scientists who have established LLNL as the premier ICF laboratory in the world. John Emmett and the LLNL Laser Science team were responsible for developing a series of lasers from Janus to Nova which have given LLNL unequaled facilities. George Zimmerman and the LASNEX group developed the numerical models essential for projecting future performance and requirements as well as for designing and analyzing the experiments. Bill Kruer, Bruce Langdon and others in the plasma theory group developed the fundamental understanding of laser plasma interactions which have played such an important role in ICF. And a series of experiment program leaders including Mike Campbell and Joe Kilkenny and their laser experimental teams developed the experimental techniques and diagnostic capabilities which have allowed us to c increasingly complex and sophisticated experiments.

  4. Inertial confinement fusion (ICF) review

    SciTech Connect

    Hammer, D.; Dyson, F.; Fortson, N.; Novick, B.; Panofsky, W.; Rosenbluth, M.; Treiman, S.; York, H.

    1996-03-01

    During its 1996 winter study JASON reviewed the DOE Inertial Confinement Fusion (ICF) program. This included the National Ignition Facility (NIF) and proposed studies. The result of the review was to comment on the role of the ICF program in support of the DOE Science Based Stockpile Stewardship program.

  5. ICF Annual Report 1997

    SciTech Connect

    Correll, D

    1998-06-01

    The continuing objective of Lawrence Livermore National Laboratory's (LLNL's) Inertial Confinement Fusion (ICF) Program is the demonstration of thermonuclear fusion ignition and energy gain in the laboratory and to support the nuclear weapons program in its use of ICF facilities. 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 Program (SSP). The mission of the US Inertial Fusion Program is twofold: (1) to address high-energy-density physics issues for the SSP and (2) to develop a laboratory microfusion capability for defense and energy applications. In pursuit of this mission, the ICF Program has developed a state-of-the-art capability to investigate high-energy-density physics in the laboratory. The near-term goals pursued by the ICF Program in support of its mission are demonstrating fusion ignition in the laboratory and expanding the Program's capabilities in high-energy-density science. The National Ignition Facility (NIF) project is a cornerstone of this effort.

  6. 1996 ICF program overview

    SciTech Connect

    Correll, D

    1996-09-30

    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

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

    SciTech Connect

    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 {approx_equal} 10{sup 13} W/cm{sup 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 {approximately}10 nm RMS. Modulation growth was examined using the Haan [Phys. Rev. A {bold 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.

  8. National Ignition Facility Risk Management Plan, Revision 2

    SciTech Connect

    Brereton, S J

    2002-06-01

    The National Ignition Facility (NIF) Risk Management Plan (LLNL, 1997a) was originally prepared in 1997 in accordance with the Department of Energy (DOE) Life Cycle Asset Management Good Practice Guide (DOE, 1996a) and supported NIF Critical Decision 3, approval to initiate construction (DOE, 1997a). The plan was updated in 1998 to reflect realized risks such as the finding and successful clean up of polychlorinated biphenyl (PCB)-filled electrical capacitors at the NIF excavation during initial construction and the litigation of the Programmatic Environmental Impact Statement for Stockpile Stewardship (DOE, 1996b) by a group of non-governmental organizations led by the Natural Resources Defense Council. The current update of the Risk Management Plan brings it into compliance with the applicable DOE Orders and Standards and addresses new risks, such as assuring safety during the period when construction, special equipment installation, and commissioning are occurring simultaneously at the NIF site, and the extensive use of models to manage technical performance risk. The objectives of the updated plan are to: (1) Identify the risks to the completion of the Project in terms of meeting performance and regulatory requirements, ES&H, cost, and schedule; (2) Assess or the risks in terms of likelihood of occurrence and their impact potential relative to technical performance, ES&H, costs, and schedule; and (3) Address suitable risk mitigation measures for each identified risk.

  9. The Edward Teller Medal Lecture: the Evolution Toward Indirect Drive and Two Decades of Progress Toward Icf Ignition and Burn (lirpp Vol. 11)

    NASA Astrophysics Data System (ADS)

    Lindl, John D.

    2016-10-01

    In 1972, I joined the Livermore ICF Theory and Target Design group led by John Nuckolls, shortly after publication of John's seminal Nature article on ICF. My primary role, working with others in the target design program including Mordy Rosen, Steve Haan, and Larry Suter, has been as a target designer and theorist who utilized the LASNEX code to perform numerical experiments, which along with analysis of laboratory and underground thermonuclear experiments allowed me to develop a series of models and physical insights which have been used to set the direction and priorities of the Livermore program...

  10. Early-Time Symmetry Tuning in the Presence of Cross-Beam Energy Transfer in ICF Experiments on the National Ignition Facility

    SciTech Connect

    Dewald, E. L.; Milovich, J. L.; Michel, P.; Landen, O. L.; Kline, J. L.; Glenn, S.; Jones, O.; Kalantar, D. H.; Pak, A.; Robey, H. F.; Kyrala, G. A.; Divol, L.; Benedetti, L. R.; Holder, J.; Widmann, K.; Moore, A.; Schneider, M. B.; Döppner, T.; Tommasini, R.; Bradley, D. K.; Bell, P.; Ehrlich, B.; Thomas, C. A.; Shaw, M.; Widmayer, C.; Callahan, D. A.; Meezan, N. B.; Town, R. P. J.; Hamza, A.; Dzenitis, B.; Nikroo, A.; Moreno, K.; Van Wonterghem, B.; Mackinnon, A. J.; Glenzer, S. H.; MacGowan, B. J.; Kilkenny, J. D.; Edwards, M. J.; Atherton, L. J.; Moses, E. I.

    2013-12-01

    At the National Ignition Facility (NIF) we have successfully tuned the early time (~2 ns) lowest order Legendre mode (P2) of the incoming radiation drive asymmetry of indirectly driven ignition capsule implosions by varying the inner power cone fraction. The measured P2/P0 sensitivity vs come fraction is similar to calculations, but a significant -15 to -20% P2/P0 offset was observed. This can be explained by a considerable early time laser energy transfer from the outer to the inner beams during the laser burn-through of the Laser Entrance Hole (LEH) windows and hohlraum fill gas when the LEH plasma is still dense and relatively cold.

  11. Early-Time Symmetry Tuning in the Presence of Cross-Beam Energy Transfer in ICF Experiments on the National Ignition Facility

    DOE PAGES

    Dewald, E. L.; Milovich, J. L.; Michel, P.; ...

    2013-12-01

    At the National Ignition Facility (NIF) we have successfully tuned the early time (~2 ns) lowest order Legendre mode (P2) of the incoming radiation drive asymmetry of indirectly driven ignition capsule implosions by varying the inner power cone fraction. The measured P2/P0 sensitivity vs come fraction is similar to calculations, but a significant -15 to -20% P2/P0 offset was observed. This can be explained by a considerable early time laser energy transfer from the outer to the inner beams during the laser burn-through of the Laser Entrance Hole (LEH) windows and hohlraum fill gas when the LEH plasma is stillmore » dense and relatively cold.« less

  12. Ignition target design for the National Ignition Facility

    SciTech Connect

    Haan, S.W.; Pollaine, S.M.; Lindl, J.D.

    1996-06-01

    The goal of inertial confinement fusion (ICF) is to produce significant thermonuclear burn from a target driven with a laser or ion beam. To achieve that goal, the national ICF Program has proposed a laser capable of producing ignition and intermediate gain. The facility is called the National Ignition Facility (NIF). This article describes ignition targets designed for the NIF and their modeling. Although the baseline NIF target design, described herein, is indirect drive, the facility will also be capable of doing direct-drive ignition targets - currently being developed at the University of Rochester.

  13. Effects of the P2 M-band flux asymmetry of laser-driven gold Hohlraums on the implosion of ICF ignition capsule

    NASA Astrophysics Data System (ADS)

    Li, Yongsheng; Gu, Jianfa; Wu, Changshu; Song, Peng; Dai, Zhensheng; Li, Shuanggui; Li, Xin; Kang, Dongguo; Gu, Peijun; Zheng, Wudi; Zou, Shiyang; Ding, Yongkun; Lan, Ke; Ye, Wenhua; Zhang, Weiyan

    2016-07-01

    Low-mode asymmetries in the laser-indirect-drive inertial confinement fusion implosion experiments conducted on the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, S228 (2004)] are deemed the main obstacles hindering further improvement of the nuclear performance of deuterium-tritium-layered capsules. The dominant seeds of these asymmetries include the P2 and P4 asymmetries of x-ray drives and P2 asymmetry introduced by the supporting "tent." Here, we explore the effects of another possible seed that can lead to low-mode asymmetric implosions, i.e., the M-band flux asymmetry (MFA) in laser-driven cylindrical gold Hohlraums. It is shown that the M-band flux facilitates the ablation and acceleration of the shell, and that positive P2 MFAs can result in negative P2 asymmetries of hot spots and positive P2 asymmetries of shell's ρR. An oblate or toroidal hot spot, depending on the P2 amplitude of MFA, forms at stagnation. The energy loss of such a hot spot via electron thermal conduction is seriously aggravated not only due to the enlarged hot spot surface but also due to the vortices that develop and help transferring thermal energy from the hotter center to the colder margin of such a hot spot. The cliffs of nuclear performance for the two methodologies of applying MFA (i.e., symmetric flux in the presence of MFA and MFA added for symmetric soft x-ray flux) are obtained locating at 9.5% and 5.0% of P2/P0 amplitudes, respectively.

  14. Fundamentals of ICF Hohlraums

    SciTech Connect

    Rosen, M D

    2005-09-30

    On the Nova Laser at LLNL, we demonstrated many of the key elements required for assuring that the next laser, the National Ignition Facility (NIF) will drive an Inertial Confinement Fusion (ICF) target to ignition. The indirect drive (sometimes referred to as ''radiation drive'') approach converts laser light to x-rays inside a gold cylinder, which then acts as an x-ray ''oven'' (called a hohlraum) to drive the fusion capsule in its center. On Nova we've demonstrated good understanding of the temperatures reached in hohlraums and of the ways to control the uniformity with which the x-rays drive the spherical fusion capsules. In these lectures we will be reviewing the physics of these laser heated hohlraums, recent attempts at optimizing their performance, and then return to the ICF problem in particular to discuss scaling of ICF gain with scale size, and to compare indirect vs. direct drive gains. In ICF, spherical capsules containing Deuterium and Tritium (DT)--the heavy isotopes of hydrogen--are imploded, creating conditions of high temperature and density similar to those in the cores of stars required for initiating the fusion reaction. When DT fuses an alpha particle (the nucleus of a helium atom) and a neutron are created releasing large amount amounts of energy. If the surrounding fuel is sufficiently dense, the alpha particles are stopped and can heat it, allowing a self-sustaining fusion burn to propagate radially outward and a high gain fusion micro-explosion ensues. To create those conditions the outer surface of the capsule is heated (either directly by a laser or indirectly by laser produced x-rays) to cause rapid ablation and outward expansion of the capsule material. A rocket-like reaction to that outward flowing heated material leads to an inward implosion of the remaining part of the capsule shell. The pressure generated on the outside of the capsule can reach nearly 100 megabar (100 million times atmospheric pressure [1b = 10{sup 6} cgs

  15. ICF quarterly report, October-December 1998, volume 8, number 4

    SciTech Connect

    Kaufmann, B

    1998-09-30

    The ICF Quarterly Report is pub-lished four times each fiscal year by the Inertial Confinement Fusion/National Ignition Facility and High-Energy-Density Experimental Science (ICF/NIF/ HEDES) Program at the Lawrence Livermore National Laboratory (LLNL). The journal summarizes selected current research achievements of the LLNLICF/NIF/HEDES Program.

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

    SciTech Connect

    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.

    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.

  17. Modeling Mix in ICF Implosions

    NASA Astrophysics Data System (ADS)

    Weber, C. R.; Clark, D. S.; Chang, B.; Eder, D. C.; Haan, S. W.; Jones, O. S.; Marinak, M. M.; Peterson, J. L.; Robey, H. F.

    2014-10-01

    The observation of ablator material mixing into the hot spot of ICF implosions correlates with reduced yield in National Ignition Campaign (NIC) experiments. Higher Z ablator material radiatively cools the central hot spot, inhibiting thermonuclear burn. This talk focuses on modeling a ``high-mix'' implosion from the NIC, where greater than 1000 ng of ablator material was inferred to have mixed into the hot spot. Standard post-shot modeling of this implosion does not predict the large amounts of ablator mix necessary to explain the data. Other issues are explored in this talk and sensitivity to the method of radiation transport is found. Compared with radiation diffusion, Sn transport can increase ablation front growth and alter the blow-off dynamics of capsule dust. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  18. Isochoric implosions for fast ignition

    SciTech Connect

    Clark, D S; Tabak, M

    2006-06-05

    Fast Ignition (FI) exploits the ignition of a dense, uniform fuel assembly by an external energy source to achieve high gain. In conventional ICF implosions, however, the fuel assembles as a dense shell surrounding a low density, high-pressure hotspot. Such configurations are far from optimal for FI. Here, it is shown that a self-similar spherical implosion of the type originally studied by Guderley [Luftfahrtforschung 19, 302 (1942).] may be employed to implode a dense, quasi-uniform fuel assembly with minimal energy wastage in forming a hotspot. A scheme for realizing these specialized implosions in a practical ICF target is also described.

  19. Observation of multiple mechanisms for stimulating ion waves in ignition scale plasmas. Revision 1

    SciTech Connect

    Kirkwood, R.K.; MacGowan, B.J.; Montgomery, D.S.

    1997-03-03

    The laser and plasma conditions expected in ignition experiments using indirect drive inertial confinement have been studied experimentally. It has been shown that there are at least three ways in which ion waves can be stimulated in these plasmas and have significant effect on the energy balance and distribution in the target. First ion waves can be stimulated by a single laser beam by the process of Stimulated Brillouin Scattering (SBS) in which an ion acoustic and a scattered electromagnetic wave grow from noise. Second, in a plasma where more than one beam intersect, ion waves can Lie excited at the `beat` frequency and wave number of the intersecting beams,, causing the side scatter instability to be seeded, and substantial energy to be transferred between the beams [R. K. Kirkwood et. al. Phys. Rev. Lett. 76, 2065 (1996)]. And third, ion waves may be stimulated by the decay of electron plasma waves produced by Stimulated Raman Scattering (SRS), thereby inhibiting the SRS process [R. K. Kirkwood et. al. Phys. Rev. Lett. 77, 2706 (1996)].

  20. Contributions to the Genesis and Progress of ICF

    SciTech Connect

    Nuckolls, J H

    2006-02-15

    Inertial confinement fusion (ICF) has progressed from the detonation of large-scale fusion explosions initiated by atomic bombs in the early 1950s to final preparations for initiating small-scale fusion explosions with giant lasers. The next major step after ignition will be development of high performance targets that can be initiated with much smaller, lower cost lasers. In the 21st century and beyond, ICF's grand challenge is to develop practical power plants that generate low cost, clean, inexhaustible fusion energy. In this chapter, I first describe the origin in 1960-61 of ICF target concepts, early speculations on laser driven 'Thermonuclear Engines' for power production and rocket propulsion, and encouraging large-scale nuclear explosive experiments conducted in 1962. Next, I recall the 40-year, multi-billion dollar ignition campaign - to develop a matched combination of sufficiently high-performance implosion lasers and sufficiently stable targets capable of igniting small fusion explosions. I conclude with brief comments on the NIF ignition campaign and very high-performance targets, and speculations on ICF's potential in a centuries-long Darwinian competition of future energy systems. My perspectives in this chapter are those of a nuclear explosive designer, optimistic proponent of ICF energy, and Livermore Laboratory leader. The perspectives of Livermore's post 1970 laser experts and builders, and laser fusion experimentalists are provided in a chapter written by John Holzrichter, a leading scientist and leader in Livermore's second generation laser fusion program. In a third chapter, Ray Kidder, a theoretical physicist and early laser fusion pioneer, provides his perspectives including the history of the first generation laser fusion program he led from 1962-1972.

  1. Plasma photonics in ICF & HED conditions

    NASA Astrophysics Data System (ADS)

    Michel, Pierre; Turnbull, David; Divol, Laurent; Pollock, Bradley; Chen, Cecilia Y.; Tubman, Eleanor; Goyon, Clement S.; Moody, John D.

    2015-11-01

    Interactions between multiple high-energy laser beams and plasma can be used to imprint refractive micro-structures in plasmas via the lasers' ponderomotive force. For example, Inertial confinement fusion (ICF) experiments at the National Ignition Facility already rely on the use of plasma gratings to redirect laser light inside an ICF target and tune the symmetry of the imploded core. More recently, we proposed new concepts of plasma polarizer and waveplate, based on two-wave mixing schemes and laser-induced plasma birefringence. In this talk, we will present new experimental results showing the first demonstration of a fully tunable plasma waveplate, which achieved near-perfect circular laser polarization. We will discuss further prospects for novel ``plasma photonics'' concepts based on two- and four-wave mixing, such as optical switches, bandpass filters, anti-reflection blockers etc. These might find applications in ICF and HED experiments by allowing to manipulate the lasers directly in-situ (i.e. inside the targets), as well as for the design of high power laser systems. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  2. The physics of radiation driven ICF hohlraums

    SciTech Connect

    Rosen, M.D.

    1995-08-07

    On the Nova Laser at LLNL, we have recently demonstrated many of the key elements required for assuring that the next proposed laser, the National Ignition Facility (NIF) will drive an Inertial Confinement Fusion (ICF) target to ignition. The target uses the recently declassified indirect drive (sometimes referred to as {open_quotes}radiation drive{close_quotes}) approach which converts laser light to x-rays inside a gold cylinder, which then acts as an x-ray {open_quotes}oven{close_quotes} (called a hohlraum) to drive the fusion capsule in its center. On Nova we`ve demonstrated good understanding of the temperatures reached in hohlraums and of the ways to control the uniformity with which the x-rays drive the spherical fusion capsules. In this lecture we briefly review the fundamentals of ICF, and describe the capsule implosion symmetry advantages of the hohlraum approach. We then concentrate on a quantitative understanding of the scaling of radiation drive with hohlraum size and wall material, and with laser pulse length and power. We demonstrate that coupling efficiency of x-ray drive to the capsule increases as we proceed from Nova to the NIF and eventually to a reactor, thus increasing the gain of the system.

  3. Effect of inactive impurities on the burning of ICF targets

    SciTech Connect

    Gus'kov, S. Yu.; Il'in, D. V.; Sherman, V. E.

    2011-12-15

    The efficiency of thermonuclear burning of the spherical deuterium-tritium (DT) plasma of inertial confinement fusion (ICF) targets in the presence of low-Z impurities (such as lithium, carbon, or beryllium) with arbitrary concentrations is investigated. The effect of impurities produced due to the mixing of the thermonuclear fuel with the material of the structural elements of the target during its compression on the process of target burning is studied, and the possibility of using solid noncryogenic thermonuclear fuels in ICF targets is analyzed. Analytical dependences of the ignition energy and target thermonuclear gain on the impurity concentration are obtained. The models are constructed for homogeneous and inhomogeneous plasmas for the case in which the burning is initiated in the central heated region of the target and then propagates into the surrounding relatively cold fuel. Two possible configurations of an inhomogeneous plasma, namely, an isobaric configuration formed in the case of spark ignition of the target and an isochoric configuration formed in the case of fast ignition, are considered. The results of numerical simulations of the burning of the DT plasma of ICF targets in a wide range of impurity concentrations are presented. The simulations were performed using the TEPA one-dimensional code, in which the thermonuclear burning kinetics is calculated by the Monte Carlo method. It is shown that the strongest negative effect related to the presence of impurities is an increase in the energy of target ignition. It is substantiated that the most promising solid noncryogenic fuel is DT hydride of beryllium (BeDT). The requirements to the plasma parameters at which BeDT can be used as a fuel in noncryogenic ICF targets are determined. Variants of using noncryogenic targets with a solid thermonuclear fuel are proposed.

  4. Ignition and Inertial Confinement Fusion at The National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Moses, Edward I.

    2016-10-01

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and for studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF is now conducting experiments to commission the laser drive, the hohlraum and the capsule and to develop the infrastructure needed to begin the first ignition experiments in FY 2010. Demonstration of ignition and thermonuclear bum in the laboratory is a major NIF goal. NIF will achieve this by concentrating the energy from the 192 beams into a mm3-sized target and igniting a deuterium-tritium mix, liberating more energy than is required to initiate the fusion reaction. NIP's ignition program is a national effort managed via the National Ignition Campaign (NIC). The NIC has two major goals: execution of DT ignition experiments starting in FY20l0 with the goal of demonstrating ignition and a reliable, repeatable ignition platform by the conclusion of the NIC at the end of FY2012. The NIC will also develop the infrastructure and the processes required to operate NIF as a national user facility. The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on laser fusion as a viable energy option. A laser fusion-based energy concept that builds on NIF, known as LIFE (Laser Inertial Fusion Energy), is currently under development. LIFE is inherently safe and can provide a global carbon-free energy generation solution in the 21st century. This paper describes recent progress on NIF, NIC, and the LIFE concept.

  5. Ignition and Inertial Confinement Fusion at The National Ignition Facility

    SciTech Connect

    Moses, E

    2009-10-01

    The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and for studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF is now conducting experiments to commission the laser drive, the hohlraum and the capsule and to develop the infrastructure needed to begin the first ignition experiments in FY 2010. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. NIF will achieve this by concentrating the energy from the 192 beams into a mm{sup 3}-sized target and igniting a deuterium-tritium mix, liberating more energy than is required to initiate the fusion reaction. NIF's ignition program is a national effort managed via the National Ignition Campaign (NIC). The NIC has two major goals: execution of DT ignition experiments starting in FY2010 with the goal of demonstrating ignition and a reliable, repeatable ignition platform by the conclusion of the NIC at the end of FY2012. The NIC will also develop the infrastructure and the processes required to operate NIF as a national user facility. The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on laser fusion as a viable energy option. A laser fusion-based energy concept that builds on NIF, known as LIFE (Laser Inertial Fusion Energy), is currently under development. LIFE is inherently safe and can provide a global carbon-free energy generation solution in the 21st century. This paper describes recent progress on NIF, NIC, and the LIFE concept.

  6. Plans for Ignition Experiments on NIF

    SciTech Connect

    Moses, E

    2007-07-27

    The National Ignition Facility (NIF) is a 192-beam Nd-glass laser facility presently under construction at Lawrence Livermore National Laboratory (LLNL) in support of inertial confinement fusion (ICF) and high-energy-density (HED) science. NIF will produce 1.8 MJ, 500 TW of ultraviolet light, making it the world's largest and most powerful laser system. NIF will be the world's preeminent facility for the study of matter at extreme temperatures and densities and for producing and developing ICF. The ignition studies will be the next important step in developing inertial fusion energy.

  7. ICF gamma-ray reaction history diagnostics

    NASA Astrophysics Data System (ADS)

    Herrmann, H. W.; Young, C. S.; Mack, J. M.; Kim, Y. H.; McEvoy, A.; Evans, S.; Sedillo, T.; Batha, S.; Schmitt, M.; Wilson, D. C.; Langenbrunner, J. R.; Malone, R.; Kaufman, M. I.; Cox, B. C.; Frogget, B.; Miller, E. K.; Ali, Z. A.; Tunnell, T. W.; Stoeffl, W.; Horsfield, C. J.; Rubery, M.

    2010-08-01

    Reaction history measurements, such as nuclear bang time and burn width, are fundamental components of diagnosing ICF implosions and will be employed to help steer the National Ignition Facility (NIF) towards ignition. Fusion gammas provide a direct measure of nuclear interaction rate (unlike x-rays) without being compromised by Doppler spreading (unlike neutrons). Gas Cherenkov Detectors that convert fusion gamma rays to UV/visible Cherenkov photons for collection by fast optical recording systems have established their usefulness in illuminating ICF physics in several experimental campaigns at OMEGA. In particular, bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF. NIF Gamma Reaction History (GRH) diagnostics are being developed based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF-specific logistics, requirements and extreme radiation environment. Implementation will occur in two phases. The first phase consists of four channels mounted to the outside of the target chamber at ~6 m from target chamber center (GRH-6m) coupled to ultra-fast photo-multiplier tubes (PMT). This system is intended to operate in the 1013-1017 neutron yield range expected during the early THD campaign. It will have high enough bandwidth to provide accurate bang times and burn widths for the expected THD reaction histories (> 80 ps fwhm). Successful operation of the first GRH-6m channel has been demonstrated at OMEGA, allowing a verification of instrument sensitivity, timing and EMI/background suppression. The second phase will consist of several channels located just inside the target bay shield wall at 15 m from target chamber center (GRH-15m) with optical paths leading through the cement shield wall to well-shielded streak cameras and PMTs. This system is intended to operate in the 1016-1020 yield range expected during the DT ignition campaign, providing higher temporal resolution for the

  8. Design and assembly of the neutron imaging lens for the National Ignition Facility

    SciTech Connect

    Malone, Robert; Kaufman, Morris

    2010-12-08

    The Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) is the world’s largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high energy density science. Neutron imaging of ICF targets provides a powerful tool for understanding the implosion conditions of deuterium and tritium (DT) filled targets. The primary purpose of imaging ICF targets at NIF is to determine the symmetry of the fuel in an imploded ICF target. The image data are then combined with other nuclear information to gain insight into the drive laser and radiation conditions required to drive the targets to ignition.

  9. Ignition experiment design based on γ-pumping gas lasers

    NASA Astrophysics Data System (ADS)

    Bonyushkin, E. K.; Il'kaev, R. I.; Morovov, A. P.; Pavlovskii, A. I.; Lazhintsev, B. V.; Basov, N.; Gus'kov, S. Yu.; Rosanov, V. B.; Zmitrenko, N. V.

    1996-05-01

    Comparative analysis of gas lasers pumped by γ-radiation for ignition experiment is carried out. The possibilities of frequency-time pulse shaping are discussed for these kinds of laser drivers. New type of ICF target (LIGHT-target), which is able to provide an uniform deposition of laser driver energy is proposed as a target for ignition experiment.

  10. Hydrodynamick instabilities on ICF capsules

    SciTech Connect

    Haan, S.W.

    1991-06-07

    This article summarizes our current understanding of hydrodynamic instabilities as relevant to ICF. First we discuss classical, single mode Rayleigh-Taylor instability, and nonlinear effects in the evolution of a single mode. Then we discuss multimode systems, considering: (1) the onset of nonlinearity; (2) a second order mode coupling theory for weakly nonlinear effects, and (3) the fully nonlinear regime. Two stabilization mechanisms relevant to ICF are described next: gradient scale length and convective stabilization. Then we describe a model which is meant to estimate the weakly nonlinear evolution of multi-mode systems as relevant to ICF, given the short-wavelength stabilization. Finally, we discuss the relevant code simulation capability, and experiments. At this time we are quite optimistic about our ability to estimate instability growth on ICF capsules, but further experiments and simulations are needed to verify the modeling. 52 refs.

  11. The ICF Status and Plans in the United States

    SciTech Connect

    Moses, E; Miller, G; Kauffman, R

    2005-10-12

    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

  12. Stability design considerations for mirror support systems in ICF lasers

    SciTech Connect

    Tietbohl, G.L.; Sommer, S.C.

    1996-10-01

    Some of the major components of laser systems used for Inertial Confinement Fusion (ICF) are the large aperture mirrors which direct the path of the laser. These mirrors are typically supported by systems which consist of mirror mounts, mirror enclosures, superstructures, and foundations. Stability design considerations for the support systems of large aperture mirrors have been developed based on the experience of designing and evaluating similar systems at the Lawrence Livermore National Laboratory (LLNL). Examples of the systems developed at LLNL include Nova, the Petawatt laser, Beamlet, and the National Ignition Facility (NIF). The structural design of support systems of large aperture mirrors has typically been controlled by stability considerations in order for the large laser system to meet its performance requirements for alignment and positioning. This paper will discuss the influence of stability considerations and will provide guidance on the structural design and evaluation of mirror support systems in ICF lasers so that this information can be used on similar systems.

  13. Cascade ICF power reactor

    SciTech Connect

    Hogan, W.J.; Pitts, J.H.

    1986-05-20

    The double-cone-shaped Cascade reaction chamber rotates at 50 rpm to keep a blanket of ceramic granules in place against the wall as they slide from the poles to the exit slots at the equator. The 1 m-thick blanket consists of layers of carbon, beryllium oxide, and lithium aluminate granules about 1 mm in diameter. The x rays and debris are stopped in the carbon granules; the neutrons are multiplied and moderated in the BeO and breed tritium in the LiAlO/sub 2/. The chamber wall is made up of SiO tiles held in compression by a network of composite SiC/Al tendons. Cascade operates at a 5 Hz pulse rate with 300 MJ in each pulse. The temperature in the blanket reaches 1600 K on the inner surface and 1350 K at the outer edge. The granules are automatically thrown into three separate vacuum heat exchangers where they give up their energy to high pressure helium. The helium is used in a Brayton cycle to obtain a thermal-to-electric conversion efficiency of 55%. Studies have been done on neutron activation, debris recovery, vaporization and recondensation of blanket material, tritium control and recovery, fire safety, and cost. These studies indicate that Cascade appears to be a promising ICF reactor candidate from all standpoints. At the 1000 MWe size, electricity could be made for about the same cost as in a future fission reactor.

  14. ICF quarterly report January - March 1997 volume 7, number 3

    SciTech Connect

    Murray, J

    1998-04-09

    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.

  15. Diagnosing ICF gamma-ray physics

    SciTech Connect

    Herrmann, Hans W; Kim, Y H; Mc Evoy, A; Young, C S; Mack, J M; Hoffman, N; Wilson, D C; Langenbrunner, J R; Evans, S; Sedillo, T; Batha, S H; Dauffy, L; Stoeffl, W; Malone, R; Kaufman, M I; Cox, B C; Tunnel, T W; Miller, E K; Rubery, M

    2010-01-01

    Gamma rays produced in an ICF environment open up a host of physics opportunities we are just beginning to explore. A branch of the DT fusion reaction, with a branching ratio on the order of 2e-5 {gamma}/n, produces 16.7 MeV {gamma}-rays. These {gamma}-rays provide a direct measure of fusion reaction rate (unlike x-rays) without being compromised by Doppler spreading (unlike neutrons). Reaction-rate history measurements, such as nuclear bang time and burn width, are fundamental quantities that will be used to optimize ignition on the National Ignition Facility (NIF). Gas Cherenkov Detectors (GCD) that convert fusion {gamma}-rays to UV/visible Cherenkov photons for collection by fast optical recording systems established their usefulness in illuminating ICF physics in several experimental campaigns at OMEGA. Demonstrated absolute timing calibrations allow bang time measurements with accuracy better than 30 ps. System impulse response better than 95 ps fwhm have been made possible by the combination of low temporal dispersion GCDs, ultra-fast microchannel-plate photomultiplier tubes (PMT), and high-bandwidth Mach Zehnder fiber optic data links and digitizers, resulting in burn width measurement accuracy better than 10ps. Inherent variable energy-thresholding capability allows use of GCDs as {gamma}-ray spectrometers to explore other interesting nuclear processes. Recent measurements of the 4.44 MeV {sup 12}C(n,n{prime}) {gamma}-rays produced as 14.1 MeV DT fusion neutrons pass through plastic capsules is paving the way for a new CH ablator areal density measurement. Insertion of various neutron target materials near target chamber center (TCC) producing secondary, neutron-induced {gamma}y-rays are being used to study other nuclear interactions and as in-situ sources to calibrate detector response and DT branching ratio. NIF Gamma Reaction History (GRH) diagnostics, based on the GCD concept, are now being developed based on optimization of sensitivity, bandwidth

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

    SciTech Connect

    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.

  17. IGNITION AND FRONTIER SCIENCE ON THE NATIONAL IGNITION FACILITY

    SciTech Connect

    Moses, E

    2009-06-22

    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 now operational at Lawrence Livermore National Laboratory (LLNL). The NIF construction Project was certified by the Department of Energy as complete on March 30, 2009. 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. On March 10, 2009, a total 192-beam energy of 1.1 MJ was demonstrated; this is approximately 30 times more energy than ever produced in an ICF laser system. 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 frontier scientific exploration. NIF experiments in support of indirect drive ignition will begin in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a 1.7 billion dollar national effort to achieve fusion ignition and is coordinated through a detailed execution plan that includes the science, technology, and equipment. Equipment required for ignition experiments include diagnostics, cryogenic target manipulator, and user optics. Participants in this effort include LLNL, General Atomics (GA), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), 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 and be ready to begin a credible ignition campaign in 2010. With NIF now operational, the long-sought goal of achieving self-sustained nuclear fusion and energy gain in the laboratory is much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of

  18. Antiproton fast ignition for Inertial Confinement Fusion

    SciTech Connect

    Perkins, L.J.

    1997-10-24

    With 180MJ/{micro}g, antiprotons offer the highest stored energy per unit mass of any known entity. We investigate the use of antiprotons to promote fast ignition in an ICF capsule and seek high gains with only modest compression of the main fuel. Unlike standard fast ignition where the ignition energy is supplied by an energetic, short pulse laser, the energy here is supplied through the ionization energy deposited when antiprotons annihilate at the center of a compressed fuel capsule. In the first of two candidate fast ignition schemes, the antiproton package is delivered by a low energy external ion beam. In the second, ''autocatalytic'' scheme, the antiprotons are pre-emplaced at the center of the capsule prior to compression. In both schemes, we estimate that {approximately}3x10{sup 13} antiprotons are required to initiate fast ignition in a typical ICF capsule and show that incorporation of a thin, heavy metal shell is desirable to enhance energy deposition in the igniter zone. In addition to obviating the need for a second energetic fast laser and vulnerable final optics, this scheme would achieve central without reliance on laser channeling through halo plasma or houlrahm debris. However, in addition to the unknowns involved in the storage and manipulation of antiprotons at low energy, the other large uncertainty for the practicality of such a scheme is the ultimate efficiency of antiproton production in, an external, optimized facility.

  19. Revising.

    ERIC Educational Resources Information Center

    Wyman, Linda, Ed.

    1983-01-01

    In focusing on recursive writing, the nine articles in this journal issue suggest that student writing should be taken seriously. The first article states that revision should occur throughout the writing process while the second discusses how to invite writers to become active readers of their own texts. The third article presents methods of…

  20. Ignition and burn of a small magnetized fuel target

    SciTech Connect

    Kirkpatrick, Ronald C.

    2012-06-01

    The crucial step for inertial confinement fusion (ICF) is ignition, which leads to sufficiently high gain to enable design of a power producing system. Thus far, this step has not been demonstrated. Magnetized targets may provide an alternative path to ignition. In addition, the 1-D calculations presented here suggest that this approach may provide the gain and other characteristics needed for a practical fusion reactor.

  1. Nonequilibrium pulsed plasma: ICF target, neutron, and x-ray sources applications

    NASA Astrophysics Data System (ADS)

    Gus'kov, Sergei Y.

    2001-04-01

    The approaches based on the properties of nonequilibrium pulsed plasmas to develop ICF target design and some ICF application problems are discussed. The methods of the creation of pulsed plasmas with essential properties on the laser radiation absorption and the emission of soft x-ray, fast ions and thermonuclear neutrons are proposed. Theoretical and experimental results are presented on the following fields: 1) laser-produced plasma of porous matter of light elements as a direct ICF target absorber smoothing the laser energy deposition nonuniformities; 2) laser- produced plasma of the composed materials which are the porous medium of light elements with a distribute solid clusters of heavy elements as a wide-range x-ray converter of the ICF target at the direct irradiation by laser beams; 3) laser-produced plasma of regularly volume-structured matter consisting of an ensemble of alternate thin layers of high and low density material containing a thermonuclear fuel or an ensemble of microshells in contact with an one another mode of a material contain such a fuel as a high power neutron source with the intensity more than 1010 DT neutron per one joule of laser energy; 4) high-power- laser-produced plasma of thin foil as a source of light Mev- ions for the direct ignition of ICF target.

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

    SciTech Connect

    Ross, P.

    2012-08-29

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

  3. Influence of radiative processes on the ignition of deuterium-tritium plasma containing inactive impurities

    NASA Astrophysics Data System (ADS)

    Gus'kov, S. Yu.; Sherman, V. E.

    2016-08-01

    The degree of influence of radiative processes on the ignition of deuterium-tritium (DT) plasma has been theoretically studied as dependent on the content of inactive impurities in plasma. The analytic criterion of plasma ignition in inertial confinement fusion (ICF) targets is modified taking into account the absorption of intrinsic radiation from plasma in the ignition region. The influence of radiative processes on the DT plasma ignition has been analytically and numerically studied for plasma that contains a significant fraction of inactive impurities either as a result of DT fuel mixing with ICF target ablator material or as a result of using light metal DT-hydrides as solid noncryogenic fuel. It has been shown that the effect of the absorption of intrinsic radiation leads to lower impurity-induced increase in the ignition energy as compared to that calculated in the approximation of optically transparent ignition region.

  4. Backlighting prospects for ICF targets

    SciTech Connect

    Rupert, V.; Matthews, D.; Ahlstrom, H.; Attwood, D.; Price, R.; Coleman, L.; Manes, K.; Slivinsky, V.

    1981-01-01

    High energy x-ray backlighters are necessary to diagnose the implosion symmetry and stability of intermediate and high density targets. Synchronization requirements between the target irradiating pulse and the radiograph place severe constraints on the type of x-ray sources which can be used and favors laser irradiated backlighters. Data gathered on line emitters as a function of laser pulselength, wavelength and intensity in the 5 to 10 keV region are used to determine which diagnostic instruments will be feasible for ICF target experiments, and the requirements for backlighter irradiation.

  5. X-ray ablation measurements and modeling for ICF applications

    SciTech Connect

    Anderson, Andrew Thomas

    1996-09-01

    X-ray ablation of material from the first wall and other components of an ICF (Inertial Confinement Fusion) chamber is a major threat to the laser final optics. Material condensing on these optics after a shot may cause damage with subsequent laser shots. To ensure the successful operation of the ICF facility, removal rates must be predicted accurately. The goal for this dissertation is to develop an experimentally validated x-ray response model, with particular application to the National Ignition Facility (NIF). Accurate knowledge of the x-ray and debris emissions from ICF targets is a critical first step in the process of predicting the performance of the target chamber system. A number of 1-D numerical simulations of NIF targets have been run to characterize target output in terms of energy, angular distribution, spectrum, and pulse shape. Scaling of output characteristics with variations of both target yield and hohlraum wall thickness are also described. Experiments have been conducted at the Nova laser on the effects of relevant x-ray fluences on various materials. The response was diagnosed using post-shot examinations of the surfaces with scanning electron microscope and atomic force microscope instruments. Judgments were made about the dominant removal mechanisms for each material. Measurements of removal depths were made to provide data for the modeling. The finite difference ablation code developed here (ABLATOR) combines the thermomechanical response of materials to x-rays with models of various removal mechanisms. The former aspect refers to energy deposition in such small characteristic depths (~ micron) that thermal conduction and hydrodynamic motion are significant effects on the nanosecond time scale. The material removal models use the resulting time histories of temperature and pressure-profiles, along with ancillary local conditions, to predict rates of surface vaporization and the onset of conditions that would lead to spallation.

  6. Improved ICF implosion performance through precision engineering features

    NASA Astrophysics Data System (ADS)

    Weber, Christopher

    2016-10-01

    The thin membrane that holds the capsule in-place in the hohlraum is recognized as one of the most significant contributors to reduced performance in indirect drive inertial confinement fusion (ICF) experiments on the National Ignition Facility (NIF). This membrane, known as the ``tent'', seeds a perturbation that is amplified by Rayleigh-Taylor and can rupture the capsule. The ICF program is undertaking a major effort to develop a less damaging capsule support mechanism. Possible alternatives include micron-scale rods spanning the hohlraum width and supporting either the capsule or stiffening the fill-tube, a larger fill-tube to both fill and support the capsule, or a low-density foam layer that protects the capsule from the tent impact. In addition to the challenges presented by nano and microscale engineering, it is difficult to model and experimentally verify improvement from these changes. The 3D nature of the proposed replacements and the radiation shadows they cast on the capsule prohibit direct simulation. Therefore a combination of reduced models and experimental verification are used to set requirements and down-select the options. Ultimately the improved capsule support will be used to repeat a DT-layered implosion and demonstrate improved performance. Work performed under the auspices of the U.S. D.O.E. by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  7. Kr X-ray spectroscopy to diagnose NIF ICF implosions

    NASA Astrophysics Data System (ADS)

    Dasgupta, A.; Ouart, N.; Giuliani, J. L.; Clark, R. W.; Schneider, M. B.; Scott, H. A.; Chen, H.; Ma, T.; Apruzese, J. P.

    2016-10-01

    X ray spectroscopy is used on the NIF to diagnose the plasma conditions in the ignition target in indirect drive ICF implosions. High-energy emission spectra from mid to high atomic number elements can provide estimates of electron temperature near stagnation of an ICF implosion. 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. 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 and compare and contrast with the existing simulations at LLNL. Work supported by DOE/NNSA and under the auspices of DOE by LLNL under Contract # DE-AC52-07NA27344.

  8. Wetted Foam Liquid DT Layer ICF Experiments at the NIF

    NASA Astrophysics Data System (ADS)

    Olson, R. E.; Leeper, R. J.; Peterson, R. R.; Yi, S. A.; Zylstra, A. B.; Kline, J. L.; Bradley, P. A.; Yin, L.; Wilson, D. C.; Haines, B. M.; Batha, S. H.

    2016-10-01

    A key physics issue in indirect-drive ICF relates to the understanding of the limitations on hot spot convergence ratio (CR), principally set by the hohlraum drive symmetry, the capsule mounting hardware (the ``tent''), and the capsule fill tube. An additional key physics issue relates to the complex process by which a hot spot must be dynamically formed from the inner ice surface in a DT ice-layer implosion. These physics issues have helped to motivate the development of a new liquid DT layer wetted foam platform at the NIF that provides an ability to form the hot spot from DT vapor and experimentally study and understand hot spot formation at a variety of CR's in the range of 12ICF ignition. This work was performed under the auspices of the U. S. DOE by LANL under contract DE-AC52-06NA25396.

  9. ICF Ablator Physics Experiments on Saturn and Nova

    NASA Astrophysics Data System (ADS)

    Olson, Rick

    1996-11-01

    In indirect drive ICF, the driver energy is absorbed in a high-Z enclosure (or "hohlraum") that surrounds a spherical shell (or "capsule") containing DT fuel. The hohlraum walls are heated by the driver and emit x-rays, which are absorbed by the capsule material (the "ablator") and drive the implosion. We have used the Saturn z-pinch at SNL and the Nova laser at LLNL to explore the behavior of ablator material in x-ray radiation environments comparable in magnitude, spectrum and duration to those that will be experienced in National Ignition Facility (NIF) hohlraums. The large x-ray outputs available from pulsed-power driven z-pinches have enabled us to drive hohlraums of full NIF ignition scale size at radiation temperatures and timescales comparable to those required for the low power "foot" pulse of an ignition capsule. The high intensity of the Nova laser has allowed us to study capsule ablator physics in smaller scale hohlraums at radiation temperatures and timescales relevant to the peak power pulse for an ignition capsule. Taken together, these experiments have allowed us test our radiation-hydrodynamics computer code predictions of ablator opacity, radiation flow, and equation of state over almost the complete range of radiation environments to be encountered in a NIF hohlraum. * in collaboration with J. Porter, G. Chandler, D. Fehl, D. Jobe, R. Leeper, K. Matzen, J. McGurn, D. Noack, L. Ruggles, P. Sawyer, J. Torres, M. Vargas, D. Zagar (SNL), and H. Kornblum, T. Orzechowski, L. Suter, R. Thiessen, R. Wallace (LLNL), and the Saturn and Nova operations and diagnostic crews at SNL and LLNL. +This work was supported by the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  10. Ignition of deuterium-trtium fuel targets

    DOEpatents

    Musinski, Donald L.; Mruzek, Michael T.

    1991-01-01

    A method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom.

  11. Ignition of deuterium-tritium fuel targets

    DOEpatents

    Musinski, D.L.; Mruzek, M.T.

    1991-08-27

    Disclosed is a method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom. 5 figures.

  12. Monte Carlo methods in ICF

    SciTech Connect

    Zimmerman, G.B.

    1997-06-24

    Monte Carlo methods appropriate to simulate the transport of x-rays, neutrons, ion and electrons in Inertial Confinement Fusion targets are described and analyzed. The Implicit Monte Carlo method of x-ray transport handles symmetry within indirect drive ICF hohlraums well, but can be improved 50X in efficiency by angular biasing the x-rays towards the fuel capsule. Accurate simulation of thermonuclear burns nd burn diagnostics involves detailed particle source spectra, charged particle ranges, inflight reaction kinematics, corrections for bulk and thermal Doppler effects and variance reduction to obtain adequate statistics for rare events. It is found that the effects of angular Coulomb scattering must be included in models of charged particle transport through heterogeneous materials.

  13. ICF machine: a web-based system for collection of ICF data.

    PubMed

    Della Mea, Vincenzo; Fioresi, Valerio

    2012-01-01

    The International Classification of Functioning, Disability and Health (ICF) is a WHO classification for health and health-related issues. In order to foster ICF application in information systems, we devised an implementation profile in ClaML (Classification Markup Language) that allows for representation of ICF subsets and we developed a web-based system for collecting ICF data based on from their ClaML representation. The implementation profile and the application have been tested on 17 subsets, which have been translated into ClaML and then submitted to the web application, to produce test documents.

  14. Thermal Ignition

    NASA Astrophysics Data System (ADS)

    Boettcher, Philipp Andreas

    Accidental ignition of flammable gases is a critical safety concern in many industrial applications. Particularly in the aviation industry, the main areas of concern on an aircraft are the fuel tank and adjoining regions, where spilled fuel has a high likelihood of creating a flammable mixture. To this end, a fundamental understanding of the ignition phenomenon is necessary in order to develop more accurate test methods and standards as a means of designing safer air vehicles. The focus of this work is thermal ignition, particularly auto-ignition with emphasis on the effect of heating rate, hot surface ignition and flame propagation, and puffing flames. Combustion of hydrocarbon fuels is traditionally separated into slow reaction, cool flame, and ignition regimes based on pressure and temperature. Standard tests, such as the ASTM E659, are used to determine the lowest temperature required to ignite a specific fuel mixed with air at atmospheric pressure. It is expected that the initial pressure and the rate at which the mixture is heated also influences the limiting temperature and the type of combustion. This study investigates the effect of heating rate, between 4 and 15 K/min, and initial pressure, in the range of 25 to 100 kPa, on ignition of n-hexane air mixtures. Mixtures with equivalence ratio ranging from 0.6 to 1.2 were investigated. The problem is also modeled computationally using an extension of Semenov's classical auto-ignition theory with a detailed chemical mechanism. Experiments and simulations both show that in the same reactor either a slow reaction or an ignition event can take place depending on the heating rate. Analysis of the detailed chemistry demonstrates that a mixture which approaches the ignition region slowly undergoes a significant modification of its composition. This change in composition induces a progressive shift of the explosion limit until the mixture is no longer flammable. A mixture that approaches the ignition region

  15. Laser ignition

    DOEpatents

    Early, James W.; Lester, Charles S.

    2002-01-01

    In the apparatus of the invention, a first excitation laser or other excitation light source capable of producing alternating beams of light having different wavelengths is used in tandem with one or more ignitor lasers to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using the single remote excitation light source for pumping one or more small lasers located proximate to one or more fuel combustion zones with alternating wavelengths of light.

  16. The National Ignition Facility project

    SciTech Connect

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

    1996-06-01

    The Secretary of the U.S. Department of Energy (DOE) commissioned a Conceptual Design Report (CDR) for the National Ignition Facility (NIF) in January 1993 as part of a Key Decision Zero (KD0), 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 {mu}m) 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, the authors 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. 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. This article presents an overview of the NIF project.

  17. The National Ignition Facility (NIF) and the National Ignition Campaign (NIC)

    SciTech Connect

    Moses, E

    2009-09-17

    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 now operational at Lawrence Livermore National Laboratory (LLNL). NIF construction was certified by the Department of Energy as complete on March 27, 2009. NIF, a 192-beam Nd:glass laser facility, will ultimately produce 1.8-MJ, 500-TW of 351-nm third-harmonic, ultraviolet light. On March 10, 2009, total 192-beam energy of 1.1 MJ was demonstrated; this is approximately 30 times more energy than ever produced in an ICF laser system. 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 broader frontier scientific exploration. NIF experiments in support of indirect-drive ignition began in August 2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a national effort to achieve fusion ignition and is coordinated through a detailed execution plan that includes the science, technology, and equipment. Equipment required for ignition experiments includes diagnostics, a cryogenic target manipulator, and user optics. Participants in this effort include LLNL, General Atomics (GA), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational, integrated into the facility, and ready to begin a credible ignition campaign in 2010. With NIF now operational, the long-sought goal of achieving self-sustained nuclear fusion and energy gain in the laboratory is 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

  18. Laser ignition

    DOEpatents

    Early, James W.; Lester, Charles S.

    2003-01-01

    In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In a third embodiment, alternating short and long pulses of light from the excitation light source are directed into the ignitor laser. Each of the embodiments of the invention can be multiplexed so as to provide laser light energy sequentially to more than one ignitor laser.

  19. The ICF and Postsurgery Occupational Therapy after Traumatic Hand Injury

    ERIC Educational Resources Information Center

    Fitinghoff, Helene; Lindqvist, Birgitta; Nygard, Louise; Ekholm, Jan; Schult, Marie-Louise

    2011-01-01

    Recent studies have examined the effectiveness of hand rehabilitation programmes and have linked the outcomes to the concept of ICF but not to specific ICF category codes. The objective of this study was to gain experience using ICF concepts to describe occupational therapy interventions during postsurgery hand rehabilitation, and to describe…

  20. Accommodation Outcomes and the ICF Framework

    ERIC Educational Resources Information Center

    Schreuer, Naomi

    2009-01-01

    Accommodation of the environment and technology is one of the key mediators of adjustment to disability and participation in community. In this article, accommodations are tested empirically as facilitators of return to work and participation, as defined by the "International Classification of Disability, Function, and Health" (ICF) and…

  1. ICF quarterly report October-December 1998 volume 8, number 1

    SciTech Connect

    Feit, M

    1998-09-08

    This issue of the ICF Quarterly Report focuses on the final section of the 192-arm, 1.8-MJ National Ignition Facility (NIF). We describe both technological advances necessary for optimal utilization of the delivered energy and the hohlraum physics resulting from extremely high energy densities. Two articles belong to the first category. The conversion of infrared light to ultraviolet occurs at the tripler in the NIF's Final Optics Assembly. It is then necessary to separate any unconverted (first- and second-harmonic) light from the tripled-frequency light passed to the target. Large-Aperture Color-Separation Gratings for Diverting Unconverted Light Away from the NIF Target describes the design and fabrication of novel diffraction gratings that fulfill this function. In both direct- and indirect-drive ICF, the symmetry of the capsule as it compresses is crucial. The NIF will have 48 clusters of four beams incident on targets. Optimization of Beam Angles for the National Ignition Facility (p. 15) presents the rationale used to assign beam angles for cylindrical indirect drive while still allowing direct-drive and tetrahedral indirect-drive experiments to be performed.

  2. Modeling and diagnosing interface mix in layered ICF implosions

    NASA Astrophysics Data System (ADS)

    Weber, C. R.; Berzak Hopkins, L. F.; Clark, D. S.; Haan, S. W.; Ho, D. D.; Meezan, N. B.; Milovich, J. L.; Robey, H. F.; Smalyuk, V. A.; Thomas, C. A.

    2015-11-01

    Mixing at the fuel-ablator interface of an inertial confinement fusion (ICF) implosion can arise from an unfavorable in-flight Atwood number between the cryogenic DT fuel and the ablator. High-Z dopant is typically added to the ablator to control the Atwood number, but recent high-density carbon (HDC) capsules have been shot at the National Ignition Facility (NIF) without this added dopant. Highly resolved post-shot modeling of these implosions shows that there was significant mixing of ablator material into the dense DT fuel. This mix lowers the fuel density and results in less overall compression, helping to explain the measured ratio of down scattered-to-primary neutrons. Future experimental designs will seek to improve this issue through adding dopant and changing the x-ray spectra with a different hohlraum wall material. To test these changes, we are designing an experimental platform to look at the growth of this mixing layer. This technique uses side-on radiography to measure the spatial extent of an embedded high-Z tracer layer near the interface. Work performed under the auspices of the U.S. D.O.E. by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  3. Wetted Foam Liquid Fuel ICF Target Experiments

    NASA Astrophysics Data System (ADS)

    Olson, R.; Leeper, R.; Yi, A.; Zylstra, A.; Kline, J.; Peterson, R.; Braun, T.; Biener, J.; Biener, M.; Kozioziemski, B.; Sater, J.; Hamza, A.; Nikroo, A.; Berzak Hopkins, L.; Lepape, S.; MacKinnon, A.; Meezan, N.

    2015-11-01

    We are developing a new NIF experimental platform that employs wetted foam liquid fuel layer ICF capsules. We plan to use the liquid fuel layer capsules in a NIF experimental campaign to explore the relationship between hot spot convergence ratio (CR) and the robustness of hot spot formation. DT or D2 Liquid Layer ICF capsules allow for flexibility in hot spot convergence ratio via the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. Our hypothesis is that the predictive capability of hot spot formation is robust and 1D-like for a relatively low CR hot spot (CR =15), but will become less reliable as hot spot CR is increased to CR>20. Simulations indicate that backing off on hot spot CR is an excellent way to reduce capsule instability growth and to improve robustness to low-mode x-ray flux asymmetries. In these initial experiments, we are testing our hypothesis by measuring hot spot size, neutron yield, ion temperature, and burn width to infer hot spot pressure and compare to predictions for implosions with hot spot CR's in the range of 12 to 25. Larger scale experiments are also being designed, with the longer-term objective of developing a liquid fuel layer ICF capsule platform with robust thermonuclear burn, modest CR, and significant α-heating with burn propagation.

  4. Implementation of the International Classification of Functioning, Disability and Health (ICF) and the ICF Children and Youth Version (ICF-CY) within the context of augmentative and alternative communication.

    PubMed

    Pless, Mia; Granlund, Mats

    2012-03-01

    The purpose of this article is to discuss the implementation of the International Classification of Functioning, Disability and Health (ICF), and the ICF version for Children and Youth (ICF-CY), within the context of augmentative and alternative communication (AAC). First, the use of the ICF and the ICF-CY in AAC research is analyzed. Second, examples of training and implementation of ICF from other contexts besides AAC are provided. Finally, we synthesize data to provide directions for future implementation of the ICF and ICF-CY in the field of AAC. We conclude that, within AAC, organizational routines and intervention documents need to be adapted to the universal language and classification framework of the ICF and ICF-CY. Furthermore, examples are needed to demonstrate how factors affect implementation at organizational and individual levels.

  5. The National Ignition Facility and the Golden Age of High Energy Density Science

    SciTech Connect

    Meier, W; Moses, E I; Newton, M

    2007-09-27

    The National Ignition Facility (NIF) is a 192-beam Nd:glass laser facility being constructed at the Lawrence Livermore National Laboratory (LLNL) to conduct research in inertial confinement fusion (ICF) and high energy density (HED) science. When completed, NIF will produce 1.8 MJ, 500 TW of ultraviolet light, making it the world's largest and highest-energy laser system. The NIF is poised to become the world's preeminent facility for conducting ICF and fusion energy research and for studying matter at extreme densities and temperatures.

  6. The National Ignition Facility and the Golden Age of High Energy Density Science

    SciTech Connect

    Moses, E

    2007-08-14

    The National Ignition Facility (NIF) is a 192-beam Nd:glass laser facility being constructed at the Lawrence Livermore National Laboratory (LLNL) to conduct research in inertial confinement fusion (ICF) and high energy density (HED) science. When completed, NIF will produce 1.8 MJ, 500 TW of ultraviolet light, making it the world's largest and highest-energy laser system. The NIF is poised to become the world's preeminent facility for conducting ICF and fusion energy research and for studying matter at extreme densities and temperatures.

  7. Progress towards polar-drive ignition for the NIF

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  8. Laser ignition

    DOEpatents

    Early, James W.; Lester, Charles S.

    2004-01-13

    Sequenced pulses of light from an excitation laser with at least two resonator cavities with separate output couplers are directed through a light modulator and a first polarzing analyzer. A portion of the light not rejected by the first polarizing analyzer is transported through a first optical fiber into a first ignitor laser rod in an ignitor laser. Another portion of the light is rejected by the first polarizing analyzer and directed through a halfwave plate into a second polarization analyzer. A first portion of the output of the second polarization analyzer passes through the second polarization analyzer to a second, oscillator, laser rod in the ignitor laser. A second portion of the output of the second polarization analyzer is redirected by the second polarization analyzer to a second optical fiber which delays the beam before the beam is combined with output of the first ignitor laser rod. Output of the second laser rod in the ignitor laser is directed into the first ignitor laser rod which was energized by light passing through the first polarizing analyzer. Combined output of the first ignitor laser rod and output of the second optical fiber is focused into a combustible fuel where the first short duration, high peak power pulse from the ignitor laser ignites the fuel and the second long duration, low peak power pulse directly from the excitation laser sustains the combustion.

  9. Ignition threshold for non-Maxwellian plasmas

    NASA Astrophysics Data System (ADS)

    Hay, Michael J.; Fisch, Nathaniel J.

    2015-11-01

    An optically thin p-11B plasma loses more energy to bremsstrahlung than it gains from fusion reactions, unless the ion temperature can be elevated above the electron temperature. In thermal plasmas, the temperature differences required are possible in small Coulomb logarithm regimes, characterized by high density and low temperature. Ignition could be reached more easily if the fusion reactivity can be improved with nonthermal ion distributions. To establish an upper bound for the potential utility of a nonthermal distribution, we consider a monoenergetic beam with particle energy selected to maximize the beam-thermal reactivity. Comparing deuterium-tritium (DT) and p-11B, the minimum Lawson criteria and minimum ρR required for inertial confinement fusion (ICF) volume ignition are calculated with and without the nonthermal feature. It turns out that channeling fusion alpha energy to maintain such a beam facilitates ignition at lower densities and ρR, improves reactivity at constant pressure, and could be used to remove helium ash. On the other hand, the reactivity gains that could be realized in DT plasmas are significant, the excess electron density in p-11B plasmas increases the recirculated power cost to maintain a nonthermal feature and thereby constrains its utility to ash removal.

  10. Ignition threshold for non-Maxwellian plasmas

    SciTech Connect

    Hay, Michael J.; Fisch, Nathaniel J.

    2015-11-15

    An optically thin p-{sup 11}B plasma loses more energy to bremsstrahlung than it gains from fusion reactions, unless the ion temperature can be elevated above the electron temperature. In thermal plasmas, the temperature differences required are possible in small Coulomb logarithm regimes, characterized by high density and low temperature. Ignition could be reached more easily if the fusion reactivity can be improved with nonthermal ion distributions. To establish an upper bound for the potential utility of a nonthermal distribution, we consider a monoenergetic beam with particle energy selected to maximize the beam-thermal reactivity. Comparing deuterium-tritium (DT) and p-{sup 11}B, the minimum Lawson criteria and minimum ρR required for inertial confinement fusion (ICF) volume ignition are calculated with and without the nonthermal feature. It turns out that channeling fusion alpha energy to maintain such a beam facilitates ignition at lower densities and ρR, improves reactivity at constant pressure, and could be used to remove helium ash. On the other hand, the reactivity gains that could be realized in DT plasmas are significant, the excess electron density in p-{sup 11}B plasmas increases the recirculated power cost to maintain a nonthermal feature and thereby constrains its utility to ash removal.

  11. ND:GLASS LASER DESIGN FOR LASER ICF FISSION ENERGY (LIFE)

    SciTech Connect

    Caird, J A; Agrawal, V; Bayramian, A; Beach, R; Britten, J; Chen, D; Cross, R; Ebbers, C; Erlandson, A; Feit, M; Freitas, B; Ghosh, C; Haefner, C; Homoelle, D; Ladran, T; Latkowski, J; Molander, W; Murray, J; Rubenchik, S; Schaffers, K; Siders, C W; Stappaerts, E; Sutton, S; Telford, S; Trenholme, J; Barty, C J

    2008-10-28

    We have developed preliminary conceptual laser system designs for the Laser ICF (Inertial Confinement Fusion) Fission Energy (LIFE) application. Our approach leverages experience in high-energy Nd:glass laser technology developed for the National Ignition Facility (NIF), along with high-energy-class diode-pumped solid-state laser (HEC-DPSSL) technology developed for the DOE's High Average Power Laser (HAPL) Program and embodied in LLNL's Mercury laser system. We present laser system designs suitable for both indirect-drive, hot spot ignition and indirect-drive, fast ignition targets. Main amplifiers for both systems use laser-diode-pumped Nd:glass slabs oriented at Brewster's angle, as in NIF, but the slabs are much thinner to allow for cooling by high-velocity helium gas as in the Mercury laser system. We also describe a plan to mass-produce pump-diode lasers to bring diode costs down to the order of $0.01 per Watt of peak output power, as needed to make the LIFE application economically attractive.

  12. Rayleigh-Taylor Experiments in Materials and Conditions Relevant to Ignition in Inertial Confinement Fusion

    NASA Astrophysics Data System (ADS)

    Hager, Jonathan David

    In direct-drive inertial confinement fusion (ICF), a spherical target is imploded by overlapping laser beams to compress and heat DT fuel to conditions necessary for efficient thermonuclear burn. The Rayleigh-Taylor instability (RTI) is of primary concern in ICF, as it can cause initial areal-density (rhoR) perturbations to grow, leading to shell degradation and quenching of the hot spot necessary to achieve ignition of thermonuclear fusion. This work addresses two RTI concerns relevant to achieving ignition in ICF; measurement of RTI growth in cryogenic D2 targets and the effect of ablators of different atomic numbers (Z) on RTI growth rates using plastic (CH) and glass (SiO 2) targets. In these experiments, the temporal evolution of 2-D areal density (rhoR) modulations is measured using face-on X-ray radiography. Measured RT growth rates in D2 showed reasonable agreement with 2-D hydrodynamic simulations indicating reduced growth in D2 compared to CH, as predicted by theory. This result is crucial to ignition target designs using cryogenic DT ablators. The effect of thin ablators with different Z's on CH and SiO2 targets at varying drive intensities showed inconsistencies between the measured modulation growth and the 2-D hydrodynamic simulations at peak intensities of 1015 W/cm2 for targets with CH ablators due to hot electron preheat. Understanding preheat for ablators of different Z's is critical to achieving ignition in ICF; this work explores the impact of hot electron generation on the RTI at conditions relevant to ignition.

  13. Wetted foam liquid fuel ICF target experiments

    SciTech Connect

    Olson, R. E.; Leeper, R. J.; Yi, S. A.; Kline, J. L.; Zylstra, A. B.; Peterson, R. R.; Shah, R.; Braun, T.; Biener, J.; Kozioziemski, B. J.; Sater, J. D.; Biener, M. M.; Hamza, A. V.; Nikroo, A.; Hopkins, L. Berzak; Ho, D.; LePape, S.; Meezan, N. B.

    2016-05-26

    We are developing a new NIF experimental platform that employs wetted foam liquid fuel layer ICF capsules. We will use the liquid fuel layer capsules in a NIF sub-scale experimental campaign to explore the relationship between hot spot convergence ratio (CR) and the predictability of hot spot formation. DT liquid layer ICF capsules allow for flexibility in hot spot CR via the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. Our hypothesis is that the predictive capability of hot spot formation is robust and 1D-like for a relatively low CR hot spot (CR~15), but will become less reliable as hot spot CR is increased to CR>20. Simulations indicate that backing off on hot spot CR is an excellent way to reduce capsule instability growth and to improve robustness to low-mode x-ray flux asymmetries. In the initial experiments, we will test our hypothesis by measuring hot spot size, neutron yield, ion temperature, and burn width to infer hot spot pressure and compare to predictions for implosions with hot spot CR's in the range of 12 to 25. Larger scale experiments are also being designed, and we will advance from sub-scale to full-scale NIF experiments to determine if 1D-like behavior at low CR is retained as the scale-size is increased. The long-term objective is to develop a liquid fuel layer ICF capsule platform with robust thermonuclear burn, modest CR, and significant α-heating with burn propagation.

  14. Wetted foam liquid fuel ICF target experiments

    NASA Astrophysics Data System (ADS)

    Olson, R. E.; Leeper, R. J.; Yi, S. A.; Kline, J. L.; Zylstra, A. B.; Peterson, R. R.; Shah, R.; Braun, T.; Biener, J.; Kozioziemski, B. J.; Sater, J. D.; Biener, M. M.; Hamza, A. V.; Nikroo, A.; Berzak Hopkins, L.; Ho, D.; LePape, S.; Meezan, N. B.

    2016-05-01

    We are developing a new NIF experimental platform that employs wetted foam liquid fuel layer ICF capsules. We will use the liquid fuel layer capsules in a NIF sub-scale experimental campaign to explore the relationship between hot spot convergence ratio (CR) and the predictability of hot spot formation. DT liquid layer ICF capsules allow for flexibility in hot spot CR via the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. Our hypothesis is that the predictive capability of hot spot formation is robust and 1D-like for a relatively low CR hot spot (CR∼15), but will become less reliable as hot spot CR is increased to CR>20. Simulations indicate that backing off on hot spot CR is an excellent way to reduce capsule instability growth and to improve robustness to low-mode x-ray flux asymmetries. In the initial experiments, we will test our hypothesis by measuring hot spot size, neutron yield, ion temperature, and burn width to infer hot spot pressure and compare to predictions for implosions with hot spot CR's in the range of 12 to 25. Larger scale experiments are also being designed, and we will advance from sub-scale to full-scale NIF experiments to determine if 1D-like behavior at low CR is retained as the scale-size is increased. The long-term objective is to develop a liquid fuel layer ICF capsule platform with robust thermonuclear burn, modest CR, and significant α-heating with burn propagation.

  15. Wetted foam liquid fuel ICF target experiments

    DOE PAGES

    Olson, R. E.; Leeper, R. J.; Yi, S. A.; ...

    2016-05-26

    We are developing a new NIF experimental platform that employs wetted foam liquid fuel layer ICF capsules. We will use the liquid fuel layer capsules in a NIF sub-scale experimental campaign to explore the relationship between hot spot convergence ratio (CR) and the predictability of hot spot formation. DT liquid layer ICF capsules allow for flexibility in hot spot CR via the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. Our hypothesis is that the predictive capability of hot spot formation is robust and 1D-like for a relatively low CR hot spot (CR~15), but will becomemore » less reliable as hot spot CR is increased to CR>20. Simulations indicate that backing off on hot spot CR is an excellent way to reduce capsule instability growth and to improve robustness to low-mode x-ray flux asymmetries. In the initial experiments, we will test our hypothesis by measuring hot spot size, neutron yield, ion temperature, and burn width to infer hot spot pressure and compare to predictions for implosions with hot spot CR's in the range of 12 to 25. Larger scale experiments are also being designed, and we will advance from sub-scale to full-scale NIF experiments to determine if 1D-like behavior at low CR is retained as the scale-size is increased. The long-term objective is to develop a liquid fuel layer ICF capsule platform with robust thermonuclear burn, modest CR, and significant α-heating with burn propagation.« less

  16. Power Balance Performance on the National Ignition Facility

    SciTech Connect

    LaFortune, K; Widmayer, C; Haynam, C; Kalantar, D; Wegner, P; Bowers, M; Dixit, S

    2009-04-09

    Recent experiments on the National Ignition Facility (NIF) have demonstrated the facility's power balance capability. Power balance is a measure of the temporal uniformity among multiple beams or beam groups in a multi-beamline laser. Users of the NIF facility will need precise control of the laser for a wide range of experiments. For example, in indirect drive Inertial Confinement Fusion (ICF) experiments, the NIF laser beams will be delivered onto the interior surface of a hohlraum, generating x-rays. In order for the x-rays emitted to be sufficiently uniform to symmetrically compress the spherical ignition capsule at the center of the hohlraum, each beamline needs to precisely deliver the requested temporal power profile to its intended target. The achieved power balance precision is determined by both the accuracy of the pulse shaping hardware and the repeatability of the energetics of the laser. The precision that is required for ICF targets is a function of time and power level during the pulse. We have developed a model that predicts the time-dependent power balance performance of an arbitrary pulse shape. In this model, performance is determined by a handful of dominant terms, whose magnitude we have characterized. The model and the power balance requirements for the current National Ignition Campaign (NIC) as well as the most recent demonstrated performance on 96-beam and full 192-beam NIF shots will be discussed.

  17. BOOK REVIEW: Inertial confinement fusion: The quest for ignition and energy gain using indirect drive

    NASA Astrophysics Data System (ADS)

    Yamanaka, C.

    1999-06-01

    Inertial confinement fusion (ICF) is an alternative way to control fusion which is based on scaling down a thermonuclear explosion to a small size, applicable for power production, a kind of thermonuclear internal combustion engine. This book extends many interesting topics concerning the research and development on ICF of the last 25 years. It provides a systematic development of the physics basis and also various experimental data on radiation driven implosion. This is a landmark treatise presented at the right time. It is based on the article ``Development of the indirect-drive approach to inertial confinement fusion and the target physics basis for ignition and gain'' by J.D. Lindl, published in Physics of Plasmas, Vol. 2, November 1995, pp. 3933-4024. As is well known, in the United States of America research on the target physics basis for indirect drive remained largely classified until 1994. The indirect drive approaches were closely related to nuclear weapons research at Lawrence Livermore and Los Alamos National Laboratories. In Japan and other countries, inertial confinement fusion research for civil energy has been successfully performed to achieve DT fuel pellet compression up to 1000 times normal density, and indirect drive concepts, such as the `Cannon Ball' scheme, also prevailed at several international conferences. In these circumstances the international fusion community proposed the Madrid Manifesto in 1988, which urged openness of ICF information to promote international collaboration on civil energy research for the future resources of the human race. This proposal was also supported by some of the US scientists. The United States Department of Energy revised its classification guidelines for ICF six years after the Madrid Manifesto. This first book from the USA treating target physics issues, covering topics from implosion dynamics to hydrodynamic stability, ignition physics, high-gain target design and the scope for energy applications is

  18. Effects of inhomogeneity at stagnation in 3D simulations of ICF implosions

    NASA Astrophysics Data System (ADS)

    Appelbe, Brian

    2016-10-01

    The stagnation phase of an ICF implosion is characterized by a hotspot and dense fuel layer that are spatially and temporally inhomogeneous. Perturbation growth during the implosion results in significant asymmetry at stagnation while the hotspot size, density and temperature change rapidly, even in non-igniting capsules. Diagnosing these inhomogeneities is necessary to increase yield in ICF experiments. In this work, 3D radiation hydrodynamic simulations of perturbed indirect drive ICF capsules are carried out using the CHIMERA code. During the stagnation phase a suite of novel and computationally efficient simulation tools are used to produce synthetic time-resolved neutron spectra and images. These tools allow a detailed study of the effects of hotspot inhomogeneities on diagnostic signals. Results show that the burn-averaged ion temperature drops rapidly during thermonuclear burn as the hotspot evolves from a localised, shock-heated region to a more massive, non-uniform plasma. Primary DD and DT neutron spectra show that there is significant residual bulk fluid motion at stagnation, complicating the measurement of ion temperature. Different perturbation modes cause different levels of anisotropic spectra shifts and broadening. However, in all cases the discrepancies between the DD and DT spectra are a reliable indicator of residual motion at stagnation. The simulations are used to examine the relationship between neutron scattering and areal density (ρR). Three measures of areal density are simulated: downscattered neutron ratio, attenuated primary neutron yield and nT backscatter edge. Each of these diagnoses the magnitude and anisotropy of the ρR with varying success, with accuracy decreasing for higher mode perturbations. Contributions to the neutron energy spectra from T +T reactions, secondary DT reactions and deuteron break-up are also evaluated.

  19. Ignitability test method

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1989-01-01

    To overcome serious weaknesses in determining the performance of initiating devices, a novel 'ignitability test method', representing actual design interfaces and ignition materials, has been developed. Ignition device output consists of heat, light, gas an burning particles. Past research methods have evaluated these parameters individually. This paper describes the development and demonstration of an ignitability test method combining all these parameters, and the quantitative assessment of the ignition performance of two widely used percussion primers, the M42C1-PA101 and the M42C2-793. The ignition materials used for this evaluation were several powder, granule and pellet sizes of black powder and boron-potassium nitrate. This test method should be useful for performance evaluation of all initiator types, quality assurance, evaluation of ignition interfaces, and service life studies of initiators and ignition materials.

  20. Overview of the National Ignition Facility.

    PubMed

    Brereton, Sandra

    2013-06-01

    The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is the world's largest and most energetic laser system for inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. The NIF is a 192-beam, Nd-glass laser facility that is capable of producing 1.8 MJ, 500 TW of ultraviolet light, and over 50 times more energetic than other existing ICF facilities. The NIF construction began in 1997, and the facility, which was completed in 2009, is now fully operational. The facility is capable of firing up to 192 laser beams onto a target placed at the center of a 10-m-diameter spherical target chamber. Experiments involving the use of tritium have been underway for some time. These experiments present radiological issues: prompt neutron/gamma radiation, neutron activation, fission product generation, and decay radiation. This paper provides an introduction to the NIF facility and its operation, describes plans for the experimental program, and discusses radiological issues associated with the NIF's operations.

  1. ICF syndrome with variable expression in sibs.

    PubMed Central

    Gimelli, G; Varone, P; Pezzolo, A; Lerone, M; Pistoia, V

    1993-01-01

    We describe a new familial case of ICF syndrome (immunodeficiency, centromeric instability, facial anomalies) in a woman of 29 years and in her brother of 30 years. The proband showed mental retardation, facial anomalies, recurrent respiratory infections, combined deficit of IgM and IgE immunoglobulin classes, and paracentromeric heterochromatin instability of chromosomes 1, 9, and 16. The brother had minor signs of the syndrome and had an apparently normal phenotype. Their parents were healthy and non-consanguineous. Chromosome anomalies consisted of homologous and non-homologous associations, chromatid and isochromatid breaks, deletions of whole arms, interchanges in the paracentromeric region, and multibranched configurations of chromosomes 1, 9, and 16. CD bands and fluorescence in situ hybridisation with alphoid DNA sequence probes specific for the centromeres of chromosomes 1 and 16 showed that the centromere was not directly implicated in the formation of multibranched configurations. These cases indicate the autosomal recessive mode of inheritance and the variable expressivity of the ICF syndrome. Images PMID:8320711

  2. Adaptive Mesh Refinement for ICF Calculations

    NASA Astrophysics Data System (ADS)

    Fyfe, David

    2005-10-01

    This paper describes our use of the package PARAMESH to create an Adaptive Mesh Refinement (AMR) version of NRL's FASTRAD3D code. PARAMESH was designed to create an MPI-based AMR code from a block structured serial code such as FASTRAD3D. FASTRAD3D is a compressible hydrodynamics code containing the physical effects relevant for the simulation of high-temperature plasmas including inertial confinement fusion (ICF) Rayleigh-Taylor unstable direct drive laser targets. These effects include inverse bremmstrahlung laser energy absorption, classical flux-limited Spitzer thermal conduction, real (table look-up) equation-of-state with either separate or identical electron and ion temperatures, multi-group variable Eddington radiation transport, and multi-group alpha particle transport and thermonuclear burn. Numerically, this physics requires an elliptic solver and a ray tracing approach on the AMR grid, which is the main subject of this paper. A sample ICF calculation will be presented. MacNeice et al., ``PARAMESH: A parallel adaptive mesh refinement community tool,'' Computer Physics Communications, 126 (2000), pp. 330-354.

  3. Progress in laboratory high gain ICF (inertial confinement fusion): Prospects for the future

    SciTech Connect

    Storm, E.; Lindl, J.D.; Campbell, E.M.; Bernat, T.P.; Coleman, L.W.; Emmett, J.L.; Hogan, W.J.; Hunt, J.T.; Krupke, W.F.; Lowdermilk, W.H.

    1988-01-01

    Inertial confinement fusion (ICF), a thermonuclear reaction in a small (/approximately/5 mm diameter) fuel capsule filled with a few milligrams of deuterium and tritium, has been the subject of very fruitful experimentation since the early 1970's. High gain ICF is now on the threshold of practical applications. With a Laboratory Microfusion Facility (LMF), these applications will have major implications for national defense, basic and applied science, and power production. With a driver capable of delivering about 10 MJ in a 10-ns pulse at an intensity of /approximately/3 /times/ 10/sup 14/ W/cm/sup 2/, an appropriately configured cryogenic capsule could be compressed to a density of about 200 g/cm/sup 3/ and a temperature of 3--5 keV. Under these conditions, up to 10 mg of DT could be ignited, and with a burn efficiency of about 30%, release up to 1000 MJ of fusion energy, an energy gain of about 100. A thousand megajoules is equivalent to about one quarter ton of TNT, or about 7 gallons of oil--an amount of energy tractable under laboratory conditions and potentially very useful for a variety of applications. 61 refs., 33 figs.

  4. Implosion Dynamics and Mix in Double-Shell ICF Capsule Designs

    NASA Astrophysics Data System (ADS)

    Gunderson, Mark; Daughton, William; Simakov, Andrei; Wilson, Douglas; Watt, Robert; Delamater, Norman; Montgomery, David

    2015-11-01

    From an implosion dynamics perspective, double-shell ICF capsule designs have several advantages over the single-shell NIF ICF capsule point design. Double shell designs do not require precise shock sequencing, do not rely on hot spot ignition, have lower peak implosion speed requirements, and have lower convergence ratio requirements. However, there are still hurdles that must be overcome. The timing of the two main shocks in these designs is important in achieving sufficient compression of the DT fuel. Instability of the inner gold shell due to preheat from the hohlraum environment can disrupt the implosion of the inner pill. Mix, in addition to quenching burn in the DT fuel, also decreases the transfer of energy between the beryllium ablator and the inner gold shell during collision thus decreasing the implosion speed of the inner shell along with compression of the DT fuel. Herein, we will discuss practical implications of these effects on double-shell design we carry out in preparation for the NIF double-shell campaign. Work performed under the auspices of DOE by LANL under contract DE-AC52-06NA25396.

  5. X-ray Digital Radiography and Computed Tomography of ICF and HEDP Materials, Subassemblies and Targets

    SciTech Connect

    Brown, W D; Martz Jr., H E

    2006-05-31

    Inertial confinement fusion (ICF) and high energy density physics (HEDP) research are being conducted at large laser facilities, such as the University of Rochester's Laboratory for Laser Energetics OMEGA facility and the Lawrence Livermore National Laboratory's (LLNL) National Ignition Facility (NIF). At such facilities, millimeter-sized targets with micrometer structures are studied in a variety of hydrodynamic, radiation transport, equation-of-state, inertial confinement fusion and high-energy density experiments. The extreme temperatures and pressures achieved in these experiments make the results susceptible to imperfections in the fabricated targets. Targets include materials varying widely in composition ({approx}3 < Z < {approx}82), density ({approx}0.03 to {approx}20 g/cm{sup 3}), geometry (planar to spherical) and embedded structures (joints to subassemblies). Fabricating these targets with structures to the tolerances required is a challenging engineering problem the ICF and HEDP community are currently undertaking. Nondestructive characterization (NDC) provides a valuable tool in material selection, component inspection, and the final pre-shot assemblies inspection. X-rays are a key method used to NDC these targets. In this paper we discuss X-ray attenuation, X-ray phase effects, and the X-ray system used, its performance and application to characterize low-temperature Raleigh-Taylor and non-cryogenic double-shell targets.

  6. Using absolute x-ray spectral measurements to infer stagnation conditions in ICF implosions

    NASA Astrophysics Data System (ADS)

    Patel, Pravesh; Benedetti, L. R.; Cerjan, C.; Clark, D. S.; Hurricane, O. A.; Izumi, N.; Jarrott, L. C.; Khan, S.; Kritcher, A. L.; Ma, T.; Macphee, A. G.; Landen, O.; Spears, B. K.; Springer, P. T.

    2016-10-01

    Measurements of the continuum x-ray spectrum emitted from the hot-spot of an ICF implosion can be used to infer a number thermodynamic properties at stagnation including temperature, pressure, and hot-spot mix. In deuterium-tritium (DT) layered implosion experiments on the National Ignition Facility (NIF) we field a number of x-ray diagnostics that provide spatial, temporal, and spectrally-resolved measurements of the radiated x-ray emission. We report on analysis of these measurements using a 1-D hot-spot model to infer thermodynamic properties at stagnation. We compare these to similar properties that can be derived from DT fusion neutron measurements. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  7. Using gamma-ray emission to measure areal density of ICF capsules

    SciTech Connect

    Hoffman, Nelson M; Wilson, Douglas C; Hermann, Hans W; Young, Carlton S

    2010-01-01

    Fusion neutrons streaming from a burning ICF capsule generate gamma rays via nuclear inelastic scattering in the ablator of the capsule. The intensity of gamma-ray emission is proportional to the product of the ablator areal density ('{rho}R') and the yield of fusion neutrons, so by detecting the gamma rays we can infer the ablator areal density, provided we also have a measurement of the capsule's total neutron yield. In plastic-shell capsules, for example, {sup 12}C nuclei emit gamma rays at 4.44 MeV after excitation by 14.1-MeV neutrons from D+T fusion. These gamma rays can be measured by the Gamma Reaction History (GRH) experiment being built at the National Ignition Facility (NIF). A linear error analysis indicates the chief sources of uncertainty in inferred areal density.

  8. The ePLAS Code for Ignition Studies

    SciTech Connect

    Mason, Rodney J

    2012-09-20

    Inertial Confinement Fusion (ICF) presents unique opportunities for the extraction of clean energy from Fusion. Intense lasers and particle beams can create and interact with such plasmas, potentially yielding sufficient energy to satisfy all our national needs. However, few models are available to help aid the scientific community in the study and optimization of such interactions. This project enhanced and disseminated the computer code ePLAS for the early understanding and control of Ignition in ICF. ePLAS is a unique simulation code that tracks the transport of laser light to a target, the absorption of that light resulting in the generation and transport of hot electrons, and the heating and flow dynamics of the background plasma. It uses an implicit electromagnetic field-solving method to greatly reduce computing demands, so that useful target interaction studies can often be completed in 15 minutes on a portable 2.1 GHz PC. The code permits the rapid scoping of calculations for the optimization of laser target interactions aimed at fusion. Recent efforts have initiated the use of analytic equations of state (EOS), K-alpha image rendering graphics, allocatable memory for source-free usage, and adaption to the latest Mac and Linux Operating Systems. The speed and utility of ePLAS are unequaled in the ICF simulation community. This project evaluated the effects of its new EOSs on target heating, compared fluid and particle models for the ions, initiated the simultaneous use of both ion models in the code, and studied long time scale 500 ps hot electron deposition for shock ignition. ePLAS has been granted EAR99 export control status, permitting export without a license to most foreign countries. Beta-test versions of ePLAS have been granted to several Universities and Commercial users. The net Project was aimed at achieving early success in the laboratory ignition of thermonuclear targets and the mastery of controlled fusion power for the nation.

  9. The First Experiments on the National Ignition Facility

    SciTech Connect

    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; Mertens, E; Munro, D; Murray, J; Neumann, J; Newton, M; Opsahl, P; Padilla, E; Parham, T; Parrish, G; Petty, C; Polk, M; Powell, C; Reinbachs, I; Rinnert, R; Riordan, B; Ross, G; Robert, V; Tobin, M; Sailors, S; Saunders, R; Schmitt, M; Shaw, M; Singh, M; Spaeth, M; Stephens, A; Tietbohl, G; Tuck, J; Van Wonterghem, B; Vidal, R; Wegner, P; Whitman, P; Williams, K; Winward, K; Work, K

    2005-11-11

    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.

  10. Thermal ignition combustion system

    DOEpatents

    Kamo, Roy; Kakwani, Ramesh M.; Valdmanis, Edgars; Woods, Melvins E.

    1988-01-01

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m.degree. C. and a specific heat greater than 480 J/kg.degree. C. with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber.

  11. Thermal ignition combustion system

    DOEpatents

    Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

    1988-04-19

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

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

    NASA Astrophysics Data System (ADS)

    Keane, Christopher

    2012-10-01

    The 192-beam National Ignition Facility (NIF) at LLNL, operational since March 2009, is conducting experiments in ICF ignition and other scientific areas. The NIF ignition program is conducted by the National Ignition Campaign (NIC). In addition to execution of the ignition program, the NIC is providing the necessary infrastructure for operation of NIF as a user facility open to both US and international scientists. NIF has made significant progress towards operation as a user facility. The NIF laser has demonstrated the necessary performance, including energy, power, precision, and reproducibility, to support NIC and other experiments. NIF has demonstrated full energy and power (1.8 MJ, 500 TW) operation at 0.35-μm. Over 50 diagnostics are operational, and a broad range of target fabrication capabilities is in place. Initial experiments by university users and other scientists external to the National Nuclear Security Administration (NNSA) national laboratory system have been conducted, and additional experiments developed by the broader user community are in process and planned. A governance model has been established, and a NIF User Group has been formed. This presentation will discuss implementation of NIF as a user facility, with emphasis on activities at NIF in fundamental science and other areas carried out in addition to the NIC.

  13. Path To Ignition: US Indirect Target Physics (LIRPP Vol. 12)

    NASA Astrophysics Data System (ADS)

    Cray, M.; Campbell, E. M.

    2016-10-01

    The United States ICF Program has been pursuing an aggressive research program in preparation for an ignition demonstration on the National Ignition Facility. Los Alamos and Livermore laboratories have collaborated on resolving indirect drive target physics issues on the Nova laser at Livermore National Laboratory. This combined with detailed modeling of laser heated indirectly driven targets likely to achieve ignition, has provided the basis for planning for the NIF. A detailed understanding of target physics, laser performance, and target fabrication is required for developing robust ignition targets. We have developed large-scale computational models to simulate complex physics which occurs in an indirectly driven target. For ignition, detailed understanding of hohlraum and implosion physics is required in order to control competing processes at the few percent level. From crucial experiments performed by Los Alamos and Livermore on the Nova laser, a comprehensive indirect drive database has been assembled. Time integrated and time dependent measurements of radiation drive and symmetry coupled with a detailed set of plasma instability measurements have confirmed our ability to predict hohlraum energetics. Implosion physics campaigns are focused on underdstanding detailed capsule hydrodynamics and instability growth. Target fabrication technology is also an active area of research at Los Alamos, Livermore, and General Atomics for NIF. NIF targets require developing technology in cryogenics and manufacturing in such areas as beryllium shell manufacture. Descriptions of our NIF target designs, experimental results, and fabrication technology supporting NIF target performance predictions will be given.

  14. Power deposition of deuteron beam in fast ignition

    NASA Astrophysics Data System (ADS)

    Azadifar, R.; Mahdavi, M.

    2017-02-01

    In ion fast ignition (FI) inertial confinement fusion (ICF), a laser accelerated ion beam called igniter provides energy required for ignition of a fuel pellet. The laser accelerated deuteron beam is considered as igniter. The deuteron beam with Maxwellian energy distribution produced at the distance d = 500 μm, from fuel surface, travels during time t = 20 ps and arrives with power P1D(t,TD) to the fuel surface. Then, the deuteron beam deposits its energy into fuel by Coulomb and nuclear interactions with background plasma particles during time t = 10 ps, with power P2D(t,TD,Tb). Since time and power of the two stages have same order, to calculate the total power deposited by igniter beam, both stages must be considered simultaneously. In this paper, the exact power of each stage has been calculated separately, and the total power Ptotal(t,TD,Tb) has been obtained. The obtained results show that the total power deposition Ptotal(t,TD,Tb) is significantly reduced due to reducing different temperature between projectile and target particles.

  15. Lawrence Livermore National Laboratory's activities to achieve ignition by x-ray drive on the National Ignition Facility

    SciTech Connect

    Bernat, T P; Hammel, B A; Kauffman, R L; Kilkenny, J D; Landen, O L; Lindl, J D; MacGowan, B J; Paisner, J A; Powell, H T

    1998-07-20

    The National Ignition Facility (NIF) is a MJ-class glass laser-based facility funded by the Department of Energy which has achieving thermonuclear ignition and moderate gain as one of its main objectives. In the summer of 1998, the project is about 40% complete, and design and construction is on schedule and on cost. The NIF will start firing onto targets in 2001, and will achieve full energy in 2004. The Lawrence Livermore National Laboratory (LLNL), together with the Los Alamos National Laboratory (LANL) have the main responsibility for achieving x-ray driven ignition on the NIF. In the 1990's, a comprehensive series of experiments on Nova at LLNL, followed by recent experiments on the Omega laser at the University of Rochester, demonstrated confidence in understanding the physics of x-ray drive implosions. The same physics at equivalent scales is used in calculations to predict target performance on the NIF, giving credence to calculations of ignition on the NIF. An integrated program of work in preparing the NIF for x-ray driven ignition in about 2007, and the key issues being addressed on the current ICF facilities [(Nova, Omega, Z at Sandia National Laboratory (SNL), and NIKE at the Naval Research Laboratory (NRL)] are described.

  16. Experiments in ICF, materials science, and astrophysics

    NASA Astrophysics Data System (ADS)

    Remington, Bruce A.

    2016-10-01

    We have been developing RED experiments on high power TCF lasers over the past two decades that span (1) the radiative hydrodynamics of TCF capsule physics; (2) the high pressure, high strain rate, solid-state dynamics relevant to novel concepts for ICF and hypervelocity impacts in space and on Earth; and (3) the shock driven turbulence of exploding stars (supernovae). These different regimes are separated by many orders of magnitude in length, time, and temperature, yet there are common threads that run through all of these phenomena, such as the occurrence of hydrodynamic instabilities. Examples from each of these three seemingly very disparate regimes are given, and the common theme of hydrodynamic instability evolution is explored.

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

    SciTech Connect

    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.

  18. Measurement of the absolute hohlraum wall albedo under ignition foot drive conditions

    SciTech Connect

    Suter, L J; Wallace, R J; Hammel, B A; Weber, F A; Landen, O L; Campbell, K M; DeWald, E L; Glenzer, S H; Rosen, M D; Jones, O S; Turner, R E; Kauffmann, R L; Hammer, J H

    2003-11-25

    We present the first measurements of the absolute albedos of hohlraums made from gold or from high-Z mixtures. The measurements are performed over the range of radiation temperatures (70-100 eV) expected during the foot of an indirect-drive temporally-shaped ignition laser pulse, where accurate knowledge of the wall albedo (i.e. soft x-ray wall re-emission) is most critical for determining capsule radiation symmetry. We find that the gold albedo agrees well with calculations using the super transition array opacity model, potentially providing additional margin for ICF ignition.

  19. Fast Ignition Experimental and Theoretical Studies

    SciTech Connect

    Akli, Kramer Ugerthen

    2006-01-01

    We are becoming dependent on energy more today than we were a century ago, and with increasing world population and booming economies, sooner or later our energy sources will be exhausted. Moreover, our economy and welfare strongly depends on foreign oil and in the shadow of political uncertainties, there is an urgent need for a reliable, safe, and cheap energy source. Thermonuclear fusion, if achieved, is that source of energy which not only will satisfy our demand for today but also for centuries to come. Today, there are two major approaches to achieve fusion: magnetic confinement fusion (MFE) and inertial confinement fusion (ICF). This dissertation explores the inertial confinement fusion using the fast ignition concept. Unlike the conventional approach where the same laser is used for compression and ignition, in fast ignition separate laser beams are used. This dissertation addresses three very important topics to fast ignition inertial confinement fusion. These are laser-to-electron coupling efficiency, laser-generated electron beam transport, and the associated isochoric heating. First, an integrated fast ignition experiment is carried out with 0.9 kJ of energy in the compression beam and 70 J in the ignition beam. Measurements of absolute Kα yield from the imploded core revealed that about 17% of the laser energy is coupled to the suprathermal electrons. Modeling of the transport of these electrons and the associated isochoric heating, with the previously determined laser-to-electron conversion efficiency, showed a maximum target temperature of 166 eV at the front where the electron flux is higher and the density is lower. The contribution of the potential, induced by charge separation, in opposing the motion of the electrons was moderate. Second, temperature sensitivity of Cu Kα imaging efficiency using a spherical Bragg reflecting crystal is investigated. It was found that due to the shifting and broadening of the K

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

    SciTech Connect

    Cobble, James Allen; Sinars, Daniel Brian

    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.

  1. Target technologies for indirect drive ignition on the NIF

    SciTech Connect

    Bernat, T P

    1999-09-09

    X-ray driven ignition targets for the NIF will include fuel capsule materials different from those used up to now in ICF experiments. They will contain cryogenic fuel layers, and will be enclosed in cryogenic hohlraums. These hohlraums must provide the thermal environment required to shape the fuel layers, and must be supported by cryogenic equipment in the NIF target chamber. The methods for filling and delivering the targets to the NIF chamber will combine high-temperature diffusion with cryogenic transport. A program is in place in the US to design and develop the ignition targets, and the cryogenic support and fill systems needed to field them. This program includes participation from Lawrence Livermore National Laboratory, Los Alamos National Laboratory, and General Atomics.

  2. Inertial fusion target development for ignition and energy

    SciTech Connect

    Schultz, K.R.; Norimatsu, T.

    1994-12-01

    The target needs of the next ICF experiments that will lead toward ignition and energy are different from those of today`s experiments. The future experiments on OMEGA Upgrade, GEKKO XII Upgrade, the National Ignition Facility and Megajoule will need large, precise, cryogenic targets. Development is needed on a number of aspects of these targets, including shell fabrication, characterization, cryogenic layering and target handling. However, coordinated R and D programs are in place and work is in process to carry out the needed development. It is vital to the success of inertial fusion that this work be sustained. Coordinated effort, like the National Cryogenic Target Program in the USA, will help make the development activities as efficient and effective as possible, and should be encouraged.

  3. Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

    SciTech Connect

    Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; Olson, R. E.; Cobble, J. A.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Parra-Vasquez, N. A. G.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

    2016-05-26

    Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Work is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. Lastly, the ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.

  4. Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; Olson, R. E.; Cobble, J. A.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Parra-Vasquez, N. A. G.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

    2016-05-01

    Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Work is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. The ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.

  5. Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

    DOE PAGES

    Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; ...

    2016-05-26

    Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Workmore » is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. Lastly, the ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.« less

  6. Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

    SciTech Connect

    Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; Olson, R. E.; Cobble, J. A.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Parra-Vasquez, N. A. G.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

    2016-05-01

    Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Work is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. Lastly, the ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.

  7. Health measurement using the ICF: Test-retest reliability study of ICF codes and qualifiers in geriatric care

    PubMed Central

    Okochi, Jiro; Utsunomiya, Sakiko; Takahashi, Tai

    2005-01-01

    Background The International Classification of Functioning, Disability and Health (ICF) was published by the World Health Organization (WHO) to standardize descriptions of health and disability. Little is known about the reliability and clinical relevance of measurements using the ICF and its qualifiers. This study examines the test-retest reliability of ICF codes, and the rate of immeasurability in long-term care settings of the elderly to evaluate the clinical applicability of the ICF and its qualifiers, and the ICF checklist. Methods Reliability of 85 body function (BF) items and 152 activity and participation (AP) items of the ICF was studied using a test-retest procedure with a sample of 742 elderly persons from 59 institutional and at home care service centers. Test-retest reliability was estimated using the weighted kappa statistic. The clinical relevance of the ICF was estimated by calculating immeasurability rate. The effect of the measurement settings and evaluators' experience was analyzed by stratification of these variables. The properties of each item were evaluated using both the kappa statistic and immeasurability rate to assess the clinical applicability of WHO's ICF checklist in the elderly care setting. Results The median of the weighted kappa statistics of 85 BF and 152 AP items were 0.46 and 0.55 respectively. The reproducibility statistics improved when the measurements were performed by experienced evaluators. Some chapters such as genitourinary and reproductive functions in the BF domain and major life area in the AP domain contained more items with lower test-retest reliability measures and rated as immeasurable than in the other chapters. Some items in the ICF checklist were rated as unreliable and immeasurable. Conclusion The reliability of the ICF codes when measured with the current ICF qualifiers is relatively low. The result in increase in reliability according to evaluators' experience suggests proper education will have positive

  8. The National Ignition Facility modular Kirkpatrick-Baez microscope

    NASA Astrophysics Data System (ADS)

    Pickworth, L. A.; Ayers, J.; Bell, P.; Brejnholt, N. F.; Buscho, J. G.; Bradley, D.; Decker, T.; Hau-Riege, S.; Kilkenny, J.; McCarville, T.; Pardini, T.; Vogel, J.; Walton, C.

    2016-11-01

    Current two-dimensional X-ray imaging at the National Ignition Facility (NIF) uses time resolved pinhole cameras with ˜10-25 μm pinholes. This method has limitations in the smallest resolvable features that can be imaged with reasonable photon statistics for inertial confinement fusion (ICF) applications. ICF sources have a broadband self-emission spectrum that causes the pinhole images obtained, through thin foil filters, to contain a similarly broadband spectrum complicating the interpretation of structure in the source. In order to study phenomena on the scale of ˜5 μm, such as dopant mix in the ICF capsule, a narrow energy band, higher spatial resolution microscope system with improved signal/noise has been developed using X-ray optics. Utilizing grazing incidence mirrors in a Kirkpatrick-Baez microscope (KBM) configuration [P. Kirkpatrick and A. V. Baez, J. Opt. Soc. Am. 38, 766-774 (1948)], an X-ray microscope has been designed and fielded on NIF with four imaging channels. The KBM has ˜12 × magnification, <8 μm resolution, and higher throughput in comparison to similar pinhole systems. The first KBM mirrors are coated with a multilayer mirror to allow a "narrow band" energy response at 10.2 keV with ΔE ˜ 3 keV. By adjusting the mirror coating only, the energy response can be matched to the future experimental requirements. Several mirror packs have been commissioned and are interchangeable in the diagnostic snout.

  9. The National Ignition Facility modular Kirkpatrick-Baez microscope.

    PubMed

    Pickworth, L A; Ayers, J; Bell, P; Brejnholt, N F; Buscho, J G; Bradley, D; Decker, T; Hau-Riege, S; Kilkenny, J; McCarville, T; Pardini, T; Vogel, J; Walton, C

    2016-11-01

    Current two-dimensional X-ray imaging at the National Ignition Facility (NIF) uses time resolved pinhole cameras with ∼10-25 μm pinholes. This method has limitations in the smallest resolvable features that can be imaged with reasonable photon statistics for inertial confinement fusion (ICF) applications. ICF sources have a broadband self-emission spectrum that causes the pinhole images obtained, through thin foil filters, to contain a similarly broadband spectrum complicating the interpretation of structure in the source. In order to study phenomena on the scale of ∼5 μm, such as dopant mix in the ICF capsule, a narrow energy band, higher spatial resolution microscope system with improved signal/noise has been developed using X-ray optics. Utilizing grazing incidence mirrors in a Kirkpatrick-Baez microscope (KBM) configuration [P. Kirkpatrick and A. V. Baez, J. Opt. Soc. Am. 38, 766-774 (1948)], an X-ray microscope has been designed and fielded on NIF with four imaging channels. The KBM has ∼12 × magnification, <8 μm resolution, and higher throughput in comparison to similar pinhole systems. The first KBM mirrors are coated with a multilayer mirror to allow a "narrow band" energy response at 10.2 keV with ΔE ∼ 3 keV. By adjusting the mirror coating only, the energy response can be matched to the future experimental requirements. Several mirror packs have been commissioned and are interchangeable in the diagnostic snout.

  10. The National Ignition Facility and the Path to Fusion Energy

    SciTech Connect

    Moses, E

    2011-07-26

    The National Ignition Facility (NIF) is operational and conducting experiments at the Lawrence Livermore National Laboratory (LLNL). The NIF is the world's largest and most energetic laser experimental facility with 192 beams capable of delivering 1.8 megajoules of 500-terawatt ultraviolet laser energy, over 60 times more energy than any previous laser system. The NIF can create temperatures of more than 100 million degrees and pressures more than 100 billion times Earth's atmospheric pressure. These conditions, similar to those at the center of the sun, have never been created in the laboratory and will allow scientists to probe the physics of planetary interiors, supernovae, black holes, and other phenomena. The NIF's laser beams are designed to compress fusion targets to the conditions required for thermonuclear burn, liberating more energy than is required to initiate the fusion reactions. Experiments on the NIF are focusing on demonstrating fusion ignition and burn via inertial confinement fusion (ICF). The ignition program is conducted via the National Ignition Campaign (NIC) - a partnership among LLNL, Los Alamos National Laboratory, Sandia National Laboratories, University of Rochester Laboratory for Laser Energetics, and General Atomics. The NIC program has also established collaborations with the Atomic Weapons Establishment in the United Kingdom, Commissariat a Energie Atomique in France, Massachusetts Institute of Technology, Lawrence Berkeley National Laboratory, and many others. Ignition experiments have begun that form the basis of the overall NIF strategy for achieving ignition. Accomplishing this goal will demonstrate the feasibility of fusion as a source of limitless, clean energy for the future. This paper discusses the current status of the NIC, the experimental steps needed toward achieving ignition and the steps required to demonstrate and enable the delivery of fusion energy as a viable carbon-free energy source.

  11. National Ignition Facility project acquisition plan

    SciTech Connect

    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.

  12. The Health and Functioning ICF-60: Development and Psychometric Properties

    PubMed Central

    Tutelyan, V A; Chatterji, S; Baturin, A K; Pogozheva, A V; Kishko, O N; Akolzina, S E

    2014-01-01

    Background This paper describes the development and psychometric properties of the Health and Functioning ICF-60 (HF-ICF-60) measure, based on the World Health Organization (WHO) ‘International Classification of Functioning, Disability and Health: ICF’ (2001). The aims of the present study were to test psychometric properties of the HF-ICF-60, developed as a measure that would be responsive to change in functioning through changes in health and nutritional status, as a prospective measure to monitor health and nutritional status of populations and to explore the relationship of the HF-ICF-60 with quality of life measures such as the World Health Organization WHOQOL-BREF quality of life assessment in relation to non-communicable diseases. Methods The HF-ICF-60 measure consists of 60 items selected from the ICF by an expert panel, which included 18 items that cover Body Functions, 21 items that cover Activities and Participation, rated on five-point scales, and 21 items that cover Environmental Factors (seven items cover Individual Environmental Factors and 14 items cover Societal Environmental Factors), rated on nine-point scales. The HF-ICF-60 measure was administered to the Russian nationally representative sample within the Russian National Population Quality of Life, Health and Nutrition Survey, in 2004 (n = 9807) and 2005 (n = 9560), as part of the two waves of the Russian Longitudinal Monitoring Survey (RLMS). The statistical analyses were carried out with the use of both classical and modern psychometric methods, such as factor analysis, and based on Item Response Theory, respectively. Results The HF-ICF-60 questionnaire is a new measure derived directly from the ICF and covers the ICF components as follows: Body Functions, Activities and Participation, and Environmental Factors (Individual Environmental Factors and Societal Environmental Factors). The results from the factor analyses (both Exploratory Factor Analyses and Confirmatory Factor

  13. PRP Comments for ICF Q1/Q2 FY17 Experiments 3/10/16

    SciTech Connect

    Kauffman, R.

    2016-04-14

    The PRP generally endorsed the Program plan during the short time for discussions. We agree that the strategy to develop a hohlraum that is symmetric and has low laser-plasma instabilities and to develop an alternative method for supporting the capsule is the best path forward for making progress in understanding ignition performance. The Program is oriented toward a milestone in 2020 for “determining the efficacy of NIF for ignition and credible physics-scaling to multi-megajoule yields for all ICF approaches.” We are concerned that the time and resources are not sufficient to vet all of the various approaches that are being pursued to make an informed decision by this date. For NIF to meet this goal, a process will be needed to to select the most promising paths forward. We recommend that the Program develop this process for selecting the path forward to optimize resources. We were glad to see that the direct drive program took our comments under consideration. We think that the proposed experiments have the program headed in a better direction. The PRP had only a short time to discuss the detailed experimental proposals. The following are comments on the detailed proposals. We did not have time to discuss them as a group. They represent individual opinions and provided to you as feedback to your proposals.

  14. Multi-Fluid Interpenetration Mixing in X-ray and Directly Laser driven ICF Capsule Implosions

    NASA Astrophysics Data System (ADS)

    Wilson, Douglas

    2003-10-01

    Mix between a surrounding shell and the fuel leads to degradation in ICF capsule performance. Both indirectly (X-ray) and directly laser driven implosions provide a wealth of data to test mix models. One model, the multi-fluid interpenetration mix model of Scannapieco and Cheng (Phys. Lett. A., 299, 49, 2002), was implemented in an ICF code and applied to a wide variety of experiments (e.g. J. D. Kilkenny et al., Proc. Conf Plasm. Phys. Contr. Nuc. Fus. Res. 3, 29(1988), P. Amendt, R. E. Turner, O. L. Landen, Phy. Rev. Lett., 89, 165001 (2002), or Li et al., Phy. Rev. Lett, 89, 165002 (2002)). With its single adjustable parameter fixed, it replicates well the yield degradation with increasing convergence ratio for both directly and indirectly driven capsules. Often, but not always the ion temperatures with mixing are calculated to be higher than in an unmixed implosion, agreeing with observations. Comparison with measured directly driven implosion yield rates ( from the neutron temporal diagnostic or NTD) shows mixing increases rapidly during the burn. The model also reproduces the decrease of the fuel "rho-r" with fill gas pressure, measured by observing escaping deuterons or secondary neutrons. The mix model assumes fully atomically mixed constituents, but when experiments with deuterated plastic layers and 3He fuel are modeled, less that full atomic mix is appropriate. Applying the mix model to the ablator - solid DT interface in indirectly driven ignition capsules for the NIF or LMJ suggests that the capsules will ignite, but that burn after ignition may be somewhat degraded. Situations in which the Scannapieco and Cheng model fails to agree with experiments can guide us to improvements or the development of other models. Some directly driven symmetric implosions suggest that in highly mixed situations, a higher value of the mix parameter may needed. Others show the model underestimating the fuel burn temperature. This work was performed by the Los Alamos

  15. D-Cluster Converter Foil for Laser-Accelerated Deuteron Beams: Towards Deuteron-Beam-Driven Fast Ignition

    SciTech Connect

    Miley, George H.

    2012-10-24

    Fast Ignition (FI) uses Petawatt laser generated particle beam pulse to ignite a small volume called a pre-compressed Inertial Confinement Fusion (ICF) target, and is the favored method to achieve the high energy gain per target burn needed for an attractive ICF power plant. Ion beams such as protons, deuterons or heavier carbon ions are especially appealing for FI as they have relative straight trajectory, and easier to focus on the fuel capsule. But current experiments have encountered problems with the 'converter-foil' which is irradiated by the Petawatt laser to produce the ion beams. The problems include depletion of the available ions in the convertor foils, and poor energy efficiency (ion beam energy/ input laser energy). We proposed to develop a volumetrically-loaded ultra-high-density deuteron deuterium cluster material as the basis for converter-foil for deuteron beam generation. The deuterons will fuse with the ICF DT while they slow down, providing an extra 'bonus' energy gain in addition to heating the hot spot. Also, due to the volumetric loading, the foil will provide sufficient energetic deuteron beam flux for 'hot spot' ignition, while avoiding the depletion problem encountered by current proton-driven FI foils. After extensive comparative studies, in Phase I, high purity PdO/Pd/PdO foils were selected for the high packing fraction D-Cluster converter foils. An optimized loading process has been developed to increase the cluster packing fraction in this type of foil. As a result, the packing fraction has been increased from 0.1% to 10% - meeting the original Phase I goal and representing a significant progress towards the beam intensities needed for both FI and pulsed neutron applications. Fast Ignition provides a promising approach to achieve high energy gain target performance needed for commercial Inertial Confinement Fusion (ICF). This is now a realistic goal for near term in view of the anticipated ICF target burn at the National Ignition

  16. Analysis of the National Ignition Facility Ignition Hohlraum Energetics Experiments

    SciTech Connect

    Town, R J; Rosen, M D; Michel, P A; Divol, L; Moody, J D; Kyrala, G A; Schneider, M B; Kline, J L; Thomas, C A; Milovich, J L; Callahan, D A; Meezan, N B; Hinkel, D E; Williams, E A; Berger, R L; Edwards, M J; Suter, L J; Haan, S W; Lindl, J D; Dixit, S; Glenzer, S H; Landen, O L; Moses, E I; Scott, H A; Harte, J A; Zimmerman, G B

    2010-11-22

    A series of forty experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] to study energy balance and implosion symmetry in reduced- and full-scale ignition hohlraums was shot at energies up to 1.3 MJ. This paper reports the findings of the analysis of the ensemble of experimental data obtained that has produced an improved model for simulating ignition hohlraums. Last year the first observation in a NIF hohlraum of energy transfer between cones of beams as a function of wavelength shift between those cones was reported [P. Michel, et al, Phys of Plasmas, 17, 056305, (2010)]. Detailed analysis of hohlraum wall emission as measured through the laser entrance hole (LEH) has allowed the amount of energy transferred versus wavelength shift to be quantified. The change in outer beam brightness is found to be quantitatively consistent with LASNEX [G. B. Zimmerman and W. L. Kruer, Comments Plasma Phys. Control. Fusion 2, 51 (1975)] simulations using the predicted energy transfer when possible saturation of the plasma wave mediating the transfer is included. The effect of the predicted energy transfer on implosion symmetry is also found to be in good agreement with gated x-ray framing camera images. Hohlraum energy balance, as measured by x-ray power escaping the LEH, is quantitatively consistent with revised estimates of backscatter and incident laser energy combined with a more rigorous non-local-thermodynamic-equilibrium atomic physics model with greater emissivity than the simpler average-atom model used in the original design of NIF targets.

  17. ICF Program: LDRD-ER Final Report

    SciTech Connect

    Glenzer, S H

    2004-02-05

    In the 01-ERD-107 LDRD-ER project, we have performed novel Thomson scattering experiments at the Trident and Omega laser facilities and provided high quality spectral data. These results have led to the development of the first quantitative understanding of laser-plasma interactions for NIF plasmas. For this purpose an green/ultraviolet probe laser, built for Nova in 1998 [1] and successfully used to measure both temperature and plasma wave amplitudes [2], has been deployed on Omega. The Thomson scattering diagnostics has been used twofold: (1) it provided independent measurements of the plasma electron and ion temperature, the plasma flow velocity, or the electron distribution function; (2) it provided measurements of the primary plasma wave and their secondary non-linear decay wave products. These experiments at Omega provide definitive quantitative results on the nonlinear saturation of stimulated Raman scattering for green (2{omega}) beams. In addition, the experiments on the Trident laser have led to a quantitative understanding of the stimulated Brillouin scattering in low-Z plasmas. A nonlinear frequency detuning model has successfully explained all the experimental observable including the SBS reflectivity. This model has been implemented into the laser-plasma interaction code pF3D as a tool to design and optimize NIF target experiments with SBS and SRS losses included. The development of quantitative models for SBS and SRS for various regimes has now been adopted as part of the WBS1 project within the ICF program.

  18. Low profile thermite igniter

    DOEpatents

    Halcomb, Danny L.; Mohler, Jonathan H.

    1991-03-05

    A thermite igniter/heat source comprising a housing, high-density thermite, and low-density thermite. The housing has a relatively low profile and can focus energy by means of a torch-like ejection of hot reaction products and is externally ignitable.

  19. Microgravity ignition experiment

    NASA Technical Reports Server (NTRS)

    Motevalli, Vahid; Elliott, William; Garrant, Keith; Marcotte, Ryan

    1992-01-01

    The purpose of this project is to develop a flight-ready apparatus of the microgravity ignition experiment for the GASCAN 2 program. The microgravity ignition experiment is designed to study how a microgravity environment affects the time to ignition of a sample of alpha-cellulose paper. A microgravity environment will result in a decrease in the heat transferred from the sample due to a lack of convection currents, which would decrease time to ignition. A lack of convection current would also cause the oxygen supply at the sample not to be renewed, which could delay or even prevent ignition. When this experiment is conducted aboard GASCAN 2, the dominant result of the lack of ignition will be determined. The experiment consists of four canisters containing four thermocouples and a sensor to detect ignition of the paper sample. This year the interior of the canister was redesigned and a mathematical model of the heat transfer around the sample was developed. This heat transfer model predicts an ignition time of approximately 5.5 seconds if the decrease of heat loss from the sample is the dominant factor of the lack of convection currents.

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

    SciTech Connect

    Moses, E

    2009-10-15

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

  1. The role of the National Ignition Facility in the development of inertial fusion energy

    SciTech Connect

    Logan, B.G.

    1996-06-01

    The authors have completed a conceptual design for a 1.8-MJ, 500-TW, 0.35-{mu}m solid-state laser system for the National Ignition Facility (NIF), which will demonstrate inertial fusion ignition and gain for national security, energy, and science applications. The technical goal of the U.S. Inertial Confinement Fusion (ICF) Program as stated in the current ICF Five-Year Program Plan is {open_quotes}to produce pure fusion ignition and burn in the laboratory, with fusion yields of 200 to 1000 MJ, in support of three missions: (1) to play an essential role in accessing physics regimes of interest in nuclear weapon design...; (2) to provide an above-ground simulation capability for nuclear weapon effects...; and (3) to develop inertial fusion energy for civilian power production.{close_quotes} This article addresses the third goal-- the development of inertial fusion energy (IFE). This article reports a variety of potential contributions the NIF could make to the development of IFE, drawn from a nationally attended workshop held at the University of California at Berkeley in Feb, 1994. In addition to demonstrating fusion ignition as a fundamental basis for IFE, the findings of the workshop, are that the NIF could also provide important data for target physics and fabrication technology, for IFE target chamber phenomena such as materials responses to target emissions, and for fusion power technology-relevant tests.

  2. Tgermonuclear Ignition in Inertial Confinement Fusion and Comparison with Magnetic Confinement

    SciTech Connect

    Betti, R.; Chang, P.Y.; Spears, B.K.; Anderson, K.S.; Edwards, J.; Fatenejad, M.; Lindl, J.D.; McCrory, R.L.; Nora, R.; Shvarts, D.

    2010-04-23

    The physics of thermonuclear ignition in inertial confinement fusion (ICF) is presented in the familiar frame of a Lawson-type criterion. The product of the plasma pressure and confinement time Ptau for ICF is cast in terms of measurable parameters and its value is estimated for cryogenic implosions. An overall ignition parameter chi including pressure, confinement time, and temperature is derived to complement the product Ptau. A metric for performance assessment should include both chi and Ptau. The ignition parameter and the product Ptau are compared between inertial and magnetic-confinement fusion. It is found that cryogenic implosions on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have achieved Ptau ~ 1.5 atm s comparable to large tokamaks such as the Joint European Torus [P. H. Rebut and B. E. Keen, Fusion Technol. 11, 13 (1987)] where Ptau ~ 1 atm s. Since OMEGA implosions are relatively cold (T ~ 2 keV), their overall ignition parameter chi ~ 0.02–0.03 is ~5X lower than in JET (chi ~ 0.13), where the average temperature is about 10 keV.

  3. Ignition Rate Measurement of Laser-Ignited Coals

    SciTech Connect

    John C. Chen; Vinayak Kabadi

    1997-10-31

    We established a novel experiment to study the ignition of pulverized coals under conditions relevant to utility boilers. Specifically, we determined the ignition mechanism of pulverized-coal particles under various conditions of particle size, coal type, and freestream oxygen concentration. We also measured the ignition rate constant of a Pittsburgh #8 high-volatile bituminous coal by direct measurement of the particle temperature at ignition, and incorporating this measurement into a mathematical model for the ignition process. The model, called Distributed Activation Energy Model of Ignition, was developed previously by our group to interpret conventional drop-tube ignition experiments, and was modified to accommodate the present study.

  4. Measurements of Deuterium-Tritium Fuel Fractionation from Kinetic Effects in Ignition-Relevant Direct-Drive Cryogenic Implosions

    NASA Astrophysics Data System (ADS)

    Forrest, C.; Glebov, V. Yu.; Knauer, J. P.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Stoeckl, C.

    2016-10-01

    Measurements of DT and DD reaction yields have been studied using ignition-relevant, cryogenically cooled deuterium-tritium gas-filled cryogenic DT targets in inertial confinement fusion (ICF) implosions. In these experiments, carried out at the Omega Laser Facility, highresolution time-of-flight spectroscopy was used to measure the primary neutron peak distribution required to infer the DT and DD reaction yields. From these measurements, it will be shown that the yield ratio has a χ2/per degree of freedom of 0.67 as compared with the measured fraction of the target fuel composition. This observation indicates that kinetic effects leading to species separation are insignificant in ICF ignition-relevant DT implosions on OMEGA. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  5. Laser Diode Ignition (LDI)

    NASA Technical Reports Server (NTRS)

    Kass, William J.; Andrews, Larry A.; Boney, Craig M.; Chow, Weng W.; Clements, James W.; Merson, John A.; Salas, F. Jim; Williams, Randy J.; Hinkle, Lane R.

    1994-01-01

    This paper reviews the status of the Laser Diode Ignition (LDI) program at Sandia National Labs. One watt laser diodes have been characterized for use with a single explosive actuator. Extensive measurements of the effect of electrostatic discharge (ESD) pulses on the laser diode optical output have been made. Characterization of optical fiber and connectors over temperature has been done. Multiple laser diodes have been packaged to ignite multiple explosive devices and an eight element laser diode array has been recently tested by igniting eight explosive devices at predetermined 100 ms intervals.

  6. Microgravity ignition experiment

    NASA Technical Reports Server (NTRS)

    Motevalli, Vahid; Elliott, William; Garrant, Keith

    1992-01-01

    The purpose of this project is to develop a flight ready apparatus of the microgravity ignition experiment for the GASCan 2 program. This involved redesigning, testing, and making final modifications to the existing apparatus. The microgravity ignition experiment is intended to test the effect of microgravity on the time to ignition of a sample of alpha-cellulose paper. An infrared heat lamp is used to heat the paper sample within a sealed canister. The interior of the canister was redesigned to increase stability and minimize conductive heat transfer to the sample. This design was fabricated and tested and a heat transfer model of the paper sample was developed.

  7. Dual-Laser-Pulse Ignition

    NASA Technical Reports Server (NTRS)

    Trinh, Huu; Early, James W.; Thomas, Matthew E.; Bossard, John A.

    2006-01-01

    A dual-pulse laser (DPL) technique has been demonstrated for generating laser-induced sparks (LIS) to ignite fuels. The technique was originally intended to be applied to the ignition of rocket propellants, but may also be applicable to ignition in terrestrial settings in which electric igniters may not be suitable.

  8. Conceptual design of the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Paisner, Jeffrey A.; Boyes, John D.; Kumpan, Steven A.; Lowdermilk, W. Howard; Sorem, Michael S.

    1995-12-01

    The Secretary of the U.S. Department of Energy (DOE) commissioned a conceptual design report (CDR) for the National Ignition Facility (NIF) in January 1993 as part of a key decision zero (KD0), 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 micrometer) 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. 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. In February 1995, the NIF Project was

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

    NASA Astrophysics Data System (ADS)

    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 ICF experiments at the NIF utilized high convergence (CR >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.

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

    PubMed

    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

    2016-12-09

    The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D_{2} and DT layer inertial confinement fusion (ICF) implosions that can access a low-to-moderate hot-spot convergence ratio (12ICF experiments at the NIF utilized high convergence (CR>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.

  11. Target Diagnostic Technology Research and Development for the LLNL ICF and HED Programs

    SciTech Connect

    Bell, P; Bennett, C; Holder, J; Kimbrough, J; Landen, O; Lerche, D; Lowry, M; McDonald, J; Perry, T; Turner, B; Weber, F

    2003-08-22

    The National Ignition Facility (NIF) is under construction at LLNL for the Department of Energy Stockpile Stewardship Program. It will be used for experiments for Inertial Confinement Fusion (ICF) Ignition, High Energy Density (HED) science, and basic science. Many issues confront experimentalists who wish to design, fabricate, and install diagnostics on the NIF. To foster this process the ICF and HED programs at LLNL have formed a diagnostic research and development group to look at issues outside the charter of facility diagnostics (core diagnostics). We will present data from instrumentation and associated technology that is being developed by this group. A major portion of our instrumentation work is on improvements for readout systems. We have several efforts related to CCD device development. Work has been done in collaboration with the University of Arizona to backthin a large format CCD device (36mm{sup 2}). This work has shown good results. The device has very high quantum efficiency, low noise readout and high charge transfer efficiency. The device is being fielded in direct optical, direct x-ray and 13-15 RV electron readout applications. In addition to readout device development we have completed work on a CCD readout system. With a commercial vendor we have developed a large format, compact, Ethernet addressable CCD camera system. This system fits in shoebox size volume, is thermal electrically cooled, supports a variety of CCD devices and can be run from remote locations via TCP/IP protocol. We are also doing work to improve streak camera systems. We have coupled our large format CCD system to an MK2 Kentech streak tube. Improvements have been made to the resolution and dynamic range of the system. Similar improvements have been made to the LLNL optical streak camera systems. We will present data from the optical and x-ray streak camera work. In addition we will present data from single shot high-speed, high dynamic range data link work. In

  12. Classification of functioning and impairment: the development of ICF core sets for autism spectrum disorder.

    PubMed

    Bölte, Sven; de Schipper, Elles; Robison, John E; Wong, Virginia C N; Selb, Melissa; Singhal, Nidhi; de Vries, Petrus J; Zwaigenbaum, Lonnie

    2014-02-01

    Given the variability seen in Autism Spectrum Disorder (ASD), accurate quantification of functioning is vital to studying outcome and quality of life in affected individuals. The International Classification of Functioning, Disability and Health (ICF) provides a comprehensive, universally accepted framework for the description of health-related functioning. ICF Core Sets are shortlists of ICF categories that are selected to capture those aspects of functioning that are most relevant when describing a person with a specific condition. In this paper, the authors preview the process for developing ICF Core Sets for ASD, a collaboration with the World Health Organization and the ICF Research Branch. The ICF Children and Youth version (ICF-CY) was derived from the ICF and designed to capture the specific situation of the developing child. As ASD affects individuals throughout the life span, and the ICF-CY includes all ICF categories, the ICF-CY will be used in this project ("ICF(-CY)" from now on). The ICF(-CY) categories to be included in the ICF Core Sets for ASD will be determined at an ICF Core Set Consensus Conference, where evidence from four preparatory studies (a systematic review, an expert survey, a patient and caregiver qualitative study, and a clinical cross-sectional study) will be integrated. Comprehensive and Brief ICF Core Sets for ASD will be developed with the goal of providing useful standards for research and clinical practice and generating a common language for functioning and impairment in ASD in different areas of life and across the life span.

  13. Magnetron co-sputtering system for coating ICF targets

    SciTech Connect

    Hsieh, E.J.; Meyer, S.F.; Halsey, W.G.; Jameson, G.T.; Wittmayer, F.J.

    1981-12-09

    Fabrication of Inertial Confinement Fusion (ICF) targets requires deposition of various types of coatings on microspheres. The mechanical strength, and surface finish of the coatings are of concern in ICF experiments. The tensile strength of coatings can be controlled through grain refinement, selective doping and alloy formation. We have constructed a magnetron co-sputtering system to produce variable density profile coatings with high tensile strength on microspheres. The preliminary data on the properties of a Au-Cu binary alloy system by SEM and STEM analysis is presented.

  14. Ignitability test method. II

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1990-01-01

    To determine functional performance of initiating devices, the NASA's Langley Research Center's novel ignitability research on percussion primers has been expanded in 1989 to include measurements of function time, the evaluation of six primer lots (five types), and the determination of the effects of the military cold-temperature requirement of -65 F and primer output closure disks. This test method, a major improvement over the prior primer output test methods, fully met all objectives, while showing a significant amount of ignition variability.

  15. 42 CFR 442.118 - Denial of payments for new admissions to an ICF/MR.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Denial of payments for new admissions to an ICF/MR... of payments for new admissions to an ICF/MR. (a) Basis for denial of payments. The Medicaid agency may deny payment for new admissions to an ICF/MR that no longer meets the applicable conditions...

  16. 42 CFR 440.150 - Intermediate care facility (ICF/MR) services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Intermediate care facility (ICF/MR) services. 440....150 Intermediate care facility (ICF/MR) services. (a) “ICF/MR services” means those items and services furnished in an intermediate care facility for the mentally retarded if the following conditions are met:...

  17. Direct spark ignition system

    SciTech Connect

    Gann, R.A.

    1986-12-02

    This patent describes a direct spark ignition system having a gas burner, an electrically operable valve connected to the burner to admit fuel thereto, a gated oscillator having a timing circuit for timing a trial ignition, a spark generator responsive to the oscillator for igniting fuel emanating from the burner, and a flame sensor for sustaining oscillations of the oscillator while a flame exists at the burner. The spark generator has an inverter connected to a low voltage dc source and responsive to the oscillator for converting the dc voltage to a high ac voltage, a means for rectifying the high ac voltage, a capacitor connected to the rectifying means for storing the rectified high voltage, an ignition coil in series between the storage capacitor and a switch, and a means for periodically turning on the switch to produce ignition pulses through the coil. The ignition system is powered from the dc source but controlled by the oscillator. An improvement described here is wherein the inverter is comprised of a step-up transformer having its primary winding connected in series with the dc source and a common emitter transistor having its collector connected to the primary winding. The transistor has its base connected to be controlled by the oscillator to chop the dc into ac in the primary winding, and a diode connected between the storage capacitor and the collector of the transistor, the diode being poled to couple into the capacitor back EMF energy when the transistor is turned off.

  18. Molded composite pyrogen igniter for rocket motors. [solid propellant ignition

    NASA Technical Reports Server (NTRS)

    Heier, W. C.; Lucy, M. H. (Inventor)

    1978-01-01

    A lightweight pyrogen igniter assembly including an elongated molded plastic tube adapted to contain a pyrogen charge was designed for insertion into a rocket motor casing for ignition of the rocket motor charge. A molded plastic closure cap provided for the elongated tube includes an ignition charge for igniting the pyrogen charge and an electrically actuated ignition squib for igniting the ignition charge. The ignition charge is contained within a portion of the closure cap, and it is retained therein by a noncorrosive ignition pellet retainer or screen which is adapted to rest on a shoulder of the elongated tube when the closure cap and tube are assembled together. A circumferentially disposed metal ring is provided along the external circumference of the closure cap and is molded or captured within the plastic cap in the molding process to provide, along with O-ring seals, a leakproof rotary joint.

  19. Crossed Beam Energy Transfer in the NIF ICF Target Design

    SciTech Connect

    Williams, E A; Hinkel, D E; Hittinger, J A

    2003-08-27

    In the National Ignition Facility (NIF) ICF point design, the cylindrical hohlraum target is illuminated by multiple laser beams through two laser entrance holes on the ends. According to simulations by LASNEX and HYDRA plasma created inside the hohlraum will stream out of the LEH, accelerate to supersonic speeds and then fan out radially. Inside the hohlraum, flows are subsonic. Forward Brillouin scattering can transfer energy between pairs of laser beams (0 and 1) if the following frequency matching condition is satisfied: {omega}{sub 0} - {omega}{sub 1} = (k{sub 0} - k{sub 1}) {center_dot} V + |k{sub 0} - k{sub 1}| c{sub s} (1) where {omega}{sub 0.1} and k{sub 0.1} are the frequencies and wave-numbers of the two laser beams, V is the plasma flow velocity and c{sub s} is the local ion sound speed. In the nominal case of equal frequency beams, this requires the component of the plasma flow velocity transverse to the bisector of the beam directions to be sonic, with the resulting transfer being to the downstream beam. In the NIF beam geometry, this is from the outer to inner cones of beams. The physics of this transfer is the same as in beam bending; the difference being that in the case of beam bending the effect is to redistribute power to the downstream side of the single beam. Were significant power transfer to occur in the point design, the delicately tuned implosion symmetry would be spoiled. To directly compensate for the transfer, the incident beam powers would have to be adjusted. The greatest vulnerability in the point design thus occurs at 15.2ns, when the inner beams are at their peak power and are at their nominal design power limit. In this situation, some other means of symmetry control would be required, such as re-pointing. At 15.2ns, the envelope focal intensities of the outer and inner beams are approximately 10{sup 15} and 6.7 10{sup 14} W/cm{sup 2} respectively. There is little absorption or diffractive spreading of the beams in the crossing

  20. Simulations of Converging Shock Collisions for Shock Ignition

    NASA Astrophysics Data System (ADS)

    Sauppe, Joshua; Dodd, Evan; Loomis, Eric

    2016-10-01

    Shock ignition (SI) has been proposed as an alternative to achieving high gain in inertial confinement fusion (ICF) targets. A central hot spot below the ignition threshold is created by an initial compression pulse, and a second laser pulse drives a strong converging shock into the fuel. The collision between the rebounding shock from the compression pulse and the converging shock results in amplification of the converging shock and increases the hot spot pressure above the ignition threshold. We investigate shock collision in SI drive schemes for cylindrical targets with a polystyrene foam interior using radiation-hydrodynamics simulations with the RAGE code. The configuration is similar to previous targets fielded on the Omega laser. The CH interior results in a lower convergence ratio and the cylindrical geometry facilitates visualization of the shock transit using an axial X-ray backlighter, both of which are important for comparison to potential experimental measurements. One-dimensional simulations are used to determine shock timing, and the effects of low mode asymmetries in 2D computations are also quantified. LA-UR-16-24773.

  1. National Ignition Facility Project Completion and Control System Status

    SciTech Connect

    Van Arsdall, P J; Azevedo, S G; Beeler, R G; Bryant, R M; Carey, R W; Demaret, R D; Fisher, J M; Frazier, T M; Lagin, L J; Ludwigsen, A P; Marshall, C D; Mathisen, D G; Reed, R K

    2009-10-02

    The National Ignition Facility (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. Completed in 2009, NIF is a stadium-sized facility containing a 1.8-MJ, 500-TW 192-beam ultraviolet laser and target chamber. A cryogenic tritium target system and suite of optical, X-ray and nuclear diagnostics will support experiments in a strategy to achieve fusion ignition starting in 2010. Automatic control of NIF is performed by the large-scale Integrated Computer Control System (ICCS), which is implemented by 2 MSLOC of Java and Ada running on 1300 front-end processors and servers. The ICCS framework uses CORBA distribution for interoperation between heterogeneous languages and computers. Laser setup is guided by a physics model and shots are coordinated by data-driven distributed workflow engines. The NIF information system includes operational tools and a peta-scale repository for provisioning experimental results. This paper discusses results achieved and the effort now underway to conduct full-scale operations and prepare for ignition.

  2. 2D X-ray radiography of imploding capsules at the national ignition facility.

    PubMed

    Rygg, J R; Jones, O S; Field, J E; Barrios, M A; Benedetti, L R; Collins, G W; Eder, D C; Edwards, M J; Kline, J L; Kroll, J J; Landen, O L; Ma, T; Pak, A; Peterson, J L; Raman, K; Town, R P J; Bradley, D K

    2014-05-16

    First measurements of the in-flight shape of imploding inertial confinement fusion (ICF) capsules at the National Ignition Facility (NIF) were obtained by using two-dimensional x-ray radiography. The sequence of area-backlit, time-gated pinhole images is analyzed for implosion velocity, low-mode shape and density asymmetries, and the absolute offset and center-of-mass velocity of the capsule shell. The in-flight shell is often observed to be asymmetric even when the concomitant core self-emission is round. A ∼ 15 μm shell asymmetry amplitude of the Y(40) spherical harmonic mode was observed for standard NIF ICF hohlraums at a shell radius of ∼ 200 μm (capsule at ∼ 5× radial compression). This asymmetry is mitigated by a ∼ 10% increase in the hohlraum length.

  3. eHXI: A permanently installed, hard x-ray imager for the National Ignition Facility

    DOE PAGES

    Doppner, T.; Bachmann, B.; Albert, F.; ...

    2016-06-14

    We have designed and built a multi-pinhole imaging system for high energy x-rays (≥ 50 keV) that is permanently installed in the equatorial plane outside of the target chamber at the National Ignition Facility (NIF). It records absolutely-calibrated, time-integrated x-ray images with the same line-of-sight as the multi-channel, spatially integrating hard x-ray detector FFLEX [McDonald et al., Rev. Sci. Instrum. 75 (2004) 3753], having a side view of indirect-drive inertial confinement fusion (ICF) implosion targets. The equatorial hard x-ray imager (eHXI) has recorded images on the majority of ICF implosion experiments since May 2011. Lastly, eHXI provides valuable information onmore » hot electron distribution in hohlraum experiments, target alignment, potential hohlraum drive asymmetries and serves as a long term reference for the FFLEX diagnostics.« less

  4. eHXI: A permanently installed, hard x-ray imager for the National Ignition Facility

    SciTech Connect

    Doppner, T.; Bachmann, B.; Albert, F.; Bell, P.; Burns, S.; Celeste, J.; Chow, R.; Divol, L.; Dewald, E. L.; Hohenberger, M.; Izumi, N.; LaCaille, G.; Landen, O. L.; Palmer, N.; Park, H. -S.; Thomas, C. A.; Huntington, C.

    2016-06-14

    We have designed and built a multi-pinhole imaging system for high energy x-rays (≥ 50 keV) that is permanently installed in the equatorial plane outside of the target chamber at the National Ignition Facility (NIF). It records absolutely-calibrated, time-integrated x-ray images with the same line-of-sight as the multi-channel, spatially integrating hard x-ray detector FFLEX [McDonald et al., Rev. Sci. Instrum. 75 (2004) 3753], having a side view of indirect-drive inertial confinement fusion (ICF) implosion targets. The equatorial hard x-ray imager (eHXI) has recorded images on the majority of ICF implosion experiments since May 2011. Lastly, eHXI provides valuable information on hot electron distribution in hohlraum experiments, target alignment, potential hohlraum drive asymmetries and serves as a long term reference for the FFLEX diagnostics.

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

    SciTech Connect

    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.

  6. eHXI: a permanently installed, hard x-ray imager for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Döppner, T.; Bachmann, B.; Albert, F.; Bell, P.; Burns, S.; Celeste, J.; Chow, R.; Divol, L.; Dewald, E. L.; Hohenberger, M.; Huntington, C. M.; Izumi, N.; LaCaille, G.; Landen, O. L.; Palmer, N.; Park, H.-S.; Thomas, C. A.

    2016-06-01

    We have designed and built a multi-pinhole imaging system for high energy x-rays (>= 50 keV) that is permanently installed in the equatorial plane outside of the target chamber at the National Ignition Facility (NIF). It records absolutely-calibrated, time-integrated x-ray images with the same line-of-sight as the multi-channel, spatially integrating hard x-ray detector FFLEX [McDonald et al., Rev. Sci. Instrum. 75 (2004) 3753], having a side view of indirect-drive inertial confinement fusion (ICF) implosion targets. The equatorial hard x-ray imager (eHXI) has recorded images on the majority of ICF implosion experiments since May 2011. eHXI provides valuable information on hot electron distribution in hohlraum experiments, target alignment, potential hohlraum drive asymmetries and serves as a long term reference for the FFLEX diagnostics.

  7. Simulation of a gamma reaction history (GRH) detector for use at the National Ignition Facility (NIF)

    NASA Astrophysics Data System (ADS)

    Grafil, Elliot; Toebbe, Jonathan

    2009-10-01

    Reaction history measurements are critical to diagnosing inertial confinement fusion (ICF) implosions. As such they will be essential components of the National Ignition Facility (NIF) diagnostics. One proposed method to record the reaction history is the construction of a gamma-sensitive gas Cerenkov detector. An array of these Cerenkov detectors can be used to discriminate between the different gamma ray energies produced during the ICF implosion. These fusion gammas are converted to optical photons for collection by fast recording systems. We have simulated the gamma reaction history (GRH) detector under development at NIF and LANL using Geant4. Our simulations have been used to determine energy cut-off ranges for photon production in various gases, optimizing converter material and thickness, and discriminating between proposed detector geometries in order to minimize the temporal spread of the signal.

  8. Kinetic Effects at Material Interfaces in ICF Implosions

    NASA Astrophysics Data System (ADS)

    Wilks, S. C.; Cabot, W.; Whitley, H.; Greenough, J.; Cohen, B. I.; Belof, J.; Zimmerman, G.; Amendt, P. A.; Lepape, S.; Divol, L.; Dimits, A.; Graziani, F.; Molvig, K.; Dodd, E.; Li, C. K.; Petrasso, R.; Laffite, S.; Larroche, O.; Casanova, M.; Masse, L.

    2014-10-01

    The mixing of materials at an interface during an ICF implosion, for example the DT- Carbon interface in an ICF capsule, is a complex process. In general, rad-hydro codes do an excellent job of modeling the important processes during an ICF implosion. However, there are certain times during the implosion when kinetic effects of the ions may play a role in how two materials mix across the interface between them, even in the absence of shocks moving through them. The Knudsen layer effect is one such example. We will describe results of multi-ion species hybrid LSP simulations where the ions are treated kinetically and the electrons are treated as a fluid. We observe that the DT and carbon ions diffuse across the interface in a self-similar manner, at a rate proportional to the square root of time, in agreement with diffusion theory. The resulting ion distributions for each species (on both sides of the interface) will be presented, and the result of this mixing on the yield will be discussed for ICF capsules. Preliminary results of a related mixing that occurs at the gas-hohlraum wall interface will also be presented. Performed under auspices of U.S. DOE by LLNL, Contract DE-AC52-07NA27344. LLNS, LLC.

  9. 76 FR 37953 - Standards of Performance for Stationary Compression Ignition and Spark Ignition Internal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... Performance for Stationary Compression Ignition and Spark Ignition Internal Combustion Engines; Final Rule #0... for Stationary Compression Ignition and Spark Ignition Internal Combustion Engines AGENCY: The... standards of performance for new stationary compression ignition internal combustion engines under...

  10. ICF Core Set for Head and Neck Cancer: Do the Categories Discriminate Among Clinically Relevant Subgroups of Patients?

    ERIC Educational Resources Information Center

    Tschiesner, Uta; Oberhauser, Cornelia; Cieza, Alarcos

    2011-01-01

    The multidisciplinary assessment of functioning in patients with head and neck cancer (HNC) according to the "ICF Core Set for Head and Neck Cancer" (ICF-HNC) was developed in an international and multi-disciplinary approach. The ICF-HNC is an application of the ICF that was adopted by the World Health Organization. The objective of this study was…

  11. Validation of the comprehensive ICF core set for low back pain: the perspective of physical therapists.

    PubMed

    Kirschneck, Michaela; Kirchberger, Inge; Amann, Edda; Cieza, Alarcos

    2011-08-01

    The "Comprehensive ICF Core Set for Low Back Pain (LBP)" is an application of the International Classification of Functioning, Disability and Health (ICF) and represents the typical spectrum of problems in functioning for patients with LBP. The aim of this study was to validate the Comprehensive ICF Core Set for low back pain from the perspective of physical therapists. Physical therapists experienced in LBP treatment were asked about the patients' problems, patients' resources and aspects of environment treated by physical therapists in a three-round survey using the Delphi technique. Responses were linked to the ICF. Eighty-four physical therapists in 32 countries named 1955 concepts that covered all ICF components. Fourteen ICF categories were not represented in the Comprehensive ICF Core Set for LBP although at least 75% of the participants have rated them as important. Most of them belonged to the ICF component "Body Functions". Twenty-eight concepts were linked to the not-yet-developed ICF component personal factors. Further, 21 issues were not covered by the ICF. The validity of the ICF components "Body Structures", "Activities and Participation" and "Environmental Factors" was largely supported by the physical therapists. However, several body functions were identified which are not covered and need further investigation.

  12. Studies of ion species separation in ICF-relevant plasmas at OMEGA

    NASA Astrophysics Data System (ADS)

    Rinderknecht, Hans; Wilks, Scott; Amendt, Peter; Ross, Steve; Park, Hye-Sook; Gatu Johnson, Maria; Frenje, Johan; Li, Chikang; Seguin, Fredrick; Sio, Hong; Petrasso, Richard; Rosenberg, Michael; Forrest, Chad; Glebov, Vladimir; Stoeckl, Christian; Sangster, Craig; Zylstra, Alex; Hoffman, Nelson; Kwan, Tom; Larroche, Olivier

    2015-11-01

    Plasmas produced in high-energy density (HED) and inertial confinement fusion (ICF) experiments generally contain multiple ion species, which allows for multiple-ion species dynamics that are not simulated in typical single-ion fluid hydro codes. In implosions of D3He-gas filled thin-glass spheres on the OMEGA laser facility, comprehensive nuclear diagnostics were used to infer the composition of the fuel during nuclear production, demonstrating that the deuterium fraction was reduced during the implosion of the fuel. Hydrodynamic simulations including an ion diffusion model indicate that pressure, temperature, and potential gradients drive diffusive separation of the ion species, producing better agreement with the experiments than standard hydrodynamic codes. The results of fully kinetic (Vlasov-Fokker-Planck and PIC) simulations confirm the importance of multi-species dynamics to the evolution of these experiments. Implications for multi-species (DT) cryogenic implosions on the National Ignition Facility will be addressed. This work was partially supported by the US DOE, NLUF, LLE, and GA.

  13. Planarization of Isolated Defects on ICF Target Capsule Surfaces by Pulsed Laser Ablation

    SciTech Connect

    Alfonso, Noel; Carlson, Lane C.; Bunn, Thomas L.

    2016-08-09

    Demanding surface quality requirements for inertial confinement fusion (ICF) capsules motivated the development of a pulsed laser ablation method to reduce or eliminate undesirable surface defects. The pulsed laser ablation technique takes advantage of a full surface (4π) capsule manipulation system working in combination with an optical profiling (confocal) microscope. Based on the defect topography, the material removal rate, the laser pulse energy and its beam profile, a customized laser raster pattern is derived to remove the defect. The pattern is a table of coordinates and number of pulses that dictate how the defect will be vaporized until its height is level with the capsule surface. This paper explains how the raster patterns are optimized to minimize surface roughness and how surface roughness after laser ablation is simulated. The simulated surfaces are compared with actual ablated surfaces. Large defects are reduced to a size regime where a tumble finishing process produces very high quality surfaces devoid of high mode defects. The combined polishing processes of laser ablation and tumble finishing have become routine fabrication steps for National Ignition Facility capsule production.

  14. Planarization of Isolated Defects on ICF Target Capsule Surfaces by Pulsed Laser Ablation

    DOE PAGES

    Alfonso, Noel; Carlson, Lane C.; Bunn, Thomas L.

    2016-08-09

    Demanding surface quality requirements for inertial confinement fusion (ICF) capsules motivated the development of a pulsed laser ablation method to reduce or eliminate undesirable surface defects. The pulsed laser ablation technique takes advantage of a full surface (4π) capsule manipulation system working in combination with an optical profiling (confocal) microscope. Based on the defect topography, the material removal rate, the laser pulse energy and its beam profile, a customized laser raster pattern is derived to remove the defect. The pattern is a table of coordinates and number of pulses that dictate how the defect will be vaporized until its heightmore » is level with the capsule surface. This paper explains how the raster patterns are optimized to minimize surface roughness and how surface roughness after laser ablation is simulated. The simulated surfaces are compared with actual ablated surfaces. Large defects are reduced to a size regime where a tumble finishing process produces very high quality surfaces devoid of high mode defects. The combined polishing processes of laser ablation and tumble finishing have become routine fabrication steps for National Ignition Facility capsule production.« less

  15. Hydrodynamic instability measurements in DT-layered ICF capsules using the layered-HGR platform

    NASA Astrophysics Data System (ADS)

    Weber, C.; Döppner, T.; Casey, D.; Bunn, T.; Carlson, L.; Dylla-Spears, R.; Kozioziemski, B.; MacPhee, A. G.; Sater, J.; Nikroo, A.; Robey, H.; Smalyuk, V.

    2016-05-01

    The first measurements of hydrodynamic instability growth at the fuel-ablator interface in an ICF implosion are reported. Previous instability measurements on the National Ignition Facility have used plastic capsules to measure ablation front Rayleigh-Taylor growth with the Hydro.-Growth Radiography (HGR) platform. These capsules substituted an additional thickness of plastic ablator material in place of the cryogenic layer of Deuterium- Tritium (DT) fuel. The present experiments are the first to include a DT ice layer, which enables measurements of the instability growth occurring at the fuel-ablator interface. Instability growth at the fuel-ablator interface is seeded differently in two independent NIF experiments. In the first case, a perturbation on the outside of the capsule feeds through and grows on the interface. Comparisons to an implosion without a fuel layer produce a measure of the fuel's modulation. In the second case, a modulation was directly machined on the inner ablator before the fuel layer was added. The measurement of growth in these two scenarios are compared to 2D rad-hydro modeling.

  16. Measurements of charged-particle stopping around the Bragg peak in OMEGA ICF plasmas

    NASA Astrophysics Data System (ADS)

    Frenje, J.; Li, C. K.; Seguin, F.; Zylstra, A.; Petrasso, R.; Grabowski, P.; Mancini, R.; Regan, S.; Delettrez, J.; Glebov, V.; Sangster, T.

    2014-10-01

    We report on measurements of charged-particle stopping around the Bragg peak in plasmas relevant to Inertial Confinement Fusion (ICF). The energy loss of DD-tritons, DD-protons, D3He-alphas and D3He-protons, which are ideal particles for validating approximations to the ion-electron collision operator, have been measured in D3He gas-filled filled implosions. These experiments are relevant to alpha-particle transport and heating in hot-sport ignition experiments. As the DD and D3He fusion products span a large range of velocities, these measurements represent the first detailed experimental study of charged-particle stopping, ranging from linear low-velocity stopping, through the Bragg peak, to high-velocity stopping. The results are contrasted to commonly used theories, including the Brown-Preston-Singleton and Li-Petrasso formalisms. The data is also used to rule out theories that neglect quantum diffraction and dynamic screening. This work was supported in part by the US DOE, NLUF, LLE and GA.

  17. Surrogate models for identifying robust, high yield regions of parameter space for ICF implosion simulations

    NASA Astrophysics Data System (ADS)

    Humbird, Kelli; Peterson, J. Luc; Brandon, Scott; Field, John; Nora, Ryan; Spears, Brian

    2016-10-01

    Next-generation supercomputer architecture and in-transit data analysis have been used to create a large collection of 2-D ICF capsule implosion simulations. The database includes metrics for approximately 60,000 implosions, with x-ray images and detailed physics parameters available for over 20,000 simulations. To map and explore this large database, surrogate models for numerous quantities of interest are built using supervised machine learning algorithms. Response surfaces constructed using the predictive capabilities of the surrogates allow for continuous exploration of parameter space without requiring additional simulations. High performing regions of the input space are identified to guide the design of future experiments. In particular, a model for the yield built using a random forest regression algorithm has a cross validation score of 94.3% and is consistently conservative for high yield predictions. The model is used to search for robust volumes of parameter space where high yields are expected, even given variations in other input parameters. Surrogates for additional quantities of interest relevant to ignition are used to further characterize the high yield regions. This work 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. LLNL-ABS-697277.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Catalytic Microtube Rocket Igniter

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Deans, Matthew C.

    2011-01-01

    Devices that generate both high energy and high temperature are required to ignite reliably the propellant mixtures in combustion chambers like those present in rockets and other combustion systems. This catalytic microtube rocket igniter generates these conditions with a small, catalysis-based torch. While traditional spark plug systems can require anywhere from 50 W to multiple kW of power in different applications, this system has demonstrated ignition at less than 25 W. Reactants are fed to the igniter from the same tanks that feed the reactants to the rest of the rocket or combustion system. While this specific igniter was originally designed for liquid methane and liquid oxygen rockets, it can be easily operated with gaseous propellants or modified for hydrogen use in commercial combustion devices. For the present cryogenic propellant rocket case, the main propellant tanks liquid oxygen and liquid methane, respectively are regulated and split into different systems for the individual stages of the rocket and igniter. As the catalyst requires a gas phase for reaction, either the stored boil-off of the tanks can be used directly or one stream each of fuel and oxidizer can go through a heat exchanger/vaporizer that turns the liquid propellants into a gaseous form. For commercial applications, where the reactants are stored as gases, the system is simplified. The resulting gas-phase streams of fuel and oxidizer are then further divided for the individual components of the igniter. One stream each of the fuel and oxidizer is introduced to a mixing bottle/apparatus where they are mixed to a fuel-rich composition with an O/F mass-based mixture ratio of under 1.0. This premixed flow then feeds into the catalytic microtube device. The total flow is on the order of 0.01 g/s. The microtube device is composed of a pair of sub-millimeter diameter platinum tubes connected only at the outlet so that the two outlet flows are parallel to each other. The tubes are each

  20. Ignition system monitoring assembly

    DOEpatents

    Brushwood, John Samuel

    2003-11-04

    An ignition system monitoring assembly for use in a combustion engine is disclosed. The assembly includes an igniter having at least one positioning guide with at least one transmittal member being maintained in a preferred orientation by one of the positioning guides. The transmittal member is in optical communication with a corresponding target region, and optical information about the target region is conveyed to the reception member via the transmittal member. The device allows real-time observation of optical characteristics of the target region. The target region may be the spark gap between the igniter electrodes, or other predetermined locations in optical communication with the transmittal member. The reception member may send an output signal to a processing member which, in turn, may produce a response to the output signal.

  1. Ignitability test method and apparatus

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J. (Inventor); Bailey, James W. (Inventor); Schimmel, Morry L. (Inventor)

    1991-01-01

    An apparatus for testing ignitability of an initiator includes a body having a central cavity, an initiator holder for holding the initiator over the central cavity of the body, an ignition material holder disposed in the central cavity of the body and having a cavity facing the initiator holder which receives a measured quantity of ignition material to be ignited by the initiator. It contains a chamber in communication with the cavity of the ignition material and the central cavity of the body, and a measuring system for analyzing pressure characteristics generated by ignition of the ignition material by the initiator. The measuring system includes at least one transducer coupled with an oscillograph for recording pressure traces generated by ignition.

  2. The National Ignition Facility Wavefront Requirements and Optical Architecture

    SciTech Connect

    Spaeth, M L; Manes, K R; Widmayer, C C; Williams, W H; Whitman, P K; Henesian, M A; Stowers, I F; Honig, J

    2004-06-03

    With the first four of its eventual 192 beams now executing shots and generating more than 100 kilojoules of laser energy at its primary wavelength of 1.06 {micro}m, the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is already the world's largest and most energetic laser. The optical system performance requirements that are in place for NIF are derived from the goals of the missions it is designed to serve. These missions include inertial confinement fusion (ICF) research and the study of matter at extreme energy densities and pressures. These mission requirements have led to a design strategy for achieving high quality focusable energy and power from the laser and to specifications on optics that are important for an ICF laser. The design of NIF utilizes a multipass architecture with a single large amplifier type that provides high gain, high extraction efficiency and high packing density. We have taken a systems engineering approach to the practical implementation of this design that specifies the wavefront parameters of individual optics in order to achieve the desired cumulative performance of the laser beamline. This presentation provides a detailed look at the causes and effects of performance degradation in large laser systems and how NIF has been designed to overcome these effects. We will also present results of spot size performance measurements that have validated many of the early design decisions that have been incorporated in the NIF laser architecture.

  3. The National Ignition Facility Wavefront Requirements and Optical Architecture

    SciTech Connect

    Spaeth, M L; Manes, K R; Widmayer, C C; Williams, W; Whitman, P A; Henesian, M

    2004-01-05

    With the first four of its eventual 192 beams now executing shots, the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is already the world's largest and most energetic laser. The optical system performance requirements that are in place for NIF are derived from the goals of the missions it is designed to serve. These missions include inertial confinement fusion (ICF) research and the study of matter at extreme energy densities and pressures. These mission requirements have led to a design strategy for achieving high quality focusable energy and power from the laser and to specifications on optics that are important for an ICF laser. The design of NIF utilizes a multipass architecture with a single large amplifier type that provides high gain, high extraction efficiency and high packing density. We have taken a systems engineering approach to the practical implementation of this design that specifies the wavefront parameters of individual optics in order to achieve the desired cumulative performance of the laser beamline. This presentation provides a detailed look at the causes and effects of performance degradation in large laser systems and how NIF has been designed to overcome these effects. We will also present results of spot size performance measurements that have validated many of the early design decisions that have been incorporated in the NIF laser architecture.

  4. Next Generation Gamma Ray Diagnostics for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Herrmann, Hans; Kim, Y. H.; McEvoy, A. M.; Zylstra, A. B.; Young, C. S.; Lopez, F. E.; Griego, J. R.; Fatherley, V. E.; Oertel, J. A.; Jorgenson, H. J.; Barlow, D. B.; Stoeffl, W.; Church, J. A.; Hernandez, J. E.; Carpenter, A.; Rubery, M. S.; Horsfield, C. J.; Gales, S.; Leatherland, A.; Hilsabeck, T.; Kilkenny, J. D.; Malone, R. M.; Moy, K.; Hares, J. D.; Milnes, J.

    Fusion reaction history and ablator areal density measurements based on gamma ray detection are an essential part of Inertial Confinement Fusion (ICF) experiments on the National Ignition Facility (NIF). Capability improvements are being implemented in sensitivity, temporal and spectral response relative to the existing Gamma Reaction History diagnostic (GRH-6m). The ``Super'' Gas Cherenkov Detector (GCD) will provide 200x more sensitivity, reduce the effective temporal resolution from 100 to 10 ps, and lower the energy threshold from 2.9 to 1.8 MeV, relative to GRH-6m. The Gamma-to-Electron Magnetic Spectrometer (GEMS) - a Compton spectrometer intended to provide true gamma energy resolution (<=5%) for isolation of specific lines such as t(d, γ) , D(n, γ) , 12C(n,n' γ) and energetic charged particle nuclear reactions indicative of ablator/fuel mix

  5. 14 CFR 23.1145 - Ignition switches.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ignition switches. 23.1145 Section 23.1145... Accessories § 23.1145 Ignition switches. (a) Ignition switches must control and shut off each ignition circuit... the grouping of switches or by a master ignition control. (c) Each group of ignition switches,...

  6. 14 CFR 23.1145 - Ignition switches.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ignition switches. 23.1145 Section 23.1145... Accessories § 23.1145 Ignition switches. (a) Ignition switches must control and shut off each ignition circuit... the grouping of switches or by a master ignition control. (c) Each group of ignition switches,...

  7. 14 CFR 23.1145 - Ignition switches.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ignition switches. 23.1145 Section 23.1145... Accessories § 23.1145 Ignition switches. (a) Ignition switches must control and shut off each ignition circuit... the grouping of switches or by a master ignition control. (c) Each group of ignition switches,...

  8. 14 CFR 23.1145 - Ignition switches.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ignition switches. 23.1145 Section 23.1145... Accessories § 23.1145 Ignition switches. (a) Ignition switches must control and shut off each ignition circuit... the grouping of switches or by a master ignition control. (c) Each group of ignition switches,...

  9. 14 CFR 23.1145 - Ignition switches.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ignition switches. 23.1145 Section 23.1145... Accessories § 23.1145 Ignition switches. (a) Ignition switches must control and shut off each ignition circuit... the grouping of switches or by a master ignition control. (c) Each group of ignition switches,...

  10. Ignition Kinetics in Fuels Oxidation

    DTIC Science & Technology

    2006-06-01

    2 . 3 . Experimental and...ignition, we have conducted a systematic study on the ignition of the four isomers of butene , namely 1- butene , cis- 2 - butene , trans- 2 - butene , and... butene , 2 - butenes and isobutene. The ignitability of cis- 2 - butene and trans- 2 - butene cannot be compared because the difference between their

  11. DTRA National Ignition Facility (NIF)

    DTIC Science & Technology

    2009-01-16

    DTRA National Ignition Facility ( NIF ) ___________________________________ JSR-08- 800 September 29...4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER DTRA National Ignition Facility ( NIF ) 5b. GRANT NUMBER 5c...only). 13. SUPPLEMENTARY NOTES 14. ABSTRACT JASON was asked to address the utility of the National Ignition Facility ( NIF ) to the Defense Threat

  12. IGNITION HARDENING OF CELLULOSIC MATERIALS,

    DTIC Science & Technology

    Similar ignition response measurements were made with specimens exposed to ionizing radiation. Alpha-cellulose samples containing a mixture of boric acid ... borax , and ammonium di-hydrogen phosphate could not be ignited by irradiances up to 4.0 cal/sq cm/sec. Above this value, transient ignition would

  13. Ignition Rate Measurement of Laser-Ignited Coals

    SciTech Connect

    Chen, J.C.; Kabadi, V.

    1997-05-01

    We are proposing to establish a novel experiment to study the ignition of pulverized coals under conditions relevant to utility boiler. Specifically, our aims are to determine the ignition mechanism, which is either homogeneous or heterogeneous, of pulverized coal particles under various condition of particle size, coal type, freestream oxygen concentration, and heating rate. Furthermore, we will measure the ignition rate constants of various coals by direct measurement of the particle temperature at ignition, and incorporating this measurement into a mathematical model for the ignition process.

  14. Inertial Confinement Fusion Program at Lawrence Livermore National Laboratory:. The National Ignition Facility, Inertial Fusion Energy, 100-1000 TW Lasers, and the Fast Igniter Concept

    NASA Astrophysics Data System (ADS)

    Howard Lowdermilk, W.

    The ultimate goal of worldwide research in inertial confinement fusion (ICF) is to develop fusion as an inexhaustible, economic, environmentally safe source of electric power. Following nearly thirty years of laboratory and underground fusion experiments, the next step toward this goal is to demonstrate ignition and propagating burn of fusion fuel in the laboratory. The National Ignition Facility (NIF) Project is being constructed at Lawrence Livermore National Laboratory (LLNL) for just this purpose. NIF will use advanced Nd-glass laser technology to deliver 1.8 MJ of 0.35 μm laser light in a shaped pulse, several nanoseconds in duration, achieving a peak power of 500 TW. A national community of U.S. laboratories is participating in this project, now in its final design phase. France and the United Kingdom are collaborating on development of required technology under bilateral agreements with the US. This paper presents key aspects of the laser design, and descriptions of principal laser and optical components. Follow-on development of lasers to meet the demands of an inertial fusion energy (IFE) power plant is reviewed. In parallel with the NIF Project and IFE developments, work is proceeding on ultrashort pulse lasers with peak power in the range of 100-1000 TW. A beamline on the Nova laser at LLNL recently delivered nearly 600 J of 1 μm light in a 0.5 ps duration pulse, for a peak power in excess of a petawatt (1015 W). This beamline, with advanced adaptive optics, will be capable of focused intensities in excess of 1021 W/cm2. Its primary purpose will be to test technological and scientific aspects of an alternate ignition concept, called the "Fast Igniter", that has the potential to produce higher fusion gain than conventional ICF.

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

    SciTech Connect

    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

    2007-09-11

    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

  16. Analysis Of Wetted-Foam ICF Capsule Perormance

    NASA Astrophysics Data System (ADS)

    Peterson, R.; Olson, R.; Zylstra, A.; Haines, B.; Yi, A.; Bradley, P.; Yin, L.; Leeper, R.; Kline, J.

    2016-10-01

    The performance of wetted-foam ICF capsules is investigated with the RAGE Eulerian radiation-hydrodynamics computer code. We are developing an experimental platform on NIF that employs a wetted foam liquid DT fuel layer ICF capsules. By varying the capsule temperature, the vapor density in the capsule can be prescribed, and the hot spot convergence ratio (CR) of the capsule implosion can be controlled. This allows us to investigate the fidelity of RAGE in modeling of capsule implosions as the value of CR is varied. In the NIF experiments, CR can be varied from 12 to 25. This presentation will cover simulations with RAGE of three NIF shots performed in 2016; a DD and a DT liquid fuel shot with CR =14 and a DT shot with CR =16. It will also discuss analysis of future experiments. This work was performed under auspices of the U. S. DOE by LANL.

  17. First measurements of deuterium-tritium and deuterium-deuterium fusion reaction yields in ignition-scalable direct-drive implosions

    DOE PAGES

    Forrest, C. J.; Radha, P. B.; Knauer, J. P.; ...

    2017-03-03

    In this study, the deuterium-tritium (D-T) and deuterium-deuterium neutron yield ratio in cryogenic inertial confinement fusion (ICF) experiments is used to examine multifluid effects, traditionally not included in ICF modeling. This ratio has been measured for ignition-scalable direct-drive cryogenic DT implosions at the Omega Laser Facility using a high-dynamic-range neutron time-of-flight spectrometer. The experimentally inferred yield ratio is consistent with both the calculated values of the nuclear reaction rates and the measured preshot target-fuel composition. These observations indicate that the physical mechanisms that have been proposed to alter the fuel composition, such as species separation of the hydrogen isotopes, aremore » not significant during the period of peak neutron production in ignition-scalable cryogenic direct-drive DT implosions.« less

  18. Simulations of laser imprint for Nova experiments and for ignition capsules

    SciTech Connect

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

    1996-11-08

    In direct drive ICF, nonuniformities in laser illumination seed ripples at the ablation front in a process called imprint. These non 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, I=10X13 W/cm3. 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 model, with linear growth 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.

  19. Targets for the National Ignition Campaign

    SciTech Connect

    Atherton, L J

    2007-09-07

    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{sup 8} K), pressures (10 GBar) and matter densities (>100 g/cm{sup 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. The targets for the NIC are both complex and precise, and are extraordinarily demanding in materials fabrication, machining, assembly, cryogenics and characterization. The DT fuel is contained in a 2-millimeter diameter graded copper/beryllium or CH shell. The 75mm thick cryogenic ice DT fuel layer is formed to sub-micron uniformity at a temperature of approximately 18 Kelvin. The capsule and its fuel layer sit at the center of a gold/depleted uranium 'cocktail' hohlraum. Researchers at LLNL have teamed with colleagues at General Atomics to lead the development of the technologies, engineering design and manufacturing infrastructure necessary to produce these demanding targets. We are also collaborating with colleagues at the Laboratory for Laser Energetics (LLE) at the University of Rochester in DT layering, and at Fraunhofer in Germany in nano-crystalline diamond as an alternate ablator to Beryllium and CH. The Beryllium capsules and cocktail hohlraums are made by physical vapor deposition onto sacrificial mandrels. These coatings must have high density (low porosity), uniform microstructure, low oxygen content and low permeability

  20. Laser ignition of pulverized coals

    SciTech Connect

    Chen, J.C.; Taniguchi, Masayuki; Narato, Kiyoshi; Ito, Kazuyuki . Hitachi Research Lab.)

    1994-04-01

    The authors present a novel experiment to study the ignition of pulverized coal. A dilute stream of particles is dropped into a laminar, upward-flow wind tunnel with a quartz test section. The gas stream is not preheated. A single pulse from a Nd:YAG laser is focused through the tunnel and ignites the fuel. The transparent test section and cool walls allow for optical detection of the ignition process. In this article they describe the experiment and demonstrate its capabilities by observing the ignition behavior of spherical, amorphous-carbon particles and two coal: an anthracite and a high-volatile bituminous coal. The ignition behaviors of the carbon spheres and the anthracite are as expected for heterogeneous ignition, while the mechanism of the bituminous coal is uncertain. Calculations are also presented to describe the physical behavior of a laser-heated particle, and the heat transfer and chemistry of heterogeneous ignition.

  1. FISH analysis on spontaneously arising micronuclei in the ICF syndrome.

    PubMed Central

    Stacey, M; Bennett, M S; Hulten, M

    1995-01-01

    The ICF syndrome is a rare disorder where patients show undercondensation of the heterochromatic blocks of chromosomes 1, 9, and 16 along with variable immunodeficiency. The undercondensation of the heterochromatic block appears to be restricted to a portion of PHA stimulated T cells. Patients with this syndrome also show an increase in micronuclei formation. We have used dual colour FISH to investigate the chromosomal content of these micronuclei in PHA stimulated peripheral blood cultures, an EBV transformed B cell line, and also micronuclei observed in vivo from peripheral blood smears. Chromosome 1 appears to be present in a higher proportion of micronuclei compared to chromosomes 9 and 16 in both a PHA stimulated culture and an EBV transformed cell line. An 18 centromeric probe, not associated with the ICF syndrome, showed no signal in any of the micronuclei observed. The implications from these observations are that the heterochromatic instability in the ICF syndrome is manifested not only in T but also in B cells and that it is present in vivo. Images PMID:7562960

  2. Hybrid-drive implosion system for ICF targets

    DOEpatents

    Mark, James W.

    1988-01-01

    Hybrid-drive implosion systems (20,40) for ICF targets (10,22,42) are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator (12) surroundingly disposed around fusion fuel (14). The ablator is first compressed to higher density by a laser system (24), or by an ion beam system (44), that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system (30,48) that is optimized for this second phase of operation of the target. The fusion fuel (14) is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion.

  3. Hybrid-drive implosion system for ICF targets

    DOEpatents

    Mark, James W.

    1988-08-02

    Hybrid-drive implosion systems (20,40) for ICF targets (10,22,42) are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator (12) surroundingly disposed around fusion fuel (14). The ablator is first compressed to higher density by a laser system (24), or by an ion beam system (44), that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system (30,48) that is optimized for this second phase of operation of the target. The fusion fuel (14) is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion.

  4. Hybrid-drive implosion system for ICF targets

    DOEpatents

    Mark, J.W.K.

    1987-10-14

    Hybrid-drive implosion systems for ICF targets are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator surroundingly disposed around fusion fuel. The ablator is first compressed to higher density by a laser system, or by an ion beam system, that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system that is optimized for this second phase of operation of the target. The fusion fuel is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion. 3 figs.

  5. Recent Advances in Indirect Drive ICF Target Physics

    SciTech Connect

    Hammel, B; Lindl, J; Amendt, P A; Bernat, G W; Collins, G W; Glenzer, S H; Koch, S H; Haan, S; Landen, O L; Suter, L J

    2002-10-08

    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 lEnergie 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 & fabrication.

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

    SciTech Connect

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

    1998-01-13

    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 1'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 & fabrication.

  7. [The term "Funktionale Gesundheit" (functional health) in the German edition of the ICF].

    PubMed

    Cibis, W

    2009-07-01

    In the preface of the German edition of the INTERNATIONAL CLASSIFICATION OF FUNCTIONING, DISABILITY AND HEALTH (ICF) the term "functional health" (Funktionale Gesundheit) is introduced and defined. There is no direct equivalent expression in the original English Version of the ICF. The definition of "Funktionale Gesundheit" was thus strongly disputed among the translators and ICF experts involved in the German translation. In the following, the author suggests reconsidering the definition critically and proposes an alternative solution.

  8. Hot-spot mix in ignition-scale implosions on the NIF [Hot-spot mix in ignition-scale implosions on the National Ignition Facility (NIF)

    SciTech Connect

    Regan, S. P.; Epstein, R.; Hammel, B. A.; Suter, L. J.; Ralph, J.; Scott, H.; Barrios, M. A.; Bradley, D. K.; Callahan, D. A.; Cerjan, C.; Collins, G. W.; Dixit, S. N.; Doeppner, T.; Edwards, M. J.; Farley, D. R.; Glenn, S.; Glenzer, S. H.; Golovkin, I. E.; Haan, S. W.; Hamza, A.; Hicks, D. G.; Izumi, N.; Kilkenny, J. D.; Kline, J. L.; Kyrala, G. A.; Landen, O. L.; Ma, T.; MacFarlane, J. J.; Mancini, R. C.; McCrory, R. L.; Meezan, N. B.; Meyerhofer, D. D.; Nikroo, A.; Peterson, K. J.; Sangster, T. C.; Springer, P.; Town, R. P. J.

    2012-03-30

    Ignition of an inertial confinement fusion (ICF) target depends on the formation of a central hot spot with sufficient temperature and areal density. Radiative and conductive losses from the hot spot can be enhanced by hydrodynamic instabilities. The concentric spherical layers of current National Ignition Facility (NIF) ignition targets consist of a plastic ablator surrounding 2 a thin shell of cryogenic thermonuclear fuel (i.e., hydrogen isotopes), with fuel vapor filling the interior volume. The Rev. 5 ablator is doped with Ge to minimize preheat of the ablator closest to the DT ice caused by Au M-band emission from the hohlraum x-ray drive. Richtmyer–Meshkov and Rayleigh–Taylor hydrodynamic instabilities seeded by high-mode (50 < t < 200) ablator-surface perturbations can cause Ge-doped ablator to mix into the interior of the shell at the end of the acceleration phase. As the shell decelerates, it compresses the fuel vapor, forming a hot spot. K-shell line emission from the ionized Ge that has penetrated into the hot spot provides an experimental signature of hot-spot mix. The Ge emission from tritium–hydrogen–deuterium (THD) and DT cryogenic targets and gas-filled plastic shell capsules, which replace the THD layer with a massequivalent CH layer, was examined. The inferred amount of hot-spot mix mass, estimated from the Ge K-shell line brightness using a detailed atomic physics code, is typically below the 75 ng allowance for hot-spot mix. Furthermore, predictions of a simple mix model, based on linear growth of the measured surface-mass modulations, are consistent with the experimental results.

  9. Hot-spot mix in ignition-scale implosions on the NIF [Hot-spot mix in ignition-scale implosions on the National Ignition Facility (NIF)

    DOE PAGES

    Regan, S. P.; Epstein, R.; Hammel, B. A.; ...

    2012-03-30

    Ignition of an inertial confinement fusion (ICF) target depends on the formation of a central hot spot with sufficient temperature and areal density. Radiative and conductive losses from the hot spot can be enhanced by hydrodynamic instabilities. The concentric spherical layers of current National Ignition Facility (NIF) ignition targets consist of a plastic ablator surrounding 2 a thin shell of cryogenic thermonuclear fuel (i.e., hydrogen isotopes), with fuel vapor filling the interior volume. The Rev. 5 ablator is doped with Ge to minimize preheat of the ablator closest to the DT ice caused by Au M-band emission from the hohlraummore » x-ray drive. Richtmyer–Meshkov and Rayleigh–Taylor hydrodynamic instabilities seeded by high-mode (50 < t < 200) ablator-surface perturbations can cause Ge-doped ablator to mix into the interior of the shell at the end of the acceleration phase. As the shell decelerates, it compresses the fuel vapor, forming a hot spot. K-shell line emission from the ionized Ge that has penetrated into the hot spot provides an experimental signature of hot-spot mix. The Ge emission from tritium–hydrogen–deuterium (THD) and DT cryogenic targets and gas-filled plastic shell capsules, which replace the THD layer with a massequivalent CH layer, was examined. The inferred amount of hot-spot mix mass, estimated from the Ge K-shell line brightness using a detailed atomic physics code, is typically below the 75 ng allowance for hot-spot mix. Furthermore, predictions of a simple mix model, based on linear growth of the measured surface-mass modulations, are consistent with the experimental results.« less

  10. Igniter electrode life control

    SciTech Connect

    Scott, J.C.

    1985-10-07

    The prevention of electrode material erosion by undercutting in the outer electrode shell of igniter electrodes of jet engine ignition systems is prevented by the application of an electrical insulation coating. The coating is applied to the surface of the outer electrode shell which faces the ceramic insulation around the center electrode where erosion patterns are known to occur. The insulation material is selected from electrical insulation substances such as oxides of aluminum, tungsten, magnesium, beryllium or zirconium by choosing a non-porous electrical-insulating substance with thermal-expansion characteristics approximately equalling those of the outer electrode shell. Since a typical outer electrode shell is composed of 446 stainless steel, an optimum choice for the electrical insulation coating is Al/sub 2/O/sub 3/ deposited with a coating thickness of between 5 and 10 mils.

  11. Burner ignition system

    DOEpatents

    Carignan, Forest J.

    1986-01-21

    An electronic ignition system for a gas burner is battery operated. The battery voltage is applied through a DC-DC chopper to a step-up transformer to charge a capacitor which provides the ignition spark. The step-up transformer has a significant leakage reactance in order to limit current flow from the battery during initial charging of the capacitor. A tank circuit at the input of the transformer returns magnetizing current resulting from the leakage reactance to the primary in succeeding cycles. An SCR in the output circuit is gated through a voltage divider which senses current flow through a flame. Once the flame is sensed, further sparks are precluded. The same flame sensor enables a thermopile driven main valve actuating circuit. A safety valve in series with the main gas valve responds to a control pressure thermostatically applied through a diaphragm. The valve closes after a predetermined delay determined by a time delay orifice if the pilot gas is not ignited.

  12. Mach-Zehnder Fiber-Optic Links for ICF Diagnostics

    SciTech Connect

    Miller, E. K., Hermann, H. W.

    2012-11-01

    This article describes the operation and evolution of Mach-Zehnder links for single-point detectors in inertial confinement fusion experimental facilities, based on the Gamma Reaction History (GRH) diagnostic at the National Ignition Facility.

  13. Mediating effects of the ICF domain of function and the gross motor function measure on the ICF domains of activity, and participation in children with cerebral palsy.

    PubMed

    Lee, Byoung-Hee; Kim, Yu-Mi; Jeong, Goo-Churl

    2015-10-01

    [Purpose] This study aimed to evaluate the mediating effect of gross motor function, measured using the Gross Motor Function Measure (GMFM) and of general function, measured using the International Classification of Functioning, Disability and Health-Child and Youth Check List (ICF-CY), on the ICF domains of activity and participation in children with cerebral palsy (CP). [Subjects] Ninety-five children with CP, from Seoul, Korea, participated in the study. [Methods] The GMFM was administered in its entirety to patients without orthoses or mobility aids. The ICF-CY was used to evaluate the degree of disability and health of subjects. [Results] GMFM score and ICF-CY function were negatively correlated to ICF-CY activity and participation. ICF-CY partially mediated the effects of the GMFM on activity and participation. [Conclusion] When establishing a treatment plan for a child with CP, limitations in activity and participation, as described by the ICF-CY, should be considered in addition to the child's physical abilities and development. In addition, the treatment plan should focus on increasing the child's activity and participation level, as well as his/her physical level.

  14. Simulations of time-dependent drive asymmetries for shock ignition

    NASA Astrophysics Data System (ADS)

    Loomis, Eric; Dodd, Evan; Cobble, James; Marinak, Marty; Sauppe, Joshua

    2016-10-01

    Shock Ignition (SI) is an extension of conventional inertial confinement fusion (ICF) where a strong shock heats low temperature, but highly compressed, deuterium-tritium fuel to ignition conditions. The conditions for maximum pressure amplification by the ignitor shock have been predicted in one-dimensional geometry where shock heating is most efficient. In real experiments, asymmetries in the flow field almost always take on 2- and 3-dimensional structure. To study the degradation in heating efficiency of the ignitor shock when interacting with asymmetric rebounding shocks and multi-dimensional flow we have performed a series of HYDRA simulations that use the indirect drive high foot design of Dittrich et al.. In our simulations we truncated the radiation drive to peak at 270 eV and used the remaining energy to directly irradiate the capsule with a spherical laser source to create the ignitor shock. Legendre mode asymmetries were applied to the radiation field at different times during implosion of the capsule producing fuel and rebounding shock asymmetries that significantly reduced the ignitor efficiency. We will present how the heating is reduced for asymmetries in the pulse foot and peak.

  15. Neutron source reconstruction from pinhole imaging at National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Volegov, P.; Danly, C. R.; Fittinghoff, D. N.; Grim, G. P.; Guler, N.; Izumi, N.; Ma, T.; Merrill, F. E.; Warrick, A. L.; Wilde, C. H.; Wilson, D. C.

    2014-02-01

    The neutron imaging system at the National Ignition Facility (NIF) is an important diagnostic tool for measuring the two-dimensional size and shape of the neutrons produced in the burning deuterium-tritium plasma during the ignition stage of inertial confinement fusion (ICF) implosions at NIF. Since the neutron source is small (˜100 μm) and neutrons are deeply penetrating (>3 cm) in all materials, the apertures used to achieve the desired 10-μm resolution are 20-cm long, single-sided tapers in gold. These apertures, which have triangular cross sections, produce distortions in the image, and the extended nature of the pinhole results in a non-stationary or spatially varying point spread function across the pinhole field of view. In this work, we have used iterative Maximum Likelihood techniques to remove the non-stationary distortions introduced by the aperture to reconstruct the underlying neutron source distributions. We present the detailed algorithms used for these reconstructions, the stopping criteria used and reconstructed sources from data collected at NIF with a discussion of the neutron imaging performance in light of other diagnostics.

  16. Neutron source reconstruction from pinhole imaging at National Ignition Facility.

    PubMed

    Volegov, P; Danly, C R; Fittinghoff, D N; Grim, G P; Guler, N; Izumi, N; Ma, T; Merrill, F E; Warrick, A L; Wilde, C H; Wilson, D C

    2014-02-01

    The neutron imaging system at the National Ignition Facility (NIF) is an important diagnostic tool for measuring the two-dimensional size and shape of the neutrons produced in the burning deuterium-tritium plasma during the ignition stage of inertial confinement fusion (ICF) implosions at NIF. Since the neutron source is small (∼100 μm) and neutrons are deeply penetrating (>3 cm) in all materials, the apertures used to achieve the desired 10-μm resolution are 20-cm long, single-sided tapers in gold. These apertures, which have triangular cross sections, produce distortions in the image, and the extended nature of the pinhole results in a non-stationary or spatially varying point spread function across the pinhole field of view. In this work, we have used iterative Maximum Likelihood techniques to remove the non-stationary distortions introduced by the aperture to reconstruct the underlying neutron source distributions. We present the detailed algorithms used for these reconstructions, the stopping criteria used and reconstructed sources from data collected at NIF with a discussion of the neutron imaging performance in light of other diagnostics.

  17. Design for environment for the National Ignition Facility

    SciTech Connect

    Cantwell, E.; Gobor, K.; Celeste, J.; Cerruti, S.

    1998-05-01

    The National Ignition Facility (NIF) will be a U.S. Department of Energy (DOE) national center for inertial confinement fusion (ICF) and other research into the physics of high temperatures and high densities, and a vital element of the DOE`s nuclear weapons Stockpile Stewardship and Management Program. It will be used by scientists from a numerous different institutions and disciplines to support research advancements in national security, energy, basic science, and economic development. Multiple powerful laser beams will `ignite` small fusion targets, helping liberate more energy than is required to initiate the fusion reactions. This paper discusses the Design for Environment process for NIF, some of the subsequent activities resulting from the initial study, and a few of the lessons learned from this process. Subsequent activities include the development of a Pollution Prevention and Waste Minimization Plan (P2/WMin) for the facility, which includes Pollution Prevention Opportunity Assessments (PPOAS) on predicted waste streams from NIF, development of construction phase recycling plans, analysis of some of the specialized materials of construction to minimize future demolition and decommissioning (D&D) costs and development of cost assessments for more benign cleaning procedures that meet the stringent cleaning specifications for this facility.

  18. A hybrid-drive nonisobaric-ignition scheme for inertial confinement fusion

    NASA Astrophysics Data System (ADS)

    He, X. T.; Li, J. W.; Fan, Z. F.; Wang, L. F.; Liu, J.; Lan, K.; Wu, J. F.; Ye, W. H.

    2016-08-01

    A new hybrid-drive (HD) nonisobaric ignition scheme of inertial confinement fusion (ICF) is proposed, in which a HD pressure to drive implosion dynamics increases via increasing density rather than temperature in the conventional indirect drive (ID) and direct drive (DD) approaches. In this HD (combination of ID and DD) scheme, an assembled target of a spherical hohlraum and a layered deuterium-tritium capsule inside is used. The ID lasers first drive the shock to perform a spherical symmetry implosion and produce a large-scale corona plasma. Then, the DD lasers, whose critical surface in ID corona plasma is far from the radiation ablation front, drive a supersonic electron thermal wave, which slows down to a high-pressure electron compression wave, like a snowplow, piling up the corona plasma into high density and forming a HD pressurized plateau with a large width. The HD pressure is several times the conventional ID and DD ablation pressure and launches an enhanced precursor shock and a continuous compression wave, which give rise to the HD capsule implosion dynamics in a large implosion velocity. The hydrodynamic instabilities at imploding capsule interfaces are suppressed, and the continuous HD compression wave provides main pdV work large enough to hotspot, resulting in the HD nonisobaric ignition. The ignition condition and target design based on this scheme are given theoretically and by numerical simulations. It shows that the novel scheme can significantly suppress implosion asymmetry and hydrodynamic instabilities of current isobaric hotspot ignition design, and a high-gain ICF is promising.

  19. 14 CFR 29.1145 - Ignition switches.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ignition switches. 29.1145 Section 29.1145... switches. (a) Ignition switches must control each ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  20. 14 CFR 27.1145 - Ignition switches.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ignition switches. 27.1145 Section 27.1145... switches. (a) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control. (b) Each group of ignition switches, except ignition switches for...

  1. 14 CFR 27.1145 - Ignition switches.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ignition switches. 27.1145 Section 27.1145... switches. (a) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control. (b) Each group of ignition switches, except ignition switches for...

  2. 14 CFR 29.1145 - Ignition switches.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ignition switches. 29.1145 Section 29.1145... switches. (a) Ignition switches must control each ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  3. 14 CFR 29.1145 - Ignition switches.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ignition switches. 29.1145 Section 29.1145... switches. (a) Ignition switches must control each ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  4. 14 CFR 25.1145 - Ignition switches.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ignition switches. 25.1145 Section 25.1145... switches. (a) Ignition switches must control each engine ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  5. 14 CFR 27.1145 - Ignition switches.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ignition switches. 27.1145 Section 27.1145... switches. (a) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control. (b) Each group of ignition switches, except ignition switches for...

  6. 14 CFR 25.1145 - Ignition switches.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ignition switches. 25.1145 Section 25.1145... switches. (a) Ignition switches must control each engine ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  7. 14 CFR 25.1145 - Ignition switches.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ignition switches. 25.1145 Section 25.1145... switches. (a) Ignition switches must control each engine ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  8. 14 CFR 27.1145 - Ignition switches.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ignition switches. 27.1145 Section 27.1145... switches. (a) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control. (b) Each group of ignition switches, except ignition switches for...

  9. 14 CFR 29.1145 - Ignition switches.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ignition switches. 29.1145 Section 29.1145... switches. (a) Ignition switches must control each ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  10. 14 CFR 25.1145 - Ignition switches.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ignition switches. 25.1145 Section 25.1145... switches. (a) Ignition switches must control each engine ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  11. 14 CFR 27.1145 - Ignition switches.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ignition switches. 27.1145 Section 27.1145... switches. (a) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control. (b) Each group of ignition switches, except ignition switches for...

  12. 14 CFR 25.1145 - Ignition switches.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ignition switches. 25.1145 Section 25.1145... switches. (a) Ignition switches must control each engine ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  13. 14 CFR 29.1145 - Ignition switches.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ignition switches. 29.1145 Section 29.1145... switches. (a) Ignition switches must control each ignition circuit on each engine. (b) There must be means to quickly shut off all ignition by the grouping of switches or by a master ignition control....

  14. Heating a plasma by a broadband stream of fast electrons: Fast ignition, shock ignition, and Gbar shock wave applications

    SciTech Connect

    Gus’kov, S. Yu.; Nicolai, Ph.; Ribeyre, X.; Tikhonchuk, V. T.

    2015-09-15

    An exact analytic solution is found for the steady-state distribution function of fast electrons with an arbitrary initial spectrum irradiating a planar low-Z plasma with an arbitrary density distribution. The solution is applied to study the heating of a material by fast electrons of different spectra such as a monoenergetic spectrum, a step-like distribution in a given energy range, and a Maxwellian spectrum, which is inherent in laser-produced fast electrons. The heating of shock- and fast-ignited precompressed inertial confinement fusion (ICF) targets as well as the heating of a target designed to generate a Gbar shock wave for equation of state (EOS) experiments by laser-produced fast electrons with a Maxwellian spectrum is investigated. A relation is established between the energies of two groups of Maxwellian fast electrons, which are responsible for generation of a shock wave and heating the upstream material (preheating). The minimum energy of the fast and shock igniting beams as well as of the beam for a Gbar shock wave generation increases with the spectral width of the electron distribution.

  15. First Measurements of Fuel-Ablator Interface Instability Growth in Inertial Confinement Fusion Implosions on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Weber, C. R.; Döppner, T.; Casey, D. T.; Bunn, T. L.; Carlson, L. C.; Dylla-Spears, R. J.; Kozioziemski, B. J.; MacPhee, A. G.; Nikroo, A.; Robey, H. F.; Sater, J. D.; Smalyuk, V. A.

    2016-08-01

    Direct measurements of hydrodynamic instability growth at the fuel-ablator interface in inertial confinement fusion (ICF) implosions are reported for the first time. These experiments investigate one of the degradation mechanisms behind the lower-than-expected performance of early ICF implosions on the National Ignition Facility. Face-on x-ray radiography is used to measure instability growth occurring between the deuterium-tritium fuel and the plastic ablator from well-characterized perturbations. This growth starts in two ways through separate experiments—either from a preimposed interface modulation or from ablation front feedthrough. These experiments are consistent with analytic modeling and radiation-hydrodynamic simulations, which say that a moderately unstable Atwood number and convergence effects are causing in-flight perturbation growth at the interface. The analysis suggests that feedthrough from outersurface perturbations dominates the interface perturbation growth at mode 60.

  16. The measurement and analysis of wavefront structure from large aperture ICF optics

    SciTech Connect

    Wolfe, C.R.; Lawson, J.K.

    1995-05-30

    This paper discusses the techniques, developed over the past year, for high spatial resolution measurement and analysis of the transmitted and/or reflected wavefront of large aperture ICF optical components. Parts up to 400 mm {times} 750 mm have been measured and include: laser slabs, windows, KDP crystals and lenses. The measurements were performed using state-of-the-art commercial phase shifting interferometers at a wavelength of 633 {mu}m. Both 1 and 2-D Fourier analysis have been used to characterize the wavefront; specifically the Power Spectral Density, (PSD), function was calculated. The PSDs of several precision optical components will be shown. The PSD(V) is proportional to the (amplitude){sup 2} of components of the Fourier frequency spectrum. The PSD describes the scattered intensity and direction as a function of scattering angle in the wavefront. The capability of commercial software is limited to 1-D Fourier analysis only. We are developing our own 2-D analysis capability in support of work to revise specifications for NIF optics. 2-D analysis uses the entire wavefront phase map to construct 2D PSD functions. We have been able to increase the signal-to-noise relative to 1-D and can observe very subtle wavefront structure.

  17. Comparison of Hot Spot Formation in DT ice layer and DT liquid layer ICF Capsules

    NASA Astrophysics Data System (ADS)

    Olson, R. E.; Leeper, R. J.

    2013-10-01

    Simulations of the implosion and hot spot formation in two DT liquid layer ICF capsule concepts - the DT wetted CH foam concept and the ``fast formed liquid'' (FFL) concept - will be described and compared to simulations of standard DT ice layer capsules. The wetted foam and FFL designs allow for flexibility in hot spot convergence ratio through the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. 1D simulations are used to compare the drive requirements, the optimal shock timing, the radial dependence of hot spot specific energy gain, and the hot spot convergence ratio in low (DT ice) and high (DT liquid) vapor pressure capsules. 2D simulations are used to compare the relative sensitivities to low-mode x-ray flux asymmetries in the DT ice and DT liquid capsules. It is found that the overall thermonuclear yields predicted for DT liquid layer capsules will be less than yields predicted for DT ice layer capsules in simulations using comparable capsule size and absorbed energy. However, the relative simplicity of the hot spot formation technique might lead to a more robust ignition experiment, a reduction in sensitivity to low-mode x-ray flux asymmetry, and an improvement in the computational prediction of hot spot behavior. This work was performed under the auspices of the U. S. DOE by LANL under contract DE-AC52-06NA25396. Sandia is a multiprogram laboratory operated by the Sandia Corporation, a Lockheed-Martin Company, for the U.S. DOE under contract DE-AC04-94AL85000.

  18. Time-dependent nuclear measurements of fuel-shell mix in ICF implosions at OMEGA

    NASA Astrophysics Data System (ADS)

    Rygg, J. Ryan

    2006-10-01

    Fuel-shell mix remains a pivotal concern in inertial confinement fusion (ICF), as it can preclude ignition. Mix is the result of saturation of Rayleigh-Taylor (RT) instability growth at a density interface that leads to small-scale, turbulent eddies and atomic-level mixing of cool, high-density fuel in the shell with hot, low-density fuel in the core. If sufficient mixing occurs, it will disrupt the formation of the ``hot-spot'' required for ignition. To sensitively probe the evolution and extent of mix in spherical implosions, the time dependence of the D^3He nuclear reaction rate was measured from implosions of capsules filled with pure ^3He. The capsule shell was comprised of a 1-μm layer of CD inside a 19-μm layer of CH. Nuclear burn will only occur in such capsules if there is sufficient mixing of D from the shell with hot ^3He in the core. By utilizing novel D^3He reaction-rate and proton spectrometers, all sensitive to the 14.7 MeV D^3He protons, a comprehensive, time dependent picture of mix was constructed. Important qualitative features were immediately evident: first, the shock burn of D^3He, always present for gas fills of D^3He, was absent, enabling a strong limit to be set on the amount and extent of D penetration into the ^3He. Second, the time necessary for RT instabilities to induce mix and to be heated by the hot core resulted in a 90 ps delay in the D^3He bang time as compared to bang time for implosions with D^3He fills. And third, when the gas pressure of ^3He was reduced from 20 to 4 atm, the extent of mix was enhanced by about a factor of 5. This work was supported in part by LLE, LLNL, the U.S. DoE, and the N.Y. State Energy Research and Development Authority.

  19. Fast ignition of an inertial fusion target with a solid noncryogenic fuel by an ion beam

    SciTech Connect

    Gus’kov, S. Yu.; Zmitrenko, N. V.; Il’in, D. V.; Sherman, V. E.

    2015-09-15

    The burning efficiency of a preliminarily compressed inertial confinement fusion (ICF) target with a solid noncryogenic fuel (deuterium-tritium beryllium hydride) upon fast central ignition by a fast ion beam is studied. The main aim of the study was to determine the extent to which the spatial temperature distribution formed under the heating of an ICF target by ion beams with different particle energy spectra affects the thermonuclear gain. The study is based on a complex numerical modeling including computer simulations of (i) the heating of a compressed target with a spatially nonuniform density and temperature distributions by a fast ion beam and (ii) the burning of the target with the initial spatial density distribution formed at the instant of maximum compression of the target and the initial spatial temperature distribution formed as a result of heating of the compressed target by the ion beam. The threshold energy of the igniting ion beam and the dependence of the thermonuclear gain on the energy deposited in the target are determined.

  20. Plastic ablator ignition capsule design for the National Ignition Facility

    SciTech Connect

    Clark, D S; Haan, S W; Hammel, B A; Salmonson, J D; Callahan, D A; Town, R P

    2009-12-01

    The National Ignition Campaign, tasked with designing and fielding targets for fusion ignition experiments on the National Ignition Facility (NIF), has carried forward three complementary target designs for the past several years: a beryllium ablator design, a plastic ablator design, and a high-density carbon or synthetic diamond design. This paper describes current simulations and design optimization to develop the plastic ablator capsule design as a candidate for the first ignition attempt on NIF. The trade-offs in capsule scale and laser energy that must be made to achieve a comparable ignition probability to that with beryllium are emphasized. Large numbers of 1-D simulations, meant to assess the statistical behavior of the target design, as well as 2-D simulations to assess the target's susceptibility to Rayleigh-Taylor growth are presented.

  1. Plastic ablator ignition capsule design for the National Ignition Facility

    SciTech Connect

    Clark, Daniel S.; Haan, Steven W.; Hammel, Bruce A.; Salmonson, Jay D.; Callahan, Debra A.; Town, Richard P. J.

    2010-05-15

    The National Ignition Campaign, tasked with designing and fielding targets for fusion ignition experiments on the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, S228 (2004)], has carried forward three complementary target designs for the past several years: a beryllium ablator design, a plastic ablator design, and a high-density carbon or synthetic diamond design. This paper describes current simulations and design optimization to develop the plastic ablator capsule design as a candidate for the first ignition attempt on NIF. The trade-offs in capsule scale and laser energy that must be made to achieve a comparable ignition probability to that with beryllium are emphasized. Large numbers of one-dimensional simulations, meant to assess the statistical behavior of the target design, as well as two-dimensional simulations to assess the target's susceptibility to Rayleigh-Taylor growth are presented.

  2. 42 CFR 431.154 - Informal reconsideration for ICFs/MR.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Process for NFs and ICFs/MR § 431.154 Informal reconsideration for ICFs/MR. The informal reconsideration must, at a minimum, include— (a) Written notice to the facility of the denial, termination or... those findings in writing, and (c) A written affirmation or reversal of the denial, termination,...

  3. Synthesis and NMR structure of p41icf, a potent inhibitor of human cathepsin L.

    PubMed

    Chiva, Cristina; Barthe, Philippe; Codina, Anna; Gairí, Margarida; Molina, Franck; Granier, Claude; Pugnière, Martine; Inui, Tatsuya; Nishio, Hideki; Nishiuchi, Yuji; Kimura, Terutoshi; Sakakibara, Shumpei; Albericio, Fernando; Giralt, Ernest

    2003-02-12

    The total synthesis and structural characterization of the MHCII-associated p41 invariant chain fragment (P41icf) is described. P41icf plays a crucial role in the maturation of MHC class II molecules and antigen processing, acting as a highly selective cathepsin L inhibitor. P41icf synthesis was achieved using a combined solid-phase/solution approach. The entire molecule (65 residues, 7246 Da unprotected) was assembled in solution from fully protected peptides in the size range of 10 residues. After deprotection, oxidative folding in carefully adjusted experimental conditions led to the completely folded and functional P41icf with a disulfide pairing identical to that of native P41icf. CD, NMR, and surface plasmon resonance (SPR) were used for the structural and functional characterization of synthetic P41icf. CD thermal denaturation showed clear cooperative behavior. Tight cathepsin L binding was demonstrated by SPR. (1)H NMR spectroscopy at 800 MHz of unlabeled P41icf was used to solve the three-dimensional structure of the molecule. P41icf behaves as a well-folded protein domain with a topology very close to the crystallographic cathepsin L-bound form.

  4. Disability and Functional Profiles of Patients with Migraine Measured with ICF Classification

    ERIC Educational Resources Information Center

    Raggi, Alberto

    2010-01-01

    To describe the functional profiles of patients with migraine, and the relationships between symptoms, activities and environmental factors, using WHO's International Classification of Functioning (ICF). Patients were consecutively enrolled at the Besta Institute of Milan. The ICF checklist was administered and two count-based indexes developed:…

  5. The ICF: A Framework for Setting Goals for Children with Speech Impairment

    ERIC Educational Resources Information Center

    McLeod, Sharynne; Bleile, Ken

    2004-01-01

    The International Classification of Functioning, Disability and Health (ICF) (World Health Organization, 2001) is proposed as a framework for integrative goal setting for children with speech impairment. The ICF incorporates both impairment and social factors to consider when selecting appropriate goals to bring about change in the lives of…

  6. Ignition of Propellants Through Nanostructured Materials

    DTIC Science & Technology

    2016-03-31

    of conditions in order to maximize the operational flexibility of energy and propulsion systems. We have studied the ignition of liquid fuel and...different ignition requirements such as ignition energy , ignition delay, pressure, temperature, and burn duration. We also studied photo-ignition of...flexibility and cost of the igniter while also minimizing the energy needed for its initiation. Through this program, we have developed greater

  7. Influence and measurement of mass ablation in ICF implosions

    SciTech Connect

    Spears, B K; Hicks, D; Velsko, C; Stoyer, M; Robey, H; Munro, D; Haan, S; Landen, O; Nikroo, A; Huang, H

    2007-09-05

    Point design ignition capsules designed for the National Ignition Facility (NIF) currently use an x-ray-driven Be(Cu) ablator to compress the DT fuel. Ignition specifications require that the mass of unablated Be(Cu), called residual mass, be known to within 1% of the initial ablator mass when the fuel reaches peak velocity. The specifications also require that the implosion bang time, a surrogate measurement for implosion velocity, be known to +/- 50 ps RMS. These specifications guard against several capsule failure modes associated with low implosion velocity or low residual mass. Experiments designed to measure and to tune experimentally the amount of residual mass are being developed as part of the National Ignition Campaign (NIC). Tuning adjustments of the residual mass and peak velocity can be achieved using capsule and laser parameters. We currently plan to measure the residual mass using streaked radiographic imaging of surrogate tuning capsules. Alternative techniques to measure residual mass using activated Cu debris collection and proton spectrometry have also been developed. These developing techniques, together with bang time measurements, will allow us to tune ignition capsules to meet NIC specs.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Interpreting Shock Tube Ignition Data

    DTIC Science & Technology

    2003-10-01

    times only for high concentrations (of order 1% fuel or greater). The requirements of engine (IC, HCCI , CI and SI) modelers also present a different...Paper 03F-61 Interpreting Shock Tube Ignition Data D. F. Davidson and R. K. Hanson Mechanical Engineering ... Engineering Department Stanford University, Stanford CA 94305 Abstract Chemical kinetic modelers make extensive use of shock tube ignition data

  10. Rocket Ignition Demonstrations Using Silane

    NASA Technical Reports Server (NTRS)

    Pal, Sibtosh; Santoro, Robert; Watkins, William B.; Kincaid, Kevin

    1998-01-01

    Rocket ignition demonstration tests using silane were performed at the Penn State Combustion Research Laboratory. A heat sink combustor with one injection element was used with gaseous propellants. Mixtures of silane and hydrogen were used as fuel, and oxygen was used as oxidizer. Reliable ignition was demonstrated using fuel lead and and a swirl injection element.

  11. Plasma jet ignition device

    DOEpatents

    McIlwain, Michael E.; Grant, Jonathan F.; Golenko, Zsolt; Wittstein, Alan D.

    1985-01-15

    An ignition device of the plasma jet type is disclosed. The device has a cylindrical cavity formed in insulating material with an electrode at one end. The other end of the cylindrical cavity is closed by a metal plate with a small orifice in the center which plate serves as a second electrode. An arc jumping between the first electrode and the orifice plate causes the formation of a highly-ionized plasma in the cavity which is ejected through the orifice into the engine cylinder area to ignite the main fuel mixture. Two improvements are disclosed to enhance the operation of the device and the length of the plasma plume. One improvement is a metal hydride ring which is inserted in the cavity next to the first electrode. During operation, the high temperature in the cavity and the highly excited nature of the plasma breaks down the metal hydride, liberating hydrogen which acts as an additional fuel to help plasma formation. A second improvement consists of a cavity insert containing a plurality of spaced, metal rings. The rings act as secondary spark gap electrodes reducing the voltage needed to maintain the initial arc in the cavity.

  12. 42 CFR 442.117 - Termination of certification for ICFs/IID whose deficiencies pose immediate jeopardy.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Termination of certification for ICFs/IID whose deficiencies pose immediate jeopardy. 442.117 Section 442.117 Public Health CENTERS FOR MEDICARE & MEDICAID... DISABILITIES Certification of ICFs/IID § 442.117 Termination of certification for ICFs/IID whose...

  13. 42 CFR 442.117 - Termination of certification for ICFs/MR whose deficiencies pose immediate jeopardy.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Termination of certification for ICFs/MR whose deficiencies pose immediate jeopardy. 442.117 Section 442.117 Public Health CENTERS FOR MEDICARE & MEDICAID... ICFs/MR § 442.117 Termination of certification for ICFs/MR whose deficiencies pose immediate...

  14. Content comparison of haemophilia specific patient-rated outcome measures with the international classification of functioning, disability and health (ICF, ICF-CY)

    PubMed Central

    2010-01-01

    Background Patient-Reported Outcomes (PROs) are considered important outcomes because they reflect the patient's experience in clinical trials. PROs have been included in the field of haemophilia only recently. Purpose Comparing the contents of PROs measures used in haemophilia, based on the ICF/ICF-CY as frame of reference. Methods Haemophilia-specific PROs for adults and children were selected on the grounds of international accessibility. The content of the selected instruments were examined by linking the concepts within the items of these instruments to the ICF/ICF-CY. Results Within the 5 selected instruments 365 concepts were identified, of which 283 concepts were linked to the ICF/ICF CY and mapped into 70 different categories. The most frequently used categories were "b152: Emotional functions" and "e1101: Drugs". Conclusions The present paper provides an overview on current PROs in haemophilia and facilitates the selection of appropriate instruments for specific purposes in clinical and research settings. This work was made possible by the grant of the European Murinet Project (Multidisciplinary Research Network on Health and Disability in Europe). PMID:21108796

  15. Kinetic studies of ICF target dynamics with ePLAS

    NASA Astrophysics Data System (ADS)

    Mason, R. J.

    2016-10-01

    The ePLAS code was recently used1 to show that a modeling change from artificial to real viscosity can result in a decrease of the predicted performance of ICF targets. This code typically follows either fluid or PIC electrons with fluid ions in self-consistent E - and B - fields computed by the Implicit Moment Method2. For the present study the ions have instead been run as PIC particles undergoing Krook-like self-collisions. The ePLAS collision model continually redistributes the ion particle properties toward a local Maxwellian, while conserving the mean density, momentum and energy. Whereas the use of real viscosity captures large Knudsen Number effects as the active target dimensions shrink below the ion mean-free-path, the new kinetic modeling can manifest additional effects such as collisional shock precursors3 from the escape and streaming of the fastest particle ions. In 2D cylindrical geometry we will explore how such kinetic shock extensions might affect shell and core compression dynamics in ICF target implosions.

  16. Field precision machining technology of target chamber in ICF lasers

    NASA Astrophysics Data System (ADS)

    Xu, Yuanli; Wu, Wenkai; Shi, Sucun; Duan, Lin; Chen, Gang; Wang, Baoxu; Song, Yugang; Liu, Huilin; Zhu, Mingzhi

    2016-10-01

    In ICF lasers, many independent laser beams are required to be positioned on target with a very high degree of accuracy during a shot. The target chamber provides a precision platform and datum reference for final optics assembly and target collimation and location system. The target chamber consists of shell with welded flanges, reinforced concrete pedestal, and lateral support structure. The field precision machining technology of target chamber in ICF lasers have been developed based on ShenGuangIII (SGIII). The same center of the target chamber is adopted in the process of design, fabrication, and alignment. The technologies of beam collimation and datum reference transformation are developed for the fabrication, positioning and adjustment of target chamber. A supporting and rotating mechanism and a special drilling machine are developed to bore the holes of ports. An adjustment mechanism is designed to accurately position the target chamber. In order to ensure the collimation requirements of the beam leading and focusing and the target positioning, custom-machined spacers are used to accurately correct the alignment error of the ports. Finally, this paper describes the chamber center, orientation, and centering alignment error measurements of SGIII. The measurements show the field precision machining of SGIII target chamber meet its design requirement. These information can be used on similar systems.

  17. Stability design of support systems in ICF lasers

    NASA Astrophysics Data System (ADS)

    Zhu, M. Z.; Wu, W. K.; Chen, G.; Zhan, H.; Xu, Y. L.; Chen, X. J.

    2016-10-01

    Within Inertial Confinement Fusion (ICF) laser systems, many independent laser beams are required to be positioned on target with a very high degree of accuracy until shots are complete. Optical elements that are capable of moving a laser beam on the target must meet the pointing error budget. Optical elements are typically supported by systems which consist of mounts, mount frames, support structures, and foundation. The stability design for support systems in ICF laser have been developed based on the designing and evaluating experience of ShenGuangIII (SGIII). This paper will provide the methodology of position error budget. The stability allocation is developed for evaluating the performance of support systems when they are subjected to multiple sources of excitations that can cause the motion of optical elements during alignment procedures and before shots. The vibrational stability design considerations of support systems are discussed on the fundamental frequency, ambient random vibration, and modal damping. The support structures of optical elements are the relatively large and massive hybrid structure of reinforced concrete and steel frame or vessels. While the reinforced concrete portions provide optical elements stability, the steel portions afford design flexibility. Finite element analyses of ambient random vibration are typically performed to evaluate the vibrational stability performances of support systems. Finally, this paper describes the ambient random vibration and beam pointing error measurements of SGIII. The measurements show the support systems of SGIII meet design requirement. These information can be used on similar systems.

  18. Opacity spectra of silicon and carbon in ICF plasmas

    NASA Astrophysics Data System (ADS)

    Benredjem, D.; Calisti, A.; Ferri, S.; Gilleron, F.; Mondet, G.; Pain, J.-C.

    2017-03-01

    The knowledge of opacity is very important when one investigates the radiative properties of ICF and astrophysical plasmas. Germanium and silicon are good candidates as dopants in the ablator of some ICF schemes (LMJ in France, NIF at Livermore). In this work we calculate the opacity spectra of silicon and carbon mixtures. Two competitive methods were used. The first one is based on a detailed line calculation in which the atomic database is provided by the MCDF code. A lineshape code based on a fast algorithm was then adapted to the calculation of opacity profiles. All major line broadening mechanisms, including Zeeman splitting and Stark effect, are taken into account. This approach provides accurate opacity spectra but becomes rapidly prohibitive when the number of lines is large. To account for systems involving many ionic stages and thousands of lines, a second approach combines detailed line calculations and statistical calculations. This approach necessitates much smaller calculation times than the first one and is then more appropriate for extensive calculations. The monochromatic opacity and the Rosseland and Planck mean opacities are calculated for relevant densities and temperatures.

  19. Ignition process in Diesel engines

    NASA Technical Reports Server (NTRS)

    Wentzel, W

    1936-01-01

    This report analyzes the heating and vaporization process of fuel droplets in a compression-ignition engine on the basis of the theory of similitude - according to which, the period for heating and complete vaporization of the average size fuel drop is only a fraction of the actually observed ignition lag. The result is that ignition takes place in the fuel vapor air mixture rather than on the surface of the drop. The theoretical result is in accord with the experimental observations by Rothrock and Waldron. The combustion shock occurring at lower terminal compression temperature, especially in the combustion of coal-tar oil, is attributable to a simultaneous igniting of a larger fuel-vapor volume formed prior to ignition.

  20. Interaction of a self-focused laser beam with a DT fusion target in a plasma-loaded cone-guided ICF scheme

    NASA Astrophysics Data System (ADS)

    Saedjalil, N.; Mehrangiz, M.; Jafari, S.; Ghasemizad, A.

    2016-06-01

    In this paper, the interaction of a self-focused laser beam with a DT fusion target in a plasma-loaded cone-guided ICF scheme has been presented. We propose here to merge a plasma-loaded cone with the precompressed DT target in order to strongly focus the incident laser beam on the core to improve the fusion gain. The WKB approximation is used to derive a differential equation that governs the evolution of beamwidth of the incident laser beam with the distance of propagation in the plasma medium. The effects of initial plasma and laser parameters, such as initial plasma electron temperature, initial radius of the laser beam, initial laser beam intensity and plasma density, on self-focusing and defocusing of the Gaussian laser beam have been studied. Numerical results indicate that with increasing the plasma frequency (or plasma density) in the cone, the laser beam will be self-focused noticeably, while for a thinner laser beam (with small radius), it will diverge as propagate in the cone. By evaluating the energy deposition of the relativistic electron ignitors in the fuel, the importance of electron transportation in the cone-attached shell was demonstrated. Moreover, by lessening the least energy needed for ignition, the electrons coupling with the pellet enhances. Therefore, it increases the fusion efficiency. In this scheme, with employing a plasma-loaded cone, the fusion process improves without needing an ultrahigh-intensity laser beam in a conventional ICF.

  1. Investigation of gamma-ray time shifts caused by capsule areal density variations in inertial confinement fusion experiments at the national ignition facility and the omega facility

    NASA Astrophysics Data System (ADS)

    Grafil, Elliot M.

    This thesis describes work on Cherenkov based gamma detectors used as diag- nostics at Inertial Confinement Fusion (ICF) facilities. The first part describes the calibration and commissioning of the Gamma Reaction History diagnostic which is a four cell Cherenkov detector array used to characterize the ICF implosion at the National Ignition Facility (NIF) by measuring the gamma rays generated during the fusion event. Two of the key metrics which the GRH measures are Gamma Bang Time (GBT) generated from the D(T,α)n thermonuclear burn and Ablator Peak Time (APT) caused by (n,n‧)gamma reactions in the surrounding capsule ablator. Simulations of ignition capsules predict that GBT and APT should be time synchronized. After GRH commissioning, the array was used during first year of NIF operation in the National Ignition Campaign. Contrary to expectations, time shifts between GBT and APT of order 10s of picoseconds were observed. In order to further investigate the possibility of these time shifts in view of testing both instrument and code credibility an ICF shot campaign at the smaller OMEGA facility in Rochester was devised. It was performed during two full shot days in April of 2013 and 2014 and confirmed in principle the viability of the Cherenkov detector approach but raised additional questions regarding the credibility of the simulation codes used to describe ICF experiments. Specifically the measurements show that the understanding of temporal behavior of GBT vs APT may not be properly modeled in the DRACO code used at OMEGA. In view of the OMEGA results which showed no time shifts between GBT and APT, the readout and timing synchronization system of the GRH setup at the NIF was reevaluated in the framework of this thesis. Motivated by the results, which highlighted the use of wrong optical fiber diameters and possible problems with the installed variable optical attenuators, the NIF equipment has been updated over the recent months and new timing tests will

  2. Plasma Igniter for Reliable Ignition of Combustion in Rocket Engines

    NASA Technical Reports Server (NTRS)

    Martin, Adam; Eskridge, Richard

    2011-01-01

    A plasma igniter has been developed for initiating combustion in liquid-propellant rocket engines. The device propels a hot, dense plasma jet, consisting of elemental fluorine and fluorine compounds, into the combustion chamber to ignite the cold propellant mixture. The igniter consists of two coaxial, cylindrical electrodes with a cylindrical bar of solid Teflon plastic in the region between them. The outer electrode is a metal (stainless steel) tube; the inner electrode is a metal pin (mild steel, stainless steel, tungsten, or thoriated-tungsten). The Teflon bar fits snugly between the two electrodes and provides electrical insulation between them. The Teflon bar may have either a flat surface, or a concave, conical surface at the open, down-stream end of the igniter (the igniter face). The igniter would be mounted on the combustion chamber of the rocket engine, either on the injector-plate at the upstream side of the engine, or on the sidewalls of the chamber. It also might sit behind a valve that would be opened just prior to ignition, and closed just after, in order to prevent the Teflon from melting due to heating from the combustion chamber.

  3. Piezoelectrically Initiated Pyrotechnic Igniter

    NASA Technical Reports Server (NTRS)

    Quince, Asia; Dutton, Maureen; Hicks, Robert; Burnham, Karen

    2013-01-01

    This innovation consists of a pyrotechnic initiator and piezoelectric initiation system. The device will be capable of being initiated mechanically; resisting initiation by EMF, RF, and EMI (electromagnetic field, radio frequency, and electromagnetic interference, respectively); and initiating in water environments and space environments. Current devices of this nature are initiated by the mechanical action of a firing pin against a primer. Primers historically are prone to failure. These failures are commonly known as misfires or hang-fires. In many cases, the primer shows the dent where the firing pin struck the primer, but the primer failed to fire. In devices such as "T" handles, which are commonly used to initiate the blowout of canopies, loss of function of the device may result in loss of crew. In devices such as flares or smoke generators, failure can result in failure to spot a downed pilot. The piezoelectrically initiated ignition system consists of a pyrotechnic device that plugs into a mechanical system (activator), which on activation, generates a high-voltage spark. The activator, when released, will strike a stack of electrically linked piezo crystals, generating a high-voltage, low-amperage current that is then conducted to the pyro-initiator. Within the initiator, an electrode releases a spark that passes through a pyrotechnic first-fire mixture, causing it to combust. The combustion of the first-fire initiates a primary pyrotechnic or explosive powder. If used in a "T" handle, the primary would ramp the speed of burn up to the speed of sound, generating a shock wave that would cause a high explosive to go "high order." In a flare or smoke generator, the secondary would produce the heat necessary to ignite the pyrotechnic mixture. The piezo activator subsystem is redundant in that a second stack of crystals would be struck at the same time with the same activation force, doubling the probability of a first strike spark generation. If the first

  4. Plastic ablator ignition capsule design for the National Ignition Facility

    SciTech Connect

    Clark, D S; Haan, S W; Hammel, B A; Salmonson, J D; Callahan, D A; Town, R J

    2009-10-06

    This paper describes current efforts to develop a plastic ablator capsule design for the first ignition attempt on the National Ignition Facility. The trade-offs in capsule scale and laser energy that must be made to achieve ignition probabilities comparable to those with other candidate ablators, beryllium and high-density carbon, are emphasized. Large numbers of 1-D simulations, meant to assess the statistical behavior of the target design, as well as 2-D simulations to assess the target's susceptibility to Rayleigh-Taylor growth are discussed.

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

    SciTech Connect

    Brown, Jr., Charles G.

    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.

  6. Contractual Revision.

    ERIC Educational Resources Information Center

    Engel, Mary F.; Sawyer, Thomas M.

    Contractual revision promotes cooperation between teachers and tutors and, being student initiated, provides a method to increase student control over the revision process and encourage students to communicate their strengths and weaknesses in writing to their teachers or tutors. The contractual revision process requires students to form contracts…

  7. Frictional ignition with coal mining

    SciTech Connect

    Courtney, W.G.

    1990-01-01

    This paper reviews recent U.S. Bureau of Mine studies of frictional ignition of a methane-air environment by coal mining bits cutting into sandstone and the effectiveness of remedial techniques to reduce the likelihood of frictional ignition. Frictional ignition with a minim bit always involves a worn bit having a wear flat on the tip of the bit. The worn bit forms hot spots on the surface of the sandstone because of frictional abrasion. The hot spots then can ignite the methane-air environment. A small wear flat forms a small hot spot, which does not give ignition, while a large wear flat forms a large hot spot, which gives ignition. The likelihood of frictional ignition can be somewhat reduced by using a mushroom-shaped tungsten-carbide bit tip on the mining bit and by increasing the bit clearance angle; it can be significantly reduced by using a water spray nozzle in back of each bit, which is carefully oriented to direct the water spray onto the sandstone surface directly behind the bit and thereby cool the hot spots formed by the worn bit. A bit replacement schedule must be used to avoid the formation of a dangerously worn bit.

  8. Clinical application of ICF key codes to evaluate patients with dysphagia following stroke.

    PubMed

    Dong, Yi; Zhang, Chang-Jie; Shi, Jie; Deng, Jinggui; Lan, Chun-Na

    2016-09-01

    This study was aimed to identify and evaluate the International Classification of Functioning (ICF) key codes for dysphagia in stroke patients. Thirty patients with dysphagia after stroke were enrolled in our study. To evaluate the ICF dysphagia scale, 6 scales were used as comparisons, namely the Barthel Index (BI), Repetitive Saliva Swallowing Test (RSST), Kubota Water Swallowing Test (KWST), Frenchay Dysarthria Assessment, Mini-Mental State Examination (MMSE), and the Montreal Cognitive Assessment (MoCA). Multiple regression analysis was performed to quantitate the relationship between the ICF scale and the other 7 scales. In addition, 60 ICF scales were analyzed by the least absolute shrinkage and selection operator (LASSO) method. A total of 21 ICF codes were identified, which were closely related with the other scales. These included 13 codes from Body Function, 1 from Body Structure, 3 from Activities and Participation, and 4 from Environmental Factors. A topographic network map with 30 ICF key codes was also generated to visualize their relationships. The number of ICF codes identified is in line with other well-established evaluation methods. The network topographic map generated here could be used as an instruction tool in future evaluations. We also found that attention functions and biting were critical codes of these scales, and could be used as treatment targets.

  9. Clinical application of ICF key codes to evaluate patients with dysphagia following stroke

    PubMed Central

    Dong, Yi; Zhang, Chang-Jie; Shi, Jie; Deng, Jinggui; Lan, Chun-Na

    2016-01-01

    Abstract This study was aimed to identify and evaluate the International Classification of Functioning (ICF) key codes for dysphagia in stroke patients. Thirty patients with dysphagia after stroke were enrolled in our study. To evaluate the ICF dysphagia scale, 6 scales were used as comparisons, namely the Barthel Index (BI), Repetitive Saliva Swallowing Test (RSST), Kubota Water Swallowing Test (KWST), Frenchay Dysarthria Assessment, Mini-Mental State Examination (MMSE), and the Montreal Cognitive Assessment (MoCA). Multiple regression analysis was performed to quantitate the relationship between the ICF scale and the other 7 scales. In addition, 60 ICF scales were analyzed by the least absolute shrinkage and selection operator (LASSO) method. A total of 21 ICF codes were identified, which were closely related with the other scales. These included 13 codes from Body Function, 1 from Body Structure, 3 from Activities and Participation, and 4 from Environmental Factors. A topographic network map with 30 ICF key codes was also generated to visualize their relationships. The number of ICF codes identified is in line with other well-established evaluation methods. The network topographic map generated here could be used as an instruction tool in future evaluations. We also found that attention functions and biting were critical codes of these scales, and could be used as treatment targets. PMID:27661012

  10. Ignition of Hydrogen Balloons by Model-Rocket-Engine Igniters.

    ERIC Educational Resources Information Center

    Hartman, Nicholas T.

    2003-01-01

    Describes an alternative method for exploding hydrogen balloons as a classroom demonstration. Uses the method of igniting the balloons via an electronic match. Includes necessary materials to conduct the demonstration and discusses potential hazards. (SOE)

  11. Content Validity of the Comprehensive ICF Core Set for Chronic Obstructive Pulmonary Diseases: An International Delphi Survey

    PubMed Central

    Jobst, Andrea; Kirchberger, Inge; Cieza, Alarcos; Stucki, Gerold; Stucki, Armin

    2013-01-01

    Introduction: The “Comprehensive ICF Core Set for Chronic Obstructive Pulmonary Diseases (COPD)“ is an application of the International Classification of Functioning, Disability and Health (ICF) and represents the typical spectrum of problems in functioning of patients with COPD. The objective of this study was to validate this ICF Core Set from the perspective of physicians. Materials and Methodology: Physicians experienced in COPD treatment were asked about the patients’ problems treated by physicians in patients with COPD in a three-round electronic mail survey using the Delphi technique. Responses were linked to the ICF. Results: Seventy-six physicians in 44 countries gave a total of 1330 responses that were linked to 148 different ICF categories. Nine ICF categories were not represented in the Comprehensive ICF Core Set for COPD although at least 75% of the participants have rated them as important. Nineteen concepts were linked to the not yet developed ICF component personal factors and seventeen concepts were not covered by the ICF. Conclusion: The high percentage of ICF categories represented in the ICF Core Set for COPD indicates satisfactory content validity from the perspective of the physicians. However, some issues were raised that were not covered and need to be investigated further. PMID:23730367

  12. Turbostar: an ICF reactor using both direct and thermal power conversion. Revision 1

    SciTech Connect

    Pitts, J.H.

    1986-07-31

    Combining direct and thermal power conversion results in a 52% gross plant efficiency with DT fuel and 68% with advanced DD fuel. We maximize the fraction of fusion-yield energy converted to kinetic energy in a liquid-lithium blanket, and use this energy directly with turbine generators to produce electricity. We use the remainder of the energy to produce electricity in a standard Rankine thermal power conversion cycle.

  13. ICF Based Comprehensive Evaluation for Post-Acute Spinal Cord Injury

    PubMed Central

    Nam, Hyung Seok; Kim, Kwang Dong

    2012-01-01

    Objective To evaluate the feasibility of the ICF for initial comprehensive evaluation of early post-acute spinal cord injury. Method A comprehensive evaluation of 62 early post-acute spinal cord injury (SCI) patients was conducted by rehabilitation team members, such as physicians, physical therapists, occupational therapists, nutritionists, medical social-workers, and nurses. They recorded each of their evaluation according to the ICF first level classification. The contents of the comprehensive evaluation were linked to the ICF second level categories, retrospectively. The linked codes were analyzed descriptively and were also compared with the brief ICF core set for early post-acute SCI. Results In the evaluation of early post-acute SCI patients based on the ICF first level categories, 19 items from the body functions domain, such as muscle power functions (b730) and urination functions (b620), 15 items from the body structures domain, including spinal cord and related structures (s120), 11 items from the activities and participation domain, such as transferring oneself (d420) and walking (d450), and 9 items from the environmental factors domain, e.g., health professionals (e355), were linked to the ICF second level categories. In total, 82.4% of all contents were linked to the brief ICF core set. Prognosis insight, a personal factor not linkable to an ICF code, was mentioned in 29.0% of all patients. Conclusion First level ICF categories can provide a structural base for a comprehensive evaluation in early post-acute spinal cord injury. However, frequently linked items, including the brief core set, as well as personal factors should be considered via a checklist in order to prevent the omission of significant contents. PMID:23342313

  14. Generation of Nonlinear Force Driven Blocks from Skin Layer Interaction of Petawatt-Picosecond Laser Pulses for ICF

    NASA Astrophysics Data System (ADS)

    Heinrich, Hora; Cang, Yu; He, Xiantu; Zhang, Jie; F, Osman; J, Badziak; F, P. Boody; S, Gammino; R, Höpfl; K, Jungwirth; B, Kralikova; J, Kraska; L, Laska; Liu, Hong; G, H. Miley; P, Parys; Peng, Hansheng; M, Pfeifer; K, Rohlena; J, Skala; Z, Skladanowski; L, Torrisi; J, Ullschmied; J, Wolowski; Zhang, Weiyan

    2004-02-01

    The discovery of the essential difference of maximum ion energy for TW - ps laser plasma interaction compared with the 100 ns laser pulses [1] led to the theory of a skin layer model [2] where the control of prepulses suppressed the usual relativistic self-focusing. The subsequent generation of two nonlinear force driven blocks has been demonstrated experimentally and in extensive numerical studies where one block moves against the laser light and the other block into the irradiated target. These blocks of nearly solid state density DT plasma correspond to ion beam current densities [3] exceeding 1010 A/cm2 where the ion velocity can be chosen up to highly relativistic values. Using the results of the expected ignition of DT fuel by light ion beams, a self-sustained fusion reaction front may be generated even into uncompressed solid DT fuel similar to the Nuckolls-Wood [4] scheme where 10 kJ laser pulses produce 100 MJ fusion energy. This new and simplified scheme of laser-ICF needs and optimisation of the involved parameters.

  15. Sol-gel optical thin films for an advanced megajoule-class Nd:glass laser ICF-driver

    SciTech Connect

    Floch, H.G.; Belleville, P.F.; Pegon, P.M.; Dijonneau, C.S.; Guerain, J.

    1995-12-31

    It is well established by manufacturers and users that optical coatings are generally prepared by the well known Physical Vapor Deposition (PVD) technology. In the authors` opinion sol-gel technology is an effective and competitive alternative. The aim of this paper is to emphasize on the sol-gel thin film work carried out at Centre d`Etudes de Limeil-Valenton (CEL-V) and concerning the technology for high power lasers. The authors will briefly discuss the chemistry of the sol-gel process, the production of optical coatings and the related deposition techniques. Finally, the paper describes the preparation and performance of sol-gel optical coatings they have developed to fulfill the requirements of a future 2 MJ/500 TW (351 nm) pulsed Nd:glass laser so-called LMJ (Laser MegaJoules). This powerful laser is to be used for their national Inertial Confinement Fusion (ICF) program, to demonstrate at the laboratory scale, ignition of deuterium-tritium fusion fuel. Moreover, the aim of this article is, hopefully, to provide a convincing argument that coatings and particularly optical coatings, are some of the useful products available from sol-gel technology, and that exciting developments in other areas are almost certain to emerge within the coming decade.

  16. Dynamics of a Z Pinch X Ray Source for Heating ICF Relevant Hohlraums to 120-160eV

    SciTech Connect

    SANFORD,THOMAS W. L.; OLSON,RICHARD E.; MOCK,RAYMOND CECIL; CHANDLER,GORDON A.; LEEPER,RAMON J.; NASH,THOMAS J.; RUGGLES,LAURENCE E.; SIMPSON,WALTER W.; STRUVE,KENNETH W.; PETERSON,D.L.; BOWERS,R.L.; MATUSKA,W.

    2000-07-10

    A z-pinch radiation source has been developed that generates 60 {+-} 20 KJ of x-rays with a peak power of 13 {+-} 4 TW through a 4-mm diameter axial aperture on the Z facility. The source has heated NIF (National Ignition Facility)-scale (6-mm diameter by 7-mm high) hohlraums to 122 {+-} 6 eV and reduced-scale (4-mm diameter by 4-mm high) hohlraums to 155 {+-} 8 eV -- providing environments suitable for indirect-drive ICF (Inertial Confinement Fusion) studies. Eulerian-RMHC (radiation-hydrodynamics code) simulations that take into account the development of the Rayleigh-Taylor instability in the r-z plane provide integrated calculations of the implosion, x-ray generation, and hohlraum heating, as well as estimates of wall motion and plasma fill within the hohlraums. Lagrangian-RMHC simulations suggest that the addition of a 6 mg/cm{sup 3} CH{sub 2} fill in the reduced-scale hohlraum decreases hohlraum inner-wall velocity by {approximately}40% with only a 3--5% decrease in peak temperature, in agreement with measurements.

  17. Sol-gel optical thin films for an advanced megajoule-class Nd:glass laser ICF driver

    NASA Astrophysics Data System (ADS)

    Floch, Herve G.; Belleville, Philippe F.; Pegon, Philippe M.; Dijonneau, Corinne S.; Guerain, Jacques R.

    1995-12-01

    It is well established by manufacturers and users that optical coatings are generally prepared by the well known physical vapor deposition (PVD) technology. In the authors' opinion sol-gel technology is an effective and competitive alternative. The aim of this paper is to emphasize the sol-gel thin film work carried out at Centre d'Etudes de Limeil-Valenton (CEL-V) and concerning the technology for high power lasers. We briefly discuss the chemistry of the sol- gel process, the production of optical coatings, and the related deposition techniques. Finally, the paper describes the preparation and performance of sol-gel optical coatings we have developed to fulfill the requirements of a future 2 MJ/500 TW (351 nm) pulsed Nd:glass laser so-called LMJ (Laser MegaJoules). This powerful laser is to be used for our national inertial confinement fusion (ICF) program, to demonstrate at the laboratory scale, ignition of deuterium-tritium fusion fuel. Moreover, the aim of this article is, hopefully, to provide a convincing argument that coatings and particularly optical coatings, are some of the useful products available from sol-gel technology , and that exciting developments in other areas are almost certain to emerge within the coming decade.

  18. 75 FR 56491 - Technical Amendments for Marine Spark-Ignition Engines and Vessels

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... AGENCY 40 CFR Part 1060 RIN 2060-AQ18 Technical Amendments for Marine Spark-Ignition Engines and Vessels... tanks that will allow for this solution. Specifically, we are proposing to revise the text in Sec. 1060...). See 42 U.S.C. 7607(d). List of Subjects in 40 CFR Part 1060 Environmental protection, Air...

  19. 78 FR 26849 - Model Specifications for Breath Alcohol Ignition Interlock Devices (BAIIDs)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-08

    ...This notice revises the Model Specifications for Breath Alcohol Ignition Interlock Devices (BAIIDs). The Model Specifications are guidelines for the performance and uniform testing of BAIIDs. These devices are designed to prevent a driver from starting a motor vehicle when the driver's breath alcohol concentration (BrAC) is at or above a set alcohol level. Every State in the United States has......

  20. Flux-limitation of the Nernst effect in magnetized ICF

    NASA Astrophysics Data System (ADS)

    Ridgers, Christopher; Barrois, Rion; Wengraf, Joshua; Bissell, John; Brodrick, Jonathan; Kingham, Robert; Read, Martin

    2016-10-01

    Magnetized ICF is a promising scheme which combines the advantages of magnetic and inertial confinement fusion. In the relevant high-energy density plasmas magnetic field evolution is often controlled by the Nernst effect where the magnetic field advects with the electron heat flow. It is well known that non-local thermal transport necessitates a flux-limiter on the heat flow. This suggests that a flux-limiter should also be applied to the Nernst effect. We have shown that this is the case using Vlasov-Fokker-Planck simulations and that the flux-limter is not the same as that required for the heat flow itself, for example when a NIF-relevant flux-limiter of 0.15 is required to limit the heat flow a Nernst flux limiter of 0.08 is required. We acknowledge support from EPSRC Grant No. EPM011372/1.

  1. Monte Carlo Methods in ICF (LIRPP Vol. 13)

    NASA Astrophysics Data System (ADS)

    Zimmerman, George B.

    2016-10-01

    Monte Carlo methods appropriate to simulate the transport of x-rays, neutrons, ions and electrons in Inertial Confinement Fusion targets are described and analyzed. The Implicit Monte Carlo method of x-ray transport handles symmetry within indirect drive ICF hohlraums well, but can be improved SOX in efficiency by angular biasing the x-rays towards the fuel capsule. Accurate simulation of thermonuclear burn and burn diagnostics involves detailed particle source spectra, charged particle ranges, inflight reaction kinematics, corrections for bulk and thermal Doppler effects and variance reduction to obtain adequate statistics for rare events. It is found that the effects of angular Coulomb scattering must be included in models of charged particle transport through heterogeneous materials.

  2. Behavior of liquid hydrogen inside an ICF target

    NASA Technical Reports Server (NTRS)

    Kim, K.; Mok, L.; Bernat, T.

    1982-01-01

    The configuration of liquid hydrogen inside spherical glass shell ICF target was studied both theoretically and experimentally. Because of the zero contact angle between the .D2 liquid and glass substrate and the limited wetting surface that is continuous, the liquid hydrogen completely covers the interior of the glass shell, resulting in the formation of a void at the center. For this reason, the present problem distinguishes itself from that for a sessile drop sitting on a flat surface. A theory was formulated to calculate the liquid hydrogen configuration by including the London-dispersion force between the liquid and the substrate molecules. The net result is an augmented Bashforth-Adams equation appropriate to a spherical substrate, which is considered to be the major contribution of the present work. Preliminary calculations indicate that this equation accurately models the liquid hydrogen behavior inside a spherical microshell.

  3. Improved algorithm of ray tracing in ICF cryogenic targets

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Yang, Yongying; Ling, Tong; Jiang, Jiabin

    2016-10-01

    The high precision ray tracing inside inertial confinement fusion (ICF) cryogenic targets plays an important role in the reconstruction of the three-dimensional density distribution by algebraic reconstruction technique (ART) algorithm. The traditional Runge-Kutta methods, which is restricted by the precision of the grid division and the step size of ray tracing, cannot make an accurate calculation in the case of refractive index saltation. In this paper, we propose an improved algorithm of ray tracing based on the Runge-Kutta methods and Snell's law of refraction to achieve high tracing precision. On the boundary of refractive index, we apply Snell's law of refraction and contact point search algorithm to ensure accuracy of the simulation. Inside the cryogenic target, the combination of the Runge-Kutta methods and self-adaptive step algorithm are employed for computation. The original refractive index data, which is used to mesh the target, can be obtained by experimental measurement or priori refractive index distribution function. A finite differential method is performed to calculate the refractive index gradient of mesh nodes, and the distance weighted average interpolation methods is utilized to obtain refractive index and gradient of each point in space. In the simulation, we take ideal ICF target, Luneberg lens and Graded index rod as simulation model to calculate the spot diagram and wavefront map. Compared the simulation results to Zemax, it manifests that the improved algorithm of ray tracing based on the fourth-order Runge-Kutta methods and Snell's law of refraction exhibits high accuracy. The relative error of the spot diagram is 0.2%, and the peak-to-valley (PV) error and the root-mean-square (RMS) error of the wavefront map is less than λ/35 and λ/100, correspondingly.

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

    SciTech Connect

    Yi, S. A. Simakov, A. N.; Wilson, D. C.; Olson, R. E.; Kline, J. L.; Batha, S. H.; Clark, D. S.; Hammel, B. A.; Milovich, J. L.; Salmonson, J. D.; Kozioziemski, B. J.

    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.

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

    SciTech Connect

    Lazaro, M.A.; Vinikour, W.; Allison, T.

    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.

  6. National Ignition Campaign Hohlraum Energetics

    SciTech Connect

    Meezan, N B; Atherton, L J; Callahan, D A; Dewald, E L; Dixit, S N; Dzenitis, E G; Edwards, M J; Haynam, C A; Hinkel, D E; Jones, O S; Landen, O; London, R A; Michel, P A; Moody, J D; Milovich, J L; Schneider, M B; Thomas, C A; Town, R J; Warrick, A L; Weber, S V; Widmann, K; Glenzer, S H; Suter, L J; MacGowan, B J; Kline, J L; Kyrala, G A; Nikroo, A

    2009-11-16

    The first series of experiments on the National Ignition Facility (NIF) [E. I. Moses, R. N. Boyd, B. A. Remington, C. J. Keane, and R. Al-Ayat, 'The National Ignition Facility: ushering in a new age for high energy density science,' Phys. Plasmas 16, 041006 (2009)] tested ignition hohlraum 'energetics,' a term described by four broad goals: (1) Measurement of laser absorption by the hohlraum; (2) Measurement of the x-ray radiation flux (T{sub RAD}{sup 4}) on the surrogate ignition capsule; (3) Quantitative understanding of the laser absorption and resultant x-ray flux; and (4) Determining whether initial hohlraum performance is consistent with requirements for ignition. This paper summarizes the status of NIF hohlraum energetics experiments. The hohlraum targets and experimental design are described, as well as the results of the initial experiments. The data demonstrate low backscattered energy (< 10%) for hohlraums filled with helium gas. A discussion of our current understanding of NIF hohlraum x-ray drive follows, including an overview of the computational tools, i.e., radiation-hydrodynamics codes, that have been used to design the hohlraums. The performance of the codes is compared to x-ray drive and capsule implosion data from the first NIF experiments. These results bode well for future NIF ignition hohlraum experiments.

  7. National Ignition Facility: Experimental plan

    NASA Astrophysics Data System (ADS)

    1994-05-01

    As part of the Conceptual Design Report (CDR) for the National Ignition Facility (NIF), scientists from Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), the University of Rochester's Laboratory for Laser Energetics (UR/LLE), and EG&G formed an NIF Target Diagnostics Working Group. The purpose of the Target Diagnostics Working Group is to prepare conceptual designs of target diagnostics for inclusion in the facility CDR and to determine how these specifications impact the CDR. To accomplish this, a subgroup has directed its efforts at constructing an approximate experimental plan for the ignition campaign of the NIF CDR. The results of this effort are contained in this document, the Experimental Plan for achieving fusion ignition in the NIF. This group initially concentrated on the flow-down requirements of the experimental campaign leading to ignition, which will dominate the initial efforts of the NIF. It is envisaged, however, that before ignition, there will be parallel campaigns supporting weapons physics, weapons effects, and other research. This plan was developed by analyzing the sequence of activities required to finally fire the laser at the level of power and precision necessary to achieve the conditions of an ignition hohlraum target, and to then use our experience in activating and running Nova experiments to estimate the rate of completing these activities.

  8. Exhaust gas ignition

    SciTech Connect

    1996-04-01

    This article describes a system developed for rapid light-off of underbody catalysts that has shown potential to meet Euro Stage III emissions targets and to be more cost-effective than some alternatives. Future emissions legislation will require SI engine aftertreatment systems to approach full operating efficiency within the first few seconds after starting to reduce the high total-emissions fraction currently contributed by the cold phase of driving. A reduction of cold-start emissions during Phase 1 (Euro) or Bag 1 (FTP), which in many cases can be as much as 80% of the total for the cycle, has been achieved by electrical heating of the catalytic converter. But electrically heated catalyst (EHC) systems require high currents (100--200 A) to heat the metallic substrate to light-off temperatures over the first 15--20 seconds. Other viable approaches to reducing cold-start emissions include use of a fuel-powered burner upstream of the catalyst. However, as with EHC, the complexity of parts and the introduction of raw fuel into the exhaust system make this device unsatisfactory. Still another approach, an exhaust gas ignition (EGI) system, was first demonstrated in 1991. The operation of a system developed by engineers at Ford Motor Co., Ltd., Cambustion Ltd., and Tickford Ltd. is described here.

  9. The National Ignition Facility

    SciTech Connect

    Miller, G H; Moses, E I; Wuest, C R

    2004-02-06

    The National Ignition Facility (NIF) at 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 and room for 100 diagnostics. NIF is 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 burn, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will study physical processes at temperatures approaching 10{sup 8} K and 10{sup 11} bar; conditions that exist naturally only in the interior of stars and planets. NIF has completed the first phases of its laser commissioning program. The first four beams of NIF have generated 106 kilojoules in 23-ns pulses of infrared light and over 16 kJ in 3.5-ns pulses 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. We follow this with a discussion of NIF's high-energy-density and inertial fusion experimental capabilities, the first experiments on NIF, and plans for future capabilities of this unique facility.

  10. Dynamics of Igniting Plasmas

    NASA Astrophysics Data System (ADS)

    Airoldi, A.; Cenacchi, G.; Coppi, Bruno

    2004-11-01

    A unique feature of the Ignitor experiment is that is designed to reach for the first time the conditions where the thermonuclear instability due to -particle heating can develop. We have investigated the means by which the instability can be controlled, including the injected plasma heating power, the deuterium/tritium concentrations, and the effects of the expected sawtooth oscillations driven by the plasma pressure gradient. An ad hoc version of the JETTO transport code [1] has been used with the deuterium and tritium densities evolving separately under independent inflows. The boundary conditions for the main ion diffusion equation include recycling that assures density conservation in the absence of external inflows. Different combinations of the inflows of the main ions and of the duration and values of the injected RF power are shown lead to a large range of possibilities, from the onset of ignition and of the thermonuclear instability to quasi-stationary burning plasmas with a fusion gain exceeding 10. [1] A. Airoldi and G. Cenacchi, Nuclear Fusion 41, 687 (1997)

  11. The National Ignition Facility

    SciTech Connect

    Miller, G H

    2003-12-19

    The National Ignition Facility (NIF) at 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 and room for 100 diagnostics. NIF is 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 burn, liberating more energy than required to initiate the fusion reactions. Other NIF experiments will study physical processes at temperatures approaching 10{sup 8} K and 10'' bar; conditions that exist naturally only in the interior of stars and planets. NIF has completed the first phases of its laser commissioning program. The first four beams of NIF have generated 106 kilojoules in 23-ns pulses of infrared light and over 16 kJ in 3.5 ns pulses at the third harmonic (351 nm). NIF's target experimental systems are being commissioned and experiments have begun. This paper discusses NIF's current and future experimental capability, plans for diagnostics, cryogenic target systems, specialized optics for experiments, and potential enhancements to NIF such as multi-color laser operation and high-energy short pulse operation.

  12. The VISTA spacecraft: Advantages of ICF (Inertial Confinement Fusion) for interplanetary fusion propulsion applications

    SciTech Connect

    Orth, C.D.; Klein, G.; Sercel, J.; Hoffman, N.; Murray, K.; Chang-Diaz, F.

    1987-10-02

    Inertial Confinement Fusion (ICF) is an attractive engine power source for interplanetary manned spacecraft, especially for near-term missions requiring minimum flight duration, because ICF has inherent high power-to-mass ratios and high specific impulses. We have developed a new vehicle concept called VISTA that uses ICF and is capable of round-trip manned missions to Mars in 100 days using A.D. 2020 technology. We describe VISTA's engine operation, discuss associated plasma issues, and describe the advantages of DT fuel for near-term applications. Although ICF is potentially superior to non-fusion technologies for near-term interplanetary transport, the performance capabilities of VISTA cannot be meaningfully compared with those of magnetic-fusion systems because of the lack of a comparable study of the magnetic-fusion systems. We urge that such a study be conducted.

  13. The VISTA spacecraft: Advantages of ICF (Inertial Confinement Fusion) for interplanetary fusions propulsion applications

    NASA Technical Reports Server (NTRS)

    Orth, Charles D.; Klein, Gail; Sercel, Joel; Hoffman, Nate; Murray, Kathy; Chang-Diaz, Franklin

    1987-01-01

    Inertial Confinement Fusion (ICF) is an attractive engine power source for interplanetary manned spacecraft, especially for near-term missions requiring minimum flight duration, because ICF has inherent high power-to-mass ratios and high specific impulses. We have developed a new vehicle concept called VISTA that uses ICF and is capable of round-trip manned missions to Mars in 100 days using A.D. 2020 technology. We describe VISTA's engine operation, discuss associated plasma issues, and describe the advantages of DT fuel for near-term applications. Although ICF is potentially superior to non-fusion technologies for near-term interplanetary transport, the performance capabilities of VISTA cannot be meaningfully compared with those of magnetic-fusion systems because of the lack of a comparable study of the magnetic-fusion systems. We urge that such a study be conducted.

  14. 42 CFR 442.15 - Duration of agreement for ICFs/MR.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) MEDICAL ASSISTANCE PROGRAMS STANDARDS FOR PAYMENT TO NURSING FACILITIES AND INTERMEDIATE CARE FACILITIES FOR THE MENTALLY RETARDED Provider Agreements § 442.15 Duration of agreement for ICFs/MR....

  15. Configuring the National Ignition Facility for direct-drive experiments

    SciTech Connect

    Eimerl, D.

    1995-07-01

    The National Ignition Facility (NIF) is a project whose primary mission is to provide an above-ground experimental capability for maintaining nuclear competence and weapons effects simulation, and to pursue the achievement of fusion ignition utilizing solid state lasers as the energy driver. In this facility a large number of laser beams are focused onto a small target located at the center of a spherical target chamber. The laser energy is delivered in a few billionths of a second, raising the temperature and density of the nuclear materials in the target to levels where significant thermonuclear energy is released. The thermonuclear reaction proceeds very rapidly, so that the target materials remain confined by their own inertia during the thermonuclear reaction. This type of approach is called inertial confinement fusion (ICF). The proposed project is described in a conceptual design report (CDR) that was released in May 1994. Early in FY95, a collaboration between the University of Rochester and the Lawrence Livermore National Laboratory was established to study reconfiguring the NIF to accommodate direct-drive experiments. The present paper is a report to the scientific community, primarily the scientists and engineers working on the design of the NIF. It represents results from work in progress, specifically work completed by the end of the second quarter FY95. This report has two main sections. The first describes the target requirements on the laser drive, and the second part describes how the NIF laser can be configured to accommodate both indirect and direct drive. The report includes a description of the scientific basis for these conclusions. Though a complete picture does not exist, the present understanding is sufficient to conclude that the primary target requirements and laser functional requirements for indirect and direct drive are quite compatible. It is evidently straightforward to reconfigure the NIF to accommodate direct and indirect drive.

  16. Overview of Progress and Future Prospects in Indirect Drive Implosions on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Hurricane, O. A.; ICF Program

    2016-05-01

    Alpha-particle self-heating, the process of deuterium-tritium (DT) fusion reaction products depositing their kinetic energy locally within the fusion reaction region and thus increasing the temperature in the reacting region with a concomitant exponential increase in the fusion reaction-rate, is the essential process needed for a fusion plasma to ignite. For the first time in the laboratory, significant alpha-heating in a fusion plasma was inferred in experiments and fusion fuel gain was demonstrated on the U.S. National Ignition Facility (NIF). Experiments on the NIF have achieved the highest yet recorded stagnation pressures (Pstagnation > 150-230 Gigabar) of any facility based inertial confinement fusion (ICF) experiments, albeit they are still short of the pressures required for ignition on the NIF (i.e. ∼ 300 - 400 Gbar), and have exhibited undesirable shape distortions that waste kinetic energy. We review the issues that have been uncovered and discuss the program strategy and plan that we are following to systematically address the known issues as we press on.

  17. Looking at the ICF and human communication through the lens of classification theory.

    PubMed

    Walsh, Regina

    2011-08-01

    This paper explores the insights that classification theory can provide about the application of the International Classification of Functioning, Disability and Health (ICF) to communication. It first considers the relationship between conceptual models and classification systems, highlighting that classification systems in speech-language pathology (SLP) have not historically been based on conceptual models of human communication. It then overviews the key concepts and criteria of classification theory. Applying classification theory to the ICF and communication raises a number of issues, some previously highlighted through clinical application. Six focus questions from classification theory are used to explore these issues, and to propose the creation of an ICF-related conceptual model of communicating for the field of communication disability, which would address some of the issues raised. Developing a conceptual model of communication for SLP purposes closely articulated with the ICF would foster productive intra-professional discourse, while at the same time allow the profession to continue to use the ICF for purposes in inter-disciplinary discourse. The paper concludes by suggesting the insights of classification theory can assist professionals to apply the ICF to communication with the necessary rigour, and to work further in developing a conceptual model of human communication.

  18. Multimodal Friction Ignition Tester

    NASA Technical Reports Server (NTRS)

    Davis, Eddie; Howard, Bill; Herald, Stephen

    2009-01-01

    The multimodal friction ignition tester (MFIT) is a testbed for experiments on the thermal and mechanical effects of friction on material specimens in pressurized, oxygen-rich atmospheres. In simplest terms, a test involves recording sensory data while rubbing two specimens against each other at a controlled normal force, with either a random stroke or a sinusoidal stroke having controlled amplitude and frequency. The term multimodal in the full name of the apparatus refers to a capability for imposing any combination of widely ranging values of the atmospheric pressure, atmospheric oxygen content, stroke length, stroke frequency, and normal force. The MFIT was designed especially for studying the tendency toward heating and combustion of nonmetallic composite materials and the fretting of metals subjected to dynamic (vibrational) friction forces in the presence of liquid oxygen or pressurized gaseous oxygen test conditions approximating conditions expected to be encountered in proposed composite material oxygen tanks aboard aircraft and spacecraft in flight. The MFIT includes a stainless-steel pressure vessel capable of retaining the required test atmosphere. Mounted atop the vessel is a pneumatic cylinder containing a piston for exerting the specified normal force between the two specimens. Through a shaft seal, the piston shaft extends downward into the vessel. One of the specimens is mounted on a block, denoted the pressure block, at the lower end of the piston shaft. This specimen is pressed down against the other specimen, which is mounted in a recess in another block, denoted the slip block, that can be moved horizontally but not vertically. The slip block is driven in reciprocating horizontal motion by an electrodynamic vibration exciter outside the pressure vessel. The armature of the electrodynamic exciter is connected to the slip block via a horizontal shaft that extends into the pressure vessel via a second shaft seal. The reciprocating horizontal

  19. Alignment mask design and image processing for the Advanced Radiographic Capability (ARC) at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Leach, Richard R.; Awwal, Abdul; Cohen, Simon; Lowe-Webb, Roger; Roberts, Randy; Salmon, Thad; Smauley, David; Wilhelmsen, Karl

    2015-09-01

    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 pulses that generate X-rays which backlight high-density inertial confinement fusion (ICF) targets. ARC is designed to produce multiple, sequential X-ray images by using up to eight back lighters. The images will be used to examine the compression and ignition of a cryogenic deuterium-tritium target with tens-of-picosecond temporal resolution during the critical phases of an ICF shot. Multi-frame, hard-X-ray radiography of imploding NIF capsules is a capability which is critical to the success of NIF's missions. As in the NIF system, ARC requires an optical alignment mask that can be inserted and removed as needed for precise positioning of the beam. Due to ARC's split beam design, inserting the nominal NIF main laser alignment mask in ARC produced a partial blockage of the mask pattern. Requirements for a new mask design were needed. In this paper we describe the ARC mask requirements, the resulting mask design pattern, and the image analysis algorithms used to detect and identify the beam and reference centers required for ARC alignment.

  20. Igniter adapter-to-igniter chamber deflection test

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1990-01-01

    Testing was performed to determine the maximum RSRM igniter adapter-to-igniter chamber joint deflection at the crown of the inner joint primary seal. The deflection data was gathered to support igniter inner joint gasket resiliency predictions which led to launch commit criteria temperature determinations. The proximity (deflection) gage holes for the first test (Test No. 1) were incorrectly located; therefore, the test was declared a non-test. Prior to Test No. 2, test article configuration was modified with the correct proximity gage locations. Deflection data were successfully acquired during Test No. 2. However, the proximity gage deflection measurements were adversely affected by temperature increases. Deflections measured after the temperature rise at the proximity gages were considered unreliable. An analysis was performed to predict the maximum deflections based on the reliable data measured before the detectable temperature rise. Deflections to the primary seal crown location were adjusted to correspond to the time of maximum expected operating pressure (2,159 psi) to account for proximity gage bias, and to account for maximum attach and special bolt relaxation. The maximum joint deflection for the igniter inner joint at the crown of the primary seal, accounting for all significant correction factors, was 0.0031 in. (3.1 mil). Since the predicted (0.003 in.) and tested maximum deflection values were sufficiently close, the launch commit criteria was not changed as a result of this test. Data from this test should be used to determine if the igniter inner joint gasket seals are capable of maintaining sealing capability at a joint displacement of (1.4) x (0.0031 in.) = 0.00434 inches. Additional testing should be performed to increase the database on igniter deflections and address launch commit criteria temperatures.

  1. Ignition problems in scramjet testing

    SciTech Connect

    Mitani, Tohru

    1995-05-01

    Ignition of H{sub 2} in heated air containing H{sub 2}O, radicals, and dust was investigated for scramjet testing. Using a reduced kinetic model for H{sub 2}{minus}O{sub 2} systems, the effects of H{sub 2}O and radicals in nozzles are discussed in relation to engine testing with vitiation heaters. Analysis using linearized rate-equations suggested that the addition of O atoms was 1.5 times more effective than the addition of H atoms for ignition. This result can be applied to the problem of premature ignition caused by residual radicals and to plasma-jet igniters. Thermal and chemical effects of dust, inevitable in storage air heaters, were studied next. The effects of heat capacity and size of dust were expressed in terms of an exponential integral function. It was found that the radical termination on the surface of dust produces an effect equivalent to heat loss. The inhibition of ignition by dust may result, if the mass fraction of dust becomes 10{sup {minus}3}.

  2. Enhanced Model for Fast Ignition

    SciTech Connect

    Mason, Rodney J.

    2010-10-12

    Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nation's energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, "implicitness and fluid modeling," can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

  3. National Ignition Facility quality assurance program plan revision 2

    SciTech Connect

    Wolfe, C R

    1998-06-01

    NIF Project activities will be conducted in a manner consistent with the guidance and direction of the DOE Order on Quality Assurance (414.1), the LLNL QA Program, and the Laser Directorate QA Plan. Quality assurance criteria will be applied in a graded manner to achieve a balance between the rigor of application of QA measures and the scale, cost, and complexity of the work involved. Accountability for quality is everyone's, extending from the Project Manager through established lines of authority to all Project personnel, who are responsible for the requisite quality of their own work. The NLF QA Program will be implemented by personnel conducting their activities to meet requirements and expectations, according to established plans and procedures that reflect the way business is to be conducted on the Project.

  4. America Revising.

    ERIC Educational Resources Information Center

    Marty, Myron

    1982-01-01

    Reviews Frances FitzGerald's book, "America Revised," and discusses FitzGerald's critique of recent revisions in secondary-level U.S. history textbooks. The author advocates the implementation of a core curriculum for U.S. history which emphasizes political and local history. (AM)

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

    SciTech Connect

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

    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.

  6. Development of an asymmetrically driven, inviscid-hydrodynamics ICF platform

    NASA Astrophysics Data System (ADS)

    Krasheninnikova, Natalia; Hsu, Scott; Thomas, Vincent

    2016-10-01

    We describe the development of a new, asymmetrically driven ICF concept, proposed to be tested on OMEGA for improving predictive capability. It is designed to experimentally investigate the evolution of low-mode-number perturbations at the pusher/gas interface, which are predicted by high-resolution RAGE simulations and are not seen in more-prevalent lower-resolution ones. These features are deterministically seeded by appropriately chosen asymmetric drive and play a dominant role in energy transport at later stages of the implosion. The proposed design will utilize spherical plastic shell of about 800 um in filled with 5-10 atm of DD gas and driven by an asymmetrical 1-ns square pulse. This concept is designed to be well described by the Euler equations (Re >> 1, Pe >> 1, and negligible radiation pressure) in order to be well suited for detailed code comparison. The laser drive is designed to grow low-mode perturbations at the pusher/gas interface (of the type seen in the high-resolution simulations) that persist late into the implosion. We show initial simulation results, comparisons with symmetrically driven implosions, and discuss the plan for diagnosing the signatures of the evolution of the low-mode features.

  7. Advances in compact proton spectrometers for diagnosing ICF experiments

    NASA Astrophysics Data System (ADS)

    Seguin, F. H.; Sinenian, N.; Manuel, M.; Rinderknecht, H. G.; Rosenberg, M.; Zylstra, A.; Frenje, J.; Li, C. K.; Petrasso, R.; Roberts, S.; Sangster, T. C.

    2011-10-01

    The compact proton spectrometer (or WRF, for Wedge-Range-Filter proton spectrometer) measures the spectra of protons in the energy range ~ 3 to 20 MeV for diagnosing ICF experiments. It utilizes CR-39 for detecting individual protons and their energies, after they pass through a ranging filter with a continuously varying thickness, and appropriate algorithms for reconstructing the incident spectrum. It has now been in use for a decade at OMEGA, and is currently being used at the NIF, for measuring spectra of primary D3He protons in D3He implosions, secondary D3He protons in DD implosions, and ablator protons in DT implosions. These spectra are used to determine proton yields, shell areal density at shock-bang time and compression-bang time, fuel areal density, and implosion symmetry. During the decade of use there have been significant changes in fabrication and in analysis algorithms. An overview will be given here of the historical development, current analysis methods, and measurement accuracy. This work was supported in part by DOE and LLE.

  8. Fuel Cavity Asymmetry at the Onset of Deceleration in ICF

    NASA Astrophysics Data System (ADS)

    Shah, Rahul C.; Wysocki, F. J.; Glebov, V.; Hakel, P.; Joshi, T.; Kagan, G.; Mancini, R. C.; Murphy, T. J.; Stoeckl, C.; Yaakobi, B.; Benage, J. F.

    2014-10-01

    In ICF, the impact on symmetry of low mode drive non-uniformity is amplified by high convergence. Measurements have shown low mode areal density variation, however, direct impact of low modes on fuel volume has remained undemonstrated. We suggest our images provide first evidence of symmetry loss at the fuel-shell interface. The experiments use direct-drive spherical implosions (Omega). The inner 100 nm layer of the plastic shell is doped with diagnostic Ti to obtain information about interface position, temperature and density. Measurement is made at onset of deceleration at which time nuclear yield rate (NTD) and time resolved (SSCA) spectrum both are in agreement with 1-D prediction. Spectrally resolved images are obtained using the Multiple Monochromatic Imager, which combines a pinhole array with x-ray dispersive mirror and gated detector. Angle averaging of the limb-brightened image data also shows agreement with the 1D calculation. However, the 2D image shows ~20% brightness variations over modes 2-10. These modulations are discussed in context of predicted variations of interface position.

  9. Options for an ignited tokamak

    SciTech Connect

    Sheffield, J.

    1984-02-01

    It is expected that the next phase of the fusion program will involve a tokamak with the goals of providing an ignited plasma for pulses of hundreds of seconds. A simple model is described in this memorandum which establishes the physics conditions for such a self-sustaining plasma, for given ion and electron thermal diffusivities, in terms of R/a, b/a, I, B/q, epsilon ..beta../sub p/, anti T/sub i/, and anti T/sub e//anti T/sub i/. The model is used to produce plots showing the wide range of tokamaks that may ignite or have a given ignition margin. The constraints that limit this range are discussed.

  10. Magnetizing NIF Sub-Scale Capsules For Reaching Ignition Using Laser Energy in the 1 MJ Range

    NASA Astrophysics Data System (ADS)

    Zimmerman, G.; Ho, D.; Perkins, J.; Kagan, G.; Logan, G.; Salmonson, J.; Rhodes, M.; Blackfield, D.

    2016-10-01

    Fusion yield for ICF can be amplified by imposing a seed B-field around 50 T to confine alphas and to reduce electron heat conduction. Achieving 58 T in offline lab tests in sample hohlraum coils driven by a pulsed-power supply was demonstrated by Rhodes. Three topics are addressed. (1) The derivation of a 0D energy balance equation that including the effect of B-field. The ignition boundary obtained from this equation shows that a strong compressed B-field substantially reduces the minimum hotspot ρR required for ignition by about 50%. (2) The design of a near-term experimental demonstration of the effect of B-field on yield improvement based on our sub-scale gas-filled Symcap design for the NIF experiment (non-magnetized) that gave 1D yield and showed good symmetry. (3) The quest and design of magnetized sub-scale capsule with DT ice layer that gives robust ignition and requires only about 1 MJ of laser energy. Our baseline non-magnetized sub-scale design, with a seed field of 50T, gives a robust ignition with 1 MJ yield. This work performed under auspices of U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

  11. Catalytic ignition of hydrogen/oxygen

    NASA Technical Reports Server (NTRS)

    Green, James M.; Zurawski, Robert L.

    1988-01-01

    An experimental program was conducted to evaluate the catalytic ignition of gaseous hydrogen and oxygen. Shell 405 granular catalyst and a unique monolithic sponge catalyst were tested. Mixture ratio, mass flow rate, propellant inlet temperature, and back pressure were varied parametrically in testing to determine the operational limits of a catalytic igniter. The test results showed that the gaseous hydrogen/oxygen propellant combination can be ignited catalytically using Shell 405 catalyst over a wide range of mixture ratios, mass flow rates, and propellant injection temperatures. These operating conditions must be optimized to ensure reliable ignition for an extended period of time. The results of the experimental program and the established operational limits for a catalytic igniter using both the granular and monolithic catalysts are presented. The capabilities of a facility constructed to conduct the igniter testing and the advantages of a catalytic igniter over other ignition systems for gaseous hydrogen and oxygen are also discussed.

  12. Generation and Beaming of Early Hot Electrons onto the Capsule in Laser-Driven Ignition Hohlraums

    NASA Astrophysics Data System (ADS)

    Dewald, E. L.; Hartemann, F.; Michel, P.; Milovich, J.; Hohenberger, M.; Pak, A.; Landen, O. L.; Divol, L.; Robey, H. F.; Hurricane, O. A.; Döppner, T.; Albert, F.; Bachmann, B.; Meezan, N. B.; MacKinnon, A. J.; Callahan, D.; Edwards, M. J.

    2016-02-01

    In hohlraums for inertial confinement fusion (ICF) implosions on the National Ignition Facility, suprathermal hot electrons, generated by laser plasma instabilities early in the laser pulse ("picket") while blowing down the laser entrance hole (LEH) windows, can preheat the capsule fuel. Hard x-ray imaging of a Bi capsule surrogate and of the hohlraum emissions, in conjunction with the measurement of time-resolved bremsstrahlung spectra, allows us to uncover for the first time the directionality of these hot electrons and infer the capsule preheat. Data and Monte Carlo calculations indicate that for most experiments the hot electrons are emitted nearly isotropically from the LEH. However, we have found cases where a significant fraction of the generated electrons are emitted in a collimated beam directly towards the capsule poles, where their local energy deposition is up to 10 × higher than the average preheat value and acceptable levels for ICF implosions. The observed "beaming" is consistent with a recently unveiled multibeam stimulated Raman scattering model [P. Michel et al., Phys. Rev. Lett. 115, 055003 (2015)], where laser beams in a cone drive a common plasma wave on axis. Finally, we demonstrate that we can control the amount of generated hot electrons by changing the laser pulse shape and hohlraum plasma.

  13. Generation and Beaming of Early Hot Electrons onto the Capsule in Laser-Driven Ignition Hohlraums.

    PubMed

    Dewald, E L; Hartemann, F; Michel, P; Milovich, J; Hohenberger, M; Pak, A; Landen, O L; Divol, L; Robey, H F; Hurricane, O A; Döppner, T; Albert, F; Bachmann, B; Meezan, N B; MacKinnon, A J; Callahan, D; Edwards, M J

    2016-02-19

    In hohlraums for inertial confinement fusion (ICF) implosions on the National Ignition Facility, suprathermal hot electrons, generated by laser plasma instabilities early in the laser pulse ("picket") while blowing down the laser entrance hole (LEH) windows, can preheat the capsule fuel. Hard x-ray imaging of a Bi capsule surrogate and of the hohlraum emissions, in conjunction with the measurement of time-resolved bremsstrahlung spectra, allows us to uncover for the first time the directionality of these hot electrons and infer the capsule preheat. Data and Monte Carlo calculations indicate that for most experiments the hot electrons are emitted nearly isotropically from the LEH. However, we have found cases where a significant fraction of the generated electrons are emitted in a collimated beam directly towards the capsule poles, where their local energy deposition is up to 10× higher than the average preheat value and acceptable levels for ICF implosions. The observed "beaming" is consistent with a recently unveiled multibeam stimulated Raman scattering model [P. Michel et al., Phys. Rev. Lett. 115, 055003 (2015)], where laser beams in a cone drive a common plasma wave on axis. Finally, we demonstrate that we can control the amount of generated hot electrons by changing the laser pulse shape and hohlraum plasma.

  14. Diagnostics for high-density implosions at nova and the national Ignition Facility

    SciTech Connect

    Cable, M.D.; Barbee, T.W., Jr.; Koch, J.A.

    1997-06-01

    The proposed National Ignition Facility (NIF) is a large (1.8 MJ on target at 0.35 {micro}m) multi-beam laser facility that will be used for Inertial Confinement Fusion (ICF). ICF implosions at this facility will produce core plasma temperatures over 10 keV and densities over 100 g/cm{sup 3}. Properties of these plasmas can be measured by a variety of optical, x-ray, and nuclear diagnostic techniques such as those used at existing facilities like the Nova laser at the Lawrence Livermore National Laboratory (LLNL). Some of these currently used techniques will be directly applicable to NIF; others require significant development. Damage of components close to the target will be a much greater issue at NIF, necessitating the development of distant detector techniques. To penetrate the larger targets, x-ray-based core diagnostics will need to utilize substantially higher energies than are in routine use today. Penetrating nuclear-particle-based diagnostics will be particularly well suited to these implosions, and the higher nuclear yields will allow new techniques to be developed. Some examples of diagnostics used for high-density-implosion experiments at Nova and corresponding development of new techniques for NIF are discussed.

  15. Flow Friction or Spontaneous Ignition?

    NASA Technical Reports Server (NTRS)

    Stoltzfus, Joel M.; Gallus, Timothy D.; Sparks, Kyle

    2012-01-01

    "Flow friction," a proposed ignition mechanism in oxygen systems, has proved elusive in attempts at experimental verification. In this paper, the literature regarding flow friction is reviewed and the experimental verification attempts are briefly discussed. Another ignition mechanism, a form of spontaneous combustion, is proposed as an explanation for at least some of the fire events that have been attributed to flow friction in the literature. In addition, the results of a failure analysis performed at NASA Johnson Space Center White Sands Test Facility are presented, and the observations indicate that spontaneous combustion was the most likely cause of the fire in this 2000 psig (14 MPa) oxygen-enriched system.

  16. Laser ablation based fuel ignition

    DOEpatents

    Early, James W.; Lester, Charles S.

    1998-01-01

    There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition.

  17. Laser ablation based fuel ignition

    DOEpatents

    Early, J.W.; Lester, C.S.

    1998-06-23

    There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition. 3 figs.

  18. Confinement of ignition and yield on the National Ignition Facility

    SciTech Connect

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

    1996-06-14

    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.

  19. Surface breakdown igniter for mercury arc devices

    DOEpatents

    Bayless, John R.

    1977-01-01

    Surface breakdown igniter comprises a semiconductor of medium resistivity which has the arc device cathode as one electrode and has an igniter anode electrode so that when voltage is applied between the electrodes a spark is generated when electrical breakdown occurs over the surface of the semiconductor. The geometry of the igniter anode and cathode electrodes causes the igniter discharge to be forced away from the semiconductor surface.

  20. Ignition and combustion phenomena in Diesel engines

    NASA Technical Reports Server (NTRS)

    Sass, F

    1928-01-01

    Evidences were found that neither gasification nor vaporization of the injected fuel occurs before ignition; also that the hydrogen coefficient has no significance. However the knowledge of the ignition point and of the "time lag" is important. After ignition, the combustion proceeds in a series of reactions, the last of which at least are now known.

  1. Integral low-energy thermite igniter

    DOEpatents

    Gibson, A.; Haws, L.D.; Mohler, J.H.

    1983-05-13

    In a thermite igniter/heat source comprising a container holding an internal igniter load, there is provided the improvement wherein the container consists essentially of consumable consolidated thermite having a low gas output upon combustion, whereby upon ignition, substantially all of the container and said load is consumed with low gas production.

  2. Integral low-energy thermite igniter

    DOEpatents

    Gibson, Albert; Haws, Lowell D.; Mohler, Jonathan H.

    1984-08-14

    In a thermite igniter/heat source comprising a container holding an internal igniter load, there is provided the improvement wherein the container consists essentially of consumable consolidated thermite having a low gas output upon combustion, whereby upon ignition, substantially all of the container and said load is consumed with low gas production.

  3. 14 CFR 33.37 - Ignition system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: AIRCRAFT ENGINES Design and Construction; Reciprocating Aircraft Engines § 33.37 Ignition system. Each spark ignition engine must have a dual ignition system with at least two spark plugs for each cylinder and two separate electric circuits with separate sources of electrical energy, or have an...

  4. Simultaneous dual mode combustion engine operating on spark ignition and homogenous charge compression ignition

    DOEpatents

    Fiveland, Scott B.; Wiggers, Timothy E.

    2004-06-22

    An engine particularly suited to single speed operation environments, such as stationary power generators. The engine includes a plurality of combustion cylinders operable under homogenous charge compression ignition, and at least one combustion cylinder operable on spark ignition concepts. The cylinder operable on spark ignition concepts can be convertible to operate under homogenous charge compression ignition. The engine is started using the cylinders operable under spark ignition concepts.

  5. Experimental Ignition of Evolution on Fitness Landscapes

    NASA Astrophysics Data System (ADS)

    Robin, Kristelle

    2011-03-01

    Microbiologist are starting to revise the single cell centered view of evolution to a multicellular view, considering it at entire population scale, and even whole ecosystem. Indeed, as Darwin recognized on the Galapagos Island, evolution of a community of bacteria is strongly influenced by the global spatial stress and depends of the neighboring communities. This collective dynamical process can be studied using micro-nanofabricated landscape to create stressed conditions. Our microfluidic device consists of interconnected chambers in 2D hexagonal geometries. The design of our ecology enables to combine gradients of antibiotic and nutrient, thus generating population gradient and motion of bacteria across them. We study here evolution of resistance to the antibiotic ciprofloxacin in highly-stressed conditions. Non-random mutations are induced in the collectivity to develop resistance to the antibiotic. Channels between microhabitats allow motion of bacteria between different islands, and once evolution is ignited in a local metapopulation, a very fast spread through the collectivity happens. In such environments, evolution is observed in typical time scales of few hours. Knowing the complexity of natural world, we believe that our approach provide a model to understand the rapid emergence of resistance to antibiotic and its spread in the entire population.

  6. COBRA accelerator for Sandia ICF diode research at Cornell University

    SciTech Connect

    Smith, D.L.; Ingwersen, P.; Bennett, L.F.; Boyes, J.D.; Anderson, D.E.; Greenly, J.B.; Sudan, R.N.

    1995-05-01

    The new COBRA accelerator is being built in stages at the Laboratory of Plasma Studies in Cornell University where its applications will include extraction diode and ion beam research in support of the light ion inertial confinement fusion (ICF) program at Sandia National Laboratories. The 4- to 5-MV, 125- to 250-kA accelerator is based on a four-cavity inductive voltage adder (IVA) design. It is a combination of new ferromagnetically-isolated cavities and self magnetically insulated transmission line (MITL) hardware and components from existing Sandia and Cornell facilities: Marx generator capacitors, hardware, and power supply from the DEMON facility; water pulse forming lines (PFL) and gas switch from the Subsystem Test Facility (STF); a HERMES-III intermediate store capacitor (ISC); and a modified ion diode from Cornell`s LION. The present accelerator consists of a single modified cavity similar to those of the Sandia SABRE accelerator and will be used to establish an operating system for the first stage initial lower voltage testing. Four new cavities will be fabricated and delivered in the first half of FY96 to complete the COBRA accelerator. COBRA is unique in the sense that each cavity is driven by a single pulse forming line, and the IVA output polarity may be reversed by rotating the cavities 180{degrees} about their vertical axis. The site preparations, tank construction, and diode design and development are taking place at Cornell with growing enthusiasm as this machine becomes a reality. Preliminary results with the single cavity and short positive inner cylinder MITL configuration will soon be available.

  7. COBRA accelerator for Sandia ICF diode research at Cornell University

    NASA Astrophysics Data System (ADS)

    Smith, David L.; Ingwersen, Pete; Bennett, Lawrence F.; Boyes, John D.; Anderson, David E.; Greenly, John B.; Sudan, Ravi N.

    The new COBRA accelerator is being built in stages at the Laboratory of Plasma Studies in Cornell University where its applications will include extraction diode and ion beam research in support of the light ion inertial confinement fusion (ICF) program at Sandia National Laboratories. The 4- to 5-MV, 125- to 250-kA accelerator is based on a four-cavity inductive voltage adder (IVA) design. It is a combination of new ferromagnetically-isolated cavities and self magnetically insulated transmission line (MITL) hardware and components from existing Sandia and Cornell facilities: Marx generator capacitors, hardware, and power supply from the DEMON facility; water pulse forming lines (PFL) and gas switch from the Subsystem Test Facility (STF); a HERMES-3 intermediate store capacitor (ISC); and a modified ion diode from Cornell's LION. The present accelerator consists of a single modified cavity similar to those of the Sandia SABRE accelerator and will be used to establish an operating system for the first stage initial lower voltage testing. Four new cavities will be fabricated and delivered in the first half of FY96 to complete the COBRA accelerator. COBRA is unique in the sense that each cavity is driven by a single pulse forming line, and the IVA output polarity may be reversed by rotating the cavities 180(degrees) about their vertical axis. The site preparations, tank construction, and diode design and development are taking place at Cornell with growing enthusiasm as this machine becomes a reality. Preliminary results with the single cavity and short positive inner cylinder MITL configuration will soon be available.

  8. Laser ignition application in a space experiment

    NASA Technical Reports Server (NTRS)

    Liou, Larry C.; Culley, Dennis E.

    1993-01-01

    A laser ignition system is proposed for the Combustion Experiment Module on an orbiting spacecraft. The results of a design study are given using the scheduled 'Flame Ball Experiment' as the design guidelines. Three laser ignition mechanisms and wavelengths are evaluated. A prototype laser is chosen and its specifications are given, followed by consideration of the beam optical arrangement, the ignition power requirement, the laser ignition system weight, size, reliability, and laser cooling and power consumption. Electromagnetic interference to the onboard electronics caused by the laser ignition process is discussed. Finally, ground tests are suggested.

  9. Desensitizing nano powders to electrostatic discharge ignition

    SciTech Connect

    Steelman, Ryan; Clark, Billy; Pantoya, Michelle L.; Heaps, Ronald J.; Daniels, Michael A.

    2015-08-01

    Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.

  10. Laser-induced magnetic fields in ICF capsules, Final Report, DE-FG02-08ER85128, Phase 1

    SciTech Connect

    Lindman, Erick L

    2009-11-05

    magnetic field spreads from the hot spot over the surface that contains the toroidal gap, it will propagate through the gap and set up a steady state in the capsule. The main compression is then initiated. First, it closes the gap and crow-bars the field, then it compresses the fuel to ignition. In addition to this application, we discuss the use of this mechanism to induce Mega-gauss fields in laboratory apparatus for measurements of the effects of large magnetic fields on material samples. A preliminary target design for this purpose is presented. It is made of high-density material with no hydrogen surface contamination to minimize fast ion losses and to minimize x-ray preheat of the sample (the material, whose magnetic properties are to be measured). In it, the gap is designed to allow the magnetic field to move into the interior of the target while minimizing the flow of hot electrons into the interior. By adjusting the size of the gap as well as its configuration, the hot electron effects can be minimized. Since the strength of the magnetic field depends on the radial distance to the sample from the center of the conductor carrying the return current, the sample is located at a point of minimum conductor radius. This location also minimizes the effects on the measurement of any hot electrons that flow into the interior. Useful experiments can be accomplished with the “seed” field alone in this geometry. Compressing the capsule after the insertion of the seed field may allow experiments with even larger magnetic fields. We have used computer-simulation techniques to address a number of issues. Our conclusions include: • This magnetic-field generating mechanism is a viable method for generating magnetic fields in ICF targets and for laboratory experiments. • Useful experiments on material samples can be done with the seed field of 1 to10 Mega gauss (100 to 1000 Tesla) and higher magnetic fields can be obtained by subsequently compressing the capsule. • The

  11. Combustion-wave ignition for rocket engines

    NASA Technical Reports Server (NTRS)

    Liou, Larry C.

    1992-01-01

    The combustion wave ignition concept was experimentally studied in order to verify its suitability for application in baffled sections of a large booster engine combustion chamber. Gaseous oxygen/gaseous methane (GOX/GH4) and gaseous oxygen/gaseous hydrogen (GOX/GH2) propellant combinations were evaluated in a subscale combustion wave ignition system. The system included four element tubes capable of carrying ignition energy simultaneously to four locations, simulating four baffled sections. Also, direct ignition of a simulated Main Combustion Chamber (MCC) was performed. Tests were conducted over a range of mixture ratios and tube geometries. Ignition was consistently attained over a wide range of mixture ratios. And at every ignition, the flame propagated through all four element tubes. For GOX/GH4, the ignition system ignited the MCC flow at mixture ratios from 2 to 10 and for GOX/GH2 the ratios is from 2 to 13. The ignition timing was found to be rapid and uniform. The total ignition delay when using the MCC was under 11 ms, with the tube-to-tube, as well as the run-to-run, variation under 1 ms. Tube geometries were found to have negligible effect on the ignition outcome and timing.

  12. Initiation system for low thrust motor igniter

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Davis, D. P.; Shafer, J. I.

    1972-01-01

    A test program was carried out to demonstrate an igniter motor initiation system utilizing the bimetallic material Pyrofuze for a solid propellant rocket with controlled low rate of thrust buildup. The program consisted of a series of vacuum ignition tests using a slab burning window motor that simulated the principal initial ballistic parameters of the full scale igniter motor. A Pyrofuze/pyrotechnic igniter system was demonstrated that uses a relatively low electrical current level for initiation and that eliminates the necessity of a pyrotechnic squib, with its accompanying accidental firing hazards and the typical basket of pyrotechnic pellets. The Pyrofuze ignition system does require an initial constraining of the igniter motor nozzle flow, and at the low initiating electrical current level the ignition delay time of this system was found to be quite sensitive to factors affecting local heat generation or loss rates.

  13. Materials processing in space: ICF target fabrication implications

    SciTech Connect

    Hendricks, C.D.

    1982-04-28

    During the last quarter of 1982, the Novette laser will become operational at Lawrence Livermore National Laboratory. The primary characteristics of the Novette laser are shown. In many ways, the new laser will serve as a proving ground and test bed for the Nova laser which is also under construction and should be operational in early 1985. Tables provide the Nova operational characteristics. The advent of the two new lasers, Novette and Nova, will make it possible to study many new and exciting aspects of laser-target interactions and of many implosion physics experiments which have previously not been possible. Some of the most interesting and exciting work will be the exploration of the parameters critical to the ignition of a significant thermonuclear burn in the deuterium-tritium fuel in the targets.

  14. Laser-driven ICF experiments: Laboratory Report No. 223

    SciTech Connect

    McCrory, R.L.

    1991-04-01

    Laser irradiation uniformity is a key issue and is treated in some detail. The basic irradiation uniformity requirements and practical ways of achieving these requirements are both discussed, along with two beam-smoothing techniques: induced spatial incoherence (ISI), and smoothing by spectral dispersion (SSD). Experiments to measure and control the irradiation uniformity are also highlighted. Following the discussion of irradiation uniformity, a brief review of coronal physics is given, including the basic physical processes and their experimental signatures, together with a summary of pertinent diagnostics and results from experiments. Methods of determining ablation rates and thermal transport are also described. The hydrodynamics of laser-driven targets must be fully understood on the basis of experiments. Results from implosion experiments, including a brief description of the diagnostics, are presented. Future experiments aimed at determining ignition scaling and demonstrating hydrodynamically equivalent physics applicable to high-gain designs.

  15. Theoretical Investigation of Strong Coupling and Degeneracy Effects in ICF Implosions

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Goncharov, V. N.; Boehly, T. R.; Radha, P. B.; Skupsky, S.; Militze, B.

    2009-11-01

    Accurate knowledge of the equation of state (EOS) and opacity is essential to inertial confinement fusion (ICF). Low-adiabat ICF implosion designs reach strongly coupled, degenerate plasma conditions. Using the first-principles, path-integral Monte Carlo method, we have established an EOS table of deuterium, spanning typical ICF shell conditions (densities of 0.001 to 100 g/cc and temperatures of 1 eV to 1 keV). Noticeable differences in energy/pressure at moderately coupled, degenerate regimes have been found in comparison to the SESAME and Thomas-Fermi EOS. Hydrodynamic simulations using these EOS's and opacities for OMEGA implosions will be presented. This work was supported by U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

  16. [Relevance of personal contextual factors of the ICF for use in practical social medicine and rehabilitation].

    PubMed

    Grotkamp, S; Cibis, W; Bahemann, A; Baldus, A; Behrens, J; Nyffeler, I D; Echterhoff, W; Fialka-Moser, V; Fries, W; Fuchs, H; Gmünder, H P; Gutenbrunner, C; Keller, K; Nüchtern, E; Pöthig, D; Queri, S; Rentsch, H P; Rink, M; Schian, H-M; Schian, M; Schmitt, K; Schwarze, M; Ulrich, P; von Mittelstaedt, G; Seger, W

    2014-03-01

    Personal contextual factors play an essential part in the model of the International Classification of Functioning, Disability and Health (ICF). The WHO has not yet classified personal factors for global use although they impact on the functioning of persons positively or negatively. In 2010, the ICF working group of the German Society of Social Medicine and Prevention (DGSMP) presented a proposal for the classification of personal factors into 72 categories previously arranged in 6 chapters. Now a positioning paper has been added in order to stimulate a discussion about the fourth component of the ICF, to contribute towards a broader and common understanding about the nature of personal factors and to incite a dialogue among all those involved in health care as well as those people with or with-out health problems in order to gain a comprehensive perspective about a person's condition.

  17. Utility of the International Classification of Functioning, Disability and Health (ICF) for educational psychologists’ work

    PubMed Central

    Aljunied, Mariam; Frederickson, Norah

    2014-01-01

    Despite embracing a bio-psycho-social perspective, the World Health Organization’s International Classification of Functioning, Disability and Health (ICF) assessment framework has had limited application to date with children who have special educational needs (SEN). This study examines its utility for educational psychologists’ work with children who have Autism Spectrum Disorders (ASD). Mothers of 40 children with ASD aged eight to 12 years were interviewed using a structured protocol based on the ICF framework. The Diagnostic Interview for Social and Communication Disorder (DISCO) was completed with a subset of 19 mothers. Internal consistency and inter-rater reliability of the interview assessments were found to be acceptable and there was evidence for concurrent and discriminant validity. Despite some limitations, initial support for the utility of the ICF model suggests its potential value across educational, health and care fields. Further consideration of its relevance to educational psychologists in new areas of multi-agency working is warranted. PMID:26157197

  18. Type C investigation of electrical fabrication projects in ICF Kaiser shops

    SciTech Connect

    Huckfeldt, R.A.

    1995-06-01

    A Type C Investigation Board was convened to investigate an electrical miswiring problem found during the operation of the electrical distribution trailer for the TWRS Rotary Mode Core Sampling Truck {number_sign}2. The trailer was designed by WHC and fabricated ICF KH on site for use in the Characterization Program. This problem resulted in a serious safety hazard since the support truck frame/chassis became electrically energized. This final report provides results of the ``Type C Investigation, Electrical Fabrication Projects in ICF KH Shops, June, 1995.`` It contains the investigation scope, executive summary, relevant facts, analysis, conclusions and corrective actions. DOE Order 5484.1, ``Environmental Protection, Safety and Health Protection Information Reporting Requirements,`` was followed in preparation of this report. Because the incident was electrical in nature and involved both Westinghouse Hanford Company and ICF Kaiser Hanford organizations, the board included members from both contractors and members with considerable electrical expertise.

  19. The effect of kerosene injection on ignition probability of local ignition in a scramjet combustor

    NASA Astrophysics Data System (ADS)

    Bao, Heng; Zhou, Jin; Pan, Yu

    2017-03-01

    The spark ignition of kerosene is investigated in a scramjet combustor with a flight condition of Ma 4, 17 km. Based plentiful of experimental data, the ignition probabilities of the local ignition have been acquired for different injection setups. The ignition probability distributions show that the injection pressure and injection location have a distinct effect on spark ignition. The injection pressure has both upper and lower limit for local ignition. Generally, the larger mass flow rate will reduce the ignition probability. The ignition position also affects the ignition near the lower pressure limit. The reason is supposed to be the cavity swallow effect on upstream jet spray near the leading edge, which will make the cavity fuel rich. The corner recirculation zone near the front wall of the cavity plays a significant role in the stabilization of local flame.

  20. 75 FR 37310 - Control of Emissions From New and In-Use Nonroad Compression-Ignition Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-29

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 1039 Control of Emissions From New and In-Use Nonroad Compression- Ignition Engines CFR Correction In Title 40 of the Code of Federal Regulations, Part 1000 to End, revised as of July...

  1. Response to Comment on "The National Ignition Facility Laser Performance Status"

    SciTech Connect

    Haynam, C A; Sacks, R A; Moses, E I; Manes, K; Haan, S; Spaeth, M L

    2007-12-11

    We appreciate Stephen Bodner's continuing interest in the performance of the NIF laser system. However, we find it necessary to disagree with the conclusions he reached in his comments [Appl. Opt. 47, XXX (2008)] on 'National Ignition Facility Laser Performance Status' [Appl. Opt. 46, 3276 (2007)]. In fact, repeated and ongoing tests of the NIF beamlines have demonstrated that NIF can be expected not only to meet or exceed its requirements as established in the mid-1990s in the document National Ignition Facility Functional Requirements and Primary Criteria [Revision 1.3, Report NIF-LLNL-93-058 (1994)], but also to have the flexibility that provides for successfully meeting an ever expanding range of mission goals, including those of ignition.

  2. 42 CFR 442.119 - Duration of denial of payments and subsequent termination of an ICF/MR.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Duration of denial of payments and subsequent termination of an ICF/MR. 442.119 Section 442.119 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... § 442.119 Duration of denial of payments and subsequent termination of an ICF/MR. (a) Period of...

  3. Tritium and ignition target management at the National Ignition Facility.

    PubMed

    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.

  4. An international qualitative study of ability and disability in ADHD using the WHO-ICF framework.

    PubMed

    Mahdi, Soheil; Viljoen, Marisa; Massuti, Rafael; Selb, Melissa; Almodayfer, Omar; Karande, Sunil; de Vries, Petrus J; Rohde, Luis; Bölte, Sven

    2017-03-28

    This is the third in a series of four cross-cultural empirical studies designed to develop International Classification of Functioning, Disability and Health (ICF, and Children and Youth version, ICF(-CY) Core Sets for Attention-Deficit Hyperactivity Disorder (ADHD). To explore the perspectives of individuals diagnosed with ADHD, self-advocates, immediate family members and professional caregivers on relevant areas of impairment and functional abilities typical for ADHD across the lifespan as operationalized by the ICF(-CY). A qualitative study using focus group discussions or semi-structured interviews of 76 participants, divided into 16 stakeholder groups. Participants from five countries (Brazil, India, Saudi Arabia, South Africa and Sweden) were included. A deductive qualitative content analysis was conducted to extract meaningful functioning and disability concepts from verbatim material. Extracted concepts were then linked to ICF(-CY) categories by independent researchers using a standardized linking procedure. In total, 82 ICF(-CY) categories were identified, of which 32 were related to activities and participation, 25 to environmental factors, 23 to body functions and 2 to body structures. Participants also provided opinions on experienced positive sides to ADHD. A high level of energy and drive, creativity, hyper-focus, agreeableness, empathy, and willingness to assist others were the most consistently reported strengths associated with ADHD. Stakeholder perspectives highlighted the need to appraise ADHD in a broader context, extending beyond diagnostic criteria into many areas of ability and disability as well as environmental facilitators and barriers. This qualitative study, along with three other studies (comprehensive scoping review, expert survey and clinical study), will provide the scientific basis to define ICF(-CY) Core Sets for ADHD, from which assessment tools can be derived for use in clinical and research setting, as well as in health care

  5. The Development of a Framework for Target Diagnostic Centralized Control System (TDCCS) in ICF Experiments

    NASA Astrophysics Data System (ADS)

    Zhang, Chi; Wang, Jian; Yu, Xiaoqi; Yang, Dong

    2008-02-01

    A framework for target diagnostic centralized control system (TDCCS) in inertial confinement fusion (ICF) experiment has been developed. The developed framework is based on the common object request broker architecture (CORBA) standard and part of the concept from the ICFRoot (a framework based on ROOT for ICF experiments) framework design. This framework is of a component architecture, including a message bus, command executer, status processor, parser and proxy. To test the function of the framework, a simplified prototype of the TDCCS has been developed as well.

  6. The role of experimental science in ICF -- examples from X-ray diagnostics and targets

    NASA Astrophysics Data System (ADS)

    Kilkenny, J. D.

    2016-10-01

    The USA Inertial Confinement Fusion (ICF) Program evolved from the Nuclear Test Program which had restricted shot opportunities for experimentalists to develop sophisticated experimental techniques. In contrast the ICF program in the US was able to increase the shot availability on its large facilities, and develop sophisticated targets and diagnostics to measure and understand the properties of the high energy density plasmas (HEDP) formed. Illustrative aspects of this evolution at Lawrence Livermore National Laboratory (LLNL), with examples of the development of diagnostics and target fabrication are described.

  7. Miniature laser ignited bellows motor

    NASA Technical Reports Server (NTRS)

    Renfro, Steven L.; Beckman, Tom M.

    1994-01-01

    A miniature optically ignited actuation device has been demonstrated using a laser diode as an ignition source. This pyrotechnic driven motor provides between 4 and 6 lbs of linear force across a 0.090 inch diameter surface. The physical envelope of the device is 1/2 inch long and 1/8 inch diameter. This unique application of optical energy can be used as a mechanical link in optical arming systems or other applications where low shock actuation is desired and space is limited. An analysis was performed to determine pyrotechnic materials suitable to actuate a bellows device constructed of aluminum or stainless steel. The aluminum bellows was chosen for further development and several candidate pyrotechnics were evaluated. The velocity profile and delivered force were quantified using an non-intrusive optical motion sensor.

  8. Diagnostics for Fast Ignition Science

    SciTech Connect

    MacPhee, A; Akli, K; Beg, F; Chen, C; Chen, H; Clarke, R; Hey, D; Freeman, R; Kemp, A; Key, M; King, J; LePape, S; Link, A; Ma, T; Nakamura, N; Offermann, D; Ovchinnikov, V; Patel, P; Phillips, T; Stephens, R; Town, R; Wei, M; VanWoerkom, L; Mackinnon, A

    2008-05-06

    The concept for Electron Fast Ignition Inertial Confinement Fusion demands sufficient laser energy be transferred from the ignitor pulse to the assembled fuel core via {approx}MeV electrons. We have assembled a suite of diagnostics to characterize such transfer. Recent experiments have simultaneously fielded absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256eV; spherically bent crystal imagers at 4 and 8keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung and electron and proton spectrometers (along the same line of sight); nuclear activation samples and a picosecond optical probe based interferometer. These diagnostics allow careful measurement of energy transport and deposition during and following laser-plasma interactions at extremely high intensities in both planar and conical targets. Augmented with accurate on-shot laser focal spot and pre-pulse characterization, these measurements are yielding new insight into energy coupling and are providing critical data for validating numerical PIC and hybrid PIC simulation codes in an area that is crucial for many applications, particularly fast ignition. Novel aspects of these diagnostics and how they are combined to extract quantitative data on ultra high intensity laser plasma interactions are discussed, together with implications for full-scale fast ignition experiments.

  9. Revision Rhinoplasty.

    PubMed

    Loyo, Myriam; Wang, Tom D

    2016-01-01

    Revision rhinoplasty is one of the most challenging operations the facial plastic surgeon performs given the complex 3-dimensional anatomy of the nose and the psychological impact it has on patients. The intricate interplay of cartilages, bone, and soft tissue in the nose gives it its aesthetic and function. Facial harmony and attractiveness depends greatly on the nose given its central position in the face. In the following article, the authors review common motivations and anatomic findings for patients seeking revision rhinoplasty based on the senior author's 30-year experience with rhinoplasty and a review of the literature.

  10. Understanding scaling of ignition metrics for high-yield implosions on the NIF

    NASA Astrophysics Data System (ADS)

    Springer, Paul; Hurricane, Omar; Hammer, J. H.; Callahan, D. A.; Casey, D. T.; Cerjan, C. J.; Edwards, M. J.; Field, J. E.; Gaffney, J.; Grim, G. P.; Kritcher, A. L.; Ma, T.; Macphee, A. G.; Munro, D. H.; Nora, R. C.; Patel, P. K.; Peterson, L.; Spears, B.

    2016-10-01

    The self-heating condition for an imploding hotspot requires understanding the balance between mechanical work, heating via fusion reactions, and the radiative and conduction losses. A 3D cognizant Lawson ignition threshold metric is derived based on net fusion hotspot heating achieved when hotspot rho-r and ion temperature exceed critical values that depend on the temperature-dependent loss mechanisms. Key to understanding and scaling such analysis is an accurate determination of hotspot density and pressure, which are generally inferred using the yield, the thermal temperature, and other experimental data. 3D flow and its effect on neutron spectra can lead to overestimation of the temperature, and underestimation of hotspot rho-r, energy, and ignition margin. In this work, we analyze these effects in NIF data, and propose new methods to avoid them. These simple, analytical methods are tested using the largest 2D ICF simulation dataset ever produced. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA273.

  11. Neutron spectrometry - An essential tool for diagnosing implosions at the National Ignition Facility

    SciTech Connect

    Mackinnon, A J; Johnson, M G; Frenje, J A; Casey, D T; Li, C K; Seguin, F H; Petrasso, R; Ashabranner, R; Cerjan, C; Clancy, T J; Bionta, R; Bleuel, D; Bond, E J; Caggiano, J A; Capenter, A; Eckart, M J; Edwards, M J; Friedrich, S; Glenzer, S H; Haan, S W; Hartouni, E P; Hatarik, R; Hachett, S P; McKernan, M; Jones, O; Lepape, S; Lerche, R A; Landen, O L; Moran, M; Moses, E; Munro, D; McNaney, J; Rygg, J R; Sepke, S; Spears, B; Springer, P; Yeamans, C; Farrell, M; Kilkenny, J D; Nikroo, A; Paguio, R; Knauer, J; Glebov, V; Sangster, T; Betti, R; Stoeckl, C; Magoon, J; Shoup, M J; Grim, G P; Moran, G L; Murphy, T J; Leeper, R J; Ruiz, C

    2012-05-02

    DT neutron yield (Y{sub n}), ion temperature (T{sub i}) and down-scatter ratio (dsr) determined from measured neutron spectra are essential metrics for diagnosing the performance of Inertial Confinement Fusion (ICF) implosions at the National Ignition Facility (NIF). A suite of neutron-Time-Of-Flight (nTOF) spectrometers and a Magnetic Recoil Spectrometer (MRS) have been implemented in different locations around the NIF target chamber, providing good implosion coverage and the redundancy required for reliable measurements of Yn, Ti and dsr. From the measured dsr value, an areal density ({rho}R) is determined from the relationship {rho}R{sub tot} (g/cm{sup 2}) = (20.4 {+-} 0.6) x dsr{sub 10-12 MeV}. The proportionality constant is determined considering implosion geometry, neutron attenuation and energy range used for the dsr measurement. To ensure high accuracy in the measurements, a series of commissioning experiments using exploding pushers have been used for in situ calibration. The spectrometers are now performing to the required accuracy, as indicated by the good agreement between the different measurements over several commissioning shots. In addition, recent data obtained with the MRS and nTOFs indicate that the implosion performance of cryogenically layered DT implosions, characterized by the experimental Ignition Threshold Factor (ITFx) which is a function of dsr (or fuel {rho}R) and Y{sub n}, has improved almost two orders of magnitude since the first shot in September, 2010.

  12. Modeling down-scattered neutron images from cryogenic fuel implosions at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Raman, Kumar; Casey, Dan; Callahan, Debra; Clark, Dan; Fittinghoff, David; Grim, Gary; Hatchett, Steve; Hinkel, Denise; Jones, Ogden; Kritcher, Andrea; Seek, Scott; Suter, Larry; Merrill, Frank; Wilson, Doug

    2016-10-01

    In experiments with cryogenic deuterium-tritium (DT) fuel layers at the National Ignition Facility (NIF), an important technique for visualizing the stagnated fuel assembly is to image the 6-12 MeV neutrons created by scatters of the 14 MeV hotspot neutrons in the surrounding cold fuel. However, such down-scattered neutron images are difficult to interpret without a model of the fuel assembly, because of the nontrivial neutron kinematics involved in forming the images. For example, the dominant scattering modes are at angles other than forward scattering and the 14 MeV neutron fluence is not uniform. Therefore, the intensity patterns in these images usually do not correspond in a simple way to patterns in the fuel distribution, even for simple fuel distributions. We describe our efforts to model synthetic images from ICF design simulations with data from the National Ignition Campaign and after. We discuss the insight this gives, both to understand how well the models are predicting fuel asymmetries and to inform how to optimize the diagnostic for the types of fuel distributions being predicted. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  13. Neutron spectrometry--an essential tool for diagnosing implosions at the National Ignition Facility (invited).

    PubMed

    Gatu Johnson, M; Frenje, J A; Casey, D T; Li, C K; Séguin, F H; Petrasso, R; Ashabranner, R; Bionta, R M; Bleuel, D L; Bond, E J; Caggiano, J A; Carpenter, A; Cerjan, C J; Clancy, T J; Doeppner, T; Eckart, M J; Edwards, M J; Friedrich, S; Glenzer, S H; Haan, S W; Hartouni, E P; Hatarik, R; Hatchett, S P; Jones, O S; Kyrala, G; Le Pape, S; Lerche, R A; Landen, O L; Ma, T; MacKinnon, A J; McKernan, M A; Moran, M J; Moses, E; Munro, D H; McNaney, J; Park, H S; Ralph, J; Remington, B; Rygg, J R; Sepke, S M; Smalyuk, V; Spears, B; Springer, P T; Yeamans, C B; Farrell, M; Jasion, D; Kilkenny, J D; Nikroo, A; Paguio, R; Knauer, J P; Glebov, V Yu; Sangster, T C; Betti, R; Stoeckl, C; Magoon, J; Shoup, M J; Grim, G P; Kline, J; Morgan, G L; Murphy, T J; Leeper, R J; Ruiz, C L; Cooper, G W; Nelson, A J

    2012-10-01

    DT neutron yield (Y(n)), ion temperature (T(i)), and down-scatter ratio (dsr) determined from measured neutron spectra are essential metrics for diagnosing the performance of inertial confinement fusion (ICF) implosions at the National Ignition Facility (NIF). A suite of neutron-time-of-flight (nTOF) spectrometers and a magnetic recoil spectrometer (MRS) have been implemented in different locations around the NIF target chamber, providing good implosion coverage and the complementarity required for reliable measurements of Y(n), T(i), and dsr. From the measured dsr value, an areal density (ρR) is determined through the relationship ρR(tot) (g∕cm(2)) = (20.4 ± 0.6) × dsr(10-12 MeV). The proportionality constant is determined considering implosion geometry, neutron attenuation, and energy range used for the dsr measurement. To ensure high accuracy in the measurements, a series of commissioning experiments using exploding pushers have been used for in situ calibration of the as-built spectrometers, which are now performing to the required accuracy. Recent data obtained with the MRS and nTOFs indicate that the implosion performance of cryogenically layered DT implosions, characterized by the experimental ignition threshold factor (ITFx), which is a function of dsr (or fuel ρR) and Y(n), has improved almost two orders of magnitude since the first shot in September, 2010.

  14. A sustained-arc ignition system for internal combustion engines

    NASA Technical Reports Server (NTRS)

    Birchenough, A. G.

    1977-01-01

    A sustained-arc ignition system was developed for internal combustion engines. It produces a very-long-duration ignition pulse with an energy in the order of 100 millijoules. The ignition pulse waveform can be controlled to predetermined actual ignition requirements. The design of the sustained-arc ignition system is presented in the report.

  15. Catalytic ignition of hydrogen and oxygen propellants

    NASA Technical Reports Server (NTRS)

    Zurawski, Robert L.; Green, James M.

    1988-01-01

    An experimental program was conducted to evaluate the catalytic ignition of gaseous hydrogen and oxygen propellants. Shell 405 granular catalyst and a monolithic sponge catalyst were tested. Mixture ratio, mass flow rate, propellant temperature, and back pressure were varied parametrically in testing to determine the operational limits of the catalytic igniter. The test results show that the gaseous hydrogen and oxygen propellant combination can be ignited catalytically using Shell 405 catalyst over a wide range of mixture ratios, mass flow rates, and propellant injection temperatures. These operating conditions must be optimized to ensure reliable ignition for an extended period of time. A cyclic life of nearly 2000, 2 sec pulses at nominal operating conditions was demonstrated with the catalytic igniter. The results of the experimental program and the established operational limits for a catalytic igniter using the Shell 405 catalyst are presented.

  16. Catalytic ignition of hydrogen and oxygen propellants

    NASA Technical Reports Server (NTRS)

    Zurawski, Robert L.; Green, James M.

    1988-01-01

    An experimental program was conducted to evaluate the catalytic ignition of gaseous hydrogen and oxygen propellants. Shell 405 granular catalyst and a monolithic sponge catalyst were tested. Mixture ratio, mass flow rate, propellant temperature, and back pressure were varied parametrically in testing to determine the operational limits of the catalytic igniter. The test results show that the gaseous hydrogen and oxygen propellant combination can be ignited catalytically using Shell 405 catalyst over a wide range of mixture ratios, mass flow rates, and propellant injection temperatures. These operating conditions must be optimized to ensure reliable ignition for an extended period of time. A cyclic life of nearly 2000, 2 sec pulses at nominal operating conditions was demonstrated with the catalytic igniter. The results of the experimental program and the established operational limits for a catalytic igniter using the Shell 405 catalysts are presented.

  17. Surface Modification of ICF Target Capsules by Pulsed Laser Ablation

    SciTech Connect

    Carlson, Lane C.; Johnson, Michael A.; Bunn, Thomas L.

    2016-06-30

    Topographical modifications of spherical surfaces are imprinted on National Ignition Facility (NIF) target capsules by extending the capabilities of a recently developed full surface (4π) laser ablation and mapping apparatus. The laser ablation method combines the precision, energy density and long reach of a focused laser beam to pre-impose sinusoidal modulations on the outside surface of High Density Carbon (HDC) capsules and the inside surface of Glow Discharge Polymer (GDP) capsules. Sinusoidal modulations described in this paper have sub-micron to 10’s of microns vertical scale and wavelengths as small as 30 μm and as large as 200 μm. The modulated patterns are created by rastering a focused laser fired at discrete capsule surface locations for a specified number of pulses. The computer program developed to create these raster patterns uses inputs such as laser beam intensity profile, the material removal function, the starting surface figure and the desired surface figure. The patterns are optimized to minimize surface roughness. Lastly, in this paper, simulated surfaces are compared with actual ablated surfaces measured using confocal microscopy.

  18. Surface Modification of ICF Target Capsules by Pulsed Laser Ablation

    DOE PAGES

    Carlson, Lane C.; Johnson, Michael A.; Bunn, Thomas L.

    2016-06-30

    Topographical modifications of spherical surfaces are imprinted on National Ignition Facility (NIF) target capsules by extending the capabilities of a recently developed full surface (4π) laser ablation and mapping apparatus. The laser ablation method combines the precision, energy density and long reach of a focused laser beam to pre-impose sinusoidal modulations on the outside surface of High Density Carbon (HDC) capsules and the inside surface of Glow Discharge Polymer (GDP) capsules. Sinusoidal modulations described in this paper have sub-micron to 10’s of microns vertical scale and wavelengths as small as 30 μm and as large as 200 μm. The modulatedmore » patterns are created by rastering a focused laser fired at discrete capsule surface locations for a specified number of pulses. The computer program developed to create these raster patterns uses inputs such as laser beam intensity profile, the material removal function, the starting surface figure and the desired surface figure. The patterns are optimized to minimize surface roughness. Lastly, in this paper, simulated surfaces are compared with actual ablated surfaces measured using confocal microscopy.« less

  19. Ignitability of some insulation and building materials

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Murphy, R. M.

    1978-01-01

    A variety of insulation and building materials were evaluated for ignitability, using a screening test method developed at the University of San Francisco. Ignitability tended to be greater with the more efficient insulation materials because the insulating qualities resulted in a more rapid rise in temperature at the exposed surface. The use of a noncombustible facing material is recommended to provide protection from surface ignition.

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

    SciTech Connect

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

    1997-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Foley, Richard J.; Karpenko, Victor P.; Adams, Chris H.; Patel, C. S.; Pittenger, L. C.; Lee, F. Dean; Reitz, T. C.; Hibbard, Wilthea J.; Horton, W. R.; Trummer, David J.; Tobin, Michael T.; McDonald, Anthony E.; Wavrik, R. W.; Pittman, P. C.

    1997-12-01

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

  2. Progress towards ignition on the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Edwards, M. J.; Patel, P. K.; Lindl, J. D.; Atherton, L. J.; Glenzer, S. H.; Haan, S. W.; Kilkenny, J. D.; Landen, O. L.; Moses, E. I.; Nikroo, A.; Petrasso, R.; Sangster, T. C.; Springer, P. T.; Batha, S.; Benedetti, R.; Bernstein, L.; Betti, R.; Bleuel, D. L.; Boehly, T. R.; Bradley, D. K.; Caggiano, J. A.; Callahan, D. A.; Celliers, P. M.; Cerjan, C. J.; Chen, K. C.; Clark, D. S.; Collins, G. W.; Dewald, E. L.; Divol, L.; Dixit, S.; Doeppner, T.; Edgell, D. H.; Fair, J. E.; Farrell, M.; Fortner, R. J.; Frenje, J.; Gatu Johnson, M. G.; Giraldez, E.; Glebov, V. Yu.; Grim, G.; Hammel, B. A.; Hamza, A. V.; Harding, D. R.; Hatchett, S. P.; Hein, N.; Herrmann, H. W.; Hicks, D.; Hinkel, D. E.; Hoppe, M.; Hsing, W. W.; Izumi, N.; Jacoby, B.; Jones, O. S.; Kalantar, D.; Kauffman, R.; Kline, J. L.; Knauer, J. P.; Koch, J. A.; Kozioziemski, B. J.; Kyrala, G.; LaFortune, K. N.; Pape, S. Le; Leeper, R. J.; Lerche, R.; Ma, T.; MacGowan, B. J.; MacKinnon, A. J.; Macphee, A.; Mapoles, E. R.; Marinak, M. M.; Mauldin, M.; McKenty, P. W.; Meezan, M.; Michel, P. A.; Milovich, J.; Moody, J. D.; Moran, M.; Munro, D. H.; Olson, C. L.; Opachich, K.; Pak, A. E.; Parham, T.; Park, H.-S.; Ralph, J. E.; Regan, S. P.; Remington, B.; Rinderknecht, H.; Robey, H. F.; Rosen, M.; Ross, S.; Salmonson, J. D.; Sater, J.; Schneider, D. H.; Séguin, F. H.; Sepke, S. M.; Shaughnessy, D. A.; Smalyuk, V. A.; Spears, B. K.; Stoeckl, C.; Stoeffl, W.; Suter, L.; Thomas, C. A.; Tommasini, R.; Town, R. P.; Weber, S. V.; Wegner, P. J.; Widman, K.; Wilke, M.; Wilson, D. C.; Yeamans, C. B.; Zylstra, A.

    2013-07-01

    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/cm3 with an areal density (ρR) of ˜1.5 g/cm2, surrounding a lower density hot spot with a temperature of ˜10 keV and a ρR ˜0.3 g/cm2, 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.

  3. Indirect drive ignition at the National Ignition Facility

    DOE PAGES

    Meezan, N. B.; Edwards, M. J.; Hurricane, O. A.; ...

    2016-10-27

    This article reviews scientific results from the pursuit of indirect drive ignition on the National Ignition Facility (NIF) and describes the program's forward looking research directions. In indirect drive on the NIF, laser beams heat an x-ray enclosure called a hohlraum that surrounds a spherical pellet. X-ray radiation ablates the surface of the pellet, imploding a thin shell of deuterium/tritium (DT) that must accelerate to high velocity (v > 350 km s-1) and compress by a factor of several thousand. Since 2009, substantial progress has been made in understanding the major challenges to ignition: Rayleigh Taylor (RT) instability seeded bymore » target imperfections; and low-mode asymmetries in the hohlraum x-ray drive, exacerbated by laser-plasma instabilities (LPI). Requirements on velocity, symmetry, and compression have been demonstrated separately on the NIF but have not been achieved simultaneously. We now know that the RT instability, seeded mainly by the capsule support tent, severely degraded DT implosions from 2009–2012. Experiments using a 'high-foot' drive with demonstrated lower RT growth improved the thermonuclear yield by a factor of 10, resulting in yield amplification due to alpha particle heating by more than a factor of 2. However, large time dependent drive asymmetry in the LPI-dominated hohlraums remains unchanged, preventing further improvements. High fidelity 3D hydrodynamic calculations explain these results. In conclusion, future research efforts focus on improved capsule mounting techniques and on hohlraums with little LPI and controllable symmetry. In parallel, we are pursuing improvements to the basic physics models used in the design codes through focused physics experiments.« less

  4. Indirect drive ignition at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Meezan, N. B.; Edwards, M. J.; Hurricane, O. A.; Patel, P. K.; Callahan, D. A.; Hsing, W. W.; Town, R. P. J.; Albert, F.; Amendt, P. A.; Berzak Hopkins, L. F.; Bradley, D. K.; Casey, D. T.; Clark, D. S.; Dewald, E. L.; Dittrich, T. R.; Divol, L.; Döppner, T.; Field, J. E.; Haan, S. W.; Hall, G. N.; Hammel, B. A.; Hinkel, D. E.; Ho, D. D.; Hohenberger, M.; Izumi, N.; Jones, O. S.; Khan, S. F.; Kline, J. L.; Kritcher, A. L.; Landen, O. L.; LePape, S.; Ma, T.; MacKinnon, A. J.; MacPhee, A. G.; Masse, L.; Milovich, J. L.; Nikroo, A.; Pak, A.; Park, H.-S.; Peterson, J. L.; Robey, H. F.; Ross, J. S.; Salmonson, J. D.; Smalyuk, V. A.; Spears, B. K.; Stadermann, M.; Suter, L. J.; Thomas, C. A.; Tommasini, R.; Turnbull, D. P.; Weber, C. R.

    2017-01-01

    This paper reviews scientific results from the pursuit of indirect drive ignition on the National Ignition Facility (NIF) and describes the program’s forward looking research directions. In indirect drive on the NIF, laser beams heat an x-ray enclosure called a hohlraum that surrounds a spherical pellet. X-ray radiation ablates the surface of the pellet, imploding a thin shell of deuterium/tritium (DT) that must accelerate to high velocity (v  >  350 km s-1) and compress by a factor of several thousand. Since 2009, substantial progress has been made in understanding the major challenges to ignition: Rayleigh Taylor (RT) instability seeded by target imperfections; and low-mode asymmetries in the hohlraum x-ray drive, exacerbated by laser-plasma instabilities (LPI). Requirements on velocity, symmetry, and compression have been demonstrated separately on the NIF but have not been achieved simultaneously. We now know that the RT instability, seeded mainly by the capsule support tent, severely degraded DT implosions from 2009-2012. Experiments using a ‘high-foot’ drive with demonstrated lower RT growth improved the thermonuclear yield by a factor of 10, resulting in yield amplification due to alpha particle heating by more than a factor of 2. However, large time dependent drive asymmetry in the LPI-dominated hohlraums remains unchanged, preventing further improvements. High fidelity 3D hydrodynamic calculations explain these results. Future research efforts focus on improved capsule mounting techniques and on hohlraums with little LPI and controllable symmetry. In parallel, we are pursuing improvements to the basic physics models used in the design codes through focused physics experiments.

  5. Indirect drive ignition at the National Ignition Facility

    SciTech Connect

    Meezan, N. B.; Edwards, M. J.; Hurricane, O. A.; Patel, P. K.; Callahan, D. A.; Hsing, W. W.; Town, R. P. J.; Albert, F.; Amendt, P. A.; Berzak Hopkins, L. F.; Bradley, D. K.; Casey, D. T.; Clark, D. S.; Dewald, E. L.; Dittrich, T. R.; Divol, L.; Döppner, T.; Field, J. E.; Haan, S. W.; Hall, G. N.; Hammel, B. A.; Hinkel, D. E.; Ho, D. D.; Hohenberger, M.; Izumi, N.; Jones, O. S.; Khan, S. F.; Kline, J. L.; Kritcher, A. L.; Landen, O. L.; LePape, S.; Ma, T.; MacKinnon, A. J.; MacPhee, A. G.; Masse, L.; Milovich, J. L.; Nikroo, A.; Pak, A.; Park, H-S; Peterson, J. L.; Robey, H. F.; Ross, J. S.; Salmonson, J. D.; Smalyuk, V. A.; Spears, B. K.; Stadermann, M.; Suter, L. J.; Thomas, C. A.; Tommasini, R.; Turnbull, D. P.; Weber, C. R.

    2016-10-27

    This article reviews scientific results from the pursuit of indirect drive ignition on the National Ignition Facility (NIF) and describes the program's forward looking research directions. In indirect drive on the NIF, laser beams heat an x-ray enclosure called a hohlraum that surrounds a spherical pellet. X-ray radiation ablates the surface of the pellet, imploding a thin shell of deuterium/tritium (DT) that must accelerate to high velocity (v > 350 km s-1) and compress by a factor of several thousand. Since 2009, substantial progress has been made in understanding the major challenges to ignition: Rayleigh Taylor (RT) instability seeded by target imperfections; and low-mode asymmetries in the hohlraum x-ray drive, exacerbated by laser-plasma instabilities (LPI). Requirements on velocity, symmetry, and compression have been demonstrated separately on the NIF but have not been achieved simultaneously. We now know that the RT instability, seeded mainly by the capsule support tent, severely degraded DT implosions from 2009–2012. Experiments using a 'high-foot' drive with demonstrated lower RT growth improved the thermonuclear yield by a factor of 10, resulting in yield amplification due to alpha particle heating by more than a factor of 2. However, large time dependent drive asymmetry in the LPI-dominated hohlraums remains unchanged, preventing further improvements. High fidelity 3D hydrodynamic calculations explain these results. In conclusion, future research efforts focus on improved capsule mounting techniques and on hohlraums with little LPI and controllable symmetry. In parallel, we are pursuing improvements to the basic physics models used in the design codes through focused physics experiments.

  6. DNA is hypomethylated at repetitive and single copy loci in patients with ICF syndrome

    SciTech Connect

    Schuffenhauer, S.; Buchholz, B.; Neitinger, T.

    1994-09-01

    ICF syndrome (immunodeficiency, centromeric heterochromatin instability, facial anomaly) is a very rare genetic disorder, reported in only 12 cases. Chromosomal rearrangements occur predominantly in the heterochromatic regions of HC 1 and 16 and include stretching, whole arm deletions and multibranched configurations. The molecular defect of these abnormalities is not known. Similar abnormalities have been found in cell cultures treated with viruses or 5-acacytidine, agents which cause DNA hypomethylation. Because heterochromatic DNA is known to be highly methylated, we hypothesise that DNA hypomethylation and subsequent disturbance of heterochromatin structure may play a role in the chromosomal rearrangements of ICF syndrome. Methylation studies in DNA from peripheral lymphocytes of two non-related ICF patients revealed hypomethylation of satellite-2 DNA localized in the heterochromatic regions of HC 1 and 16. DNA hypomethylation was also found at single copy loci, e.g. D15S63, D15S9, H19 and DXS255. Differences between the two patients suggest a random distribution of DNA hypomethylation. While a causal relationship between the molecular and cytogenetic abnormalities is likely, the postulated relationship between hypomethylation and the clinical symptoms in ICF syndrome remains to be elucidated.

  7. Analyses in support of the Laboratory Microfusion Facility and ICF commercial reactor designs

    SciTech Connect

    Meier, W.R.; Monsler, M.J.

    1988-12-28

    Our work on this contract was divided into two major categories; two thirds of the total effort was in support of the Laboratory Microfusion Facility (LMF), and one third of the effort was in support of Inertial Confinement Fusion (ICF) commercial reactors. This final report includes copies of the formal reports, memoranda, and viewgraph presentations that were completed under this contract.

  8. Disability and Functional Profiles of Patients with Myasthenia Gravis Measured with ICF Classification

    ERIC Educational Resources Information Center

    Leonardi, Matilde; Raggi, Alberto; Antozzi, Carlo; Confalonieri, Paolo; Maggi, Lorenzo; Cornelio, Ferdinando; Mantegazza, Renato

    2009-01-01

    The objective of this study is to describe functional profiles of patients with myasthenia gravis (MG), and the relationships among symptoms, activities and environmental factors (EF), by using WHO's International Classification of Functioning Disability and Health (ICF). Patients were consecutively enrolled at the Besta Institute of Milan, Italy.…

  9. LANL Q2 2016 Quarterly Progress Report. Science Campaign and ICF

    SciTech Connect

    Douglas, Melissa Rae

    2016-04-07

    This progress report includes highlights for the Science Campaign and ICF about Advanced Certification and Assessment Methodologies, Implosion Hydrodynamics (C-1, SCE), Materials and Nuclear Science (C-1, C-2), Capabilities for Nuclear Intelligence, and High Energy Density Science (C-1, C-4, C-10). Upcoming meetings, briefings, and experiments are then listed for April and May.

  10. 42 CFR 442.15 - Duration of agreement for ICF/IIDs.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Duration of agreement for ICF/IIDs. 442.15 Section 442.15 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS STANDARDS FOR PAYMENT TO NURSING FACILITIES AND INTERMEDIATE...

  11. Utility of the International Classification of Functioning, Disability and Health (ICF) for Educational Psychologists' Work

    ERIC Educational Resources Information Center

    Aljunied, Mariam; Frederickson, Norah

    2014-01-01

    Despite embracing a bio-psycho-social perspective, the World Health Organization's International Classification of Functioning, Disability and Health (ICF) assessment framework has had limited application to date with children who have special educational needs (SEN). This study examines its utility for educational psychologists' work with…

  12. The development and application of advanced analytical methods to commercial ICF reactor chambers. Final report

    SciTech Connect

    Cousseau, P.; Engelstad, R.; Henderson, D.L.

    1997-10-01

    Progress is summarized in this report for each of the following tasks: (1) multi-dimensional radiation hydrodynamics computer code development; (2) 2D radiation-hydrodynamic code development; (3) ALARA: analytic and Laplacian adaptive radioactivity analysis -- a complete package for analysis of induced activation; (4) structural dynamics modeling of ICF reactor chambers; and (5) analysis of self-consistent target chamber clearing.

  13. Disability and Profiles of Functioning of Patients with Parkinson's Disease Described with ICF Classification

    ERIC Educational Resources Information Center

    Raggi, Alberto; Leonardi, Matilde; Ajovalasit, Daniela; Carella, Francesco; Soliveri, Paola; Albanese, Alberto; Romito, Luigi

    2011-01-01

    The objective of this study was to describe the functional profiles of patients with Parkinson's disease (PD), and the relationships between impairment in body functions, limitations in activities, and environmental factors, using the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). Patients…

  14. Advanced Concept Exploration for Fast Ignition Science Program, Final Report

    SciTech Connect

    Stephens, Richard Burnite; McLean, Harry M.; Theobald, Wolfgang; Akli, Kramer U.; Beg, Farhat N.; Sentoku, Yasuhiko; Schumacher, Douglass W.; Wei, Mingsheng

    2013-09-04

    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 reactors. FI differs from conventional “central hot spot” (CHS) target ignition by decoupling compression from heating: using a laser (or heavy ion beam or Z pinch) drive pulse (10’s of nanoseconds) to create a dense fuel and a second, much shorter (~10 picoseconds) high intensity pulse to ignite a small volume within the dense fuel. The physics of fast ignition process was the focus of our Advanced Concept Exploration (ACE) program. Ignition depends critically on two major issues involving Relativistic High Energy Density (RHED) physics: The laser-induced creation of fast electrons and their propagation in high-density plasmas. Our program has developed new experimental platforms, diagnostic packages, computer modeling analyses, and taken advantage of the increasing energy available at laser facilities to advance understanding of the fundamental physics underlying these issues. Our program had three thrust areas: • Understand the production and characteristics of fast electrons resulting from FI relevant laser-plasma interactions and their dependence on laser prepulse and laser pulse length. • Investigate the subsequent fast electron transport in solid and through hot (FI-relevant) plasmas. • Conduct and understand integrated core-heating experiments by comparison to simulations. Over the whole period of this project (three years for this contract), we have greatly advanced our fundamental understanding of the underlying properties in all three areas: • Comprehensive studies on fast electron source characteristics have shown that they are controlled by the laser intensity distribution and the topology and plasma density gradient. Laser pre-pulse induced pre-plasma in front of a solid surface results in increased stand-off distances from the electron origin to the high density

  15. Modelling piloted ignition of wood and plastics

    SciTech Connect

    Blijderveen, Maarten van; Bramer, Eddy A.; Brem, Gerrit

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We model piloted ignition times of wood and plastics. Black-Right-Pointing-Pointer The model is applied on a packed bed. Black-Right-Pointing-Pointer When the air flow is above a critical level, no ignition can take place. - Abstract: To gain insight in the startup of an incinerator, this article deals with piloted ignition. A newly developed model is described to predict the piloted ignition times of wood, PMMA and PVC. The model is based on the lower flammability limit and the adiabatic flame temperature at this limit. The incoming radiative heat flux, sample thickness and moisture content are some of the used variables. Not only the ignition time can be calculated with the model, but also the mass flux and surface temperature at ignition. The ignition times for softwoods and PMMA are mainly under-predicted. For hardwoods and PVC the predicted ignition times agree well with experimental results. Due to a significant scatter in the experimental data the mass flux and surface temperature calculated with the model are hard to validate. The model is applied on the startup of a municipal waste incineration plant. For this process a maximum allowable primary air flow is derived. When the primary air flow is above this maximum air flow, no ignition can be obtained.

  16. A premixed hydrogen/oxygen catalytic igniter

    NASA Technical Reports Server (NTRS)

    Green, James M.

    1989-01-01

    The catalytic ignition of hydrogen and oxygen propellants was studied using a premixing hydrogen/oxygen injector. The premixed injector was designed to eliminate problems associated with catalytic ignition caused by poor propellant mixing in the catalyst bed. Mixture ratio, mass flow rate, and propellant inlet temperature were varied parametrically in testing, and a pulse mode life test of the igniter was conducted. The results of the tests showed that the premixed injector eliminated flame flashback in the reactor and increased the life of the igniter significantly. The results of the experimental program and a comparison with data collected in a previous program are given.

  17. To adopt is to adapt: the process of implementing the ICF with an acute stroke multidisciplinary team in England

    PubMed Central

    Tempest, Stephanie; Harries, Priscilla; Kilbride, Cherry; De Souza, Lorraine

    2012-01-01

    Purpose: The success of the International Classifcation of Functioning, Disability and Health (ICF) depends on its uptake in clinical practice. This project aimed to explore ways the ICF could be used with an acute stroke multidisciplinary team and identify key learning from the implementation process. Method: Using an action research approach, iterative cycles of observe, plan, act and evaluate were used within three phases: exploratory; innovatory and refective. Thematic analysis was undertaken, using a model of immersion and crystallisation, on data collected via interview and focus groups, e-mail communications, minutes from relevant meetings, feld notes and a refective diary. Results: Two overall themes were determined from the data analysis which enabled implementation. There is a need to: (1) adopt the ICF in ways that meet local service needs; and (2) adapt the ICF language and format. Conclusions: The empirical fndings demonstrate how to make the ICF classifcation a clinical reality. First, we need to adopt the ICF as a vehicle to implement local service priorities e.g. to structure a multidisciplinary team report, thus enabling ownership of the implementation process. Second, we need to adapt the ICF terminology and format to make it acceptable for use by clinicians. PMID:22372376

  18. Systematic Literature Review on ICF From 2001 to 2013 in the Nordic Countries Focusing on Clinical and Rehabilitation Context

    PubMed Central

    Maribo, Thomas; Petersen, Kirsten S.; Handberg, Charlotte; Melchiorsen, Hanne; Momsen, Anne-Mette H.; Nielsen, Claus V.; Leonardi, Matilde; Labriola, Merete

    2016-01-01

    We present a systematic review on International Classification of Functioning, Disability and Health (ICF) used in the Nordic countries from 2001 through 2013, describing and quantifying the development in utilization of ICF, and describe the extent to which the different components of the ICF have been used. A search was conducted in EMBASE, MEDLINE and PsycInfo. Papers from Nordic countries were included if ICF was mentioned in title or abstract. Papers were assigned to one of eight categories covering the wide rehabilitation area; furthermore, area of focus was assigned. Use of ICF components and intervention were coded in papers categorized as “clinical and/or rehabilitation contexts” or “non-clinical contexts”. One hundred seventy papers were included, of these 99 papers were from the categories “clinical and/or rehabilitation contexts” or “non-clinical contexts”. Forty-two percent of the 170 included papers were published in the period 2011 - 2013. There was an increase in ICF-relevant papers from 2001 to 2013, especially in the categories “clinical and/or rehabilitation contexts” and “non-clinical contexts”. The most represented focus areas were neurology, musculoskeletal, and work-related areas. All five or at least four ICF components were mentioned in the results or discussions in most papers, and activity was most frequently mentioned. PMID:26668676

  19. First Measurements of Deuterium-Tritium and Deuterium-Deuterium Fusion Reaction Yields in Ignition-Scalable Direct-Drive Implosions

    NASA Astrophysics Data System (ADS)

    Forrest, C. J.; Radha, P. B.; Knauer, J. P.; Glebov, V. Yu.; Goncharov, V. N.; Regan, S. P.; Rosenberg, M. J.; Sangster, T. C.; Shmayda, W. T.; Stoeckl, C.; Gatu Johnson, M.

    2017-03-01

    The deuterium-tritium (D-T) and deuterium-deuterium neutron yield ratio in cryogenic inertial confinement fusion (ICF) experiments is used to examine multifluid effects, traditionally not included in ICF modeling. This ratio has been measured for ignition-scalable direct-drive cryogenic DT implosions at the Omega Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997), 10.1016/S0030-4018(96)00325-2] using a high-dynamic-range neutron time-of-flight spectrometer. The experimentally inferred yield ratio is consistent with both the calculated values of the nuclear reaction rates and the measured preshot target-fuel composition. These observations indicate that the physical mechanisms that have been proposed to alter the fuel composition, such as species separation of the hydrogen isotopes [D. T. Casey et al., Phys. Rev. Lett. 108, 075002 (2012), 10.1103/PhysRevLett.108.075002], are not significant during the period of peak neutron production in ignition-scalable cryogenic direct-drive DT implosions.

  20. Analysis of the confluence of three patterns using the Centering and Pointing System (CAPS) images for the Advanced Radiographic Capability (ARC) at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Leach, Richard R.; Awwal, Abdul; Bliss, Erlan; Roberts, Randy; Rushford, Michael; Wilhelmsen, Karl; Zobrist, Thomas

    2014-09-01

    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 pulses that generate X-rays which backlight highdensity internal confinement fusion (ICF) targets. Employing up to eight backlighters, ARC can produce an X-ray "motion picture" to diagnose the compression and ignition of a cryogenic deuterium-tritium target with tens-ofpicosecond temporal resolution during the critical phases of an ICF shot. Multi-frame, hard-X-ray radiography of imploding NIF capsules is a capability which is critical to the success of NIF's missions. The function of the Centering and Pointing System (CAPS) in ARC is to provide superimposed near-field and far-field images on a common optical path. The Images are then analyzed to extract beam centering and pointing data for the control system. The images contain the confluence of pointing, centering, and reference patterns. The patterns may have uneven illumination, particularly when the laser is misaligned. In addition, the simultaneous appearance of three reference patterns may be co-incidental, possibly masking one or more of the patterns. Image analysis algorithms have been developed to determine the centering and pointing position of ARC from these images. In the paper we describe the image analysis algorithms used to detect and identify the centers of these patterns. Results are provided, illustrating how well the process meets system requirements.

  1. Comparing contents of outcome measures in cerebral palsy using the International Classification of Functioning (ICF-CY): a systematic review.

    PubMed

    Schiariti, Veronica; Klassen, Anne F; Cieza, Alarcos; Sauve, Karen; O'Donnell, Maureen; Armstrong, Robert; Mâsse, Louise C

    2014-01-01

    The International Classification of Functioning children and youth version (ICF-CY) provides a universal framework for defining and classifying functioning and disability in children worldwide. To facilitate the application of the ICF in practice, ICF based-tools like the "ICF Core Sets" are being developed. In the context of the development of the ICF-CY Core Sets for children with Cerebral Palsy (CP), the aims of this study were as follows: to identify and compare the content of outcome measures used in studies of children with CP using the ICF-CY coding system; and to describe the most frequently addressed areas of functioning in those studies. We searched multiple databases likely to capture studies involving children with CP from January 1998 to March 2012. We included all English language articles that studied children aged 2-18 years and described an interventional or observational study. Constructs of the outcome measures identified in studies were linked to the ICF-CY by two trained professionals. We found 231 articles that described 238 outcome measures. The outcome measures contained 2193 concepts that were linked to the ICF-CY and covered 161 independent ICF-CY categories. Out of the 161 categories, 53 (33.5%) were related to body functions, 75 (46%) were related to activities/participation, 26 (16.1%) were related to environmental factors, and 7 (4.3%) were related to body structures. This systematic review provides information about content of measures that may guide researchers and clinicians in their selection of an outcome measure for use in a study and/or clinical practice with children with CP.

  2. Mutual colliding impact fast ignition

    SciTech Connect

    Winterberg, Friedwardt

    2014-09-15

    It is proposed to apply the well established colliding beam technology of high energy physics to the fast hot spot ignition of a highly compressed DT (deuterium-tritium) target igniting a larger D (deuterium) burn, by accelerating a small amount of solid deuterium, and likewise a small amount of tritium, making a head-on collision in the center of the target, projecting them through conical ducts situated at the opposite side of the target and converging in its center. In their head-on collision, the relative collision velocity is 5/3 times larger compared to the collision velocity of a stationary target. The two pieces have for this reason to be accelerated to a smaller velocity than would otherwise be needed to reach upon impact the same temperature. Since the velocity distribution of the two head-on colliding projectiles is with its two velocity peaks non-Maxwellian, the maximum cross section velocity product turns out to be substantially larger than the maximum if averaged over a Maxwellian. The D and T projectiles would have to be accelerated with two sabots driven by powerful particle or laser beams, permitting a rather large acceleration length. With the substantially larger cross section-velocity product by virtue of the non-Maxwellian velocity distribution, a further advantage is that the head-on collision produces a large magnetic field by the thermomagnetic Nernst effect, enhancing propagating burn. With this concept, the ignition of the neutron-less hydrogen-boron (HB{sup 11}) reaction might even be possible in a heterogeneous assembly of the hydrogen and the boron to reduce the bremsstrahlung-losses, resembling the heterogeneous assembly in a graphite-natural uranium reactor, there to reduce the neutron losses.

  3. Manufacturing of Igniters for NHB 8060.1 Testing

    NASA Technical Reports Server (NTRS)

    Williams, James

    1996-01-01

    The purpose of this WJI is to incorporate a standard procedure to prepare, certify, and ship standard NHB 8060.1B and NHB 8060.1C igniters for flammability testing and to update LJI-320-35-18. The operations are divided into five parts as follows: A. Preparing the igniter mix; B. Extruding the igniters; C. Curing, cutting, and weighing the igniters; D. Certifying the igniters and E. Packaging, storing, and shipping the igniters

  4. A Concept Exploration Program in Fast Ignition Inertial Fusion — Final Report

    SciTech Connect

    Stephens, Richarad Burnite; Freeman, Richard R.; Van Woekom, L. D.; Key, M.; MacKinnon, Andrew J.; Wei, Mingsheng

    2014-02-27

    The Fast Ignition (FI) approach to Inertial Confinement Fusion (ICF) holds particular promise for fusion energy because the independently generated compression and ignition pulses allow ignition with less compression, resulting in (potentially) higher gain. Exploiting this concept effectively requires an understanding of the transport of electrons in prototypical geometries and at relevant densities and temperatures. Our consortium, which included General Atomics (GA), The Ohio State University (OSU), the University of California, San Diego (UCSD), University of California, Davis (UC-Davis), and Princeton University under this grant (~$850K/yr) and Lawrence Livermore National Laboratory (LLNL) under a companion grant, won awards in 2000, renewed in 2005, to investigate the physics of electron injection and transport relevant to the FI concept, which is crucial to understand electron transport in integral FI targets. In the last two years we have also been preparing diagnostics and starting to extend the work to electron transport into hot targets. A complementary effort, the Advanced Concept Exploration (ACE) program for Fast Ignition, was funded starting in 2006 to integrate this understanding into ignition schemes specifically suitable for the initial fast ignition attempts on OMEGA and National Ignition Facility (NIF), and during that time these two programs have been managed as a coordinated effort. This result of our 7+ years of effort has been substantial. Utilizing collaborations to access the most capable laser facilities around the world, we have developed an understanding that was summarized in a Fusion Science & Technology 2006, Special Issue on Fast Ignition. The author lists in the 20 articles in that issue are dominated by our group (we are first authors in four of them). Our group has published, or submitted 67 articles, including 1 in Nature, 2 Nature Physics, 10 Physical Review Letters, 8 Review of Scientific Instruments, and has been invited to

  5. National Ignition Facility for Inertial Confinement Fusion

    SciTech Connect

    Paisner, J.A.; Murray, J.R.

    1997-10-08

    The National Ignition Facility for inertial confinement fusion will contain a 1.8 MJ, 500 TW frequency-tripled neodymium glass laser system that will be used to explore fusion ignition and other problems in the physics of high temperature and density. We describe the facility briefly. The NIF is scheduled to be completed in 2003.

  6. Advanced ignition and propulsion technology program

    SciTech Connect

    Oldenborg, R.; Early, J.; Lester, C.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Reliable engine re-ignition plays a crucial role in enabling commercial and military aircraft to fly safely at high altitudes. This project addressed research elements critical to the optimization of laser-based igniter. The effort initially involved a collaborative research and development agreement with B.F. Goodrich Aerospace and Laser Fare, Inc. The work involved integrated experiments with theoretical modeling to provide a basic understanding of the chemistry and physics controlling the laser-induced ignition of fuel aerosols produced by turbojet engine injectors. In addition, the authors defined advanced laser igniter configurations that minimize laser packaging size, weight, complexity and power consumption. These innovative ignition concepts were shown to reliably ignite jet fuel aerosols over a broad range of fuel/air mixture and a t fuel temperatures as low as -40 deg F. The demonstrated fuel ignition performance was highly superior to that obtained by the state-of-the-art, laser-spark ignition method utilizing comparable laser energy. The authors also developed a laser-based method that effectively removes optically opaque deposits of fuel hydrocarbon combustion residues from laser window surfaces. Seven patents have been either issued or are pending that resulted from the technology developments within this project.

  7. Igniting Women's Passion for Careers in STEM

    ERIC Educational Resources Information Center

    Platz, Cheryl

    2012-01-01

    One educator's attempt to pique girls' interest in nontraditional careers in the Seattle School District led to the creation of the now-international nonprofit IGNITE (Inspiring Girls Now in Technology Education). From its humble beginnings, IGNITE has impacted the lives of more than 20,000 girls, with thousands more across the globe each year.…

  8. 33 CFR 183.410 - Ignition protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Electrical Systems Manufacturer Requirements § 183.410 Ignition protection. (a) Each electrical component must not ignite a propane gas and air mixture that is 4.25 to 5.25 percent propane gas by volume surrounding the electrical component when it is operated...

  9. 14 CFR 33.69 - Ignitions system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ignitions system. 33.69 Section 33.69 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.69 Ignitions system....

  10. 14 CFR 33.69 - Ignitions system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ignitions system. 33.69 Section 33.69 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.69 Ignitions system....

  11. Heat transfer characteristics of igniter output plumes

    NASA Astrophysics Data System (ADS)

    Evans, N. A.; Durand, N. A.

    Seven types of pyrotechnic igniters were each mounted at one end of a closed cylindrical bore hole representative of the center hole in a thermal battery. Measurements of local bore wall temperature, T(sub w), using commercially available, fast response (10 microsec) sheathed chromel-constantan thermocouples allowed calculation of local heat transfer rates, q, and wall heat flows, Q. The principal charge constituents of all these igniters were titanium and potassium perchlorate, while three types also contained barium styphnate as an ignition sensitizer. Igniter closure disc materials included glass-ceramic, glass, metal (plain, scored, with and without capture cone), and kapton/RTV. All igniters produced the lowest values of T(sub w) and q at the beginning of the bore, and, except for the igniter with the kapton/RTV closure disc, these quantities increased with distance along the bore. For igniters containing only titanium/potassium perchlorate, the rates of increase of Q along the bore length, compared with those for T(sub w) and q, were generally lower and more variable. The inclusion of barium styphnate produced rates of change in Q that were essentially constant to the end of the bore. The highest overall average wall temperatures were achieved by two igniter types with metal closure discs and no capture cone. No clear correlation was established between peak bore pressure and maximum wall temperature.

  12. The use of beam propagation modeling of Beamlet and Nova to ensure a ``safe`` National Ignition Facility laser system design

    SciTech Connect

    Henesian, M.A.; Renard, P.; Auerbach, J.

    1997-03-17

    An exhaustive set of Beamlet and Nova laser system simulations were performed over a wide range of power levels in order to gain understanding about the statistical trends in Nova and Beamlet`s experimental data sets, and to provide critical validation of propagation tools and design ``rules`` applied to the 192-arm National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL). The experiments considered for modeling were at 220-ps FWHM duration with unpumped booster slabs on Beamlet, and 100-ps FWHM with pumped 31.5-cm and 46-cm disk amplifiers on Nova. Simulations indicated that on Beamlet, the AB (the intensity pendent phase shift parameter characterizing the tendency towards beam filamentation) for the booster amplifier stage without pumping, would be nearly identical to the AB expected on NIF at the peak of a typical 20-ns long shaped pulse intended for ICF target irradiation. Therefore, with energies less than I kJ in short-pulses, we examined on Beamlet the comparable AB-driven filamentation conditions predicted for long ICF pulseshapes in the 18 kJ regime on the NIF, while avoiding fluence dependent surface damage. Various spatial filter pinhole configurations were examined on Nova and Beamlet. Open transport spatial filter pinholes were used in some experiments to allow the direct measurement of the onset of beam filamentation. Schlieren images on Beamlet of the far field irradiance measuring the scattered light fraction outside of 33-{micro}radians were also obtained and compared to modeled results.

  13. Combined effects of laser and non-thermal electron beams on hydrodynamics and shock formation in the Shock Ignition scheme

    NASA Astrophysics Data System (ADS)

    Nicolai, Ph.; Feugeas, J. L.; Touati, M.; Breil, J.; Dubroca, B.; Nguyen-Buy, T.; Ribeyre, X.; Tikhonchuk, V.; Gus'kov, S.

    2014-10-01

    An issue to be addressed in Inertial Confinement Fusion (ICF) is the detailed description of the kinetic transport of relativistic or non-thermal electrons generated by laser within the time and space scales of the imploded target hydrodynamics. We have developed at CELIA the model M1, a fast and reduced kinetic model for relativistic electron transport. The latter has been implemented into the 2D radiation hydrodynamic code CHIC. In the framework of the Shock Ignition (SI) scheme, it has been shown in simplified conditions that the energy transferred by the non-thermal electrons from the corona to the compressed shell of an ICF target could be an important mechanism for the creation of ablation pressure. Nevertheless, in realistic configurations, taking the density profile and the electron energy spectrum into account, the target has to be carefully designed to avoid deleterious effects on compression efficiency. In addition, the electron energy deposition may modify the laser-driven shock formation and its propagation through the target. The non-thermal electron effects on the shock propagation will be analyzed in a realistic configuration.

  14. Ignition of a granular propellant bed

    SciTech Connect

    Wildegger-Gaissmaier, A.E.; Johnston, I.R.

    1996-08-01

    An experimental and theoretical study is reported on the ignition process of a low vulnerability ammunition (LOVA) propellant bed in a 127-mm (5-in) bore gun charge. The theoretical investigation was with a two-phase flow interior ballistics code and the model predictions showed the marked influence the igniter system can have on pressure wave development, flame spreading, and the overall interior ballistics performance. A number of different igniter systems were investigated in an empty and propellant-filled gun simulator. Pressure, flame spreading, and high-speed film records were used to analyze the ignition/combustion event. The model predictions for flame spreading were confirmed qualitatively by the experimental data. Full-scale instrumented gun firings were conducted with the optimized igniter design. Pressure waves were not detected in the charge during the firings. Model predictions on overall interior ballistics performance agreed well with the firing data.

  15. Ignition apparatus for internal combustion engine

    SciTech Connect

    Imoto, K.; Katada, H.

    1986-10-07

    An ignition apparatus is described for an internal combustion engine having a crankshaft and a camshaft coupled to the crankshaft to be rotated thereby, comprising: crankshaft position signal generating means for detecting that the crankshaft has rotated to a predetermined angular position and for generating crankshaft position signals in response to the detection; camshaft position signal generating means for detecting that the camshaft has rotated to a predetermined angular position and for generating camshaft position signals in response to the detection; command signal generating means coupled to receive the crankshaft position signals, for generating ignition command signals in response to the crankshaft position signals; and ignition circuit means for generating a high ignition voltage in response to the ignition command signals.

  16. Frictional Ignition Testing of Composite Materials

    NASA Technical Reports Server (NTRS)

    Peralta, Steve; Rosales, Keisa; Robinson, Michael J.; Stoltzfus, Joel

    2006-01-01

    The space flight community has been investigating lightweight composite materials for use in propellant tanks for both liquid and gaseous oxygen for space flight vehicles. The use of these materials presents some risks pertaining to ignition and burning hazards in the presence of oxygen. Through hazard analysis process, some ignition mechanisms have been identified as being potentially credible. One of the ignition mechanisms was reciprocal friction; however, test data do not exist that could be used to clear or fail these types of materials as "oxygen compatible" for the reciprocal friction ignition mechanism. Therefore, testing was performed at White Sands Test Facility (WSTF) to provide data to evaluate this ignition mechanism. This paper presents the test system, approach, data results, and findings of the reciprocal friction testing performed on composite sample materials being considered for propellant tanks.

  17. Introduction to the international classification of functioning disability and health - ICF - in the context of vestibular rehabilitation.

    PubMed

    Graziano, Mariella

    2013-01-01

    Vestibular rehabilitation focuses at decreasing the impact of symptoms, such as vertigo dizziness and imbalance have on people's daily life and their role in society. The international Classification of Functioning Disability and Health - ICF offers a unified and standard language and framework for describing health and health related states. The ICF aims at facilitating communication information about health, like functioning and disability. For this purpose the ICF has a systematic coding scheme for health data with more than 1400 categories. The big number of categories is impractical to apply in a specific area like vestibular disorders. Therefore a narrowing down to the relevant categories in a comprehensive core set for vertigo (100 categories) and a brief core set (29 categories) were developed. The purpose of this article is to reflect on the potential use of ICF in vestibular rehabilitation.

  18. [ICF and social medicine evaluation of capability of gainful activity: is everything clear?--a discussion article].

    PubMed

    Körner, M

    2005-08-01

    The ICF (International Classification of Functioning, Disability and Health) calls attention to the complexities associated with disturbances of health. The question raised is how the various constituents and the resulting network as defined by this Classification can gain importance for medical expertise under the statutory pension insurance scheme concerning work-related capacity. Possible variations of strategy are discussed: clinical intuition, algorithmic pathways, proved medical diagnostics, particular diagnostics of activity according to ICF. A genuine "silver bullet" is not in evidence thus far. It cannot be expected that diagnostics relating to a certain sector of the ICF will basically eclipse the rest. Future standards of medical expertise should specify as clearly as possible the impact of the diverse diagnostic findings on the assessment of work-related capacity. Framing emphasis in this way cannot be performed by the ICF on its own.

  19. Effect of initial conditions and Mach number on the Richtmyer-Meshkov instability in ICF like conditions

    NASA Astrophysics Data System (ADS)

    Rao, Pooja; She, Dan; Lim, Hyunkyung; Glimm, James

    2015-11-01

    The qualitative and quantitative effect of initial conditions (linear and non-linear) and high Mach number (1.3 and 1.45) is studied on the turbulent mixing induced by the Richtmyer-Meshkov instability in idealized ICF conditions. The Richtmyer-Meshkov instability seeds Rayleigh-taylor instabilities in ICF experiments and is one of the factors that contributes to reduced performance of ICF experiments. Its also found in collapsing cores of stars and supersonic combustion. We use the Stony Brook University code, FronTier, which is verified via a code comparison study against the AMR multiphysics code FLASH, and validated against vertical shock tube experiments done by the LANL Extreme Fluids Team. These simulations are designed as a step towards simulating more realistic ICF conditions and quantifying the detrimental effects of mixing on the yield.

  20. Feasibility of Applying the Extended ICF Core Set for Stroke to Clinical Settings in Rehabilitation: A Preliminary Study

    PubMed Central

    Han, Kyu Yong; Kim, Hyo Jong

    2015-01-01

    Objective To evaluate the potential feasibility of application of the extended International Classification of Functioning, Disability and Health (ICF) Core Set for stroke. Methods We retrospectively reviewed the medical records of 40 stroke outpatients (>6 months after onset) admitted to the Department of Rehabilitation Medicine for comprehensive rehabilitation. Clinical information of the patients were respectively evaluated to link to the 166 second-level categories of the extended ICF Core Set for stroke. Results Clinical information could be linked to 111 different ICF categories, 58 categories of the body functions component, eight categories of the body structures component, 38 categories of the activities and participation component, and seven categories of the environmental factors component. Conclusion The body functions component might be feasible for application of the extended ICF Core Set for stroke to clinical settings. The activities and participation component and environmental factors component may not be directly applied to clinical settings without additional evaluation tools including interview and questionnaire. PMID:25750873

  1. Health professionals identify components of the International Classification of Functioning, Disability and Health (ICF) in questionnaires for the upper limb

    PubMed Central

    Philbois, Stella V.; Martins, Jaqueline; Souza, Cesário S.; Sampaio, Rosana F.; Oliveira, Anamaria S.

    2016-01-01

    BACKGROUND: Several Brazilian studies have addressed the International Classification of Functioning, Disability and Health (ICF), but few have analyzed the knowledge of the health professionals with regards to the ICF. OBJECTIVE: To verify whether the classification of the items in the Brazilian-Portuguese versions of The Shoulder Pain and Disability Index (SPADI) and The Disabilities Arm, Shoulder and Hand (DASH) questionnaires, obtained from health professionals who worked with patients having upper limb injuries, could be related to ICF components as defined by others studies. METHOD: There were 4 participants for the group "professionals with high familiarity of the ICF (PHF)" and 19 for the group of "professionals with some or no familiarity of the ICF (PSNF)". The participants judged whether the items on the two questionnaires belonged to the ICF body function, body structure or activity-participation component, and marked a confidence level for each trial using a numerical scale ranging from zero to 10. The items were classified by the discriminant content validity method using the Student'st-test and the Hochberg correction. The ratings were compared to the literature by the percentage of agreement and Kappa coefficient. RESULTS: The percentage of agreement of the rating from the PSNF and the PHF groups with the literature was equal to or greater than 77%. For the DASH, the agreement of the PSNF and PHF groups with the literature were, respectively, moderate (Kappa=0.46 to 0.48) and substantial (Kappa=0.62 to 0.70). CONCLUSIONS: Health professionals were able to correlate the three components of the ICF for most items on the 2 questionnaires, demonstrating some ease of understanding the ICF components. However, the relation of concept of pain with body function component is not clear for professional and deserves a more attentive approach. PMID:26786076

  2. ACL Revision

    PubMed Central

    Costa-Paz, Matias; Dubois, Julieta Puig; Zicaro, Juan Pablo; Rasumoff, Alejandro; Yacuzzi, Carlos

    2017-01-01

    Objectives: The purpose of this study was to evaluate a series of patients one year after an ACL revision with clinical evaluation and MRI, to consider their condition before returning to sports activities. Methods: A descriptive, prospective and longitudinal study was performed. A series of patients who underwent an ACL revision between March 2014 and March 2015 were evaluated after one year post surgery. They were evaluated using the Lysholm score, IKDC, Tegner, artrometry and MRI (3.0 t). A signal pattern and osteointegration was determined in the MRI. Graft signal intensity of the ACL graft using the signal/noise quotient value (SNQ) was also determined to evaluate the ligamentatization process state. Results: A total of 18 male patients were evaluated with a mean age of 31 years old.Average scores were: Lysholm 88 points, IKDC 80 points, Pre-surgical Tegner 9 points and postoperative 4 points. Artrhometry (KT1000) at 20 newtons showed a side to side difference of less than 3 mm in 88%. Only 44% of patients returned to their previous sport activity one year after revision.The MRI showed a heterogeneous signal in neoligaments in 34% of patients. SNQ showed graft integration in only 28%. Synovial fluid was found in bone-graft interphase in 44% of tunnels, inferring partial osteointegration. The heterogeneous signal was present in 50% of patients who did not return to the previous sport level activity. (Fisher statistics: p = 0.043) There were no meaningful differences in patients with auto or allografts. Conclusion: Although the clinical evaluation was satisfactory, only 44% of patients returned to the previous level of sport activity one year after the ACL surgery. The ligamentatization process was found in 28% of knees evaluated with MRI one year later. Partial osteointegration is inferred in 44%. Results showed a meaningful relation between the signal of neoligaments in the MRI and the return to sport activity in said series of patients. MRI is a useful tool

  3. Sensitivity of NIF-scale backlit thin shell implosions to hohlraum symmetry in the foot of the ignition drive pulse

    SciTech Connect

    Kirkwood, R K; Milovich, J; Bradley, D K; Schmitt, M; Goldman, S R; Kalantar, D H; Meeker, D; Jones, O S; Pollaine, S M; Amendt, P A; Dewald, E; Edwards, J; Landen, O L; Nikroo, A

    2008-07-28

    A necessary condition for igniting indirectly-driven inertial confinement fusion (ICF) spherical capsules on the National Ignition Facility (NIF) is controlling drive flux asymmetry to the 1% level time-integrated over the pulse and with < 10%/ns swings during the pulse [J. D. Lindl et al., 'The Physics Basis for Ignition using Indirect Drive Targets on the National Ignition Facility', Physics of Plasmas 11, 339 (2003)]. While drive symmetry during the first 2 ns of the pulse can be inferred by using the re-emission pattern from a surrogate high Z sphere [E. Dewald et al. to be published in Rev. Sci. Inst.] and symmetry during the last 5 ns inferred from the shape of fully imploded capsules [A. Hauer, N. Delamater, D. Ress et al. Rev. Sci. Instrum. 66, 672-7 (1995)], the midportion ({approx} 2-10 ns) has been shown to be amenable to detection by the in-flight shape of x-ray backlit thin shell capsules [Pollaine et. al., Physics of Plasmas 8 2357 (2001)]. In this paper, we present sensitivity studies conducted on the University of Rochester's OMEGA laser of the thin shell symmetry measurement technique at near NIF-scale for two candidate capsule ablator materials, Ge-doped CH and Cu-doped Be. These experiments use both point and area backlighting to cast 4.7 keV radiographs of thin 1.4 mm initial-diameter Ge-doped CH and Cu-doped Be shells when converged a factor of {approx} 0.5 x in radius. Distortions in the position of the transmission limb of the shells resulting from drive asymmetries are measured to an accuracy of a few {micro}ms, meeting requirements. The promising results to date allow us to compare measured and predicted distortions and by inference drive asymmetries for the first 4 asymmetry modes as a function of hohlraum illumination conditions.

  4. A concept of needs-oriented design and evaluation of assistive robots based on ICF.

    PubMed

    Matsumoto, Yoshio; Nishida, Yoshifumi; Motomura, Yoichi; Okawa, Yayoi

    2011-01-01

    In the robotics community, a great number of assistive robots for elderly and handicapped people have been developed in the past few decades. However, very few of them became commercially available. It is often claimed that the major problems for the commercialization of robotic technologies are the "cost" and the "safety." However we believe that the mismatch of "needs in daily lives" and "seeds in the technologies" is also a major problem. In this paper, we describe our novel ideas on the development of assistive robots which fit the real needs of users based on ICF (International Classification of Functioning, Disability and Health), which is a part of the WHO Family of International Classifications for describing whole activities of a person in daily lives. By utilizing ICF, the development process of assistive robots - analyzing and discovering needs in daily lives, designing robots and evaluating the products - will be achieved in an objective manner.

  5. Interaction of high power laser beams with plasma in ICF hohlraum using the FDTD method

    NASA Astrophysics Data System (ADS)

    Lin, Zhili

    2016-11-01

    In the indirect-drive Inertial confinement fusion (ICF) system, groups of laser beams are injected into a gold cylindrical hohlraum and plasma is stimulated with the ablation of the wall of hohlraum by the laser beams. In our work, the finite-difference time-domain (FDTD) method associated with the bilinear transform and Maclaurin series expansion approaches is utilized to examine the laser beam propagation in plasma described by the Drude model. The state-of-the-art approaches for generating the laser beams are presented and realized according to the full utilization of the TF/SF source condition. Base on the previous technologies, the quantitatively numerical analysis of the propagation characteristics of laser beams in the plasma is conducted. The obtained results are illustrated and discussed that are helpful for the parameter optimization of laser beams for an ICF system.

  6. Vesicourethral reflux-induced renal failure in a patient with ICF syndrome due to a novel DNMT3B mutation.

    PubMed

    Kutluğ, Seyhan; Ogur, Gönül; Yilmaz, Aysegül; Thijssen, Peter E; Abur, Ummet; Yildiran, Alisan

    2016-12-01

    ICF syndrome is a primary immunodeficiency disease characterized by hypo- or agammaglobulinemia, centromeric instability mainly on chromosomes 1, 9, and 16 and facial anomalies. ICF syndrome presents with frequent respiratory tract infections in infancy. A 20-month-old female patient was referred to our clinic due to frequent lower respiratory tract infections. ICF syndrome was considered because of comorbidity of hypogammaglobulinemia, facial anomalies, and neuromotor growth retardation. Metaphase chromosome analysis revealed centromeric instability on chromosomes 1, 9, and 16 and through Sanger a previously unreported homozygous missense mutation (c.1805T>C; [p.V602A]) was identified in the DNMT3B, confirming ICF1. The patient was found to have a breakdown in renal function 1 year later; the urinary system was examined and bilateral vesicoureteral reflux was found, warranting the need for dialysis in time. This report expands the mutation spectrum of ICF1 and is the first to describe bilateral vesicoureteral reflux accompanying ICF syndrome. © 2016 Wiley Periodicals, Inc.

  7. Vocational rehabilitation from the client's perspective using the International Classification of Functioning, Disability and Health (ICF) as a reference.

    PubMed

    Glässel, Andrea; Finger, Monika E; Cieza, Alarcos; Treitler, Christine; Coenen, Michaela; Escorpizo, Reuben

    2011-06-01

    INTRODUCTION A mixed-methods (qualitative-quantitative), multicenter study was conducted using a focus group design to explore the lived experiences of persons in vocational rehabilitation (VR) with regard to functioning and contextual factors using six open-ended questions related to the ICF components. The results were classified by using the International Classification of Functioning, Disability and Health (ICF) as a frame of reference. METHODS The meaningful concepts within the transcribed data were identified and linked to ICF categories according to established linking rules. RESULTS The seven focus groups with 26 participants yielded a total of 4,813 relevant concepts which were linked to a total of 160 different second-level ICF categories. From the client perspective, the ICF components (a) body functions, (b) activities and participation and (c) environmental factors were equally represented, while (d) body structures appeared less frequently. Out of the total number of concepts, 864 concepts (18%) were assigned to the ICF component personal factors which is not yet classified but could indicate important aspects of resource management and strategy development of patients in VR. CONCLUSION Therefore, VR of patients must not be limited to anatomical and pathophysiologic changes, but should also consider a more comprehensive view which includes client's demands, strategies and resources in daily life and the context around the individual and social circumstances of their work situation.

  8. Laser ignition of engines: a realistic option!

    NASA Astrophysics Data System (ADS)

    Weinrotter, M.; Srivastava, D. K.; Iskra, K.; Graf, J.; Kopecek, H.; Klausner, J.; Herdin, G.; Wintner, E.

    2006-01-01

    Due to the demands of the market to increase efficiencies and power densities of gas engines, existing ignition schemes are gradually reaching their limits. These limitations initially triggered the development of laser ignition as an effective alternative, first only for gas engines and now for a much wider range of internal combustion engines revealing a number of immediate advantages like no electrode erosion or flame kernel quenching. Furthermore and most noteworthy, already the very first engine tests about 5 years ago had resulted in a drastic reduction of NO x emissions. Within this broad range investigation, laser plasmas were generated by ns Nd-laser pulses and characterized by emission and Schlieren diagnostic methods. High-pressure chamber experiments with lean hydrogen-methane-air mixtures were successfully performed and allowed the determination of essential parameters like minimum pulse energies at different ignition pressures and temperatures as well as at variable fuel air compositions. Multipoint ignition was studied for different ignition point locations. In this way, relevant parameters were acquired allowing to estimate future laser ignition systems. Finally, a prototype diode-pumped passively Q-switched Nd:YAG laser was tested successfully at a gasoline engine allowing to monitor the essential operation characteristics. It is expected that laser ignition involving such novel solid-state lasers will allow much lower maintenance efforts.

  9. Ignition and combustion of lunar propellants

    NASA Technical Reports Server (NTRS)

    Burton, Rodney L.; Roberts, Ted A.; Krier, Herman

    1993-01-01

    The ignition and combustion of Al, Mg, and Al/Mg alloy particles in 99 percent O2/1 percent N2 mixtures is investigated at high temperatures and pressures for rocket engine applications. The 20 micron particles contain 0, 5, 10, 20, 40, 60, 80, and 100 weight percent Mg alloyed with Al, and are ignited in oxygen using the reflected shock in a shock tube near the endwall. Using this technique, the ignition delay and combustion times of the particles are measured at temperatures up to 3250 K as a function of Mg content for oxygen pressures of 8.5, 17, and 34 atm. An ignition model is developed which employs a simple lumped capacitance energy equation and temperature and pressure dependent particle and gas properties. Good agreement is achieved between the measured and predicted trends in the ignition delay times. For the particles investigated, the contribution of heterogeneous reaction to the heating of the particle is found to be significant at lower temperatures, but may be neglected as gas temperatures above 3000 K. As little as 10 percent Mg reduces the ignition delay time substantially at all pressures tested. The particle ignition delay times decrease with increasing Mg content, and this reduction becomes less pronounced as oxidizer temperature and pressure are increased.

  10. VizieR Online Data Catalog: Star forming regions sulphur ICFs (Dors+, 2016)

    NASA Astrophysics Data System (ADS)

    Dors, O. L.; Perez-Montero, E.; Hagele, G. F.; Cardaci, M. V.; Krabbe, A. C.

    2016-10-01

    We compiled from the literature emission-line intensities of HII regions and star-forming galaxies obtained in the optical and infrared spectral ranges. These measurements were used to obtain sulphur and oxygen ionic abundances in order to verify if our photoionization models are representative of real HIi regions, to check if the theoretical ICFs are compatible with the ones derived directly from observations and investigating the S/O-O/H relation. (5 data files).

  11. Progress in development of low density polymer foams for the ICF Program

    SciTech Connect

    Letts, S.A.; Lucht, L.M.; Morgan, R.J.; Cook, R.C.; Tillotson, T.M.; Mercer, M.B.; Miller, D.E.

    1985-06-10

    This report describes the status of CH foam development with densities of 50 mg/ccs and cell sizes of 1 ..mu..m for the ICF Program. Two approaches that both involve polymer phase separation are being investigated. The first involves a gelation-crystallization of high molecular weight polyethylene from solution, whereas the second approach involves the modification of the phase separation morphology of water-styrene emulsions by molecularly-tailored surfactants followed by polymerization of the continuous styrene phase.

  12. Application of spectral line shapes to the study of high density ICF plasmas

    SciTech Connect

    Keane, C.J.; Hammel, B.A.; Langer, S.H.; Lee, R.W.; Calisti, A.; Godbert, L.; Stamm, R.; Talin, B.

    1994-09-01

    Spectral line broadening manifests itself in the study of high density inertial confinement fusion (ICF) plasmas in two important ways. First, comparison between measured and calculated lineshapes of individual spectral lines or groups of lines is used to diagnose plasma conditions in dense ICF plasmas, particularly in implosions. Secondly, through the emission and absorption coefficients spectral lineshapes serve as important inputs to plasma spectroscopy simulation codes which calculate simulated spectra from ICF targets. We discuss recent results from each of these areas. With regard to lineshape diagnostics, the advent of generalized line broadening codes has allowed the line profiles of complex multielectron emitters to be considered for diagnostic purposes. Particular example of this is the use of Ar He-{beta} and its associated dielectronic satellites as a diagnostic of T{sub e} and N{sub e}, as well as the development of Ne-like Xe line broadening as a density diagnostic. With respect to simulation codes, the implementation of detailed lineshapes in calculations of this type is in many ways in its infancy. We present here examples of cases where effects related to spectral lineshapes such as continuum lowering and line transfer of Stark broadened lines are important so as to provide a stimulus for future work in this field. 34 refs., 9 figs., 1 tab.

  13. Mapping SAGE questionnaire to the International Classification of Functioning, Disability and Health (ICF).

    PubMed

    Raggi, Alberto; Quintas, Rui; Russo, Emanuela; Martinuzzi, Andrea; Costardi, Daniela; Frisoni, Giovanni Battista; Franco, Maria Grazia; Andreotti, Alessandra; Ojala, Matti; Peña, Sebastián; Perales, Jaime; Chatterji, Somnath; Miret, Marta; Tobiasz-Adamczyk, Beata; Koskinen, Seppo; Frattura, Lucilla; Leonardi, Matilde

    2014-01-01

    The collaborative research on ageing in Europe protocol was based on that of the World Health Organization Study on global AGEing and adult health (SAGE) project that investigated the relationship between health and well-being and provided a set of instruments that can be used across countries to monitor health and health-related outcomes of older populations as well as the strategies for addressing issues concerning the ageing process. To evaluate the degree to which SAGE protocol covered the spectrum of disability given the scope of the World Health Organization International Classification of Functioning, Disability and Health (ICF), a mapping exercise was performed with SAGE protocol. Results show that the SAGE protocol covers ICF domains in a non-uniform way, with environmental factors categories being underrepresented, whereas mental, cardiovascular, sensory functions and mobility were overrepresented. To overcome this partial coverage of ICF functioning categories, new assessment instruments have been developed. PRACTITIONER MESSAGE: Mapping exercises are valid procedures to understand the extent to which a survey protocol covers the spectrum of functioning. The mapping exercise with SAGE protocol shows that it provides only a partial representation of body functions and activities and participation domains, and the coverage of environmental factors is poor. New instruments are therefore needed for researchers to properly understand the health and disability of ageing populations.

  14. Ignition Temperatures of Metals in Oxygen Atmospheres

    NASA Technical Reports Server (NTRS)

    Laurendeau, N. M.; Glassman, I.

    1971-01-01

    The ignition temperature of ten common non-toxic metals has been determined experimentally in an oxygen environment. In this investigation a induction furnace facility that emphasized the preignition surface.oxidation effects upon the ignition temperature was used. The bulk ignition temperatures of barium, bismuth, calcium, iron, lead, magnesium, molybdenum, strontium, tin, and zinc were found and compared to the previous results of Grosse and Conway. The differences in the results are attributed to how the heating cycle is carried out and how the cycle affects the surface oxide coat.

  15. Accelerated hypergolic ignition with lowering of temperature

    SciTech Connect

    Panda, S.P.; Kulkarni, S.G.; Prabhakaran, C. . Faculty of Explosives and Applied Chemistry)

    1994-06-01

    Hypergolic liquid fuels known to undergo cationic polymerization at the preignition stage with red fuming nitric acid (RFNA) as oxidizer have been found to exhibit synergistic hypergolic ignition at zero and subzero temperatures. This accelerated ignition with lowering of temperature has been ascribed to negative activation energy usually associated with most cationic polymerization systems. The best ignition was obtained with blends of fuels consisting of norbornadiene and furfuryl alcohol which underwent strong cationic polymerization with protonic acids and possibly Diels-Alder addition to each other.

  16. Overview of the Compact Ignition tokamak

    SciTech Connect

    Flanagan, C. A.; Peng, Yueng Kay Martin

    1986-01-01

    The Compact Ignition Tokamak (CIT) mission is to achieve ignition and provide the capability to experimentally study burning plasma behavior. A national team has developed a baseline concept including definition of the necessary research and development. The baseline concept satisfies the physics performance objectives established for the project and complies with defined design specifications. To ensure that the mission is achieved, the design requires large magnetic fields on axis (10 T) and use of large plasma currents (10 MA). The design is capable of accommodating significant auxiliary heating to enter the ignited regime. The CIT is designed to operate in plasma parameter regimes that a are directly relevant to future fusion power reactors.

  17. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Autogenous-ignition temperature test. 35.20... Autogenous-ignition temperature test. (a) Purpose. The purpose of this test, referred to hereinafter as the ignition-temperature test, is to determine the lowest autogenous-ignition temperature of a hydraulic...

  18. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Autogenous-ignition temperature test. 35.20... Autogenous-ignition temperature test. (a) Purpose. The purpose of this test, referred to hereinafter as the ignition-temperature test, is to determine the lowest autogenous-ignition temperature of a hydraulic...

  19. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Autogenous-ignition temperature test. 35.20... Autogenous-ignition temperature test. (a) Purpose. The purpose of this test, referred to hereinafter as the ignition-temperature test, is to determine the lowest autogenous-ignition temperature of a hydraulic...

  20. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Autogenous-ignition temperature test. 35.20... Autogenous-ignition temperature test. (a) Purpose. The purpose of this test, referred to hereinafter as the ignition-temperature test, is to determine the lowest autogenous-ignition temperature of a hydraulic...

  1. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Autogenous-ignition temperature test. 35.20... Autogenous-ignition temperature test. (a) Purpose. The purpose of this test, referred to hereinafter as the ignition-temperature test, is to determine the lowest autogenous-ignition temperature of a hydraulic...

  2. 14 CFR 25.981 - Fuel tank ignition prevention.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel tank ignition prevention. 25.981... ignition prevention. (a) No ignition source may be present at each point in the fuel tank or fuel tank... fuel tank if means are provided to mitigate the effects of an ignition of fuel vapors within that...

  3. Hot electron measurements in ignition relevant Hohlraums on the National Ignition Facility.

    PubMed

    Dewald, E L; Thomas, C; Hunter, S; Divol, L; Meezan, N; Glenzer, S H; Suter, L J; Bond, E; Kline, J L; Celeste, J; Bradley, D; Bell, P; Kauffman, R L; Kilkenny, J; Landen, O L

    2010-10-01

    On the National Ignition Facility (NIF), hot electrons generated in laser heated Hohlraums are inferred from the >20 keV bremsstrahlung emission measured with the time integrated FFLEX broadband spectrometer. New high energy (>200 keV) time resolved channels were added to infer the generated >170 keV hot electrons that can cause ignition capsule preheat. First hot electron measurements in near ignition scaled Hohlraums heated by 96-192 NIF laser beams are presented.

  4. LOX/Methane Main Engine Igniter Tests and Modeling

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin J.; Ajmani, Kumund

    2008-01-01

    The LOX/methane propellant combination is being considered for the Lunar Surface Access Module ascent main engine propulsion system. The proposed switch from the hypergolic propellants used in the Apollo lunar ascent engine to LOX/methane propellants requires the development of igniters capable of highly reliable performance in a lunar surface environment. An ignition test program was conducted that used an in-house designed LOX/methane spark torch igniter. The testing occurred in Cell 21 of the Research Combustion Laboratory to utilize its altitude capability to simulate a space vacuum environment. Approximately 750 ignition test were performed to evaluate the effects of methane purity, igniter body temperature, spark energy level and frequency, mixture ratio, flowrate, and igniter geometry on the ability to obtain successful ignitions. Ignitions were obtained down to an igniter body temperature of approximately 260 R with a 10 torr back-pressure. The data obtained is also being used to anchor a CFD based igniter model.

  5. Capsule Ablator Inflight Performance Measurements Via Streaked Radiography Of ICF Implosions On The NIF*

    NASA Astrophysics Data System (ADS)

    Dewald, E. L.; Tommasini, R.; Mackinnon, A.; MacPhee, A.; Meezan, N.; Olson, R.; Hicks, D.; LePape, S.; Izumi, N.; Fournier, K.; Barrios, M. A.; Ross, S.; Pak, A.; Döppner, T.; Kalantar, D.; Opachich, K.; Rygg, R.; Bradley, D.; Bell, P.; Hamza, A.; Dzenitis, B.; Landen, O. L.; MacGowan, B.; LaFortune, K.; Widmayer, C.; Van Wonterghem, B.; Kilkenny, J.; Edwards, M. J.; Atherton, J.; Moses, E. I.

    2016-03-01

    Streaked 1-dimensional (slit imaging) radiography of 1.1 mm radius capsules in ignition hohlraums was recently introduced on the National Ignition Facility (NIF) and gives an inflight continuous record of capsule ablator implosion velocities, shell thickness and remaining mass in the last 3-5 ns before peak implosion time. The high quality data delivers good accuracy in implosion metrics that meets our requirements for ignition and agrees with recently introduced 2-dimensional pinhole radiography. Calculations match measured trajectory across various capsule designs and laser drives when the peak laser power is reduced by 20%. Furthermore, calculations matching measured trajectories give also good agreement in ablator shell thickness and remaining mass.

  6. Design of a streaked radiography instrument for ICF ablator tuning measurements.

    PubMed

    Olson, R E; Hicks, D G; Spears, B K; Celliers, P M; Holder, J P; Landen, O L; Geissel, M; Kellogg, J W; Bennett, G R; Edens, A D; Atherton, B W; Leeper, R J

    2008-10-01

    A streaked radiography diagnostic has been proposed as a technique to determine the ablator mass remaining in an inertial confinement fusion ignition capsule at peak velocity. This instrument, the "HXRI-5," has been designed to fit within a National Ignition Facility Diagnostic Instrument Manipulator. The HXRI-5 will be built at Sandia National Laboratories (SNL), and initial testing will be done at the SNL Z-Beamlet Facility. In this paper, we will describe the National Ignition Campaign requirements for this diagnostic, the instrument design, and the planned test experiments.

  7. Experiments and simulations on non-plasma ignition of semiconductor bridge igniter

    NASA Astrophysics Data System (ADS)

    Du, Weiqiang; Zhou, Bin; Liu, Jupeng; Li, Yong; Wang, Jun

    2017-01-01

    Since semiconductor bridge (SCB) igniter has been invented, it is commonly considered as a plasma generator. However, the plasma ignition mechanism may be affected by the hotspot ignition temperature of the primary explosives that is lower than the melting point of SCB in the igniter. In an effort to investigate the non-plasma ignition performance of SCB igniter, a one-dimensional model was established for temperature distribution analysis under constant current and capacitor discharge excitation. The simulation results featured the progress of heat transfer and the energy level required by non-plasma ignition of SCB was estimated. Furthermore, sensitivity experiments were carried out to test simulation results and to obtain the firing current range of SCB igniter with lead styphnate (LTNR). Experiment results indicated that safety conditions are 1.953 A constant current input lasting 1 ms under constant current excitation and 7.072 V voltage input using 47 µF storage capacitor under capacitor discharge excitation. All-firing conditions of non-plasma ignition are 2.035 A constant current input lasting 1 ms under constant current excitation and 7.647 V voltage input using 47 µF storage capacitor under capacitor discharge excitation.

  8. Scar revision

    PubMed Central

    Sharma, Mohit; Wakure, Abhijeet

    2013-01-01

    Most surgical patients end up with a scar and most of these would want at least some improvement in the appearance of the scar. Using sound techniques for wound closure surgeons can, to a certain extent, prevent suboptimal scars. This article reviews the principles of prevention and treatment of suboptimal scars. Surgical techniques of scar revision, i.e., Z plasty, W plasty, and geometrical broken line closure are described. Post-operative care and other adjuvant therapies of scars are described. A short description of dermabrasion and lasers for management of scars is given. It is hoped that this review helps the surgeon to formulate a comprehensive plan for management of scars of these patients. PMID:24516292

  9. Plasma igniter for internal-combustion engines

    NASA Technical Reports Server (NTRS)

    Breshears, R. R.; Fitzgerald, D. J.

    1978-01-01

    Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

  10. Ignition-Spark Detector for Engine Testing

    NASA Technical Reports Server (NTRS)

    Kuhr, G.

    1985-01-01

    Optical fiber views sparks directly. In fuel or oxidizer tube, optical fiber collects light from ignition spark. Fibers also used to collect light from combustion reactions for spectrographic analysis. Useful in engine testing, detector helps determine reason for engine failure.

  11. Ignition of thermonuclear microexplosions with antimatter

    SciTech Connect

    Shmatov, M.L.

    1994-10-01

    The use of antimatter for the indirect ignition of staged thermonuclear microexplosions is proposed. The space propulsion system based on this method may become economically acceptable earlier than that which uses only the energy of annihilation. 19 refs.

  12. Ignition of metals in high pressure oxygen

    NASA Technical Reports Server (NTRS)

    Bransford, J. W.

    1985-01-01

    A description of an experimental facility used to determine the ignition and combustion characteristics of metallic materials is given. The results obtained for aluminum 6061, 302 stainless steel, and the nickel alloy - N06625 are presented.

  13. Confinement scaling and ignition in tokamaks

    SciTech Connect

    Perkins, F.W.; Sun, Y.C.

    1985-10-01

    A drift wave turbulence model is used to compute the scaling and magnitude of central electron temperature and confinement time of tokamak plasmas. The results are in accord with experiment. Application to ignition experiments shows that high density (1 to 2) . 10/sup 15/ cm/sup -3/, high field, B/sub T/ > 10 T, but low temperature T approx. 6 keV constitute the optimum path to ignition.

  14. Ignition transition in turbulent premixed combustion

    SciTech Connect

    Shy, S.S.; Liu, C.C.; Shih, W.T.

    2010-02-15

    Recently, Shy and his co-workers reported a turbulent ignition transition based on measurements of minimum ignition energies (MIE) of lean premixed turbulent methane combustion in a centrally-ignited, fan-stirred cruciform burner capable of generating intense isotropic turbulence. Using the same methodology, this paper presents new complete MIE data sets for stoichiometric and rich cases at three different equivalence ratios {phi} = 1.0, 1.2 and 1.3, each covering a wide range of a turbulent Karlovitz number (Ka) indicating a time ratio between chemical reaction and turbulence. Thus, ignition transition in premixed turbulent combustion depending on both Ka and {phi} can be identified for the first time. It is found that there are two distinct modes on ignition in randomly stirred methane-air mixtures (ignition transition) separated by a critical Ka where values of Ka{sub c} {approx} 8-26 depending on {phi} with the minimum Ka{sub c} occurring near {phi} = 1. For Ka < Ka{sub c}, MIE increases gradually with Ka, flame kernel formation is similar to laminar ignition remaining a torus, and 2D laser tomography images of subsequent outwardly-propagating turbulent flames show sharp fronts. For Ka > Ka{sub c}, MIE increases abruptly with Ka, flame kernel is disrupted, and subsequent randomly-propagating turbulent flames reveal distributed-like fronts. Moreover, we introduce a reaction zone Peclet number (P{sub RZ}) indicating the diffusivity ratio between turbulence and chemical reaction, such that the aforementioned very scattering MIE data depending on Ka and {phi} can be collapsed into a single curve having two drastically different increasing slopes with P{sub RZ} which are separated by a critical P{sub RZ} {approx} 4.5 showing ignition transition. Finally, a physical model is proposed to explain these results. (author)

  15. Computational Studies and Designs for Fast Ignition

    NASA Astrophysics Data System (ADS)

    Nagatomo, H.; Johzaki, T.; Nakamura, T.; Sakagami, H.; Mima, K.

    2006-12-01

    The fast ignition scheme is one of the most fascinating and feasible ignition schemes for the inertial fusion energy. At ILE Osaka University, FIREX (Fast Ignition Realization Experiment) project is in progress. Implosion experiments of the cryogenic target are scheduled in near future. There are two key issues for the fast ignition. One is controlling the implosion dynamics to form high density core plasma in non-spherical implosion, and the other is heating the core plasma efficiently by the short pulse high intense laser. The time and space scale in the fast ignition scheme vary widely from initial laser irradiation to solid target, to relativistic laser plasma interaction and final fusion burning. The numerical simulation plays an important role in demonstrating the performance of the fast ignition, designing the targets, and optimizing laser pulse shapes for the scheme. These all the physics are desired to be self-consistently described. In order to study these physics of FI, we have developed "Fast Ignition Integrated Interconnecting code" (FI3), which consists of collective Particle-in-Cell (PIC) code (FISCOF1D/2D), Relativistic Fokker-Planck with hydro code (FIBMET), and 2-dimensional Arbitrary-Lagrangian-Eulerian (ALE) radiation hydrodynamics code (PINOCO). Those codes are sophisticated in each suitable plasma parameters, and boundaries conditions and initial conditions for them are imported/exported to each other by way of DCCP, a simple and compact communication tool which enable these codes to communicate each others under executing different machines. We show the feature of the FI3 code, and numerical results of whole process of fast ignition. Individual important physics behind the FI are explained with the numerical results also.

  16. The Revamping of an Ignition Test Facility

    NASA Technical Reports Server (NTRS)

    Kearns, Kimberly A.

    2002-01-01

    The revamping of an Ignition Test Facility, located in the Research Combustion Laboratory at the NASA Glenn Research Center, is presented. The history of how the test cell has adapted efficiently to a variety of test programs is discussed. The addition of a second test stand for ignition and small-scale rocket testing is detailed. An overview of the facility and the current test programs is offered. Planned upgrades for the future are outlined.

  17. Ignition methods and apparatus using microwave energy

    DOEpatents

    DeFreitas, Dennis Michael; Migliori, Albert

    1997-01-01

    An ignition apparatus for a combustor includes a microwave energy source that emits microwave energy into the combustor at a frequency within a resonant response of the combustor, the combustor functioning as a resonant cavity for the microwave energy so that a plasma is produced that ignites a combustible mixture therein. The plasma preferably is a non-contact plasma produced in free space within the resonant cavity spaced away from with the cavity wall structure and spaced from the microwave emitter.

  18. Trends in Surface-Ignition Temperatures

    DTIC Science & Technology

    1944-09-01

    air ratio, and surface-ignition advance. Scope. - Tests were made on a supercharged CFR engine to deter- mine surface-ignition temperature as a...laboratory has conducted tests on a supercharged CFR engine to determine the rela- tionships between a hot-spot temperature required for surface igni...February 1, 1944. APPARATUS The tests were performed on a high-speed, supercharged CFR engine coupled to a 25-hcrsepower, alternating-ourront

  19. Spark Ignition of Monodisperse Fuel Sprays. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Danis, Allen M.; Cernansky, Nicholas P.; Namer, Izak

    1987-01-01

    A study of spark ignition energy requirements was conducted with a monodisperse spray system allowing independent control of droplet size, equivalent ratio, and fuel type. Minimum ignition energies were measured for n-heptane and methanol sprays characterized at the spark gap in terms of droplet diameter, equivalence ratio (number density) and extent of prevaporization. In addition to sprays, minimum ignition energies were measured for completely prevaporized mixtures of the same fuels over a range of equivalence ratios to provide data at the lower limit of droplet size. Results showed that spray ignition was enhanced with decreasing droplet size and increasing equivalence ratio over the ranges of the parameters studied. By comparing spray and prevaporized ignition results, the existence of an optimum droplet size for ignition was indicated for both fuels. Fuel volatility was seen to be a critical factor in spray ignition. The spray ignition results were analyzed using two different empirical ignition models for quiescent mixtures. Both models accurately predicted the experimental ignition energies for the majority of the spray conditions. Spray ignition was observed to be probabilistic in nature, and ignition was quantified in terms of an ignition frequency for a given spark energy. A model was developed to predict ignition frequencies based on the variation in spark energy and equivalence ratio in the spark gap. The resulting ignition frequency simulations were nearly identical to the experimentally observed values.

  20. Toolbox of multiple-item measures aligning with the ICF Core Sets for children and youth with cerebral palsy.

    PubMed

    Schiariti, Verónica; Tatla, Sandy; Sauve, Karen; O'Donnell, Maureen

    2017-03-01

    Selecting appropriate measure(s) for clinical and/or research applications for children and youth with Cerebral Palsy (CP) poses many challenges. The newly developed International Classification of Functioning, Disability and Health (ICF) Core Sets for children and youth with CP serve as universal guidelines for assessment, intervention and follow-up. The aims of this study were: 1) to identify valid and reliable measures used in studies with children and youth with CP, 2) to characterize the content of each measure using the ICF Core Sets for children and youth with CP as a framework, and finally 3) to create a toolbox of psychometrically sound measures covering the content of each ICF Core Set for children and youth with CP. All clearly defined multiple-item measures used in studies with CP between 1998 and 2015 were identified. Psychometric properties were extracted when available. Construct of the measures were linked to the ICF Core Sets. Overall, 83 multiple-item measures were identified. Of these, 68 measures (80%) included reliability and validity testing. The majority of the measures were discriminative, generic and designed for school-aged children. The degree to which measures with proven psychometric properties represented the ICF Core Sets for children and youth with CP varied considerably. Finally, 25 valid and reliable measures aligned highly with the content of the ICF Core Sets, and as such, these measures are proposed as a novel ICF Core Sets-based toolbox of measures for CP. Our results will guide professionals seeking appropriate measures to meet their research and clinical needs worldwide.

  1. Health promotion and education: application of the ICF in the US and Canada using an ecological perspective.

    PubMed

    Howard, David; Nieuwenhuijsen, Els R; Saleeby, Patricia

    2008-01-01

    Health promotion is an issue comprised of complex and multi-layered concepts that involves a process of enabling people to increase control over and improve their health. The aims and applications of the World Health Organization's International Classification of Functioning, Disability and Health (ICF), with its focus on components of functioning, activities and participation, and environmental factors are salient to health promotion and health education efforts. For individuals with or without disabilities, health promotion occurs within the community in which they reside and is influenced by a complex interaction of personal and environmental factors. The aim of this paper is to discuss how the ICF can be useful in enhancing social change through health promotion and health education for all people, in particular those with disabilities and chronic conditions. In doing so health promotion concepts and the ecological approach linked with the ICF, the relationship of social change and social support to the ICF, the potential role of the ICF for national and local (city) policies, and the role of health professionals in this process will be examined. Building on this body of knowledge, the authors recommend that future research should focus on the relationship between policies and the social participation of people with disabilities in the community, the use of ICF measurement tools to improve the indicators established by the National Organization on Disability, the development of a new ICF core set for community accessibility and inclusion, better interventions to enhance social support, and enhancing the role of professionals in health promotion for people with disabilities or chronic health conditions.

  2. Concept of a Helias ignition experiment

    NASA Astrophysics Data System (ADS)

    Wobig, H.; Andreeva, T.; Beidler, C. D.; Harmeyer, E.; Herrnegger, F.; Igitkhanov, Y.; Kisslinger, J.; Kolesnichenko, Ya. I.; Lutsenko, V. V.; Marchenko, V. S.; Nührenberg, C.; Sidorenko, I.; Turkin, Y.; Wieczorek, A.; Yakovenko, Yu. V.

    2003-09-01

    The Helias ignition experiment is an upgraded version of the Wendelstein 7-X experiment. The magnetic configuration is a four-period Helias configuration (major radius 18 m, plasma radius 2.0 m, B = 4.5 T), which presents a more compact option than the five-period configuration. Much effort has been focused on two versions of the four-period configuration. One option is the power reactor HSR4/18 providing at least 3 GW of fusion power and the second is the ignition experiment HSR 4/18i aiming at a minimum of fusion power and the demonstration of self-sustaining burn. The design criteria of the ignition experiment HSR 4/18i are the following: The experiment should demonstrate a safe and reliable route to ignition; self-sustained burn without external heating; steady-state operation during several hundred seconds; reliability of the technical components and tritium breeding in a test blanket. The paper discusses the technical issues of the coil system and describes the vacuum vessel and the shielding blanket. The power balance will be modelled with a transport code and the ignition conditions will be investigated using current scaling laws of energy confinement in stellarators. The plasma parameters of the ignition experiment are: peak density 2-3×1020 m-3, peak temperature 11-15 keV, average beta 3.6% and fusion power 1500-1700 MW.

  3. Engineering the National Ignition Facility

    SciTech Connect

    Bowers, J; Hackel, R; Larson, D; Manes, K; Murray, J; Sawicki, R

    1998-08-19

    The engineering team of the National Ignition Facility (NIF) has developed a highly optimized hardware design that satisfies stringent cost, performance and schedule requirements. After a 3-year effort, the design will culminate at the end of FY98 with the completion of major Title II design reviews. Every element of the facility from optic configuration, facility layout and hardware specifications to material selection, fabrication techniques and part tolerancing has been examined to assure the minimum cost per joule of laser energy delivered on target. In this paper, the design of the major subsystems will be discussed from the perspective of this optimization emphasis. Focus will be placed on the special equipment hardware which includes laser, beam transport, opto-mechanical , system control and target area systems. Some of the unique features in each of these areas will be discussed to highlight how significant cost savings have been achieved while maintaining reasonable and acceptable performance risk. Key to the success has also been a vigorous development program that commenced nearly 4 years ago and has been highly responsive to the specific needs of the NIF project. Supporting analyses and prototyping work that evolved from these parallel activities will also be discussed.

  4. Science and code validation program to secure ignition on LMJ

    NASA Astrophysics Data System (ADS)

    Lefebvre, E.; Boniface, C.; Bonnefille, M.; Casner, A.; Esnault, C.; Galmiche, D.; Gauthier, P.; Girard, F.; Gisbert, R.; Leidinger, J.-P.; Loiseau, P.; Masse, L.; Masson-Laborde, P.-E.; Mignon, P.; Monteil, M.-C.; Seytor, P.; Tassin, V.

    2016-03-01

    The CEA/DAM ICF experimental program is currently conducted on LIL and Omega with the goal of improving our simulation tool, the FCI2 code. In this effort, we focus on typical ICF observables: hohlraum radiation drive history, capsule core shape and neutron emission history, hydrodynamic instability growth. In addition to integrated experiment, specific designs are also helpful to pinpoint a particular phenomenon. In this article, we review our current efforts and status, and our future projects on Omega and LMJ.

  5. Expanded Ignition Effectiveness Tests of Selected Igniter Materials with Navy Propellants

    DTIC Science & Technology

    1983-09-01

    phase and the condensed phase materials, the condensed phase energy flux is given by (approximately) Scp ( hcp + + ub (hub + (11) In the present analysis...Thickness 1.00 in) Igniter Propellant Test Mass 6M Mass Ignition Nwnber Configuration atl ( (g) qatl (g) (yes/no) 2015 4080AV NC 2.3 .3 N318 40 Yes 2016

  6. 75 FR 47520 - Standards of Performance for Stationary Compression Ignition and Spark Ignition Internal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... Compression Ignition and Spark Ignition Internal Combustion Engines AGENCY: Environmental Protection Agency... combustion engines. In this ] notice, we are announcing a 30-day extension of the public comment period for... combustion engines. After publication of the proposed rule, EPA received requests from the American...

  7. Aerospace Laser Ignition/Ablation Variable High Precision Thruster

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan W. (Inventor); Edwards, David L. (Inventor); Campbell, Jason J. (Inventor)

    2015-01-01

    A laser ignition/ablation propulsion system that captures the advantages of both liquid and solid propulsion. A reel system is used to move a propellant tape containing a plurality of propellant material targets through an ignition chamber. When a propellant target is in the ignition chamber, a laser beam from a laser positioned above the ignition chamber strikes the propellant target, igniting the propellant material and resulting in a thrust impulse. The propellant tape is advanced, carrying another propellant target into the ignition chamber. The propellant tape and ignition chamber are designed to ensure that each ignition event is isolated from the remaining propellant targets. Thrust and specific impulse may by precisely controlled by varying the synchronized propellant tape/laser speed. The laser ignition/ablation propulsion system may be scaled for use in small and large applications.

  8. International Classification of Functioning, Disability and Health (ICF) Core Set for patients with vertigo, dizziness and balance disorders.

    PubMed

    Grill, Eva; Bronstein, Adolfo; Furman, Joseph; Zee, David S; Müller, Martin

    2012-01-01

    Vertigo, dizziness and balance disorders have major impact on independence, employability, activities and participation. There are many measures for the assessment of the impact of vertigo, but no consensus exists on which aspects should be measured. The objective of this study was to develop international standards (ICF Core Sets) for patients with vertigo and dizziness to describe functioning. The development of the ICF Core Sets involved a formal decision-making and consensus process, integrating evidence from preparatory studies including qualitative interviews with patients, a systematic review of the literature, a survey with health professionals, and empirical data collection from patients. Twenty-seven experts selected 100 second level categories for the comprehensive Core Set and 29 second level categories for the Brief Core Set. The largest number of categories was selected from the ICF component Activities and Participation (40). Twenty-five categories were selected from the component Body Functions, six from Body Structures, and 29 from Environmental Factors. The ICF Core Set for vertigo is designed for physicians, nurses, therapists and other health professionals working in inpatient or ambulatory settings. ICF Core Sets create patient-relevant outcomes that can be used as evidence for the success of treatments.

  9. Identification of relevant ICF categories for indication, intervention planning and evaluation of health resort programs: a Delphi exercise

    NASA Astrophysics Data System (ADS)

    Morita, E.; Weigl, M.; Schuh, A.; Stucki, G.

    2006-01-01

    Health resort programs have a long tradition, mainly in European countries and Japan. They rely on local resources and the physical environment, physical medicine interventions and traditional medicine to optimise functioning and health. Arguably because of the long tradition, there is only a limited number of high-quality studies that examine the effectiveness of health resort programs. Specific challenges to the evaluation of health resort programs are to randomise the holistic approach with a varying number of specific interventions but also the reliance on the effect of the physical environment. Reference standards for the planning and reporting of health resort studies would be highly beneficial. With the International Classification of Functioning Disability and Health (ICF), we now have such a standard that allows us to describe body functions and structures, activities and participation and interaction with environmental factors. A major challenge when applying the ICF in practice is its length. Therefore, the objective of this project was to identify the ICF categories most relevant for health resort programs. We conducted a consensus-building, three-round, e-mail survey using the Delphi technique. Based on the consensus of the experts, it was possible to come up with an ICF Core Set that can serve as reference standards for the indication, intervention planning and evaluation of health resort programs. This preliminary ICF Core Set should be tested in different regions and in subsets of health resort visitors with varying conditions.

  10. Selective demethylation and altered gene expression are associated with ICF syndrome in human-induced pluripotent stem cells and mesenchymal stem cells

    PubMed Central

    Huang, Kevin; Wu, Zhourui; Liu, Zhenshan; Hu, Ganlu; Yu, Juehua; Chang, Kai H.; Kim, Kee-Pyo; Le, Thuc; Faull, Kym F.; Rao, Nagesh; Gennery, Andrew; Xue, Zhigang; Wang, Cun-yu; Pellegrini, Matteo; Fan, Guoping

    2014-01-01

    Immunodeficiency, centromeric instability and facial anomalies type I (ICF1) syndrome is a rare genetic disease caused by mutations in DNA methyltransferase (DNMT) 3B, a de novo DNA methyltransferase. However, the molecular basis of how DNMT3B deficiency leads to ICF1 pathogenesis is unclear. Induced pluripotent stem cell (iPSC) technology facilitates the study of early human developmental diseases via facile in vitro paradigms. Here, we generate iPSCs from ICF Type 1 syndrome patient fibroblasts followed by directed differentiation of ICF1-iPSCs to mesenchymal stem cells (MSCs). By performing genome-scale bisulfite sequencing, we find that DNMT3B-deficient iPSCs exhibit global loss of non-CG methylation and select CG hypomethylation at gene promoters and enhancers. Further unbiased scanning of ICF1-iPSC methylomes also identifies large megabase regions of CG hypomethylation typically localized in centromeric and subtelomeric regions. RNA sequencing of ICF1 and control iPSCs reveals abnormal gene expression in ICF1-iPSCs relevant to ICF syndrome phenotypes, some directly associated with promoter or enhancer hypomethylation. Upon differentiation of ICF1 iPSCs to MSCs, we find virtually all CG hypomethylated regions remained hypomethylated when compared with either wild-type iPSC-derived MSCs or primary bone-marrow MSCs. Collectively, our results show specific methylome and transcriptome defects in both ICF1-iPSCs and differentiated somatic cell lineages, providing a valuable stem cell system for further in vitro study of the molecular pathogenesis of ICF1 syndrome. GEO accession number: GSE46030. PMID:25027325

  11. National Ignition Facility system alignment.

    PubMed

    Burkhart, S C; Bliss, E; Di Nicola, P; Kalantar, D; Lowe-Webb, R; McCarville, T; Nelson, D; Salmon, T; Schindler, T; Villanueva, J; Wilhelmsen, K

    2011-03-10

    The National Ignition Facility (NIF) is the world's largest optical instrument, comprising 192 37 cm square beams, each generating up to 9.6 kJ of 351 nm laser light in a 20 ns beam precisely tailored in time and spectrum. The Facility houses a massive (10 m diameter) target chamber within which the beams converge onto an ∼1 cm size target for the purpose of creating the conditions needed for deuterium/tritium nuclear fusion in a laboratory setting. A formidable challenge was building NIF to the precise requirements for beam propagation, commissioning the beam lines, and engineering systems to reliably and safely align 192 beams within the confines of a multihour shot cycle. Designing the facility to minimize drift and vibration, placing the optical components in their design locations, commissioning beam alignment, and performing precise system alignment are the key alignment accomplishments over the decade of work described herein. The design and positioning phases placed more than 3000 large (2.5 m×2 m×1 m) line-replaceable optics assemblies to within ±1 mm of design requirement. The commissioning and alignment phases validated clear apertures (no clipping) for all beam lines, and demonstrated automated laser alignment within 10 min and alignment to target chamber center within 44 min. Pointing validation system shots to flat gold-plated x-ray emitting targets showed NIF met its design requirement of ±50 μm rms beam pointing to target chamber. Finally, this paper describes the major alignment challenges faced by the NIF Project from inception to present, and how these challenges were met and solved by the NIF design and commissioning teams.

  12. Damage behavior of Nd:glass of high-power disk amplifier medium in ICF Facility

    NASA Astrophysics Data System (ADS)

    He, Shaobo; Chen, Lin; Yuan, Xiaodong; Chen, Yuanbin; Cheng, Xiaofeng; Xie, Xudong; Wang, Wenyi; Zu, Xiaotao

    2016-12-01

    Large aperture Nd:glass disk is often used as the amplifier medium in the inertial confinement fusion (ICF) facilities. The typical size of Nd:glass is up to 810mm×460mm×40mm and more than 3,000 Nd:glass components are needed in the ICF facility. At present, the 3ω fused silica glass and DKDP crystal are mainly responsible for the damage of driver used for ICF. However, with the enlargement of the facility and increase of laser shot number, the laser damage of Nd:glass at 1ω waveband is still an important problem to limit the stable operation of facility and improvement of laser beam quality. In this work, the influence of Nd:glass material itself, mechanical processing, service environment, and laser beam quality on its damage behavior is investigated experimentally and theoretically. The results and conclusions can be summarized as follows: (1) It is very important to control the concentration of platinum impurity particles during melting and the sputtering effect of the cladding materials. (2) The number and length of fractural and brittle scratches should be strictly suppressed during mechanical processing of Nd:glass. (3) The B-integral of high power laser beam should be rigorously controlled. Particularly, the top shape of pulses must be well controlled when operating at high peak laser power. (4) The service environment should be well managed to make sure the cleanness of the surface of Nd:glass better than 100/A level during mounting and running. (5) The service environment and beam quality should be monitored during operation.

  13. Possibilities and Implications of Using the ICF and Other Vocabulary Standards in Electronic Health Records.

    PubMed

    Vreeman, Daniel J; Richoz, Christophe

    2015-12-01

    There is now widespread recognition of the powerful potential of electronic health record (EHR) systems to improve the health-care delivery system. The benefits of EHRs grow even larger when the health data within their purview are seamlessly shared, aggregated and processed across different providers, settings and institutions. Yet, the plethora of idiosyncratic conventions for identifying the same clinical content in different information systems is a fundamental barrier to fully leveraging the potential of EHRs. Only by adopting vocabulary standards that provide the lingua franca across these local dialects can computers efficiently move, aggregate and use health data for decision support, outcomes management, quality reporting, research and many other purposes. In this regard, the International Classification of Functioning, Disability, and Health (ICF) is an important standard for physiotherapists because it provides a framework and standard language for describing health and health-related states. However, physiotherapists and other health-care professionals capture a wide range of data such as patient histories, clinical findings, tests and measurements, procedures, and so on, for which other vocabulary standards such as Logical Observation Identifiers Names and Codes and Systematized Nomenclature Of Medicine Clinical Terms are crucial for interoperable communication between different electronic systems. In this paper, we describe how the ICF and other internationally accepted vocabulary standards could advance physiotherapy practise and research by enabling data sharing and reuse by EHRs. We highlight how these different vocabulary standards fit together within a comprehensive record system, and how EHRs can make use of them, with a particular focus on enhancing decision-making. By incorporating the ICF and other internationally accepted vocabulary standards into our clinical information systems, physiotherapists will be able to leverage the potent

  14. Relation Between Inflammables and Ignition Sources in Aircraft Environments

    NASA Technical Reports Server (NTRS)

    Scull, Wilfred E

    1950-01-01

    A literature survey was conducted to determine the relation between aircraft ignition sources and inflammables. Available literature applicable to the problem of aircraft fire hazards is analyzed and, discussed herein. Data pertaining to the effect of many variables on ignition temperatures, minimum ignition pressures, and minimum spark-ignition energies of inflammables, quenching distances of electrode configurations, and size of openings incapable of flame propagation are presented and discussed. The ignition temperatures and the limits of inflammability of gasoline in air in different test environments, and the minimum ignition pressure and the minimum size of openings for flame propagation of gasoline - air mixtures are included. Inerting of gasoline - air mixtures is discussed.

  15. Relation between inflammables and ignition sources in aircraft environments

    NASA Technical Reports Server (NTRS)

    Scull, Wilfred E

    1951-01-01

    A literature survey was conducted to determine the relation between aircraft ignition sources and inflammables. Available literature applicable to the problem of aircraft fire hazards is analyzed and discussed. Data pertaining to the effect of many variables on ignition temperatures, minimum ignition pressures, minimum spark-ignition energies of inflammables, quenching distances of electrode configurations, and size of openings through which flame will not propagate are presented and discussed. Ignition temperatures and limits of inflammability of gasoline in air in different test environments, and the minimum ignition pressures and minimum size of opening for flame propagation in gasoline-air mixtures are included; inerting of gasoline-air mixtures is discussed.

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

    NASA Astrophysics Data System (ADS)

    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 (λ0-210 nm) will be used to optimize the scattered signal for plasma densities of 5 × 1020 electrons/cm3 while a 3ω probe will be used for experiments investigating lower density plasmas of 1 × 1019 electrons/cm3. 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.

  17. Radiation Hydrodynamic Simulations in the Planar Scheme for the Fundamental Studies of Shock Ignition

    NASA Astrophysics Data System (ADS)

    Dong, Yunsong; Yang, Jiamin; Song, Tianming; Zhu, Tuo; Huang, Chengwu

    2016-04-01

    As a fundamental and crucial research topic in the direct-driven inertial confinement fusion (ICF), especially for shock ignition (SI), investigation on the laser coupling with planar low-Z targets is beneficial for deep physical comprehension at the primary phase of SI. The production of the intense shock and the shock coalescence in the multi-layer targets, driven by the 3ω intense laser (351 nm the wavelength), were studied in detail with the 1D and 2D radiation hydrodynamic simulations. It was inferred that the 1D simulation would overrate the shock velocity and the ablation pressure of the spike; the coalescence time and the velocity of the coalescence shock depended evidently on the pulse shape and the start time of the spike. The present study can also provide a semi-quantitative reference for the design of the SI decomposition experiments on the Shenguang-III prototype laser facility. supported by the National High-Tech R&D Program (863 Program) of China and National Natural Science Foundation of China (Nos. 11205143, 11505167)

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

    PubMed

    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 (λ0-210 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.

  19. Ignition in convective-diffusive systems

    NASA Astrophysics Data System (ADS)

    Fotache, Catalin Grig

    The main goal of this work is understanding the controlling mechanisms and responses of forced ignition in an environment where chemistry and transport phenomena are intimately coupled. To analyze systematically this interaction the well-characterized counterflow configuration is selected whereupon a cold fuel jet impinges on a heated air jet, and ignites as the air temperature is raised gradually. In this configuration the ignition response is studied experimentally and numerically with extensive variations of the fuel dilution, flow strain rate, and ambient pressure, for hydrogen and Csb1{-}Csb4 paraffins. Experimentally, the temperatures are measured by thermocouple and Raman spectroscopy, while flow strain rates are determined through laser Doppler velocimetry. The experimental envelope comprises pressures of 0.1-8.0 atm, fuel concentrations from 0 to 100%, and strain rates between 50 and 700 ssp{-1}. Computations are performed using various detailed kinetic and transport models, whose adequacy is assessed by comparison with the experimental results. Through computational simulations, the controlling ignition mechanisms are isolated and analyzed. Simplified kinetic models are derived and evaluated, by using sensitivity/flux analyses and the Computational Singular Perturbation (CSP) method. The investigation demonstrates that the coupling chemistry-transport can produce unexpected responses, even for the arguably simplest Hsb2-air kinetic system. Here, up to three stable steady-states are identified experimentally for identical boundary conditions, corresponding to the distinct regimes of frozen flow, mild oxidation, and flaming combustion, respectively. These states can be accessed in a dual-staged ignition sequence, with radical runaway followed by thermokinetic ignition. The pattern, however, depends on the imposed parameters. Specifically, three ignition limits are found when pressure is varied; the first two are characterized by radical runaway only

  20. Ultrasonic vibration modal analysis of ICF targets using a photorefractive optical lock-in

    NASA Astrophysics Data System (ADS)

    Hale, Thomas C.; Asaki, Thomas J.; Telschow, Kenneth L.; Hoffer, Jim

    1998-03-01

    A photorefractive optical lock-in is discussed in relation to ultrasonic vibration modal analysis of inertial confinement fusion (ICF) targets. In this preliminary report, the method is used to analyze specimens with similar response characteristics to ICF targets with emphasis on both the displacement and frequency resolution of the technique. The experimental method, based on photorefractive frequency domain processing, utilizes a synchronous detection approach to measure phase variations in light scattered from optically rough, continuously vibrating surfaces with very high, linear sensitivity. In this photorefractive four-wave mixing technique, a small, point image of the object surface is made to interfere with a uniform, frequency modulated reference beam inside a Bismith Silicon Oxide crystal. Optical interference and the photorefractive effect of electronic charge redistribution leads to the formation of a refractive index grating in the medium that responds to the modulated beams at a frequency equal to the difference between the signal and reference frequencies. By retro-reflecting the reference beam back into the crystal, a diffracted beam, counter-propagating with respect to the original transmitted beam, is generated. Using a beamsplitter, the counter-propagating beam can be picked-off and deflected toward a photodetector. The intensity of this diffracted beam is shown to be a function of the first-order ordinary Bissel function, and therefore linearly dependent on the vibration displacement induced phase modulation depth (delta) , for small (delta) ((delta) < 4 (pi) (xi) /(lambda) < < 1) where (xi) is the vibration displacement and (lambda) is the source wavelength; analytical description and experimental verification of this linear response are given. The technique is applied to determine the modal characteristics of a rigidly clamped disc from 10 kHz to 100 kHz, a frequency range similar to that used to characterize ICF targets. The results

  1. Theory and simulations of neutralization and focusing of ICF ion beams

    SciTech Connect

    Lemons, D.S.; Jones, M.E.

    1985-10-01

    Inertial Confinement Fusion (ICF) ion beams must be focused to a small spot during final propagation to the target. In general, both beam emittance and space charge limit the achievable spot size. Here we consider the latter and how its effect can be eliminated by injecting into the target chamber electrons which are comoving and coexstensive with the ions. Unlike focusing an ion beam through a neutralizing plasma channel, the present propagation mode requires a hard vacuum (10/sup -4/ to 10/sup -5/ Torr) target chamber into which both ions and electrons are injected, and thus avoids possibly deleterious beam plasma interactions.

  2. Studying areal density evolution in D-3He implosions at the National Ignition Facility using pTOF-measured shock- and compression-bang times and WRF-measured shock and compression ρR

    NASA Astrophysics Data System (ADS)

    Kabadi, N.; Sio, H.; Lahmann, B.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Petrasso, R. D.; Rinderknecht, H. G.; Berzak-Hopkins, L.; Meezan, N.; Casey, D. T.; Baker, K.; Khan, S.; Thomas, C. A.; Spears, B. K.; Barbosa, F.; Bionta, R. M.; Zylstra, A.; Kilkenny, J. D.; Sangster, T. C.

    2016-10-01

    Understanding the time evolution of inertial confinement fusion (ICF) experiments is critical for making further improvements on the road to ignition. In an ICF implosion at the National Ignition Facility (NIF) shocks are launched into the ablator by a laser pulse. These shocks coalesce at the fuel-shell interface and then converge at the center of the implosion which causes significant heating and a period of nuclear burn (``shock phase''), followed by a compression phase due to the imploding shell. The particle-time-of-flight (pTOF) and the magnetic particle-time-of-flight (magPTOF) detectors were developed to measure both the shock and compression bang-times in NIF D-3He implosions. These timing measurements in combination with shock and compression areal densities (ρR) from wedge range filters (WRFs) provide a direct measurement of ρR evolution, which can be used to guide theory and heavily constrain simulations. This presentation shows a first analysis of ρR evolution from shock phase to compression phase in a variety of NIF implosions as measured by pTOF and WRFs. This work was supported in part by LLE, the U.S. DoE (NNSA, NLUF) and LLNL.

  3. Dark Matter Ignition of Type Ia Supernovae.

    PubMed

    Bramante, Joseph

    2015-10-02

    Recent studies of low redshift type Ia supernovae (SN Ia) indicate that half explode from less than Chandrasekhar mass white dwarfs, implying ignition must proceed from something besides the canonical criticality of Chandrasekhar mass SN Ia progenitors. We show that 1-100 PeV mass asymmetric dark matter, with imminently detectable nucleon scattering interactions, can accumulate to the point of self-gravitation in a white dwarf and collapse, shedding gravitational potential energy by scattering off nuclei, thereby heating the white dwarf and igniting the flame front that precedes SN Ia. We combine data on SN Ia masses with data on the ages of SN Ia-adjacent stars. This combination reveals a 2.8σ inverse correlation between SN Ia masses and ignition ages, which could result from increased capture of dark matter in 1.4 vs 1.1 solar mass white dwarfs. Future studies of SN Ia in galactic centers will provide additional tests of dark-matter-induced type Ia ignition. Remarkably, both bosonic and fermionic SN Ia-igniting dark matter also resolve the missing pulsar problem by forming black holes in ≳10  Myr old pulsars at the center of the Milky Way.

  4. Physics aspects of the Compact Ignition Tokamak

    SciTech Connect

    Post, D.; Bateman, G.; Houlberg, W.; Bromberg, L.; Cohn, D.; Colestock, P.; Hughes, M.; Ignat, D.; Izzo, R.; Jardin, S.

    1986-11-01

    The Compact Ignition Tokamak (CIT) is a proposed modest-size ignition experiment designed to study the physics of alpha-particle heating. The basic concept is to achieve ignition in a modest-size minimum cost experiment by using a high plasma density to achieve the condition of ntau/sub E/ approx. 2 x 10/sup 20/ sec m/sup -3/ required for ignition. The high density requires a high toroidal field (10 T). The high toroidal field allows a large plasma current (10 MA) which improves the energy confinement, and provides a high level of ohmic heating. The present CIT design also has a gigh degree of elongation (k approx. 1.8) to aid in producing the large plasma current. A double null poloidal divertor and a pellet injector are part of the design to provide impurity and particle control, improve the confinement, and provide flexibility for impurity and particle control, improve the confinement, and provide flexibility for improving the plasma profiles. Since auxiliary heating is expected to be necessary to achieve ignition, 10 to 20 MW of Ion Cyclotron Radio Frequency (ICRF) is to be provided.

  5. Piloted Ignition Regimes of Wildland Fuel Beds

    NASA Astrophysics Data System (ADS)

    Thomas, J. C.; Simeoni, A.; Colella, F.; Torero, J. L.

    2012-04-01

    Pine needle litters, a key fuel in North American and Mediterranean forest systems, are highly porous fuel beds. They provide a source of continuous fuel medium that can be easily ignited and will sustain flame spread in forest fires. This study is a continuation of previous piloted ignition experimentation [1]. Here, focus was drawn to the influence of airflow in a porous fuel bed for three species: Pinus halepensis, Pinus strobus, and Pinus resinosa. Each needle species is characterized by surface-to-volume ratio and density. The tests samples are characterized by the bulk density, porosity and absorptivity. The needles are subjected to an external radiant heat flux using the FM Global Fire Propagation Apparatus. Ignition delay times and surface temperatures were recorded under a range of different test conditions (basket open area, flow conditions and different level of the radiant heat flux). A comparison of the results indicates that the flow condition must be considered for the modeling of such fuel beds. For conditions where the air flow through the sample is blocked a solid like behavior can be observed. The results show that this cannot be granted for open sample baskets. The goal of this study is to understand the effects, cooling and mixing, of airflow through the porous medium on the time to ignition of the sample and aid in the development of new models for characterizing the ignition behavior.

  6. Analytical model for fast-shock ignition

    SciTech Connect

    Ghasemi, S. A. Farahbod, A. H.; Sobhanian, S.

    2014-07-15

    A model and its improvements are introduced for a recently proposed approach to inertial confinement fusion, called fast-shock ignition (FSI). The analysis is based upon the gain models of fast ignition, shock ignition and considerations for the fast electrons penetration into the pre-compressed fuel to examine the formation of an effective central hot spot. Calculations of fast electrons penetration into the dense fuel show that if the initial electron kinetic energy is of the order ∼4.5 MeV, the electrons effectively reach the central part of the fuel. To evaluate more realistically the performance of FSI approach, we have used a quasi-two temperature electron energy distribution function of Strozzi (2012) and fast ignitor energy formula of Bellei (2013) that are consistent with 3D PIC simulations for different values of fast ignitor laser wavelength and coupling efficiency. The general advantages of fast-shock ignition in comparison with the shock ignition can be estimated to be better than 1.3 and it is seen that the best results can be obtained for the fuel mass around 1.5 mg, fast ignitor laser wavelength ∼0.3  micron and the shock ignitor energy weight factor about 0.25.

  7. Low power arcjet thruster pulse ignition

    NASA Technical Reports Server (NTRS)

    Sarmiento, Charles J.; Gruber, Robert P.

    1987-01-01

    An investigation of the pulse ignition characteristics of a 1 kW class arcjet using an inductive energy storage pulse generator with a pulse width modulated power converter identified several thruster and pulse generator parameters that influence breakdown voltage including pulse generator rate of voltage rise. This work was conducted with an arcjet tested on hydrogen-nitrogen gas mixtures to simulate fully decomposed hydrazine. Over all ranges of thruster and pulser parameters investigated, the mean breakdown voltages varied from 1.4 to 2.7 kV. Ignition tests at elevated thruster temperatures under certain conditions revealed occasional breakdowns to thruster voltages higher than the power converter output voltage. These post breakdown discharges sometimes failed to transition to the lower voltage arc discharge mode and the thruster would not ignite. Under the same conditions, a transition to the arc mode would occur for a subsequent pulse and the thruster would ignite. An automated 11 600 cycle starting and transition to steady state test demonstrated ignition on the first pulse and required application of a second pulse only two times to initiate breakdown.

  8. A hydrocode study of explosive shock ignition

    NASA Astrophysics Data System (ADS)

    Butler, George C.; Horie, Yasuyuki

    2012-03-01

    This paper discusses the results of hydrocode simulations of shock-induced ignition of PBXN-109, Octol, PETN, and HNS explosives using the History Variable Reactive Burn model in the CTH hydrocode. Normalized values of pressure and time were derived from the equations defining the HVRB model, and used to define an upper bound for ignition. This upper bound corresponds to the well established Pop-plot data for supported detonation, i.e. detonations in which a constant shock pressure is applied to an explosive until full detonation is achieved. Subsequently, one-dimensional flyer-plate simulations were conducted in which the responses to varied constant-amplitude, limitedduration shock pulses into semi-infinite explosive samples were examined. These simulations confirmed not only the existence of an upper bound for ignition as expected, but also showed ignition by "lower level" shocks, in which full detonation is reached at a time longer than the input shock duration. These lower-level shocks can be used to define a distinct minimal ignition threshold, below which shock pulses do not result in detonation. Numerical experiments using these bounds offer a new framework for interpreting explosive initiation data.

  9. Advanced-Ignition-Concept Exploration on OMEGA

    SciTech Connect

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

    2009-11-24

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

  10. Advanced-Ignition-Concept Exploration on OMEGA

    SciTech Connect

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

    2009-11-24

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

  11. Capsule Design for Hybrid Shock Ignition

    NASA Astrophysics Data System (ADS)

    Baumgaertel, J. A.; Dodd, E. S.; Loomis, E. N.

    2014-10-01

    Hybrid Shock-Ignition (HSI) is an alternate fusion energy concept that combines indirect drive and shock ignition schemes in order to access new regimes in National Ignition Facility (NIF) hohlraum physics. Building off of tetrahedral hohlraum experiments at the OMEGA laser facility, we have preliminary designs for spherical hohlraums that combine symmetrically arranged laser entrance holes for indirect-drive beams (to initially compress the capsule) and holes for direct-drive beams to drive a strong ignitor shock (to further compress and ignite the fuel). A LANL Eulerian hydrodynamic code is being used to find optimal laser drive, hohlraum, and capsule specifications, via criteria such as implosion symmetry, implosion time, and neutron yield. At first, drive will be modeled using a radiation source to mimic the hohlraum drive, and later, ignitor beams will be added. Initial capsule designs will be presented for experiments to develop the HSI platform on the sub-ignition scale OMEGA laser facility in FY15. Supported under the U.S. Department of Energy by the Los Alamos National Security, LLC under Contract DE-AC52-06NA25396. LA-UR-14-25071.

  12. Telomeres in ICF syndrome cells are vulnerable to DNA damage due to elevated DNA:RNA hybrids

    PubMed Central

    Sagie, Shira; Toubiana, Shir; Hartono, Stella R.; Katzir, Hagar; Tzur-Gilat, Aya; Havazelet, Shany; Francastel, Claire; Velasco, Guillaume; Chédin, Frédéric; Selig, Sara

    2017-01-01

    DNA:RNA hybrids, nucleic acid structures with diverse physiological functions, can disrupt genome integrity when dysregulated. Human telomeres were shown to form hybrids with the lncRNA TERRA, yet the formation and distribution of these hybrids among telomeres, their regulation and their cellular effects remain elusive. Here we predict and confirm in several human cell types that DNA:RNA hybrids form at many subtelomeric and telomeric regions. We demonstrate that ICF syndrome cells, which exhibit short telomeres and elevated TERRA levels, are enriched for hybrids at telomeric regions throughout the cell cycle. Telomeric hybrids are associated with high levels of DNA damage at chromosome ends in ICF cells, which are significantly reduced with overexpression of RNase H1. Our findings suggest that abnormally high TERRA levels in ICF syndrome lead to accumulation of telomeric hybrids that, in turn, can result in telomeric dysfunction. PMID:28117327

  13. A Method to Compare ICF and SNOMED CT for Coverage of U.S. Social Security Administration's Disability Listing Criteria.

    PubMed

    Tu, Samson W; Nyulas, Csongor I; Tudorache, Tania; Musen, Mark A

    2015-01-01

    We developed a method to evaluate the extent to which the International Classification of Function, Disability, and Health (ICF) and SNOMED CT cover concepts used in the disability listing criteria of the U.S. Social Security Administration's "Blue Book." First we decomposed the criteria into their constituent concepts and relationships. We defined different types of mappings and manually mapped the recognized concepts and relationships to either ICF or SNOMED CT. We defined various metrics for measuring the coverage of each terminology, taking into account the effects of inexact matches and frequency of occurrence. We validated our method by mapping the terms in the disability criteria of Adult Listings, Chapter 12 (Mental Disorders). SNOMED CT dominates ICF in almost all the metrics that we have computed. The method is applicable for determining any terminology's coverage of eligibility criteria.

  14. Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

    SciTech Connect

    Westbrook, C.K.

    2000-07-07

    Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another.

  15. Application of the International Classification of Functioning, Disability and Health (ICF) to people with dysphagia following non-surgical head and neck cancer management.

    PubMed

    Nund, Rebecca L; Scarinci, Nerina A; Cartmill, Bena; Ward, Elizabeth C; Kuipers, Pim; Porceddu, Sandro V

    2014-12-01

    The International Classification of Functioning, Disability, and Health (ICF) is an internationally recognized framework which allows its user to describe the consequences of a health condition on an individual in the context of their environment. With growing recognition that dysphagia can have broad ranging physical and psychosocial impacts, the aim of this paper was to identify the ICF domains and categories that describe the full functional impact of dysphagia following non-surgical head and neck cancer (HNC) management, from the perspective of the person with dysphagia. A secondary analysis was conducted on previously published qualitative study data which explored the lived experiences of dysphagia of 24 individuals with self-reported swallowing difficulties following HNC management. Categories and sub-categories identified by the qualitative analysis were subsequently mapped to the ICF using the established linking rules to develop a set of ICF codes relevant to the impact of dysphagia following HNC management. The 69 categories and sub-categories that had emerged from the qualitative analysis were successfully linked to 52 ICF codes. The distribution of these codes across the ICF framework revealed that the components of Body Functions, Activities and Participation, and Environmental Factors were almost equally represented. The findings confirm that the ICF is a valuable framework for representing the complexity and multifaceted impact of dysphagia following HNC. This list of ICF codes, which reflect the diverse impact of dysphagia associated with HNC on the individual, can be used to guide more holistic assessment and management for this population.

  16. The Role of the WHO ICF as a Framework to Interpret Barriers and to Inclusion: Visually Impaired People's Views and Experiences of Personal Computers

    ERIC Educational Resources Information Center

    Douglas, Graeme; Corcoran, Christine; Pavey, Sue

    2007-01-01

    This article describes how the World Health Organisation's International Classification of Functioning, Disability, and Health (ICF), 2001, was used as a framework for the design of the interview schedule used in the Network 1000 project. It is argued that the ICF offers a vocabulary to enable visually impaired participants to describe their lives…

  17. A fluidic sounding rocket motor ignition system.

    NASA Technical Reports Server (NTRS)

    Marchese, V. P.; Rakowsky, E. L.; Bement, L. J.

    1972-01-01

    Fluidic sounding rocket motor ignition has been found to be feasible using a system without stored energy and with the complete absence of electrical energy and wiring. The fluidic ignitor is based on a two component aerodynamic resonance heating device called the pneumatic match. Temperatures in excess of 600 C were generated in closed resonance tubes which were excited by a free air jet from a simple convergent nozzle. Using nitrocellulose interface material, ignition of boron potassium nitrate was accomplished with air supply pressures as low as 45 psi. This paper describes an analytical and experimental program which established a fluidic rocket motor ignition system concept incorporating a pneumatic match with a simple hand pump as the only energy source.

  18. Low current extended duration spark ignition system

    DOEpatents

    Waters, Stephen Howard; Chan, Anthony Kok-Fai

    2005-08-30

    A system for firing a spark plug is disclosed. The system includes a timing controller configured to send a first timing signal and a second timing signal. The system also includes an ignition transformer having a primary winding and a secondary winding and a spark-plug that is operably associated with the secondary winding. A first switching element is disposed between the timing controller and the primary winding of the ignition transformer. The first switching element controls a supply of power to the primary winding based on the first timing signal. Also, a second switching element is disposed between the timing controller and the primary winding of the ignition transformer. The second switching element controls the supply of power to the primary winding based on the second timing signal. A method for firing a spark plug is also disclosed.

  19. Spontaneous ignition limits of silane and phosphine

    SciTech Connect

    Kondo, Shigeo; Tokuhashi, Kazuaki; Nagai, Hidekazu; Iwasaka, Masaji; Kaise, Masahiro

    1995-04-01

    Spontaneous ignition limits of silane and phosphine have been investigated at relatively low concentrations. For silane, the spontaneous ignition occurs if the mixture concentration is such that the silane/oxygen ratio is higher than a certain threshold limit value. In other words, the mixture is not stable if the ratio is higher than a certain value. On the other hand. in the case of phosphine the threshold limit line has been found to be a little curved, though the reason for the fact is not clear. At any rate, it is concluded that the spontaneous ignition of both silane and phosphine occurs as a result of a competition of chain branching and chain breaking reactions, in a way that is qualitatively similar to that in hydrogen oxidation.

  20. Laser ignited engines: progress, challenges and prospects.

    PubMed

    Dearden, Geoff; Shenton, Tom

    2013-11-04

    Laser ignition (LI) has been shown to offer many potential benefits compared to spark ignition (SI) for improving the performance of internal combustion (IC) engines. This paper outlines progress made in recent research on laser ignited IC engines, discusses the potential advantages and control opportunities and considers the challenges faced and prospects for its future implementation. An experimental research effort has been underway at the University of Liverpool (UoL) to extend the stratified speed/load operating region of the gasoline direct injection (GDI) engine through LI research, for which an overview of some of the approaches, testing and results to date are presented. These indicate how LI can be used to improve control of the engine for: leaner operation, reductions in emissions, lower idle speed and improved combustion stability.

  1. Laser Ignition of Energetic Materials Workshop

    NASA Astrophysics Data System (ADS)

    Devries, Nora M.; Oreilly, John J.; Forch, Brad E.

    1993-11-01

    Lasers inherently possess many desirable attributes making them excellent igniters for a wide range of energetic materials such as pyrotechnics, explosives, and gun propellants. Lasers can be made very small, have modest powereD requirements, are invulnerable to external stimuli, are very reliable, and can deliver radiative energy to remote locations through optical fibers. Although the concept of using lasers for the initiation of energetic materials is not new, successful integration of laser technology into military systems has the potential to provide significant benefits. In order to efficiently expedite the evolution of the laser ignition technology for military applications, it was desirable to coordinate the effort with the JANNAF combustion community. The laser ignition of Energetic Materials Workshop was originated by Brad Forch, Austin Barrows, Richard Beyer and Arthur Cohen of the Army Research Laboratory (ARL).

  2. Ignition characteristics of some aircraft interior fabrics

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Brandt, D. L.

    1978-01-01

    Six samples of aircraft interior fabrics were evaluated with regard to resistance to ignition by radiant heat. Five samples were aircraft seat upholstery fabrics and one sample was an aircraft curtain fabric. The aircraft seat fabrics were 100% wool (2 samples), 83% wool/17% nylon, 49% wool/51% polyvinyl chloride, and 100% rayon. The aircraft curtain fabric was 92% modacrylic/8% polyester. The five samples of aircraft seat upholstery fabrics were also evaluated with regard to resistance to ignition by a smoldering cigarette. The four samples of wool-containing aircraft seat fabrics appeared to be superior to the sample of rayon seat fabric in resistance to ignition, both by radiant heat and by a smoldering cigarette.

  3. Target Visualization at the National Ignition Facility

    SciTech Connect

    Potter, Daniel Abraham

    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.

  4. Ignition of THKP and TKP pyrotechnic powders :

    SciTech Connect

    Maharrey, Sean P.; Erikson, William W; Highley, Aaron M.; Wiese-Smith, Deneille; Kay, Jeffrey J

    2014-03-01

    We have conducted Simultaneous Thermogravimetric Modulated Beam Mass Spectrometry (STMBMS) experiments on igniter/actuator pyrotechnic powders to characterize the reactive processes controlling the ignition and combustion behavior of these materials. The experiments showed a complex, interactive reaction manifold involving over ten reaction pathways. A reduced dimensionality reaction manifold was developed from the detailed 10-step manifold and is being incorporated into existing predictive modeling codes to simulate the performance of pyrotechnic powders for NW component development. The results from development of the detailed reaction manifold and reduced manifold are presented. The reduced reaction manifold has been successfully used by SNL/NM modelers to predict thermal ignition events in small-scale testing, validating our approach and improving the capability of predictive models.

  5. The National Ignition Facility and Industry

    NASA Astrophysics Data System (ADS)

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

    1994-09-01

    The mission of the National Ignition Facility is to achieve ignition and gain in inertial confinement fusion targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. The National Ignition Facility construction project will require the best of our construction industries and its success will depend on the best products offered by hundreds of the nation's high technology companies. Three-fourths of the construction costs will be invested in industry. This article reviews the design, cost and schedule, and required industrial involvement associated with the construction project.

  6. National Ignition Facility Target Chamber

    SciTech Connect

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

    2000-10-05

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

  7. Robustness studies of ignition targets for the National Ignition Facility in two dimensionsa)

    NASA Astrophysics Data System (ADS)

    Clark, Daniel S.; Haan, Steven W.; Salmonson, Jay D.

    2008-05-01

    Inertial confinement fusion capsules are critically dependent on the integrity of their hot spots to ignite. At the time of ignition, only a certain fractional perturbation of the nominally spherical hot spot boundary can be tolerated and the capsule still achieve ignition. The degree to which the expected hot spot perturbation in any given capsule design is less than this maximum tolerable perturbation is a measure of the ignition margin or robustness of that design. Moreover, since there will inevitably be uncertainties in the initial character and implosion dynamics of any given capsule, all of which can contribute to the eventual hot spot perturbation, quantifying the robustness of that capsule against a range of parameter variations is an important consideration in the capsule design. Here, the robustness of the 300eV indirect drive target design for the National Ignition Facility [Lindl et al., Phys. Plasmas 11, 339 (2004)] is studied in the parameter space of inner ice roughness, implosion velocity, and capsule scale. A suite of 2000 two-dimensional simulations, run with the radiation hydrodynamics code LASNEX, is used as the data base for the study. For each scale, an ignition region in the two remaining variables is identified and the ignition cliff is mapped. In accordance with the theoretical arguments of Levedahl and Lindl [Nucl. Fusion 37, 165 (1997)] and Kishony and Shvarts [Phys. Plasmas 8, 4925 (2001)], the location of this cliff is fitted to a power law of the capsule implosion velocity and scale. It is found that the cliff can be quite well represented in this power law form, and, using this scaling law, an assessment of the overall (one- and two-dimensional) ignition margin of the design can be made. The effect on the ignition margin of an increase or decrease in the density of the target fill gas is also assessed.

  8. Ignition characterization of the GOX/ethanol propellant combination

    NASA Technical Reports Server (NTRS)

    Lawver, B. R.; Rousar, D. C.; Boyd, W. C.

    1984-01-01

    This paper describes the results of a study to define the ignition characteristics and thruster pulse mode capabilities of the GOX/ethanol propellant combination. Ignition limits were defined in terms of mixture ratio and cold flow pressure using a spark initiated torch igniter. Igniter tests were run over a wide range of cold flow pressure, propellant temperature and mixture ratio. The product of cold flow pressure and igniter chamber diameter was used to correlate mixture ratio regimes of ignition and nonignition. Engine ignition reliability and pulse mode capability were demonstrated using a 620 lbF thruster with an integrated torch igniter. The nominal chamber pressure and mixture ratio were 150 psia and 1.8, respectively, thruster tests were run over a wide range of chamber pressures and mixture ratios. The feasibility of thruster pulse mode operation with the non-hypergolic GOX/ethanol propellant combination was demonstrated.

  9. Fast Ignition Transport Simulations for NIF

    SciTech Connect

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

    2009-10-05

    This paper shows work at Lawrence Livermore National Lab (LLNL) devoted to modeling the propagation of, and heating by, a relativistic electron beam in a idealized dense fuel assembly for fast ignition. The implicit particle-in-cell (PIC) code LSP is used. Experiments planned on the National Ignition Facility (NIF) in the next few years using the Advanced Radiography Capability (ARC) short-pulse laser motivate this work. We demonstrate significant improvement in the heating of dense fuel due to magnetic forces, increased beam collimation, and insertion of a finite-radius carbon region between the beam excitation and fuel regions.

  10. Ignition and combustion of metallized propellants

    NASA Technical Reports Server (NTRS)

    Turns, Stephen R.

    1991-01-01

    The overall objective is the development of a fundamental understanding of the ignition and combustion of aluminum-based slurry (or gel) propellant droplets using a combination of experiment and analysis. Specific objectives are the following: (1) The development and application of a burner/spray rig and single particle optical diagnosis to study the detailed ignition and combustion behavior of small droplets; (2) Understanding the role of surfactants and gellants (or other additives) in promoting or inhibiting secondary atomization of propellant droplets; and (3) The extension of previously developed analytical models and the development of new models to address the phenomena associated with microexplosions (secondary atomization).

  11. Plasma igniter for internal combustion engine

    NASA Technical Reports Server (NTRS)

    Fitzgerald, D. J.; Breshears, R. R. (Inventor)

    1978-01-01

    An igniter for the air/fuel mixture used in the cylinders of an internal combustion engine is described. A conventional spark is used to initiate the discharge of a large amount of energy stored in a capacitor. A high current discharge of the energy in the capacitor switched on by a spark discharge produces a plasma and a magnetic field. The resultant combined electromagnetic current and magnetic field force accelerates the plasma deep into the combustion chamber thereby providing an improved ignition of the air/fuel mixture in the chamber.

  12. Radiation Driven Capsules for Fast Ignition

    SciTech Connect

    Herrmann, M; Slutz, S A

    2001-06-08

    The energy required to ignite compressed deuterium-tritium fuel is a strong function of the fuel density. Through a series of detailed numerical simulations, peak fuel densities have been calculated as a function of the peak radiation drive temperature. Note that the time dependence of the radiation temperature (pulse shaping) has been optimized to obtain maximum density for each scaling point. A simple analytic scaling is developed, which agrees well with the numerical results. These scaling results are then used to obtain the required ignition energy as a function of peak drive temperature.

  13. Fast ignition transport simulations for NIF

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

    This paper shows work at Lawrence Livermore National Lab (LLNL) devoted to modeling the propagation of, and heating by, a relativistic electron beam in a idealized dense fuel assembly for fast ignition [1]. The implicit particle-in-cell (PIC) code LSP is used. Experiments planned on the National Ignition Facility (NIF) in the next few years using the Advanced Radiography Capability (ARC) short-pulse laser motivate this work. We demonstrate significant improvement in the heating of dense fuel due to magnetic forces, increased beam collimation, and insertion of a finite-radius carbon region between the beam excitation and fuel regions.

  14. The Path to Ignition on NIF

    NASA Astrophysics Data System (ADS)

    Lindl, John

    2005-10-01

    Advances in ignition target designs, including both indirect and direct drive schemes, have opened up a significantly larger and more robust operating space for ignition on NIF. The point design for our 2010 ignition experiments relies on indirect drive, and uses beryllium capsules with copper doped in a radially varying concentration. In simulations, these targets tolerate surface roughness several times the best previous target designs. The target will utilize a small fill-tube to introduce DT into the Be capsule. Be capsules absorb about 30% more energy in a given hohlraum than a CH capsule. The hohlraums for the 2010 experiments include several design modifications to increase efficiency. Mixtures of high-z materials (cocktails) can ``fill holes'' in the x-ray opacity and result in reduced losses into the hohlraum wall. Laser entrance hole (LEH)shields, which block the view of the LEH as seen by the capsule, increase the energy absorbed by the capsule. These advances increase the ignition margin on NIF by almost a factor of two. With significant advances in target fabrication technology, most requirements for the ignition targets have now been demonstrated. When all 192 beams of NIF are available for precision experiments in 2010, we will conduct an ignition campaign to obtain the required hohlraum drive, to tune symmetry, to optimize ablator performance for ablation depth and stability, and to adjust shock timing prior to the first ignition attempts. Polar Direct Drive is also being developed for ignition on NIF. In this scheme, the arrangement of the NIF beams developed for Indirect Drive is utilized for Direct Drive by employing a combination of re-pointing, phase-plate design, and target geometry. Recent experiments on the Omega laser at LLE have demonstrated an ability to control symmetry using these techniques. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. W-7405

  15. Semiconductor bridge, SCB, ignition of energetic materials

    SciTech Connect

    Bickes, R.W.; Grubelich, M.D.; Harris, S.M.; Merson, J.A.; Tarbell, W.W.

    1997-04-01

    Sandia National Laboratories` semiconductor bridge, SCB, is now being used for the ignition or initiation of a wide variety of exeoergic materials. Applications of this new technology arose because of a need at the system level to provide light weight, small volume and low energy explosive assemblies. Conventional bridgewire devices could not meet the stringent size, weight and energy requirements of our customers. We present an overview of SCB technology and the ignition characteristics for a number of energetic materials including primary and secondary explosives, pyrotechnics, thermites and intermetallics. We provide examples of systems designed to meet the modern requirements that sophisticated systems must satisfy in today`s market environments.

  16. Review of progress in Fast Ignition

    NASA Astrophysics Data System (ADS)

    Tabak, Max

    2004-11-01

    Marshall Rosenbluth's extensive contributions included seminal analysis of the inertial fusion program. Over the last decade he avidly followed the efforts of many scientists around the world who have studied with increasing intensity Fast Ignition, an alternate form of inertial fusion. In this scheme, the fuel is first compressed by a long pulse driver and then ignited by the short pulse laser. Due to technological advances, external energy sources (such as short pulse lasers) can focus intensity equivalent to that produced by the hydrodynamic stagnation of conventional inertial fusion capsules. This review will discuss the ignition requirements and gain curves starting from simple models and then describing how these are modified, as more detailed physics understanding is included. The critical design issues revolve around two questions: How can we efficiently assemble the compressed fuel? And how can we deliver the power from the driver to the ignition region? We will describe schemes to shorten the distance between the critical surface, where the high intensity laser deposits its energy into relativistic electrons, and the ignition region. We will review the theoretical and experimental status of the "hole boring" and "cone focus" schemes. In the hole-boring scheme an additional laser beam's ponderomotive light pressure is used to push the coronal plasma out of the ignition laser's beam path. For the cone focus scheme the implosion target is manufactured such that a vacuum path for the ignition laser is maintained during the implosion phase. We will describe what is known about the efficiency with which light couples to a plasma and the transport properties of the relativistic electrons that are generated during the interaction. An alternate route to coupling the energy to the ignition region passes through an intermediate stage where protons are generated from a virtual cathode and then focused into the compressed fuel . Experiments and modeling of the

  17. Heat energy of various ignition sparks

    NASA Technical Reports Server (NTRS)

    Silsbee, F B; Loeb, L B; Fonseca, E L

    1920-01-01

    This report describes a method developed at the Bureau of Standards for measuring the total energy liberated as heat in a spark gap by an ignition system. Since this heat energy is obtained from the electromagnetic energy stored in the windings of the magneto or coil, it is a measure of the effectiveness of the device as an electric generator. Part 2 gives the results of measurements in absolute units of the total heat supplied to a spark gap by ignition systems of different types operating at various speeds, under conditions substantially equivalent to those in the cylinder of a high-compression aviation engine.

  18. Improved hard x-ray (50-80 keV) imaging of hohlraum implosion experiments at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Bachmann, B.; Chow, R.; Palmer, N. E.; Hoover, M.; Huffman, E.; Lee, J. J.; Romano, E.; Kumar, C.; Hulbert, R. D.; Albert, F.; Dewald, E. L.; Divol, L.; Hohenberger, M.; Landen, O. L.; Warrick, A.; Döppner, T.

    2016-09-01

    We recently designed, built and commissioned a new pinhole / filter assembly for the equatorial hard x-ray imager (eHXI) at the National Ignition Facility (NIF). In this paper we describe the design and metrology of the new diagnostic as well as the spectral and spatial response of the hard x-ray detector. The new eHXI assembly has improved the photon collection efficiency along with spectral and spatial resolution by making use of 1D imaging channels and various hard x-ray filters. In addition we added a Ross pair filter set for Au K-alpha emission (67-69 keV). The new eHXI design will improve our understanding of the sourcing of hot electrons, generated in laser-plasma-instabilities, along the vertical hohlraum axis. This information is an important input for simulating and eventually limiting the DT fuel preheat in ICF implosions.

  19. Novel gas-dynamic levitation scheme for noncontact coating of spherical ICF targets

    SciTech Connect

    Kim, K.; Feng, Q.

    1995-12-01

    A novel gas-dynamic levitation technique has been developed to facilitate noncontact coating of spherical ICF targets. Using this technique three metal balls 450 {mu}m, 650 {mu}m and 950 {mu}m in diameter were levitated very stably for several hours, with the balls rotating continuously. Unlike the conventional gas-dynamic levitation scheme in which a single gas-emitting fixture, placed below an object, lifts it up and contains it in a confined volume, the present scheme relies on two fixtures, one placed under and the other above the object. The bottom fixture, as is with the conventional scheme, is a gas emitter; however, the top one is a gas collector shaping the flow field around the object so as to confine the object near the axis of symmetry of the levitation system. As a result, the present system exhibits excellent stability and robustness, and is immune to such external disturbances as nonuniform temperature fields and air currents, and small changes in the levitation gas pressure. The apparatus is inexpensive to fabricate and simple to operate. The details of the apparatus and the preliminary data demonstrating the capability of the levitation scheme are presented. A target coating method, compatible with the present target levitation scheme and suitable for uniform coating of ICF targets, is indicated. 6 refs., 5 figs.

  20. Demonstration of the use of the ICF framework in detailing complex functional deficits after major burn.

    PubMed

    Grisbrook, T L; Stearne, S M; Reid, S L; Wood, F M; Rea, S M; Elliott, C M

    2012-02-01

    Burns can result in long term impairments, activity limitations and participation restrictions in a patients' life. The focus of current surgeries and therapy is to improve body functions and structures. However, often this does not translate to an improvement in activity and participation for the patient. Improvement in activity and participation is the ultimate goal of all therapy to enhance patient's quality of life. The incorporation of assessment measures at all levels of the International Classification of Functioning, Disability and Health (ICF) can assist in a holistic, patient centred approach to identify the complex impairments that impact on activity and participation, with a view to appropriately targeting future therapeutic interventions. This paper presents an example case of how implementing measures at all levels of the ICF can improve our understanding of a patient's body functions and structures, activity and participation. A number of the outcome measures utilised in this study are novel in the burns population, such that video footage supplements the methodology where relevant.