Science.gov

Sample records for achieving fusion ignition

  1. Fast Ignition: Physics Progress in the US Fusion Energy Program and Prospects for Achieving Ignition.

    SciTech Connect

    Key, M H; Andersen, C; Cowan, T; Fisch, N; Freeman, R; Hatchett, S; Hill, J; King, J; Koch, J; Lasinski, B; Langdon, B; MacKinnon, A; Parks, P; Rosenbluth, M; Ruhl, H; Snavely, R; Stephens, R; Tabak, M; Town, R

    2002-10-16

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

  2. 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.

  3. 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.

  4. a Tutorial on Ignition and Gain for Small Fusion Targets

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, R. C.

    2009-07-01

    Nuclear fusion was discovered experimentally in 1933-34[1] and other charged particle nuclear reactions were documented shortly thereafter. [2] Work in earnest on the fusion ignition problem began with Edward Teller's group at Los Alamos during the war years. His group quantified all the important basic atomic and nuclear processes and summarized their interactions. A few years later, the success of the early theory developed at Los Alamos led to very successful thermonuclear weapons, but also to decades of unsuccessful attempts to harness fusion as an energy source of the future. The reasons for this history are many, but it seems appropriate to review some of the basics with the objective of identifying what is essential for success and what is not. This tutorial discusses only the conditions required for ignition in small fusion targets and how the target design impacts driver requirements. Generally speaking, the driver must meet the energy, power and power density requirements needed by the fusion target. The most relevant parameters for ignition of the fusion fuel are the minimum temperature and areal density (ρR), but these parameters set secondary conditions that must be achieved, namely an implosion velocity, target size and pressure, which are interrelated. Despite the apparent simplicity of inertial fusion targets, there is not a single mode of fusion ignition, and the necessary combination of minimum temperature and areal density depends on the mode of ignition. However, by providing a magnetic field of sufficient strength, the conditions needed for fusion ignition can be drastically altered. Magnetized target fusion potentially opens up a vast parameter space between the extremes of magnetic and inertial fusion.

  5. 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.

  6. Shock ignition: a new approach to high gain inertial confinement fusion on the national ignition facility.

    PubMed

    Perkins, L J; Betti, R; LaFortune, K N; Williams, W H

    2009-07-24

    Shock ignition, an alternative concept for igniting thermonuclear fuel, is explored as a new approach to high gain, inertial confinement fusion targets for the National Ignition Facility (NIF). Results indicate thermonuclear yields of approximately 120-250 MJ may be possible with laser drive energies of 1-1.6 MJ, while gains of approximately 50 may still be achievable at only approximately 0.2 MJ drive energy. The scaling of NIF energy gain with laser energy is found to be G approximately 126E (MJ);{0.510}. This offers the potential for high-gain targets that may lead to smaller, more economic fusion power reactors and a cheaper fusion energy development path. PMID:19659364

  7. First Intended Experiment for Impact Fusion Ignition

    NASA Astrophysics Data System (ADS)

    Azechi, H.; Obenschain, S.; Aglitskiy, Y.

    2005-10-01

    Sufficient suppression of the Rayleigh-Taylor (RT) instability not only increases compressed density, but it may also revive an old ignition idea: High velocity implosion with 1000 km/s may configure a hot-spark without a surrounding cold main fuel and thereby ignite at a very low laser energy of 30-100 kJ. A major criticism of no pathway towards high gain may be solved by the impact fusion ignition (IFI) configuration [M. Murakami, NIM-A 05]. In this scheme, a main fuel is first imploded, whereas the ignition is made by impact collision of the second partial shell with high velocity of 1000 km/s. The first intended experiment using a RT suppressed target has demonstrated the velocity of 600 km/s. We plan to employ several RT suppression schemes in attempts to reach higher velocities using the HIPER and NIKE lasers.

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

    NASA Astrophysics Data System (ADS)

    Moses, Edward I.

    2009-10-01

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

  9. Low Fuel Convergence Path to Direct-Drive Fusion Ignition.

    PubMed

    Molvig, Kim; Schmitt, Mark J; Albright, B J; Dodd, E S; Hoffman, N M; McCall, G H; Ramsey, S D

    2016-06-24

    A new class of inertial fusion capsules is presented that combines multishell targets with laser direct drive at low intensity (2.8×10^{14}  W/cm^{2}) to achieve robust ignition. The targets consist of three concentric, heavy, metal shells, enclosing a volume of tens of μg of liquid deuterium-tritium fuel. Ignition is designed to occur well "upstream" from stagnation, with minimal pusher deceleration to mitigate interface Rayleigh-Taylor growth. Laser intensities below thresholds for laser plasma instability and cross beam energy transfer facilitate high hydrodynamic efficiency (∼10%). PMID:27391731

  10. Low Fuel Convergence Path to Direct-Drive Fusion Ignition

    NASA Astrophysics Data System (ADS)

    Molvig, Kim; Schmitt, Mark J.; Albright, B. J.; Dodd, E. S.; Hoffman, N. M.; McCall, G. H.; Ramsey, S. D.

    2016-06-01

    A new class of inertial fusion capsules is presented that combines multishell targets with laser direct drive at low intensity (2.8 ×1014 W /cm2 ) to achieve robust ignition. The targets consist of three concentric, heavy, metal shells, enclosing a volume of tens of μ g of liquid deuterium-tritium fuel. Ignition is designed to occur well "upstream" from stagnation, with minimal pusher deceleration to mitigate interface Rayleigh-Taylor growth. Laser intensities below thresholds for laser plasma instability and cross beam energy transfer facilitate high hydrodynamic efficiency (˜10 %).

  11. 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.

  12. Physics of laser-plasma interaction for shock ignition of fusion reactions

    NASA Astrophysics Data System (ADS)

    Tikhonchuk, V. T.; Colaïtis, A.; Vallet, A.; Llor Aisa, E.; Duchateau, G.; Nicolaï, Ph; Ribeyre, X.

    2016-01-01

    The shock ignition scheme is an alternative approach, which aims to achieve ignition of fusion reactions in two subsequent steps: first, the target is compressed at a low implosion velocity and second, a strong converging shock is launched during the stagnation phase and ignites the hot spot. In this paper we describe the major elements of this scheme and recent achievements concerning the laser-plasma interaction, the crucial role of hot electrons in the shock generation, the shock amplification in the imploding shell and the ignition conditions.

  13. The ignition design space of magnetized target fusion

    NASA Astrophysics Data System (ADS)

    Lindemuth, Irvin R.

    2015-12-01

    The simple magnetized target implosion model of Lindemuth and Kirkpatrick [Nucl. Fusion 23, 263 (1983)] has been extended to survey the potential parameter space in which three types of magnetized targets—cylindrical with axial magnetic field, cylindrical with azimuthal magnetic field, and spherical with azimuthal magnetic field—might achieve ignition and produce large gain at achievable radial convergence ratios. The model has been used to compute the dynamic, time-dependent behavior of many initial parameter sets that have been based upon projected ignition conditions using the quasi-adiabatic and quasi-flux-conserving properties of magnetized target implosions. The time-dependent calculations have shown that energy gains greater than 30 can potentially be achieved for each type of target. By example, it is shown that high gain may be obtained at extremely low convergence ratios, e.g., less than 15, for appropriate initial conditions. It is also shown that reaching the ignition condition, i.e., when fusion deposition rates equal total loss rates, does not necessarily lead to high gain and high fuel burn-up. At the lower densities whereby fusion temperatures can be reached in magnetized targets, the fusion burn rate may be only comparable with the hydrodynamic heating/cooling rates. On the other hand, when the fusion burn rates significantly exceed the hydrodynamic rates, the calculations show a characteristic rapid increase in temperature due to alpha particle deposition with a subsequent increased burn rate and high gain. A major result of this paper is that each type of target operates in a different initial density-energy-velocity range. The results of this paper provide initial target plasma parameters and driver parameters that can be used to guide plasma formation and driver development for magnetized targets. The results indicate that plasmas for spherical, cylindrical with azimuthal field, and cylindrical with axial field targets must have an initial

  14. The ignition design space of magnetized target fusion

    SciTech Connect

    Lindemuth, Irvin R.

    2015-12-15

    The simple magnetized target implosion model of Lindemuth and Kirkpatrick [Nucl. Fusion 23, 263 (1983)] has been extended to survey the potential parameter space in which three types of magnetized targets—cylindrical with axial magnetic field, cylindrical with azimuthal magnetic field, and spherical with azimuthal magnetic field—might achieve ignition and produce large gain at achievable radial convergence ratios. The model has been used to compute the dynamic, time-dependent behavior of many initial parameter sets that have been based upon projected ignition conditions using the quasi-adiabatic and quasi-flux-conserving properties of magnetized target implosions. The time-dependent calculations have shown that energy gains greater than 30 can potentially be achieved for each type of target. By example, it is shown that high gain may be obtained at extremely low convergence ratios, e.g., less than 15, for appropriate initial conditions. It is also shown that reaching the ignition condition, i.e., when fusion deposition rates equal total loss rates, does not necessarily lead to high gain and high fuel burn-up. At the lower densities whereby fusion temperatures can be reached in magnetized targets, the fusion burn rate may be only comparable with the hydrodynamic heating/cooling rates. On the other hand, when the fusion burn rates significantly exceed the hydrodynamic rates, the calculations show a characteristic rapid increase in temperature due to alpha particle deposition with a subsequent increased burn rate and high gain. A major result of this paper is that each type of target operates in a different initial density-energy-velocity range. The results of this paper provide initial target plasma parameters and driver parameters that can be used to guide plasma formation and driver development for magnetized targets. The results indicate that plasmas for spherical, cylindrical with azimuthal field, and cylindrical with axial field targets must have an initial

  15. Fusion Ignition Rocket Engine with Ballistic Ablative Lithium Liner

    NASA Technical Reports Server (NTRS)

    Martin, Adam; Eskridge, Richard; Fimognari, Peter J., III.

    2005-01-01

    Thermo-nuclear fusion may be the key to a high Isp, high specific power (low alpha) propulsion system. In a fusion system energy is liberated within, and imparted directly to, the propellant. In principle, this can overcome the performance limitations inherent in systems that require thermal power transfer across a material boundary, and/or multiple power conversion stages (NTR, NEP). A thermo-nuclear propulsion system, which attempts to overcome some of the problems inherent in the ORION concept, is described. A passive tapered liner is launched behind a vehicle, through a hole in a pusher-plate, that is connected to the vehicle by a shock-absorbing mechanism. A dense FRC plasmoid is then accelerated to high velocity (in excess of 1,000 km/s) and shot through the hole into the liner, when it has reached a given point down-range. The kinetic energy of the FRC is converted into thermal and magnetic-field energy, igniting a fusion bum in the magnetically confined plasma. The fusion reaction serves as an ignition source for the liner, which is made out of detonable materials. The energy liberated in this process is converted to thrust by the pusher-plate, as in the classic ORION concept. However with this concept, the vehicle does not carry a magazine of pre-fabricated pulse-units. A magnetic nozzle may also be used, in place of the pusher-plate. Estimates of the conditions needed to achieve a sufficient gain will be presented, along with a description of the driver characteristics. The incorporation of this concept into the propulsion system of a spacecraft will also be discussed.

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

    SciTech Connect

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

    2014-05-15

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

  17. 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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Tobin, M.; Logan, G.; Diazdelarubia, T.; Schrock, V.; Schultz, K.; Tokheim, Robert E.; Abdou, M.; Bangerter, R.

    1994-06-01

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

  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. Proton Beam Fast Ignition Fusion: Synergy of Weibel and Rayleigh-Taylor Instabilities

    NASA Astrophysics Data System (ADS)

    Stefan, V. Alexander

    2011-04-01

    The proton beam generation and focusing in fast ignition inertial confinement fusion is studied. The spatial and energy spread of the proton beam generated in a laser-solid interaction is increased due to the synergy of Weibel and Rayleigh-Taylor instabilities. The focal spot radius can reach 100 μm, which is nearly an order of magnitude larger than the optimal value. The energy spread decreases the beam deposition energy in the focal spot. Under these conditions, ignition of a precompressed DT fuel is achieved with the beam powers much higher than the values presently in consideration. Work supported in part by NIKOLA TESLA Laboratories (Stefan University), La Jolla, CA.

  2. Contributions of the National Ignition Facility to the development of inertial fusion energy. Revision 1

    SciTech Connect

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

    1994-10-01

    The Department of Energy is proposing to construct the National Ignition Facility (NIF) to embark on a program to achieve ignition and modest gain in the laboratory early in the next century. The NM will use a {ge}1.8-MJ, 0.35-mm laser with 192 independent beams, a fifty-fold increase over the energy of the Nova laser. System performance analyses suggest yields as great as 20 MJ may be achievable. NIF will conduct more than 600 shots per year. The benefits of a micro-fusion capability in the laboratory include: Essential contributions to defense programs, resolution of important Inertial Fusion Energy issues, and unparalleled conditions of energy density for basic science and technology research. We have begun to consider the role the National Ignition Facility will fill in the development of Inertial Fusion Energy. While the achievement of ignition and gain speaks for itself in terms of its impact on developing IFE, we believe there are areas of IFE development, such as fusion power technology, IFE target design and fabrication, and understanding chamber dynamics, that would significantly benefit from NIF experiments. In the area of IFE target physics, ion targets will be designed using the NIF laser, and feasibility of high gain targets will be confirmed. Target chamber dynamics experiments will benefit from x-ray and debris energies that mimic in-IFE-chamber conditions. Fusion power technology will benefit from using single-shot neutron yields to measure spatial distribution of neutron heating, activation, and tritium breeding in relevant materials. IFE target systems will benefit from evaluating low-cost target fabrication techniques by testing such targets on NIF.

  3. Advanced Tokamak Plasmas in the Fusion Ignition Research Experiment

    SciTech Connect

    C.E. Kessel; D. Meade; D.W. Swain; P. Titus; M.A. Ulrickson

    2003-10-13

    The Advanced Tokamak (AT) capability of the Fusion Ignition Research Experiment (FIRE) burning plasma experiment is examined with 0-D systems analysis, equilibrium and ideal-MHD stability, radio-frequency current-drive analysis, and full discharge dynamic simulations. These analyses have identified the required parameters for attractive burning AT plasmas, and indicate that these are feasible within the engineering constraints of the device.

  4. The National Ignition Facility and the Promise of Inertial Fusion Energy

    SciTech Connect

    Moses, E I

    2010-12-13

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

  5. Plasmonic energy nanofocusing for high-efficiency laser fusion ignition

    NASA Astrophysics Data System (ADS)

    Tanabe, Katsuaki

    2016-08-01

    We propose an efficient laser fusion ignition system consisting of metal nanoparticles or nanoshells embedded in conventional deuterated polystyrene fuel targets. The incident optical energy of the heating laser is highly concentrated around the metallic particulates randomly dispersed inside imploded targets due to the electromagnetic-field-enhancement effect by surface plasmon resonance, and thus effectively triggers nuclear-fusion chain reactions. Our preliminary calculations exhibit field enhancement factors of around 50 and 1100 for spherical Ag nanoparticles and Ag/SiO2 nanoshells, respectively, in the 1-µm band.

  6. Impact ignition as a track to laser fusion

    NASA Astrophysics Data System (ADS)

    Murakami, M.; Nagatomo, H.; Johzaki, T.; Sakaiya, T.; Velikovich, A.; Karasik, M.; Gus'kov, S.; Zmitrenko, N.

    2014-05-01

    In impact ignition, the compressed deuterium-tritium main fuel is ignited by impact with a separately imploded portion of fuel, which is accelerated in a hollow conical target to hyperspeeds of the order of 1000 km s-1. Its kinetic energy is directly converted into thermal energy corresponding to an ignition temperature of about 5 keV upon collision with the compressed fuel. The ignitor shell is irradiated by nanosecond pulses at intensities of between 1015 and 1016 W cm-2 with a wavelength of 0.25-0.35 µm, resulting in ablation pressures of several hundred mega-bars. Hydrodynamics-dominated physics and avoidance of ultra-intense petawatt lasers are notable features of this scheme. Experimental results for velocities exceeding 1000 km s-1, ion temperatures up to 3 keV, and neutron yield increases of 100-fold due to the impact effect indicate the potential of impact ignition for fusion energy production. The overall performance of impact ignition is reviewed with new analyses on the neutron yield and shell acceleration.

  7. FIREBALL: Fusion Ignition Rocket Engine with Ballistic Ablative Lithium Liner

    SciTech Connect

    Martin, Adam K.; Eskridge, Richard H.; Lee, Michael H.; Fimognari, Peter J.

    2006-01-20

    Thermo-nuclear fusion may be the key to a high Isp, high specific power propulsion system. In a fusion system energy is liberated within, and imparted directly to, the propellant. In principle, this can overcome the performance limitations inherent in systems that require thermal power transfer across a material boundary, and/or multiple power conversion stages (NTR, NEP). A thermo-nuclear propulsion system, which attempts to overcome some of the problems inherent in the Orion concept, is described. A dense FRC plasmoid is accelerated to high velocity (in excess of 500 km/s) and is compressed into a detached liner (pulse unit). The kinetic energy of the FRC is converted into thermal and magnetic-field energy, igniting a fusion burn in the magnetically confined plasma. The fusion reaction serves as an ignition source for the liner, which is made out of detonable materials. The energy liberated in this process is converted to thrust by a pusher-plate, as in the classic Orion concept. However with this concept, the vehicle does not carry a magazine of autonomous pulse-units. By accelerating a second, heavier FRC, which acts as a piston, right behind the first one, the velocity required to initiate the fusion burn is greatly reduced.

  8. 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.

  9. Thermonuclear ignition in inertial confinement fusion and comparison with magnetic confinement

    SciTech Connect

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

    2010-05-15

    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 Ptauapprox1.5 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 Ptauapprox1 atm s. Since OMEGA implosions are relatively cold (Tapprox2 keV), their overall ignition parameter chiapprox0.02-0.03 is approx5x lower than in JET (chiapprox0.13), where the average temperature is about 10 keV.

  10. 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.

  11. Can 250 fusions per muon be achieved

    SciTech Connect

    Jones, S.E.

    1987-01-01

    Nuclear fusion of hydrogen isotopes can be induced by negative muons ( ) in reactions such as: + d + t + n + . This reaction is analagous to the nuclear fusion reaction achieved in stars in which hydrogen isotopes (such as deuterium, d, and tritium, t) at very high temperatures first penetrate the Coulomb repulsive barrier and then fuse together to produce an alpha particle ( ) and a neutron (n), releasing energy. The muon in general reappears after inducing fusion so that the reaction can be repeated many (N) times. Thus, the muon may serve as an effective catalyst for nuclear fusion. Muon-catalozed fusion is unique in that it proceeds rapidly in deuterium-tritium mixtures at relatively cold temperatures, e.g., room temperature. The need for plasma temperatures to initiate fusion is overcome by the presence of the muon.

  12. Mission and Design of the Fusion Ignition Research Experiment (FIRE)

    SciTech Connect

    Meade, D. M.; Jardin, S. C.; Schmidt, J. A.; Thome, R. J.; Sauthoff, N. R.; Heitzenroeder, P.; Nelson, Brad E; Ulrickson, M. A.; Kessel, C. E.; Mandrekas, J.; Neumeyer, C. L.; Schultz, J. H.; Rutherford, P. H.; Wesley, J. C.; Young, K. M.; Nevins, W. M.; Houlberg, Wayne A; Uckan, Nermin A; Woolley, R. W.; Baker, C. C.

    2001-01-01

    Experiments are needed to test and extend present understanding of confinement, macroscopic stability, alpha-driven instabilities, and particle/power exhaust in plasmas dominated by alpha heating. A key issue is to what extent pressure profile evolution driven by strong alpha heating will act to self-organize advanced configurations with large bootstrap current fractions and internal transport barriers. A design study of a Fusion Ignition Research Experiment (FIRE) is underway to assess near term opportunities for advancing the scientific understanding of self-heated fusion plasmas. The emphasis is on understanding the behavior of fusion plasmas dominated by alpha heating (Q ≥ 5) that are sustained for durations comparable to the characteristic plasma time scales (≥ 20 τE and ~ τskin, where τskin is the time for the plasma current profile to redistribute at fixed current). The programmatic mission of FIRE is to attain, explore, understand and optimize alphadominated plasmas to provide knowledge for the design of attractive magnetic fusion energy systems. The programmatic strategy is to access the alpha-heating-dominated regime with confidence using the present advanced tokamak data base (e.g., Elmy-H-mode, ≤ 0.75 Greenwald density) while maintaining the flexibility for accessing and exploring other advanced tokamak modes (e. g., reversed shear, pellet enhanced performance) at lower magnetic fields and fusion power for longer durations in later stages of the experimental program. A major goal is to develop a design concept that could meet these physics objectives with a construction cost in the range of $1B.

  13. Fast Ignition Thermonuclear Fusion: Enhancement of the Pellet Gain by the Colossal-Magnetic-Field Shells

    NASA Astrophysics Data System (ADS)

    Stefan, V. Alexander

    2013-10-01

    The fast ignition fusion pellet gain can be enhanced by a laser generated B-field shell. The B-field shell, (similar to Earth's B-field, but with the alternating B-poles), follows the pellet compression in a frozen-in B-field regime. A properly designed laser-pellet coupling can lead to the generation of a B-field shell, (up to 100 MG), which inhibits electron thermal transport and confines the alpha-particles. In principle, a pellet gain of few-100s can be achieved in this manner. Supported in part by Nikola Tesla Labs, Stefan University, 1010 Pearl, La Jolla, CA 92038-1007.

  14. The HiPER project for inertial confinement fusion and some experimental results on advanced ignition schemes

    NASA Astrophysics Data System (ADS)

    Batani, D.; Koenig, M.; Baton, S.; Perez, F.; Gizzi, L. A.; Koester, P.; Labate, L.; Honrubia, J.; Antonelli, L.; Morace, A.; Volpe, L.; Santos, J.; Schurtz, G.; Hulin, S.; Ribeyre, X.; Fourment, C.; Nicolai, P.; Vauzour, B.; Gremillet, L.; Nazarov, W.; Pasley, J.; Richetta, M.; Lancaster, K.; Spindloe, Ch; Tolley, M.; Neely, D.; Kozlová, M.; Nejdl, J.; Rus, B.; Wolowski, J.; Badziak, J.; Dorchies, F.

    2011-12-01

    This paper presents the goals and some of the results of experiments conducted within the Working Package 10 (Fusion Experimental Programme) of the HiPER Project. These experiments concern the study of the physics connected to 'advanced ignition schemes', i.e. the fast ignition and the shock ignition approaches to inertial fusion. Such schemes are aimed at achieving a higher gain, as compared with the classical approach which is used in NIF, as required for future reactors, and make fusion possible with smaller facilities. In particular, a series of experiments related to fast ignition were performed at the RAL (UK) and LULI (France) Laboratories and studied the propagation of fast electrons (created by a short-pulse ultra-high-intensity beam) in compressed matter, created either by cylindrical implosions or by compression of planar targets by (planar) laser-driven shock waves. A more recent experiment was performed at PALS and investigated the laser-plasma coupling in the 1016 W cm-2 intensity regime of interest for shock ignition.

  15. Results from D-T Experiments on TFTR and Implications for Achieving an Ignited Plasma

    SciTech Connect

    Hawryluk, R.J. and the TFTR Group

    1998-07-14

    Progress in the performance of tokamak devices has enabled not only the production of significant bursts of fusion energy from deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. As a result of the worldwide research on tokamaks, the scientific and technical issues for achieving an ignited plasma are better understood and the remaining questions more clearly defined. The principal research topics which have been studied on TFTR are transport, magnetohydrodynamic stability, and energetic particle confinement. The integration of separate solutions to problems in each of these research areas has also been of major interest. Although significant advances, such as the reduction of turbulent transport by means of internal transport barriers, identification of the theoretically predicted bootstrap current, and the study of the confinement of energetic fusion alpha-particles have been made, interesting and important scientific and technical issues remain for achieving a magnetic fusion energy reactor. In this paper, the implications of the TFTR experiments for overcoming these remaining issues will be discussed.

  16. Fast ignition of a compressed inertial confinement fusion hemispherical capsule by two proton beams

    SciTech Connect

    Temporal, Mauro

    2006-12-15

    A hemispherical conically guided indirectly driven inertial confinement fusion capsule has been considered. The fast ignition of the precompressed capsule driven by one or two laser-accelerated proton beams has been numerically investigated. The energy distribution of the protons is Gaussian with a mean energy of 12 MeV and a full width at half maximum of 1 MeV. A new scheme that uses two laser-accelerated proton beams is proposed. It is found that the energy deposition of 1 kJ provided by a first proton beam generates a low-density cylindrical channel and launches a forward shock. A second proton beam, delayed by a few tens of ps and driving the energy of 6 kJ, crosses the low-density channel and heats the dense shocked region where the ignition of the deuterium-tritium nuclear fuel is achieved. For the considered capsule, this new two-beam configuration reduces the ignition energy threshold to 7 kJ.

  17. Lessons from Two Years of Building Fusion Ignition Targets with the Precision Robotic Assembly Machine

    SciTech Connect

    Montesanti, R C; Alger, E T; Atherton, L J; Bhandarkar, S D; Castro, C; Dzenitis, E G; Hamza, A V; Klingmann, J L; Nikroo, A; Parham, T G; Reynolds, J L; Seugling, R M; Swisher, M F; Taylor, J S; Witte, M C

    2010-02-19

    The Precision Robotic Assembly Machine was developed to manufacture the small and intricate laser-driven fusion ignition targets that are being used in the world's largest and most energetic laser, the National Ignition Facility (NIF). The National Ignition Campaign (NIC) goal of using the NIF to produce a self-sustaining nuclear fusion burn with energy gain - for the first time ever in a laboratory setting - requires targets that are demanding in materials fabrication, machining, and assembly. We provide an overview of the design and function of the machine, with emphasis on the aspects that revolutionized how NIC targets are manufactured.

  18. Fast-Shock Ignition: A New Concept to Inertial Confinement Fusion

    NASA Astrophysics Data System (ADS)

    Ghasemi, Seyed; Farahbod, Amir; Laser Plasma Interaction Team

    2013-03-01

    A new concept for inertial confinement fusion called fast-shock ignition (FSI) is introduced to obtain high target gain. In the proposed model, the separation of fuel ignition into two successive steps, under the suitable conditions, reduces required ignitor energy. The main procedure in FSI concept is at first, compressing the fuel up to stagnation. Then, two high intensity short pulse laser spikes with energy and power lower than those required for shock ignition (SI) and fast ignition (FI) with a proper delay time launched at the fuel which increases the central hot-spot temperature and complete the ignition of the pre compressed fuel. The introduced semi-analytical model indicates that with fast-shock ignition, the total required energy for compression and ignition of the fuel can be slightly reduced in comparison with pure shock ignition. Furthermore, for fuel mass greater than 2mg, the target energy gain increases up to 15 percent and the contribution of fast ignitor could be decreased about 20 percent over pure fast ignition. The FSI scheme is beneficial from technological considerations for the construction of short pulse high power laser drivers. The general advantages of fast-shock ignition over pure shock ignition can be better than 1.3.

  19. Dynamic symmetry of indirectly driven inertial confinement fusion capsules on the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Town, R. P. J.; Bradley, D. K.; Kritcher, A.; Jones, O. S.; Rygg, J. R.; Tommasini, R.; Barrios, M.; Benedetti, L. R.; Berzak Hopkins, L. F.; Celliers, P. M.; Döppner, T.; Dewald, E. L.; Eder, D. C.; Field, J. E.; Glenn, S. M.; Izumi, N.; Haan, S. W.; Khan, S. F.; Kline, J. L.; Kyrala, G. A.; Ma, T.; Milovich, J. L.; Moody, J. D.; Nagel, S. R.; Pak, A.; Peterson, J. L.; Robey, H. F.; Ross, J. S.; Scott, R. H. H.; Spears, B. K.; Edwards, M. J.; Kilkenny, J. D.; Landen, O. L.

    2014-05-01

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

  20. Magnetized Inertial Confinement Fusion on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Perkins, L. John; Logan, G.; Rhodes, M.; Zimmermann, G.; Ho, D.; Strozzi, D.; Blackfield, D.; Hawkins, S.

    2015-11-01

    We are assessing the potential of imposed magnetic fields on ignition targets for the National Ignition Facility. Both magnetized room-temperature DT gas targets and CH/diamond cryo-ignition capsules are under study. Initial applied fields of 30-70T that compress to greater than 10,000T (100MG) under capsule implosion may relax conditions required for ignition and burn due to suppression of electron heat conduction, reduction of alpha deposition range and stabilization of hydro instabilities. This may permit recovery of ignition, or at least significant alpha particle heating, in otherwise submarginal capsules. We will report on the design and performance simulations of magnetized ignition targets and hohlraum physics, and summarize present experiments testing the attainable magnetic field limits in hohlraum-coil systems driven by a pulsed power supply. Work performed under auspices of U.S. DOE by LLNL under DE-AC52-07NA27344 and LDRD 14-ERD-028.

  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. Results from D-T experiments on TFTR and implications for achieving an ignited plasma

    SciTech Connect

    Hawryluk, R.J.; Blanchard, W.; Batha, S.

    1998-07-01

    Progress in the performance of tokamak devices has enable not only the production of significant bursts of fusion energy from deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. As a result of the worldwide research on tokamaks, the scientific and technical issues for achieving an ignited plasma are better understood and the remaining questions more clearly defined. The principal research topics which have been studied on TFTR are transport, magnetohydrodynamic stability, and energetic particle confinement. The integration of separate solutions to problems in each of these research areas has also been of major interest. Although significant advances, such as the reduction of turbulent transport by means of internal transport barriers, identification of the theoretically predicted bootstrap current, and the study of the confinement of energetic fusion alpha-particles have been made, interesting and important scientific and technical issues remain. In this paper, the implications for the TFTR experiments for overcoming these remaining issues will be discussed.

  3. The status of Fast Ignition Realization Experiment (FIREX) and prospects for inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Azechi, H.; FIREX Project Team

    2016-05-01

    Here we report recent progress for the fast ignition inertial confinement fusion demonstration. The fraction of low energy (< 1 MeV) component of the relativistic electron beam (REB), which efficiently heats the fuel core, increases by a factor of 4 by enhancing pulse contrast of heating laser and removing preformed plasma sources. Kilo-tesla magnetic field is studied to guide the diverging REB to the fuel core. The transport simulation of the REB accelerated by the heating laser in the externally applied and compressed magnetic field indicates that the REB can be guided efficiently to the fuel core. The integrated simulation shows > 4% of the heating efficiency and > 4 keV of ion temperature are achievable by using GEKKO-XII and LFEX, properly designed cone-fuel and an external magnetic field.

  4. Analytical criterion for shock ignition of fusion reaction in hot spot

    NASA Astrophysics Data System (ADS)

    Ribeyre, X.; Tikhonchuk, V. T.; Breil, J.; Lafon, M.; Vallet, A.; Le Bel, E.

    2013-11-01

    Shock ignition of DT capsules involves two major steps. First, the fuel is assembled by means of a low velocity conventional implosion. At stagnation, the central core has a temperature lower than the one needed for ignition. Then a second, strong spherical converging shock, launched from a high intensity laser spike, arrives to the core. This shock crosses the core, rebounds at the target center and increases the central pressure to the ignition conditions. In this work we consider this latter phase by using the Guderley self-similar solution for converging flows. Our model accounts for the fusion reaction energy deposition, thermal and radiation losses thus describing the basic physics of hot spot ignition. The ignition criterion derived from the analytical model is successfully compared with full scale hydrodynamic simulations.

  5. Laser Channeling in an Inhomogeneous Plasma for Fast-Ignition Laser Fusion

    NASA Astrophysics Data System (ADS)

    Ivancic, S.; Haberberger, D.; Theobald, W.; Anderson, K. S.; Froula, D. H.; Meyerhofer, D. D.; Tanaka, K.; Habara, H.; Iwawaki, T.

    2014-10-01

    The evacuation of a plasma cavity by a high-intensity laser beam is of practical importance to the channeling fast-ignition concept. The channel in the plasma corona of an imploded inertial confinement fusion capsule provides a clear path through the plasma so that the energy from a second high-intensity laser can be deposited close to the dense core of the assembled fuel to achieve ignition. This study reports on experiments that demonstrate the transport of high-intensity (>1017 W/cm2) laser light through an inhomogeneous kilojoule-laser-produced plasma up to overcritical density. The multikilojoule high-intensity light evacuates a cavity inside the focal spot, leaving a parabolic trough that is observed using a novel optical probing technique--angular filter refractometery. The cavity forms in less than 100 ps using a 20-TW laser pulse and bores at a velocity of ~ 2 μm/ps. The experimentally measured depths of the cavity are consistent with a ponderomotive hole-boring model. The experiments show that 100-ps IR pulses with an intensity of ~ 5 ×1017 W/cm2 produced a channel up to the critical density, while 10-ps pulses with the same energy but higher intensity did not propagate as far. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  6. Elliptical magnetic mirror generated via resistivity gradients for fast ignition inertial confinement fusion

    NASA Astrophysics Data System (ADS)

    Robinson, A. P. L.; Schmitz, H.

    2013-06-01

    The elliptical magnetic mirror scheme for guiding fast electrons for Fast Ignition proposed by Schmitz et al. (Plasma Phys. Controlled Fusion 54, 085016 (2012)) is studied for conditions on the multi-kJ scale which are much closer to full-scale Fast Ignition. When scaled up, the elliptical mirror scheme is still highly beneficial to Fast Ignition. An increase in the coupling efficiency by a factor of 3-4 is found over a wide range of fast electron divergence half-angles.

  7. Elliptical magnetic mirror generated via resistivity gradients for fast ignition inertial confinement fusion

    SciTech Connect

    Robinson, A. P. L.; Schmitz, H.

    2013-06-15

    The elliptical magnetic mirror scheme for guiding fast electrons for Fast Ignition proposed by Schmitz et al. (Plasma Phys. Controlled Fusion 54, 085016 (2012)) is studied for conditions on the multi-kJ scale which are much closer to full-scale Fast Ignition. When scaled up, the elliptical mirror scheme is still highly beneficial to Fast Ignition. An increase in the coupling efficiency by a factor of 3–4 is found over a wide range of fast electron divergence half-angles.

  8. 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

  9. Ion beam requirements for fast ignition of inertial fusion targets

    SciTech Connect

    Honrubia, J. J.; Murakami, M.

    2015-01-15

    Ion beam requirements for fast ignition are investigated by numerical simulation taking into account new effects, such as ion beam divergence, not included before. We assume that ions are generated by the TNSA scheme in a curved foil placed inside a re-entrant cone and focused on the cone apex or beyond. From the focusing point to the compressed core, ions propagate with a given divergence angle. Ignition energies are obtained for two compressed fuel configurations heated by proton and carbon ion beams. The dependence of the ignition energies on the beam divergence angle and on the position of the ion beam focusing point has been analyzed. Comparison between TNSA and quasi-monoenergetic ions is also shown.

  10. The LLNL (Lawrence Livermore National Laboratory) ICF (Inertial Confinement Fusion) Program: Progress toward ignition in the Laboratory

    SciTech Connect

    Storm, E.; Batha, S.H.; Bernat, T.P.; Bibeau, C.; Cable, M.D.; Caird, J.A.; Campbell, E.M.; Campbell, J.H.; Coleman, L.W.; Cook, R.C.; Correll, D.L.; Darrow, C.B.; Davis, J.I.; Drake, R.P.; Ehrlich, R.B.; Ellis, R.J.; Glendinning, S.G.; Haan, S.W.; Haendler, B.L.; Hatcher, C.W.; Hatchett, S.P.; Hermes, G.L.; Hunt, J.P.; Kania, D.R.; Kauffman, R.L.; Kilkenny, J.D.; Kornblum, H.N.; Kruer, W.L.; Kyrazis, D.T.; Lane, S.M.; Laumann

    1990-10-02

    The Inertial Confinement Fusion (ICF) Program at the Lawrence Livermore National Laboratory (LLNL) has made substantial progress in target physics, target diagnostics, and laser science and technology. In each area, progress required the development of experimental techniques and computational modeling. The objectives of the target physics experiments in the Nova laser facility are to address and understand critical physics issues that determine the conditions required to achieve ignition and gain in an ICF capsule. The LLNL experimental program primarily addresses indirect-drive implosions, in which the capsule is driven by x rays produced by the interaction of the laser light with a high-Z plasma. Experiments address both the physics of generating the radiation environment in a laser-driven hohlraum and the physics associated with imploding ICF capsules to ignition and high-gain conditions in the absence of alpha deposition. Recent experiments and modeling have established much of the physics necessary to validate the basic concept of ignition and ICF target gain in the laboratory. The rapid progress made in the past several years, and in particular, recent results showing higher radiation drive temperatures and implosion velocities than previously obtained and assumed for high-gain target designs, has led LLNL to propose an upgrade of the Nova laser to 1.5 to 2 MJ (at 0.35 {mu}m) to demonstrate ignition and energy gains of 10 to 20 -- the Nova Upgrade.

  11. Shock ignition target design for inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Schmitt, Andrew J.; Bates, Jason W.; Obenschain, Steven P.; Zalesak, Steven T.; Fyfe, David E.

    2010-04-01

    Continuing work in the design of shock ignition targets is described. Because of reduced implosion velocity requirements, low target adiabats, and efficient drive by short wavelength lasers, these targets produce high gain (>100) at laser energies well below 1 MJ. Effects of hydrodynamic instabilities such as Rayleigh-Taylor or Richtmyer-Meshkov are greatly reduced in these low-aspect ratio targets. Of particular interest is the optimum ratio of ignitor to compression pulse energy. A simple pellet model and simulation-derived coupling coefficients are used to analyze optimal fuel assembly, and determine that shock ignition allows enough control to create theoretically optimum assemblies. The effects on target design due to constraints on the compression and ignitor pulse intensities are also considered and addressed. Significant sensitivity is observed from low-mode perturbations because of large convergence ratios, but a more powerful ignitor can mitigate this.

  12. Ion Fast Ignition-Establishing a Scientific Basis for Inertial Fusion Energy --- Final Report

    SciTech Connect

    Stephens, Richard Burnite; Foord, Mark N.; Wei, Mingsheng; Beg, Farhat N.; Schumacher, Douglass W.

    2013-10-31

    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 compressed fuel is opaque to laser light. The ignition laser energy must be converted to a jet of energetic charged particles to deposit energy in the dense fuel. The original concept called for a spray of laser-generated hot electrons to deliver the energy; lack of ability to focus the electrons put great weight on minimizing the electron path. An alternative concept, proton-ignited FI, used those electrons as intermediaries to create a jet of protons that could be focused to the ignition spot from a more convenient distance. Our program focused on the generation and directing of the proton jet, and its transport toward the fuel, none of which were well understood at the onset of our program. We have developed new experimental platforms, diagnostic packages, computer modeling analyses, and taken advantage of the increasing energy available at laser facilities to create a self-consistent understanding of the fundamental physics underlying these issues. Our strategy was to examine the new physics emerging as we added the complexity necessary to use proton beams in an inertial fusion energy (IFE) application. From the starting point of a proton beam accelerated from a flat, isolated foil, we 1) curved it to focus the beam, 2) attached the foil to a superstructure, 3) added a side sheath to protect it from the surrounding plasma, and finally 4) studied the proton beam behavior as it passed through a protective end cap into plasma. We built up, as we proceeded

  13. Experimental research on indirectly-driven fast ignition in the research center of laser fusion

    NASA Astrophysics Data System (ADS)

    Zhou, Weimin; Shan, Lianqiang; Liu, Hongjie; Gu, Yuqiu; Ding, Yongkun; Zhang, Baohan

    2011-10-01

    Compared with central ignition of laser fusion, fast ignition separates compression and ignition thus it can relax the requirements on the implosion symmetry and the driven energy. Since 2008, the Research Center of Laser Fusion has begun the experimental researches on fast ignition based on Shenguang and SILEX-I laser facilities. The small scale cone-in-shell target for fast ignition was pre-compressed by the Shenguang II eight 260J/2ns/3 ω laser beams indirectly since beam smoothing was not available currently. The maximum density of the compressed cone-in-shell target 1.3 ns after the lasers' irradiation on the inside wall of hohlraum is about 4.8 g/cm3, and the implosion velocity is close to 1.9*107 cm/s, which are well consistent with the simulation results with two-dimensional radiation hydrodynamic code. Experiments on the production and the transport of hot electrons were performed on SILEX-I 200TW femtosecond laser facility. The laser-hot electrons conversion efficiency of metal film target was measured to be 10% ~20% with various laser parameters. The transport of hot electrons over hundreds of microns was carried out successfully in experiment by the use of axially symmetrical two-layer target.

  14. 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

  15. A new ignition hohlraum design for indirect-drive inertial confinement fusion

    NASA Astrophysics Data System (ADS)

    Li, Xin; Wu, Chang-Shu; Dai, Zhen-Sheng; Zheng, Wu-Di; Gu, Jian-Fa; Gu, Pei-Jun; Zou, Shi-Yang; Liu, Jie; Zhu, Shao-Ping

    2016-08-01

    In this paper, a six-cylinder-port hohlraum is proposed to provide high symmetry flux on capsule. It is designed to ignite a capsule with 1.2-mm radius in indirect-drive inertial confinement fusion (ICF). Flux symmetry and laser energy are calculated by using three-dimensional view factor method and laser energy balance in hohlraum. Plasma conditions are analyzed based on the two-dimensional radiation-hydrodynamic simulations. There is no Y lm (l ⩽ 4) asymmetry in the six-cylinder-port hohlraum when the influences of laser entrance holes (LEHs) and laser spots cancel each other out with suitable target parameters. A radiation drive with 300 eV and good flux symmetry can be achieved by using a laser energy of 2.3 MJ and peak power of 500 TW. According to the simulations, the electron temperature and the electron density on the wall of laser cone are high and low, respectively, which are similar to those of outer cones in the hohlraums on National Ignition Facility (NIF). And the laser intensity is also as low as those of NIF outer cones. So the backscattering due to laser plasma interaction (LPI) is considered to be negligible. The six-cyliner-port hohlraum could be superior to the traditional cylindrical hohlraum and the octahedral hohlraum in both higher symmetry and lower backscattering without supplementary technology at an acceptable laser energy level. It is undoubted that the hohlraum will add to the diversity of ICF approaches. Project supported by the National Natural Science Foundation of China (Grant Nos. 11435011 and 11575034).

  16. The National Ignition Facility: Status and Plans for Laser Fusion and High-Energy-Density Experimental Studies

    SciTech Connect

    Moses, E I; Wuest, C R

    2002-10-16

    The National Ignition Facility (NIF), currently under construction at the University of California's Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, 351-nm laser system and a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. NIF is being built by the National Nuclear Security Administration and when completed will be the world's largest laser experimental system, providing a national center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF will provide 192 energetic laser beams that will compress small fusion targets to conditions where they will ignite and burn, liberating more energy than is required to initiate the fusion reactions. NIF experiments will allow the study of physical processes at temperatures approaching 100 million K and 100 billion times atmospheric pressure. These conditions exist naturally only in the interior of stars and in nuclear weapons explosions. In the course of designing the world's most energetic laser system, a number of significant technology breakthroughs have been achieved. Research is also underway to develop a shorter pulse capability on NIF for very high power and extreme electromagnetic field research and applications. We discuss here the technology challenges and solutions that have made NIF possible, along with enhancements to NIF's design that could lead to near-exawatt power levels.

  17. The National Ignition Facility: Status and Plans for Laser Fusion and High-Energy-Density Experimental Studies

    SciTech Connect

    Moses, E I

    2002-01-11

    The National Ignition Facility (NIF), currently under construction at the University of California's Lawrence Livermore National Laboratory is a $2.25B stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, 351-nm laser system. NIF is being built by the National Nuclear Security Agency and when completed will be the world's largest laser system, providing a national center to study inertial confinement fusion and the physics of extreme energy densities and pressures. In NIF up to 192 energetic laser beams will compress small fusion targets to conditions where they will ignite and burn, liberating more energy than is required to initiate the fusion reactions. NIF experiments will allow the study of physical processes at temperatures approaching 100 million K and 100 billion times atmospheric pressure. These conditions exist naturally only in the interior of stars and in nuclear weapons explosions. In the course of designing the world's most energetic laser system, a number of significant technology breakthroughs have been achieved. Research is also underway to develop a shorter pulse capability on NIF for high power applications. We discuss here the technology challenges and solutions that have made NIF possible along with enhancements to NIF's design that could lead to exawatt power levels.

  18. Demonstration of Ignition Radiation Temperatures in Indirect-Drive Inertial Confinement Fusion Hohlraums

    SciTech Connect

    Glenzer, S. H.; MacGowan, B. J.; Meezan, N. B.; Adams, P. A.; Alfonso, J. B.; Alger, E. T.; Alherz, Z.; Alvarez, L. F.; Alvarez, S. S.; Amick, P. V.; Andersson, K. S.; Andrews, S. D.; Antonini, G. J.; Arnold, P. A.; Atkinson, D. P.; Auyang, L.; Azevedo, S. G.; Balaoing, B. N. M.; Baltz, J. A.; Barbosa, F.

    2011-02-25

    We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T{sub RAD}=300 eV and a symmetric implosion to a 100 {mu}m diameter hot core.

  19. Demonstration of Ignition Radiation Temperatures in Indirect-Drive Inertial Confinement Fusion Hohlraums

    NASA Astrophysics Data System (ADS)

    Glenzer, S. H.; MacGowan, B. J.; Meezan, N. B.; Adams, P. A.; Alfonso, J. B.; Alger, E. T.; Alherz, Z.; Alvarez, L. F.; Alvarez, S. S.; Amick, P. V.; Andersson, K. S.; Andrews, S. D.; Antonini, G. J.; Arnold, P. A.; Atkinson, D. P.; Auyang, L.; Azevedo, S. G.; Balaoing, B. N. M.; Baltz, J. A.; Barbosa, F.; Bardsley, G. W.; Barker, D. A.; Barnes, A. I.; Baron, A.; Beeler, R. G.; Beeman, B. V.; Belk, L. R.; Bell, J. C.; Bell, P. M.; Berger, R. L.; Bergonia, M. A.; Bernardez, L. J.; Berzins, L. V.; Bettenhausen, R. C.; Bezerides, L.; Bhandarkar, S. D.; Bishop, C. L.; Bond, E. J.; Bopp, D. R.; Borgman, J. A.; Bower, J. R.; Bowers, G. A.; Bowers, M. W.; Boyle, D. T.; Bradley, D. K.; Bragg, J. L.; Braucht, J.; Brinkerhoff, D. L.; Browning, D. F.; Brunton, G. K.; Burkhart, S. C.; Burns, S. R.; Burns, K. E.; Burr, B.; Burrows, L. M.; Butlin, R. K.; Cahayag, N. J.; Callahan, D. A.; Cardinale, P. S.; Carey, R. W.; Carlson, J. W.; Casey, A. D.; Castro, C.; Celeste, J. R.; Chakicherla, A. Y.; Chambers, F. W.; Chan, C.; Chandrasekaran, H.; Chang, C.; Chapman, R. F.; Charron, K.; Chen, Y.; Christensen, M. J.; Churby, A. J.; Clancy, T. J.; Cline, B. D.; Clowdus, L. C.; Cocherell, D. G.; Coffield, F. E.; Cohen, S. J.; Costa, R. L.; Cox, J. R.; Curnow, G. M.; Dailey, M. J.; Danforth, P. M.; Darbee, R.; Datte, P. S.; Davis, J. A.; Deis, G. A.; Demaret, R. D.; Dewald, E. L.; di Nicola, P.; di Nicola, J. M.; Divol, L.; Dixit, S.; Dobson, D. B.; Doppner, T.; Driscoll, J. D.; Dugorepec, J.; Duncan, J. J.; Dupuy, P. C.; Dzenitis, E. G.; Eckart, M. J.; Edson, S. L.; Edwards, G. J.; Edwards, M. J.; Edwards, O. D.; Edwards, P. W.; Ellefson, J. C.; Ellerbee, C. H.; Erbert, G. V.; Estes, C. M.; Fabyan, W. J.; Fallejo, R. N.; Fedorov, M.; Felker, B.; Fink, J. T.; Finney, M. D.; Finnie, L. F.; Fischer, M. J.; Fisher, J. M.; Fishler, B. T.; Florio, J. W.; Forsman, A.; Foxworthy, C. B.; Franks, R. M.; Frazier, T.; Frieder, G.; Fung, T.; Gawinski, G. N.; Gibson, C. R.; Giraldez, E.; Glenn, S. M.; Golick, B. P.; Gonzales, H.; Gonzales, S. A.; Gonzalez, M. J.; Griffin, K. L.; Grippen, J.; Gross, S. M.; Gschweng, P. H.; Gururangan, G.; Gu, K.; Haan, S. W.; Hahn, S. R.; Haid, B. J.; Hamblen, J. E.; Hammel, B. A.; Hamza, A. V.; Hardy, D. L.; Hart, D. R.; Hartley, R. G.; Haynam, C. A.; Heestand, G. M.; Hermann, M. R.; Hermes, G. L.; Hey, D. S.; Hibbard, R. L.; Hicks, D. G.; Hinkel, D. E.; Hipple, D. L.; Hitchcock, J. D.; Hodtwalker, D. L.; Holder, J. P.; Hollis, J. D.; Holtmeier, G. M.; Huber, S. R.; Huey, A. W.; Hulsey, D. N.; Hunter, S. L.; Huppler, T. R.; Hutton, M. S.; Izumi, N.; Jackson, J. L.; Jackson, M. A.; Jancaitis, K. S.; Jedlovec, D. R.; Johnson, B.; Johnson, M. C.; Johnson, T.; Johnston, M. P.; Jones, O. S.; Kalantar, D. H.; Kamperschroer, J. H.; Kauffman, R. L.; Keating, G. A.; Kegelmeyer, L. M.; Kenitzer, S. L.; Kimbrough, J. R.; King, K.; Kirkwood, R. K.; Klingmann, J. L.; Knittel, K. M.; Kohut, T. R.; Koka, K. G.; Kramer, S. W.; Krammen, J. E.; Krauter, K. G.; Krauter, G. W.; Krieger, E. K.; Kroll, J. J.; La Fortune, K. N.; Lagin, L. J.; Lakamsani, V. K.; Landen, O. L.; Lane, S. W.; Langdon, A. B.; Langer, S. H.; Lao, N.; Larson, D. W.; Latray, D.; Lau, G. T.; Le Pape, S.; Lechleiter, B. L.; Lee, Y.; Lee, T. L.; Li, J.; Liebman, J. A.; Lindl, J. D.; Locke, S. F.; Loey, H. K.; London, R. A.; Lopez, F. J.; Lord, D. M.; Lowe-Webb, R. R.; Lown, J. G.; Ludwigsen, A. P.; Lum, N. W.; Lyons, R. R.; Ma, T.; MacKinnon, A. J.; Magat, M. D.; Maloy, D. T.; Malsbury, T. N.; Markham, G.; Marquez, R. M.; Marsh, A. A.; Marshall, C. D.; Marshall, S. R.; Maslennikov, I. L.; Mathisen, D. G.; Mauger, G. J.; Mauvais, M.-Y.; McBride, J. A.; McCarville, T.; McCloud, J. B.; McGrew, A.; McHale, B.; Macphee, A. G.; Meeker, J. F.; Merill, J. S.; Mertens, E. P.; Michel, P. A.; Miller, M. G.; Mills, T.; Milovich, J. L.; Miramontes, R.; Montesanti, R. C.; Montoya, M. M.; Moody, J.; Moody, J. D.; Moreno, K. A.; Morris, J.; Morriston, K. M.; Nelson, J. R.; Neto, M.; Neumann, J. D.; Ng, E.; Ngo, Q. M.; Olejniczak, B. L.; Olson, R. E.; Orsi, N. L.; Owens, M. W.; Padilla, E. H.; Pannell, T. M.; Parham, T. G.; Patterson, R. W., Jr.; Pavel, G.; Prasad, R. R.; Pendlton, D.; Penko, F. A.; Pepmeier, B. L.; Petersen, D. E.; Phillips, T. W.; Pigg, D.; Piston, K. W.; Pletcher, K. D.; Powell, C. L.; Radousky, H. B.; Raimondi, B. S.; Ralph, J. E.; Rampke, R. L.; Reed, R. K.; Reid, W. A.; Rekow, V. V.; Reynolds, J. L.; Rhodes, J. J.; Richardson, M. J.; Rinnert, R. J.; Riordan, B. P.; Rivenes, A. S.; Rivera, A. T.; Roberts, C. J.; Robinson, J. A.; Robinson, R. B.; Robison, S. R.; Rodriguez, O. R.; Rogers, S. P.; Rosen, M. D.; Ross, G. F.; Runkel, M.; Runtal, A. S.; Sacks, R. A.; Sailors, S. F.; Salmon, J. T.; Salmonson, J. D.; Saunders, R. L.; Schaffer, J. R.; Schindler, T. M.; Schmitt, M. J.; Schneider, M. B.; Segraves, K. S.; Shaw, M. J.; Sheldrick, M. E.; Shelton, R. T.; Shiflett, M. K.; Shiromizu, S. J.; Shor, M.; Silva, L. L.; Silva, S. A.; Skulina, K. M.; Smauley, D. A.; Smith, B. E.; Smith, L. K.; Solomon, A. L.; Sommer, S.; Soto, J. G.; Spafford, N. I.; Speck, D. E.; Springer, P. T.; Stadermann, M.; Stanley, F.; Stone, T. G.; Stout, E. A.; Stratton, P. L.; Strausser, R. J.; Suter, L. J.; Sweet, W.; Swisher, M. F.; Tappero, J. D.; Tassano, J. B.; Taylor, J. S.; Tekle, E. A.; Thai, C.; Thomas, C. A.; Thomas, A.; Throop, A. L.; Tietbohl, G. L.; Tillman, J. M.; Town, R. P. J.; Townsend, S. L.; Tribbey, K. L.; Trummer, D.; Truong, J.; Vaher, J.; Valadez, M.; van Arsdall, P.; van Prooyen, A. J.; Vergel de Dios, E. O.; Vergino, M. D.; Vernon, S. P.; Vickers, J. L.; Villanueva, G. T.; Vitalich, M. A.; Vonhof, S. A.; Wade, F. E.; Wallace, R. J.; Warren, C. T.; Warrick, A. L.; Watkins, J.; Weaver, S.; Wegner, P. J.; Weingart, M. A.; Wen, J.; White, K. S.; Whitman, P. K.; Widmann, K.; Widmayer, C. C.; Wilhelmsen, K.; Williams, E. A.; Williams, W. H.; Willis, L.; Wilson, E. F.; Wilson, B. A.; Witte, M. C.; Work, K.; Yang, P. S.; Young, B. K.; Youngblood, K. P.; Zacharias, R. A.; Zaleski, T.; Zapata, P. G.; Zhang, H.; Zielinski, J. S.; Kline, J. L.; Kyrala, G. A.; Niemann, C.; Kilkenny, J. D.; Nikroo, A.; van Wonterghem, B. M.; Atherton, L. J.; Moses, E. I.

    2011-02-01

    We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of TRAD=300eV and a symmetric implosion to a 100μm diameter hot core.

  20. Engineering Status of the Fusion Ignition Research Experiment (FIRE)

    SciTech Connect

    Philip J. Heitzenroeder; Dale Meade; Richard J. Thome

    2000-10-24

    FIRE is a compact, high field tokamak being studied as an option for the next step in the US magnetic fusion energy program. FIRE's programmatic mission is to attain, explore, understand, and optimize alpha-dominated plasmas to provide the knowledge necessary for the design of attractive magnetic fusion energy systems. This study began in 1999 with broad participation of the US fusion community, including several industrial participants. The design under development has a major radius of 2 m, a minor radius of 0.525 m, a field on axis of 10T and capability to operate at 12T with upgrades to power supplies. Toroidal and poloidal field magnets are inertially cooled with liquid nitrogen. An important goal for FIRE is a total project cost in the $1B range. This paper presents an overview of the engineering details which were developed during the FIRE preconceptual design study in FY99 and 00.

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

    SciTech Connect

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

    2014-04-15

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

  2. Symmetry of spherically converging shock waves through reflection, relating to the shock ignition fusion energy scheme.

    PubMed

    Davie, C J; Evans, R G

    2013-05-01

    We examine the properties of perturbed spherically imploding shock waves in an ideal fluid through the collapse, bounce, and development into an outgoing shock wave. We find broad conservation of the size and shape of ingoing and outgoing perturbations when viewed at the same radius. The outgoing shock recovers the velocity of the unperturbed shock outside the strongly distorted core. The results are presented in the context of the robustness of the shock ignition approach to inertial fusion energy. PMID:23683207

  3. Influence of laser induced hot electrons on the threshold for shock ignition of fusion reactions

    NASA Astrophysics Data System (ADS)

    Colaïtis, A.; Ribeyre, X.; Le Bel, E.; Duchateau, G.; Nicolaï, Ph.; Tikhonchuk, V.

    2016-07-01

    The effects of Hot Electrons (HEs) generated by the nonlinear Laser-Plasma Interaction (LPI) on the dynamics of Shock Ignition Inertial Confinement Fusion targets are investigated. The coupling between the laser beam, plasma dynamics and hot electron generation and propagation is described with a radiative hydrodynamics code using an inline model based on Paraxial Complex Geometrical Optics [Colaïtis et al., Phys. Rev. E 92, 041101 (2015)]. Two targets are considered: the pure-DT HiPER target and a CH-DT design with baseline spike powers of the order of 200-300 TW. In both cases, accounting for the LPI-generated HEs leads to non-igniting targets when using the baseline spike powers. While HEs are found to increase the ignitor shock pressure, they also preheat the bulk of the imploding shell, notably causing its expansion and contamination of the hotspot with the dense shell material before the time of shock convergence. The associated increase in hotspot mass (i) increases the ignitor shock pressure required to ignite the fusion reactions and (ii) significantly increases the power losses through Bremsstrahlung X-ray radiation, thus rapidly cooling the hotspot. These effects are less prominent for the CH-DT target where the plastic ablator shields the lower energy LPI-HE spectrum. Simulations using higher laser spike powers of 500 TW suggest that the CH-DT capsule marginally ignites, with an ignition window width significantly smaller than without LPI-HEs, and with three quarters of the baseline target yield. The latter effect arises from the relation between the shock launching time and the shell areal density, which becomes relevant in presence of a LPI-HE preheating.

  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. First downscattered neutron images from Inertial Confinement Fusion experiments at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Guler, Nevzat; Aragonez, Robert J.; Archuleta, Thomas N.; Batha, Steven H.; Clark, David D.; Clark, Deborah J.; Danly, Chris R.; Day, Robert D.; Fatherley, Valerie E.; Finch, Joshua P.; Gallegos, Robert A.; Garcia, Felix P.; Grim, Gary; Hsu, Albert H.; Jaramillo, Steven A.; Loomis, Eric N.; Mares, Danielle; Martinson, Drew D.; Merrill, Frank E.; Morgan, George L.; Munson, Carter; Murphy, Thomas J.; Oertel, John A.; Polk, Paul J.; Schmidt, Derek W.; Tregillis, Ian L.; Valdez, Adelaida C.; Volegov, Petr L.; Wang, Tai-Sen F.; Wilde, Carl H.; Wilke, Mark D.; Wilson, Douglas C.; Atkinson, Dennis P.; Bower, Dan E.; Drury, Owen B.; Dzenitis, John M.; Felker, Brian; Fittinghoff, David N.; Frank, Matthias; Liddick, Sean N.; Moran, Michael J.; Roberson, George P.; Weiss, Paul; Buckles, Robert A.; Cradick, Jerry R.; Kaufman, Morris I.; Lutz, Steve S.; Malone, Robert M.; Traille, Albert

    2013-11-01

    Inertial Confinement Fusion experiments at the National Ignition Facility (NIF) are designed to understand and test the basic principles of self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic (CH) capsules. The experimental campaign is ongoing to tune the implosions and characterize the burning plasma conditions. Nuclear diagnostics play an important role in measuring the characteristics of these burning plasmas, providing feedback to improve the implosion dynamics. The Neutron Imaging (NI) diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by collecting images at two different energy bands for primary (13-15 MeV) and downscattered (10-12 MeV) neutrons. From these distributions, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. The first downscattered neutron images from imploding ICF capsules are shown in this paper.

  6. Major achievements and challenges of fusion research

    NASA Astrophysics Data System (ADS)

    Tendler, Michael

    2015-09-01

    The ITER project is truly at the frontier of knowledge, a collective effort to explore the tantalizing future of free, clean and inexhaustible energy offered by nuclear fusion. Where the Large Hadron Collider at CERN pushes the boundaries of physics to find the origins of matter, the ITER Project seeks to give humans an endless stream of power which could have potentially game-changing consequences for the entire planet. Seminal contributions to the general physics knowledge accomplished by the plasma physics research for the benefit of the ITER project will be brought to light. The legacy of Professor H Alfvén within the framework of the ITER project will be described.

  7. Time-resolved compression of a capsule with a cone to high density for fast-ignition laser fusion

    NASA Astrophysics Data System (ADS)

    Theobald, W.; Solodov, A. A.; Stoeckl, C.; Anderson, K. S.; Beg, F. N.; Epstein, R.; Fiksel, G.; Giraldez, E. M.; Glebov, V. Yu.; Habara, H.; Ivancic, S.; Jarrott, L. C.; Marshall, F. J.; McKiernan, G.; McLean, H. S.; Mileham, C.; Nilson, P. M.; Patel, P. K.; Pérez, F.; Sangster, T. C.; Santos, J. J.; Sawada, H.; Shvydky, A.; Stephens, R. B.; Wei, M. S.

    2014-12-01

    The advent of high-intensity lasers enables us to recreate and study the behaviour of matter under the extreme densities and pressures that exist in many astrophysical objects. It may also enable us to develop a power source based on laser-driven nuclear fusion. Achieving such conditions usually requires a target that is highly uniform and spherically symmetric. Here we show that it is possible to generate high densities in a so-called fast-ignition target that consists of a thin shell whose spherical symmetry is interrupted by the inclusion of a metal cone. Using picosecond-time-resolved X-ray radiography, we show that we can achieve areal densities in excess of 300 mg cm-2 with a nanosecond-duration compression pulse—the highest areal density ever reported for a cone-in-shell target. Such densities are high enough to stop MeV electrons, which is necessary for igniting the fuel with a subsequent picosecond pulse focused into the resulting plasma.

  8. Time-resolved compression of a capsule with a cone to high density for fast-ignition laser fusion

    SciTech Connect

    Theobald, W.; Solodov, A. A.; Stoeckl, C.; Anderson, K. S.; Beg, F. N.; Epstein, R.; Fiksel, G.; Giraldez, E. M.; Glebov, V. Yu.; Habara, H.; Ivancic, S.; Jarrott, L. C.; Marshall, F. J.; McKiernan, G.; McLean, H. S.; Mileham, C.; Nilson, P. M.; Patel, P. K.; Pérez, F.; Sangster, T. C.; Santos, J. J.; Sawada, H.; Shvydky, A.; Stephens, R. B.; Wei, M. S.

    2014-12-12

    The advent of high-intensity lasers enables us to recreate and study the behaviour of matter under the extreme densities and pressures that exist in many astrophysical objects. It may also enable us to develop a power source based on laser-driven nuclear fusion. Achieving such conditions usually requires a target that is highly uniform and spherically symmetric. Here we show that it is possible to generate high densities in a so-called fast-ignition target that consists of a thin shell whose spherical symmetry is interrupted by the inclusion of a metal cone. Using picosecond-time-resolved X-ray radiography, we show that we can achieve areal densities in excess of 300 mg cm -2 with a nanosecond-duration compression pulse -- the highest areal density ever reported for a cone-in-shell target. Such densities are high enough to stop MeV electrons, which is necessary for igniting the fuel with a subsequent picosecond pulse focused into the resulting plasma.

  9. Time-resolved compression of a capsule with a cone to high density for fast-ignition laser fusion.

    PubMed

    Theobald, W; Solodov, A A; Stoeckl, C; Anderson, K S; Beg, F N; Epstein, R; Fiksel, G; Giraldez, E M; Glebov, V Yu; Habara, H; Ivancic, S; Jarrott, L C; Marshall, F J; McKiernan, G; McLean, H S; Mileham, C; Nilson, P M; Patel, P K; Pérez, F; Sangster, T C; Santos, J J; Sawada, H; Shvydky, A; Stephens, R B; Wei, M S

    2014-01-01

    The advent of high-intensity lasers enables us to recreate and study the behaviour of matter under the extreme densities and pressures that exist in many astrophysical objects. It may also enable us to develop a power source based on laser-driven nuclear fusion. Achieving such conditions usually requires a target that is highly uniform and spherically symmetric. Here we show that it is possible to generate high densities in a so-called fast-ignition target that consists of a thin shell whose spherical symmetry is interrupted by the inclusion of a metal cone. Using picosecond-time-resolved X-ray radiography, we show that we can achieve areal densities in excess of 300 mg cm(-2) with a nanosecond-duration compression pulse--the highest areal density ever reported for a cone-in-shell target. Such densities are high enough to stop MeV electrons, which is necessary for igniting the fuel with a subsequent picosecond pulse focused into the resulting plasma. PMID:25503788

  10. Thin shell, high velocity inertial confinement fusion implosions on the national ignition facility.

    PubMed

    Ma, T; Hurricane, O A; Callahan, D A; Barrios, M A; Casey, D T; Dewald, E L; Dittrich, T R; Döppner, T; Haan, S W; Hinkel, D E; Berzak Hopkins, L F; Le Pape, S; MacPhee, A G; Pak, A; Park, H-S; Patel, P K; Remington, B A; Robey, H F; Salmonson, J D; Springer, P T; Tommasini, R; Benedetti, L R; Bionta, R; Bond, E; Bradley, D K; Caggiano, J; Celliers, P; Cerjan, C J; Church, J A; Dixit, S; Dylla-Spears, R; Edgell, D; Edwards, M J; Field, J; Fittinghoff, D N; Frenje, J A; Gatu Johnson, M; Grim, G; Guler, N; Hatarik, R; Herrmann, H W; Hsing, W W; Izumi, N; Jones, O S; Khan, S F; Kilkenny, J D; Knauer, J; Kohut, T; Kozioziemski, B; Kritcher, A; Kyrala, G; Landen, O L; MacGowan, B J; Mackinnon, A J; Meezan, N B; Merrill, F E; Moody, J D; Nagel, S R; Nikroo, A; Parham, T; Ralph, J E; Rosen, M D; Rygg, J R; Sater, J; Sayre, D; Schneider, M B; Shaughnessy, D; Spears, B K; Town, R P J; Volegov, P L; Wan, A; Widmann, K; Wilde, C H; Yeamans, C

    2015-04-10

    Experiments have recently been conducted at the National Ignition Facility utilizing inertial confinement fusion capsule ablators that are 175 and 165  μm in thickness, 10% and 15% thinner, respectively, than the nominal thickness capsule used throughout the high foot and most of the National Ignition Campaign. These three-shock, high-adiabat, high-foot implosions have demonstrated good performance, with higher velocity and better symmetry control at lower laser powers and energies than their nominal thickness ablator counterparts. Little to no hydrodynamic mix into the DT hot spot has been observed despite the higher velocities and reduced depth for possible instability feedthrough. Early results have shown good repeatability, with up to 1/2 the neutron yield coming from α-particle self-heating. PMID:25910132

  11. Hot-spot mix in ignition-scale inertial confinement fusion targets.

    PubMed

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

    2013-07-26

    Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. Low neutron yields and hot-spot mix mass between 34(-13,+50)  ng and 4000(-2970,+17 160)  ng are observed. PMID:23931375

  12. Thin Shell, High Velocity Inertial Confinement Fusion Implosions on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Ma, T.; Hurricane, O. A.; Callahan, D. A.; Barrios, M. A.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Döppner, T.; Haan, S. W.; Hinkel, D. E.; Berzak Hopkins, L. F.; Le Pape, S.; MacPhee, A. G.; Pak, A.; Park, H.-S.; Patel, P. K.; Remington, B. A.; Robey, H. F.; Salmonson, J. D.; Springer, P. T.; Tommasini, R.; Benedetti, L. R.; Bionta, R.; Bond, E.; Bradley, D. K.; Caggiano, J.; Celliers, P.; Cerjan, C. J.; Church, J. A.; Dixit, S.; Dylla-Spears, R.; Edgell, D.; Edwards, M. J.; Field, J.; Fittinghoff, D. N.; Frenje, J. A.; Gatu Johnson, M.; Grim, G.; Guler, N.; Hatarik, R.; Herrmann, H. W.; Hsing, W. W.; Izumi, N.; Jones, O. S.; Khan, S. F.; Kilkenny, J. D.; Knauer, J.; Kohut, T.; Kozioziemski, B.; Kritcher, A.; Kyrala, G.; Landen, O. L.; MacGowan, B. J.; Mackinnon, A. J.; Meezan, N. B.; Merrill, F. E.; Moody, J. D.; Nagel, S. R.; Nikroo, A.; Parham, T.; Ralph, J. E.; Rosen, M. D.; Rygg, J. R.; Sater, J.; Sayre, D.; Schneider, M. B.; Shaughnessy, D.; Spears, B. K.; Town, R. P. J.; Volegov, P. L.; Wan, A.; Widmann, K.; Wilde, C. H.; Yeamans, C.

    2015-04-01

    Experiments have recently been conducted at the National Ignition Facility utilizing inertial confinement fusion capsule ablators that are 175 and 165 μ m in thickness, 10% and 15% thinner, respectively, than the nominal thickness capsule used throughout the high foot and most of the National Ignition Campaign. These three-shock, high-adiabat, high-foot implosions have demonstrated good performance, with higher velocity and better symmetry control at lower laser powers and energies than their nominal thickness ablator counterparts. Little to no hydrodynamic mix into the DT hot spot has been observed despite the higher velocities and reduced depth for possible instability feedthrough. Early results have shown good repeatability, with up to 1 /2 the neutron yield coming from α -particle self-heating.

  13. Thin Shell, High Velocity Inertial Confinement Fusion Implosions on the National Ignition Facility

    SciTech Connect

    Ma, T.; Hurricane, O. A.; Callahan, D. A.; Barrios, M. A.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Doppner, T.; Haan, S. W.; Hinkel, D. E.; Berzak Hopkins, L. F.; Le Pape, S.; MacPhee, A. G.; Pak, A.; Park, H. S.; Patel, P. K.; Remington, B. A.; Robey, H. F.; Salmonson, J. D.; Springer, P. T.; Tommasini, R.; Benedetti, L. R.; Bionta, R.; Bond, E.; Bradley, D. K.; Caggiano, J.; Celliers, P.; Cerjan, C. J.; Church, J. A.; Dixit, S.; Dylla-Spears, R.; Edgell, D.; Edwards, M. J.; Field, J.; Fittinghoff, D. N.; Frenje, J. A.; Gatu Johnson, M.; Grim, G.; Guler, N.; Hatarik, R.; Herrmann, H. W.; Hsing, W. W.; Izumi, N.; Jones, O. S.; Khan, S. F.; Kilkenny, J. D.; Knauer, J.; Kohut, T.; Kozioziemski, B.; Kritcher, A.; Kyrala, G.; Landen, O. L.; MacGowan, B. J.; Mackinnon, A. J.; Meezan, N. B.; Merrill, F. E.; Moody, J. D.; Nagel, S. R.; Nikroo, A.; Parham, T.; Ralph, J. E.; Rosen, M. D.; Rygg, J. R.; Sater, J.; Sayre, D.; Schneider, M. B.; Shaughnessy, D.; Spears, B. K.; Town, R.P. J.; Volegov, P. L.; Wan, A.; Widmann, K.; Wilde, C. H.; Yeamans, C.

    2015-04-06

    Experiments have recently been conducted at the National Ignition Facility utilizing inertial confinement fusion capsule ablators that are 175 and 165 μm in thickness, 10% and 15% thinner, respectively, than the nominal thickness capsule used throughout the high foot and most of the National Ignition Campaign. These three-shock, high-adiabat, high-foot implosions have demonstrated good performance, with higher velocity and better symmetry control at lower laser powers and energies than their nominal thickness ablator counterparts. Little to no hydrodynamic mix into the DT hot spot has been observed despite the higher velocities and reduced depth for possible instability feedthrough. Earlier results have shown good repeatability, with up to 1/2 the neutron yield coming from α-particle self-heating.

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

    NASA Astrophysics Data System (ADS)

    Miley, George H.; Hora, H.; Badziak, J.; Wolowski, J.; Sheng, Zheng-Ming; Zhang, Jie; Osman, F.; Zhang, Weiyan; tu He, Xia

    2009-03-01

    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 B11 with proton clusters imbedded. This then makes p-B11 fusion practical, assuming all of the physics issues such as stability of the clusters during compression are resolved. Indeed, p-B11 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. Power plants using p

  15. 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

  16. Stability of shocks relating to the shock ignition inertial fusion energy scheme

    SciTech Connect

    Davie, C. J. Bush, I. A.; Evans, R. G.

    2014-08-15

    Motivated by the shock ignition approach to improve the performance of inertial fusion targets, we make a series of studies of the stability of shock waves in planar and converging geometries. We examine stability of shocks moving through distorted material and driving shocks with non-uniform pressure profiles. We then apply a fully 3D perturbation, following this spherically converging shock through collapse to a distorted plane, bounce and reflection into an outgoing perturbed, broadly spherical shock wave. We find broad shock stability even under quite extreme perturbation.

  17. Physics Basis and Simulation of Burning Plasma Physics for the Fusion Ignition Research Experiment (FIRE)

    SciTech Connect

    C.E. Kessel; D. Meade; S.C. Jardin

    2002-01-18

    The FIRE [Fusion Ignition Research Experiment] design for a burning plasma experiment is described in terms of its physics basis and engineering features. Systems analysis indicates that the device has a wide operating space to accomplish its mission, both for the ELMing H-mode reference and the high bootstrap current/high beta advanced tokamak regimes. Simulations with 1.5D transport codes reported here both confirm and constrain the systems projections. Experimental and theoretical results are used to establish the basis for successful burning plasma experiments in FIRE.

  18. The Stagnation Pressure of Imploding Shells and Ignition Scaling of Fusion Targets

    NASA Astrophysics Data System (ADS)

    Meyer-Ter-Vehn, Juergen; Kemp, Andreas

    2000-10-01

    The stagnation pressure ps of imploding cylindrical (n=2) and spherical (n=3) shells is found to scale like p_s/p0 M_0^2(n+1)/(γ+1), where M0 is the Mach number of the imploding shell and p0 its maximum pressure. It is derived analytically on the basis of similarity solutions (see J. Meyer-ter-Vehn and C. Schalk, Z. Naturforschung 37a, 302 (1982)) for an ideal gas with adiabatic parameter γ. The result holds approximately for Mach numbers in the range 3 < M0 < 10 relevant for inertial fusion capsules. The importance for the ignition scaling of fusion targets and, in particular, concerning the recent results of Herrmann, Tabak and Lindl (LLNL) will be discussed.

  19. Time-resolved compression of a capsule with a cone to high density for fast-ignition laser fusion

    DOE PAGESBeta

    Theobald, W.; Solodov, A. A.; Stoeckl, C.; Anderson, K. S.; Beg, F. N.; Epstein, R.; Fiksel, G.; Giraldez, E. M.; Glebov, V. Yu.; Habara, H.; et al

    2014-12-12

    The advent of high-intensity lasers enables us to recreate and study the behaviour of matter under the extreme densities and pressures that exist in many astrophysical objects. It may also enable us to develop a power source based on laser-driven nuclear fusion. Achieving such conditions usually requires a target that is highly uniform and spherically symmetric. Here we show that it is possible to generate high densities in a so-called fast-ignition target that consists of a thin shell whose spherical symmetry is interrupted by the inclusion of a metal cone. Using picosecond-time-resolved X-ray radiography, we show that we can achievemore » areal densities in excess of 300 mg cm -2 with a nanosecond-duration compression pulse -- the highest areal density ever reported for a cone-in-shell target. Such densities are high enough to stop MeV electrons, which is necessary for igniting the fuel with a subsequent picosecond pulse focused into the resulting plasma.« less

  20. Simulations of high-gain shock-ignited inertial-confinement-fusion implosions using less than 1 MJ of direct KrF-laser energy

    NASA Astrophysics Data System (ADS)

    Bates, Jason W.; Schmitt, Andrew J.; Fyfe, David E.; Obenschain, Steve P.; Zalesak, Steve T.

    2010-06-01

    In this paper, we report on recent numerical simulations of inertial-confinement-fusion (ICF) implosions using the FAST radiation hydrocode at the U.S. Naval Research Laboratory. Our study focuses on three classes of shock-ignited target designs utilizing less than 1 MJ of direct, krypton-fluoride (KrF) laser energy, which was "zoomed" to maximize the coupling efficiency. In the shock-ignition approach [R. Betti, C.D. Zhou, K.S. Anderson, et al., Phys. Rev. Lett. 98 (2007) 155001], a moderate-intensity, compressive laser pulse is followed by a short-duration high-intensity spike that launches a spherically-convergent shock wave to ignite a thick shell of compressed fuel. Such an arrangement appears to offer several significant advantages, including a low ignition threshold, high gain, and less susceptibility to the deleterious effects of hydrodynamic and laser-plasma instabilities. According to one-dimensional simulations, fusion gains over 200 can be achieved with shock-ignited targets using less than 750 kJ of laser energy. This represents a significant improvement in performance over conventional centrally-ignited designs. To examine the stability of these targets, several two-dimensional simulations were also performed that incorporated realistic perturbation sources such as laser imprinting and roughness spectra for inner/outer pellet surfaces. Although the simulations indicate that appreciable low-mode distortion of the fuel shell can occur at late time as a result of these perturbations, high gains are still achieved in many cases owing to the low in-flight aspect ratios of shock-ignited targets. We should remark, though, that the high convergence ratios of these same designs suggest that other sources of low-mode asymmetries, which were not considered in this study (e.g., beam misalignment and energy-balance errors), may be important in determining overall pellet stability and performance. We discuss these issues, as well as other salient design

  1. On thermonuclear ignition criterion at the National Ignition Facility

    SciTech Connect

    Cheng, Baolian; Kwan, Thomas J. T.; Wang, Yi-Ming; Batha, Steven H.

    2014-10-15

    Sustained thermonuclear fusion at the National Ignition Facility remains elusive. Although recent experiments approached or exceeded the anticipated ignition thresholds, the nuclear performance of the laser-driven capsules was well below predictions in terms of energy and neutron production. Such discrepancies between expectations and reality motivate a reassessment of the physics of ignition. We have developed a predictive analytical model from fundamental physics principles. Based on the model, we obtained a general thermonuclear ignition criterion in terms of the areal density and temperature of the hot fuel. This newly derived ignition threshold and its alternative forms explicitly show the minimum requirements of the hot fuel pressure, mass, areal density, and burn fraction for achieving ignition. Comparison of our criterion with existing theories, simulations, and the experimental data shows that our ignition threshold is more stringent than those in the existing literature and that our results are consistent with the experiments.

  2. Progress in Hydrodynamics Theory adn Experiments for Direct-Drive and Fast Ignition Inertial Confinement Fusion

    SciTech Connect

    Betti, R.; Anderson, K.; Boehly, T.R.; Collins, T.J.B.; Craxton, R.S.; Delettrez, J.A.; Edgell, D.H.; Epstein, R.; Glebov, V.Yu.; Goncharov, V.N.; Harding, D.R.; Keck, R.L.; Kelly, J.H.; Knauer, J.P.; Loucks, S.J.; Marozas, J.A.; Marshall, F.J.; Maximov, A.V.; Maywar, D.N.; McCrory, R.L.; McKenty, P.W.; Meyerhofer, D.D.; Myatt, J,; Radha, P.B.; Regan, S.P.; Ren, C.; Sangster, T.C.; Seka, W.; Skupsky, S.; Solodov, A.A.; Smalyuk, V.A.; Soures, J.M.; Stoeck, C.; Theobald, W.; Yaakobi, B.; Zhou, C.; Zuegel, J.D.; Frenje, J.A.; Li, C.K.; Petrasso, R.D.; Seguin, F.H.

    2006-11-20

    Recent advances in hydrodynamics theory and experiments at the Laboratory for Laser Energetics are described. Particular emphasis is laid on improvements in the implosion stability achieved by shaping the ablator adiabat and on the newly developed designs for fast ignition fuel assembly. The results of two-dimensional simulations and a recent set of implosion experiments on OMEGA are presented to verify the role of adiabat shaping on the hydrodynamic stability of direct-drive implosions.

  3. Picosecond-petawatt laser-block ignition for avalanche fusion of boron by ultrahigh acceleration and ultrahigh magnetic fields

    NASA Astrophysics Data System (ADS)

    Hora, H.; Lalousis, P.; Giuffrida, L.; Margarone, D.; Korn, G.; Eliezer, S.; Miley, G. H.; Moustaizis, S.; Mourou, G.; Barty, C. P. J.

    2016-05-01

    Fusion energy from reacting hydrogen (protons) with the boron isotope 11 (HB11) resulting in three stable helium nuclei, is without problem of nuclear radiation in contrast to DT fusion. But the HB11 reaction driven by nanosecond laser pulses with thermal compression and ignition by lasers is extremely difficult. This changed radically when irradiation with picosecond laser pulses produces a non-thermal plasma block ignition with ultrahigh acceleration. This uses the nonlinear (ponderomotive) force to surprizingly resulting in same thresholds as DT fusion even under pessimistic assumption of binary reactions. After evaluation of reactions trapped cylindrically by kilotesla magnetic fields and using the measured highly increased HB11 fusion gains for the proof of an avalanche of the three alphas in secondary reactions, possibilities for an absolutely clean energy source at comptitive costs were concluded.

  4. 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.

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

    SciTech Connect

    Amendt, Peter; Cerjan, C.; Hamza, A.; Hinkel, D. E.; Milovich, J. L.; Robey, H. F.

    2007-05-15

    The goal of demonstrating ignition on the National Ignition Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2003)] has motivated a revisit of double-shell (DS) targets as a complementary path to the cryogenic baseline approach. Expected benefits of DS ignition targets include noncryogenic deuterium-tritium (DT) fuel preparation, minimal hohlraum-plasma-mediated laser backscatter, low threshold-ignition temperatures ({approx_equal}4 keV) for relaxed hohlraum x-ray flux asymmetry tolerances, and minimal (two-) shock timing requirements. On the other hand, DS ignition presents several formidable challenges, encompassing room-temperature containment of high-pressure DT ({approx_equal}790 atm) in the inner shell, strict concentricity requirements on the two shells (<3 {mu}m), development of nanoporous (<100 nm cell size) low-density (<100 mg/cc) metallic foams for structural support of the inner shell and hydrodynamic instability mitigation, and effective control of hydrodynamic instabilities on the high-Atwood-number interface between the DT fuel and the high-Z inner shell. Recent progress in DS ignition designs and required materials science advances at the nanoscale are described herein. Two new ignition designs that use rugby-shaped vacuum hohlraums are presented that utilize either 1 or 2 MJ of laser energy at 3{omega}. The capability of the National Ignition Facility to generate the requested 2 MJ reverse-ramp pulse shape for DS ignition is expected to be comparable to the planned high-contrast ({approx_equal}100) pulse shape at 1.8 MJ for the baseline cryogenic target. Nanocrystalline, high-strength, Au-Cu alloy inner shells are under development using electrochemical deposition over a glass mandrel, exhibiting tensile strengths well in excess of 790 atm. Novel, low-density (85 mg/cc) copper foams have recently been demonstrated using 10 mg/cc SiO{sub 2} nanoporous aerogels with suspended Cu particles. A prototype demonstration of an ignition DS is planned

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

    SciTech Connect

    Amendt, P; Cerjan, C; Hamza, A; Hinkel, D; Milovich, J L; Robey, H F

    2006-10-26

    The goal of demonstrating ignition on the National Ignition Facility (NIF) has motivated a revisit of double-shell (DS) targets as a complementary path to the cryogenic baseline approach. Expected benefits of DS ignition targets include non-cryogenic deuterium-tritium (DT) fuel preparation, minimal hohlraum-plasma mediated laser backscatter, low threshold ignition temperatures ({approx} 4 keV) for relaxed hohlraum x-ray flux asymmetry tolerances, and minimal (two-) shock timing requirements. On the other hand, DS ignition presents several formidable challenges, encompassing room-temperature containment of high-pressure DT ({approx} 790 atm) in the inner shell, strict concentricity requirements on the two shells (< 3 {micro}m), development of nano-porous (<100 nm) low-density (<100 mg/cc) metallic foams for structural support of the inner shell and hydrodynamic instability mitigation, and effective control of hydrodynamic instabilities on the high-Atwood number interface between the DT fuel and the high-Z inner shell. Recent progress in DS ignition designs and required materials-science advances at the nanoscale are described herein. Two new ignition designs that use rugby-shaped vacuum hohlraums are presented which utilize either 1 MJ or 2 MJ of laser energy at 3{omega}. The capability of the NIF to generate the requested reverse-ramp pulse shape for DS ignition is expected to be comparable to the planned high-contrast ({approx}100) pulse-shape at 1.8 MJ for the baseline cryogenic target. Nano-crystalline, high-strength, Au-Cu alloy inner shells are under development using electrochemical deposition over a glass mandrel, exhibiting tensile strengths well in excess of 790 atm. Novel, low-density (85 mg/cc) copper foams have recently been demonstrated using 10 mg/cc SiO{sub 2} nano-porous aerogels with suspended Cu particles. A prototype demonstration of an ignition DS is planned for 2008, incorporating the needed novel nano-materials science developments and the

  7. Limitation on Prepulse Level for Cone-Guided Fast-Ignition Inertial Confinement Fusion

    SciTech Connect

    MacPhee, A. G.; Divol, L.; Kemp, A. J.; Chen, C. D.; Chen, H.; Hey, D. S.; Henesian, M.; Key, M. H.; Le Pape, S.; Mackinnon, A. J.; Patel, P. K.; Phillips, T. W.; Tabak, M.; Town, R.; Wilks, S. C.; Akli, K. U.; Stephens, R. B.; Beg, F. N.; Wei, M. S.; Fedosejevs, R. J.

    2010-02-05

    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. Preformed plasma due to the laser prepulse strongly influences ultraintense 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. Simulation of the radiation hydrodynamics of the preplasma and particle in cell modeling of the main pulse interaction agree well with the measured deposition zones and provide an insight into the energy deposition mechanism and electron distribution. It was demonstrated that a under these conditions a 100 mJ prepulse eliminates the forward going component of {approx}2-4 MeV electrons.

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

    PubMed

    Shaughnessy, D A; Moody, K J; Gharibyan, N; Grant, P M; Gostic, J M; Torretto, P C; Wooddy, P T; Bandong, B B; Despotopulos, J D; Cerjan, C J; Hagmann, C A; Caggiano, J A; Yeamans, C B; Bernstein, L A; Schneider, D H G; Henry, E A; Fortner, R J

    2014-06-01

    We describe a radiochemical measurement of the ratio of isotope concentrations produced in a gold hohlraum surrounding an Inertial Confinement Fusion capsule at the National Ignition Facility (NIF). We relate the ratio of the concentrations of (n,γ) and (n,2n) products in the gold hohlraum matrix to the down-scatter of neutrons in the compressed fuel and, consequently, to the fuel's areal density. The observed ratio of the concentrations of (198m+g)Au and (196g)Au is a performance signature of ablator areal density and the fuel assembly confinement time. We identify the measurement of nuclear cross sections of astrophysical importance as a potential application of the neutrons generated at the NIF. PMID:24985820

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

    SciTech Connect

    Shaughnessy, D. A. Moody, K. J.; Gharibyan, N.; Grant, P. M.; Gostic, J. M.; Torretto, P. C.; Wooddy, P. T.; Bandong, B. B.; Cerjan, C. J.; Hagmann, C. A.; Caggiano, J. A.; Yeamans, C. B.; Bernstein, L. A.; Schneider, D. H. G.; Henry, E. A.; Fortner, R. J.; Despotopulos, J. D.

    2014-06-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    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.

  11. Reconfigurable Assembly Station for Precision Manufacture of Nuclear Fusion Ignition Targets

    SciTech Connect

    Castro, C; Montesanti, R C; Taylor, J S; Hamza, A V; Dzenitis, E G

    2009-08-11

    This paper explores the design and testing of a reconfigurable assembly station developed for assembling the inertial confinement nuclear fusion ignition targets that will be fielded in the National Ignition Facility (NIF) laser [1]. The assembly station, referred to as the Flexible Final Assembly Machine (FlexFAM) and shown in Figure 1, is a companion system to the earlier Final Assembly Machine (FAM) [2]. Both machines consist of a manipulator system integrated with an optical coordinate measuring machine (OCMM). The manipulator system has six groups of stacked axis used to manipulate the millimeter-sized target components with submicron precision, and utilizes the same force and torque feedback sensing as the FAM. Real-time dimensional metrology is provided by the OCMM's vision system and through-the-lens (TTL) laser-based height measuring probe. The manually actuated manipulator system of the FlexFAM provides a total of thirty degrees-of-freedom to the target components being assembled predominantly in a cubic centimeter work zone.

  12. High-adiabat high-foot inertial confinement fusion implosion experiments on the national ignition facility.

    PubMed

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

    2014-02-01

    This Letter reports on a series of high-adiabat implosions of cryogenic layered deuterium-tritium (DT) capsules indirectly driven by a "high-foot" laser drive pulse at the National Ignition Facility. High-foot implosions have high ablation velocities and large density gradient scale lengths and are more resistant to ablation-front Rayleigh-Taylor instability induced mixing of ablator material into the DT hot spot. Indeed, the observed hot spot mix in these implosions was low and the measured neutron yields were typically 50% (or higher) of the yields predicted by simulation. On one high performing shot (N130812), 1.7 MJ of laser energy at a peak power of 350 TW was used to obtain a peak hohlraum radiation temperature of ∼300  eV. The resulting experimental neutron yield was (2.4±0.05)×10(15) DT, the fuel ρR was (0.86±0.063)  g/cm2, and the measured Tion was (4.2±0.16)  keV, corresponding to 8 kJ of fusion yield, with ∼1/3 of the yield caused by self-heating of the fuel by α particles emitted in the initial reactions. The generalized Lawson criteria, an ignition metric, was 0.43 and the neutron yield was ∼70% of the value predicted by simulations that include α-particle self-heating. PMID:24580603

  13. 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.

  14. Preliminary results from recent experiments and future roadmap to Shock Ignition of Fusion Targets

    NASA Astrophysics Data System (ADS)

    Batani, D.; Malka, G.; Schurtz, G.; Ribeyre, X.; Lebel, E.; Giuffrida, L.; Tikhonchuk, V.; Volpe, L.; Patria, A.; Koester, P.; Labate, L.; Gizzi, L. A.; Antonelli, L.; Richetta, M.; Nejdl, J.; Sawicka, M.; Margarone, D.; Krus, M.; Krousky, E.; Skala, J.; Dudzak, R.; Velyhan, A.; Ullshmied, J.; Renner, O.; Smid, M.; Klimo, O.; Atzeni, S.; Marocchino, A.; Schiavi, A.; Spindloe, C.; O'Dell, T.; Vinci, T.; Wolowski, J.; Badziak, J.; Pysarcizck, T.; Rosinski, M.; Kalinowska, Z.; Chodukowski, T.

    2012-11-01

    Shock ignition (SI) is a new approach to Inertial Confinement Fusion (ICF) based on decoupling the compression and ignition phase. The last one relies on launching a strong shock through a high intensity laser spike (<= 1016 W/cm2) at the end of compression. In this paper, first we described an experiment performed using the PALS iodine laser to study laser-target coupling and laser-plasma interaction in an intensity regime relevant for SI. A first beam with wavelength λ = 1.33 μm and low intensity was used to create an extended preformed plasma, and a second one with λ = 0.44 μm to create a strong shock. Several diagnostics characterized the preformed plasma and the interaction of the main pulse. Pressure up to 90 Mbar was inferred. In the last paper of the paper, we discuss the relevant steps, which can be followed in order to approach the demonstration of SI on laser facilities like LMJ.

  15. Effects of perturbations and radial profiles on ignition of inertial confinement fusion hotspots

    NASA Astrophysics Data System (ADS)

    Taylor, S.; Chittenden, J. P.

    2014-06-01

    Perturbations of inertial confinement fusion hotspots from spherical symmetry cause an increase in the implosion velocity required for ignition, as investigated analytically by [R. Kishony and D. Shvarts, Phys. Plasmas 8, 4925 (2001)] and in numerical studies by many authors. In this paper, we analyse the mechanisms behind this effect by comparing fully 3D fluid simulations of National Ignition Facility targets to a novel analytic model of the thermal energy balance of the hotspot. The analytic model takes into account the radial variation of the state variables within the hotspot and provides an accurate relationship between the hotspot's 0D parameters (ρc, Tc, R , uR, and q) and its heating and cooling rates. The dominant effect of perturbations appears to be an increase in the inflow velocity at the hotspot's surface due to transverse flow of material between perturbation structures, causing premature thermalisation of kinetic energy before the hotspot is fully compressed. In hotspots with a broad perturbation spectrum, thermalisation of energy is inhibited by nonradial motion introduced by mode-mode interaction, reducing the yield further.

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

    SciTech Connect

    Simakov, Andrei N. Wilson, Douglas C.; Yi, Sunghwan A.; Kline, John L.; Batha, Steven H.; Clark, Daniel S.; Milovich, Jose L.; Salmonson, Jay D.

    2014-02-15

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

  17. 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.

  18. Suppression of Weibel Instabilities by High Harmonic Electron Bernstein Modes in Advanced Fast Ignition Laser Fusion Pellets

    NASA Astrophysics Data System (ADS)

    Stefan, V.

    2006-10-01

    A novel mechanism for the suppression of Weibel instabilities in the core of advanced fast ignition pellets is addressed. The propagation of generated suprathermal electron beam toward the core may lead to the appearance of colossal (˜10MG), small scale (L˜c/φpe, c---velocity of light, φpe---local electron plasma frequency) magnetic fields. The suppression synergy of high harmonic electron Bernstein, (EB), modes and Weibel modes, (WB), in the cone-attached laser fusion pellets is based on nonlinear mode-mode coupling. EB modes are excited by ignition, a cone guided, or implosion laser beams. High harmonic EB modes easily propagate to the core of the pellet whereby they nonlinearly interact with, and suppress, the WB. The suppression synergy is maximized at the simultaneous action of ignition and implosion lasers. E. S. Weibel, Phys. Rev. Lett., 2,83 (1959) in the core of advanced fast ignition pellets M. Tabak, J. Hammer, M.E. Glinsky, W.L. Kruer, S. C. Wilks, J. Woodworth, E. M. Campbell, and M.D. Perry, Phys. Plasmas 1 (5), 1626 (1994). V. Stefan, (a) Quasi-Stationary B-Fields due to Weibel Instability in FI Laser Fusion Pellets; (b) Pellet Core Heating Via High Harmonic EB Modes in FI Laser Fusion. 35th Annual A.A.C, 2005,

  19. Development of a Cost-Effective Design for the Fusion Ignition Research Experiment

    SciTech Connect

    Philip J. Heitzenroeder

    1999-12-01

    The Fusion Ignition Research Experiment (FIRE) is one of the components of a US Next Step Options (NSO) study which is considering what major experiments might be undertaken in a restructured US Fusion Sciences Program. FIRE is designed for a plasma current of {approx}6.5 MA, a burn time of at least 10 s, and a Q in the range of 5 to 10. FIRE has a major radius of 2.0 m, a minor radius of 0.525 m, and a field on axis of 10T. All of the coils are inertially cooled by liquid nitrogen. FIRE will operate primarily in a double null configuration with an x-point triangularity of 0.8 and an x-point elongation of 2.2. In addition to these technical requirements, a major goal for the FIRE project is for a total project cost of approximately $1B (in FY 99 dollars). This paper describes the process and rationale for the engineering design chosen for FIRE, taking into account both the performance and cost goals.

  20. The National Ignition Facility - Applications for Inertial Fusion Energy and High Energy Density Science

    SciTech Connect

    Campbell, E.M.; Hogan, W.J.

    1999-08-12

    Over the past several decades, significant and steady progress has been made in the development of fusion energy and its associated technology and in the understanding of the physics of high-temperature plasmas. While the demonstration of net fusion energy (fusion energy production exceeding that required to heat and confine the plasma) remains a task for the next millennia and while challenges remain, this progress has significantly increased confidence that the ultimate goal of societally acceptable (e.g. cost, safety, environmental considerations including waste disposal) central power production can be achieved. This progress has been shared by the two principal approaches to controlled thermonuclear fusion--magnetic confinement (MFE) and inertial confinement (ICF). ICF, the focus of this article, is complementary and symbiotic to MFE. As shown, ICF invokes spherical implosion of the fuel to achieve high density, pressures, and temperatures, inertially confining the plasma for times sufficient long (t {approx} 10{sup -10} sec) that {approx} 30% of the fuel undergoes thermonuclear fusion.

  1. The National Ignition Facility Project. Revision 1

    SciTech Connect

    Paisner, J.A.; Campbell, E.M.; Hogan, W.J.

    1994-06-16

    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. This paper reviews the design, schedule, and costs associated with the construction project.

  2. Suppression of Weibel Instabilities in Advanced Fast Ignition Laser Fusion Pellets by Two Cone-Guided Relativistic Laser Beams

    NASA Astrophysics Data System (ADS)

    Stefan, V.

    2007-11-01

    I propose utilization of two cone-guided relativistic laser beams in antiparallel interaction with the fusion pellet as a novel approach for the suppression of Weibel instabilities in the core of advanced fast ignition pellets.ootnotetextM. Tabak, J. Hammer, M.E. Glinsky, W.L. Kruer, S. C. Wilks, J. Woodworth, E. M. Campbell, and M.D. Perry, Phys. Plasmas 1 (5), 1626 (1994). The propagation of generated suprathermal electron beam toward the core may lead to the appearance of colossal (˜10MG), small scale (L˜velocity of light/local electron plasma frequencyootnotetextV. Stefan, Suppression of Weibel Instabilities by High-Harmonic Electron Bernstein Modes in Advanced Fast Ignition Laser Fusion Pellets.APS-2006. October 30-November 3, 2006; Philadelphia, Pennsylvania. magnetic fields. This would suppress the transport of magnetic fields into the core of the pellet and may eliminate the difficulties in the nonlinear-relativistic treatment of magnetized core plasma.

  3. The National Ignition Facility Project

    SciTech Connect

    Paisner, J.A.; Campbell, E.M.; Hogan, W.J.

    1994-06-16

    The mission of the National Ignition Facility is to achieve ignition and gain in ICF targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effect testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. This paper reviews the design, schedule and costs associated with the construction project.

  4. The use of tritium rich capsules with 25-35% deuterium to achieve ignition at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Wilson, D. C.; Spears, B. K.; Hatchett, S. P., Ii; Cerjan, C. J.; Springer, P. T.; Clark, D. S.; Edwards, M. J.; Salmonson, J. D.; Weber, S. V.; Hammel, B. A.; Grim, G. P.; Herrmann, H. W.; Wilke, M. D.

    2010-08-01

    Diagnostics such as neutron yield, ion temperature, image size and shape, and bang time in capsules with >~25 % deuterium fuel show changes due to burn product heating. The comparison of performance between a THD(2%) and THD(35%) can help predict ignition in a TD(50%) capsule. Surrogacy of THD capsules to TD(50%) is incomplete due to variations in fuel molecular vapour pressures. TD(25-35%) capsules might be preferred to study hot spot heating, but at the risk of increased fuel/ablator mixing.

  5. Liquid Scoping Study for Tritium-Lean, Fast Ignition Inertial Fusion Energy Power Plants

    SciTech Connect

    Schmitt, R C; Latkowski, J F; Durbin, S G; Meier, W R; Reyes, S

    2001-08-14

    In a thick-liquid protected chamber design, such as HYLIFE-II, a molten-salt is used to attenuate neutrons and protect the chamber structures from radiation damage. The molten-salt absorbs some of the material and energy given off by the target explosion. In the case of a fast ignition inertial fusion system, advanced targets have been proposed that may be Self-sufficient in the tritium breeding (i.e., the amount of tritium bred in target exceeds the amount burned). These ''tritium-lean'' targets contain approximately 0.5% tritium and 99.5% deuterium, but require a large pr of 10-20 g/cm{sup 2}. Although most of the yield is provided by D-T reactions, the majority of fusion reactions are D-D, which produces a net surplus of tritium. This aspect allows for greater freedom when selecting a liquid for the protective blanket (lithium-bearing compounds are not required). This study assesses characteristics of many single, binary, and ternary molten-salts. Using the NIST Properties of Molten Salts Database, approximately 4300 molten-salts were included in the study [1]. As an initial screening, salts were evaluated for their safety and environmental (S&E) characteristics, which included an assessment of waste disposal rating, contact dose, and radioactive afterheat. Salts that passed the S&E criteria were then evaluated for neutron shielding ability and pumping power. The pumping power was calculated using three components: velocity head losses, frictional losses, and lift. This assessment left us with 57 molten-salts to recommend for further analysis. Many of these molten-salts contain elements such as sodium, lithium, beryllium, boron, fluorine, and oxygen. Recommendations for further analysis are also made.

  6. Interaction physics for the shock ignition scheme of inertial confinement fusion targets

    NASA Astrophysics Data System (ADS)

    Depierreux, S.; Goyon, C.; Lewis, K.; Bandulet, H.; Michel, D. T.; Loisel, G.; Yahia, V.; Tassin, V.; Stenz, C.; Borisenko, N. G.; Nazarov, W.; Limpouch, J.; Masson Laborde, P. E.; Loiseau, P.; Casanova, M.; Nicolaï, Ph; Hüller, S.; Pesme, D.; Riconda, C.; Tikhonchuk, V. T.; Labaune, C.

    2011-12-01

    This paper presents an analysis of laser-plasma interaction risks of the shock ignition (SI) scheme and experimental results under conditions relevant to the corona of a compressed target. Experiments are performed on the LIL facility at the 10 kJ level, on the LULI 2000 facility with two beams at the kJ level and on the LULI 6-beam facility with 100 J in each beam. Different aspects of the interaction of the SI pulse are studied exploiting either the flexibility of the LULI 6-beam facility to produce a very high intensity pulse or the high energy of the LIL to produce long and hot plasmas. A continuity is found allowing us to draw some conclusions regarding the coupling quality and efficiency of the SI spike pulse. It is shown that the propagation of the SI beams in the underdense plasma present in the corona of inertial confinement fusion targets could strongly modify the initial spot size of the beam through filamentation. Detailed experimental studies of the growth and saturation of backscattering instabilities in these plasmas indicate that significant levels of stimulated scattering reflectivities (larger than 40%) may be reached at least for some time during the SI pulse.

  7. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Direct ignition of inertial fusion targets by a laser-plasma ion stream

    NASA Astrophysics Data System (ADS)

    Gus'kov, Sergei Yu

    2001-10-01

    This paper outlines the theoretical direct-ignition model of the pre-compressed thermonuclear material of an inertial fusion target under the action of a high-power pulse of light ions from a laser plasma. It is shown that plasma streams with parameters required for the ignition can be obtained from a plane target-generator, located separately from the fusion target upon its fast thermal explosion driven by a high-power laser pulse. This method of direct ignition implies the use of a fusion target whose design provides the supply of the igniting driver energy to the compressed thermonuclear material. This target may be a cylindrical target with partially open ends or a spherical target with one or two conic openings.

  8. 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.

  9. Radiation hydrodynamics modeling of the highest compression inertial confinement fusion ignition experiment from the National Ignition Campaign

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    The recently completed National Ignition Campaign (NIC) on the National Ignition Facility (NIF) showed significant discrepancies between post-shot simulations of implosion performance and experimentally measured performance, particularly in thermonuclear yield. This discrepancy between simulation and observation persisted despite concerted efforts to include all of the known sources of performance degradation within a reasonable two-dimensional (2-D), and even three-dimensional (3-D), simulation model, e.g., using measured surface imperfections and radiation drives adjusted to reproduce observed implosion trajectories [Clark et al., Phys. Plasmas 20, 056318 (2013)]. Since the completion of the NIC, several effects have been identified that could explain these discrepancies and that were omitted in previous simulations. In particular, there is now clear evidence for larger than anticipated long-wavelength radiation drive asymmetries and a larger than expected perturbation seeded by the capsule support tent. This paper describes an updated suite of one-dimensional (1-D), 2-D, and 3-D simulations that include the current best understanding of these effects identified since the NIC, as applied to a specific NIC shot. The relative importance of each effect on the experimental observables is compared. In combination, these effects reduce the simulated-to-measured yield ratio from 125:1 in 1-D to 1.5:1 in 3-D, as compared to 15:1 in the best 2-D simulations published previously. While the agreement with the experimental data remains imperfect, the comparison to the data is significantly improved and suggests that the largest sources for the previous discrepancies between simulation and experiment are now being included.

  10. Radiation hydrodynamics modeling of the highest compression inertial confinement fusion ignition experiment from the National Ignition Campaign

    SciTech Connect

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

    2015-02-15

    The recently completed National Ignition Campaign (NIC) on the National Ignition Facility (NIF) showed significant discrepancies between post-shot simulations of implosion performance and experimentally measured performance, particularly in thermonuclear yield. This discrepancy between simulation and observation persisted despite concerted efforts to include all of the known sources of performance degradation within a reasonable two-dimensional (2-D), and even three-dimensional (3-D), simulation model, e.g., using measured surface imperfections and radiation drives adjusted to reproduce observed implosion trajectories [Clark et al., Phys. Plasmas 20, 056318 (2013)]. Since the completion of the NIC, several effects have been identified that could explain these discrepancies and that were omitted in previous simulations. In particular, there is now clear evidence for larger than anticipated long-wavelength radiation drive asymmetries and a larger than expected perturbation seeded by the capsule support tent. This paper describes an updated suite of one-dimensional (1-D), 2-D, and 3-D simulations that include the current best understanding of these effects identified since the NIC, as applied to a specific NIC shot. The relative importance of each effect on the experimental observables is compared. In combination, these effects reduce the simulated-to-measured yield ratio from 125:1 in 1-D to 1.5:1 in 3-D, as compared to 15:1 in the best 2-D simulations published previously. While the agreement with the experimental data remains imperfect, the comparison to the data is significantly improved and suggests that the largest sources for the previous discrepancies between simulation and experiment are now being included.

  11. Comparison of the Recently proposed Super Marx Generator Approach to Thermonuclear Ignition with the DT Laser Fusion-Fission Hybrid Concept (LIFE) by the Lawrence Livermore National Laboratory.

    NASA Astrophysics Data System (ADS)

    Winterberg, Friedwardt

    2009-05-01

    The recently proposed Super Marx pure deuterium micro-detonation ignition concept [1] is compared to the Lawrence Livermore National Ignition Facility (NIF) laser DT fusion-fission hybrid concept (LIFE) [2]. A typical example of the LIFE concept is a fusion gain 30, and a fission gain of 10, making up for a total gain of 300, with about 10 times more energy released into fission as compared to fusion. This means a substantial release of fission products, as in fusion-less pure fission reactors. In the Super Marx approach for the ignition of a pure deuterium micro-detonation gains of the same magnitude can in theory be reached. If the theoretical prediction can be supported by more elaborate calculations, the Super Marx approach is likely to make lasers obsolete as a means for the ignition of thermonuclear micro-explosions. [1] ``Ignition of a Deuterium Micro-Detonation with a Gigavolt Super Marx Generator,'' Winterberg, F., Journal of Fusion Energy, Springer, 2008. http://www.springerlink.com/content/r2j046177j331241/fulltext.pdf. [2] ``LIFE: Clean Energy from Nuclear Waste,'' https://lasers.llnl.gov/missions/energy&_slash;for&_slash;the&_slash;future/life/

  12. Grand challenges of inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Nuckolls, J. H.

    2010-08-01

    As soon as practical, Earth's low-cost, abundant, environmentally attractive fusion energy resources should be applied to the urgent global challenges of climate change, energy supply, economic growth, and the developing world. A National Ignition Campaign is under way at the recently completed National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) to ignite high-gain inertial fusion targets in the 2010-2012 time frame. Achieving ignition on NIF could be the catalyst for national and global leaders to support the development of inertial fusion energy (IFE) to meet the future's worldwide electric power demand. With sustained, high-priority funding could practical IFE be possible by the 2020 timeframe? The answer lies in how well can the community address and solve technical challenges in four key areas: achieving ignition, producing advanced targets and drivers, creating a practical fusion engine, and developing economical fusion power plants.

  13. Fast ignition when heating the central part of an inertial confinement fusion target by an ion beam

    SciTech Connect

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

    2014-11-15

    We investigate the ignition and burning of a precompressed laser fusion target when it is rapidly heated by an ion beam with the formation of a temperature peak in the central part of the target. We present the results of our comprehensive numerical simulations of the problem that include the following components: (1) the target compression under the action of a profiled laser pulse, (2) the heating of the compressed target with spatially nonuniform density and temperature distributions by a beam of high-energy ions, and (3) the burning of the target with the initial spatial density distribution formed at the instant of maximum target compression and the initial spatial temperature distribution formed as a result of the compressed-target heating by an ion beam. The dependences of the threshold energies of the igniting ion beam and the thermonuclear gain on the width of the Gaussian beam ion energy spectrum have been established. The peculiarities of fast ignition by an ion beam related to the spatial distribution of parameters for the target precompressed by a laser pulse are discussed.

  14. Ion kinetic effects on the ignition and burn of inertial confinement fusion targets: A multi-scale approach

    SciTech Connect

    Peigney, B. E.; Larroche, O.

    2014-12-15

    In this article, we study the hydrodynamics and burn of the thermonuclear fuel in inertial confinement fusion pellets at the ion kinetic level. The analysis is based on a two-velocity-scale Vlasov-Fokker-Planck kinetic model that is specially tailored to treat fusion products (suprathermal α-particles) in a self-consistent manner with the thermal bulk. The model assumes spherical symmetry in configuration space and axial symmetry in velocity space around the mean flow velocity. A typical hot-spot ignition design is considered. Compared with fluid simulations where a multi-group diffusion scheme is applied to model α transport, the full ion-kinetic approach reveals significant non-local effects on the transport of energetic α-particles. This has a direct impact on hydrodynamic spatial profiles during combustion: the hot spot reactivity is reduced, while the inner dense fuel layers are pre-heated by the escaping α-suprathermal particles, which are transported farther out of the hot spot. We show how the kinetic transport enhancement of fusion products leads to a significant reduction of the fusion yield.

  15. Scientific and technological advancements in inertial fusion energy

    DOE PAGESBeta

    Hinkel, D. E.

    2013-09-26

    Scientific advancements in inertial fusion energy (IFE) were reported on at the IAEA Fusion Energy Conference, October 2012. Results presented transect the different ways to assemble the fuel, different scenarios for igniting the fuel, and progress in IFE technologies. The achievements of the National Ignition Campaign within the USA, using the National Ignition Facility (NIF) to indirectly drive laser fusion, have found beneficial the achievements in other IFE arenas such as directly driven laser fusion and target fabrication. Moreover, the successes at NIF have pay-off to alternative scenarios such as fast ignition, shock ignition, and heavy-ion fusion as well asmore » to directly driven laser fusion. As a result, this synergy is summarized here, and future scientific studies are detailed.« less

  16. Scientific and technological advancements in inertial fusion energy

    SciTech Connect

    Hinkel, D. E.

    2013-09-26

    Scientific advancements in inertial fusion energy (IFE) were reported on at the IAEA Fusion Energy Conference, October 2012. Results presented transect the different ways to assemble the fuel, different scenarios for igniting the fuel, and progress in IFE technologies. The achievements of the National Ignition Campaign within the USA, using the National Ignition Facility (NIF) to indirectly drive laser fusion, have found beneficial the achievements in other IFE arenas such as directly driven laser fusion and target fabrication. Moreover, the successes at NIF have pay-off to alternative scenarios such as fast ignition, shock ignition, and heavy-ion fusion as well as to directly driven laser fusion. As a result, this synergy is summarized here, and future scientific studies are detailed.

  17. Can solid-state laser technology serve usefully beyond fusion ignition facilities?

    SciTech Connect

    Payne, S.A.; Powell, H.T.; Krupke, W.F.

    1995-07-28

    We have explored the major technical and conceptual issues relating to the suitability of a diode-pumped solid state laser as a driver for an inertial fusion energy power plant. While solid state lasers have long served as the workhorse of inertial confinement fusion physics studies, the deployment of a driver possessing adequate efficiency, reliability, and repetition rate for inertial fusion energy requires the implementation of several technical innovations discussed in this article.

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

    PubMed

    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

    2016-08-12

    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. PMID:27563971

  19. 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.

  20. A diamond detector for inertial confinement fusion X-ray bang-time measurements at the National Ignition Facility

    SciTech Connect

    MacPhee, A G; Brown, C; Burns, S; Celeste, J; Glenzer, S H; Hey, D; Jones, O S; Landen, O; Mackinnon, A J; Meezan, N; Parker, J; Edgell, D; Glebov, V Y; Kilkenny, J; Kimbrough, J

    2010-11-09

    An instrument has been developed to measure X-ray bang-time for inertial confinement fusion capsules; the time interval between the start of the laser pulse and peak X-ray emission from the fuel core. The instrument comprises chemical vapor deposited polycrystalline diamond photoconductive X-ray detectors with highly ordered pyrolytic graphite X-ray monochromator crystals at the input. Capsule bang-time can be measured in the presence of relatively high thermal and hard X-ray background components due to the selective band pass of the crystals combined with direct and indirect X-ray shielding of the detector elements. A five channel system is being commissioned at the National Ignition Facility at Lawrence Livermore National Laboratory for implosion optimization measurements as part of the National Ignition Campaign. Characteristics of the instrument have been measured demonstrating that X-ray bang-time can be measured with {+-} 30ps precision, characterizing the soft X-ray drive to +/- 1eV or 1.5%.

  1. Fast ignition in system Dynamic Hohlraum with Monte-Carlo simulations of fusion kinetic and radiation processes

    NASA Astrophysics Data System (ADS)

    Andreev, Alexander A.; Platonov, Konstantin Y.; Zacharov, Sergey V.; Gus'kov, Sergei Y.; Rozanov, Vladimir B.; Il'in, Dmitrii V.; Levkovskii, Aleksey A.; Sherman, Vladimir E.

    2004-06-01

    The scheme of fast ignition by super-intense laser of DT target placed at a cavity of the radiate plasma liner, created in a "dynamic-hohlraum" system is considered. It is shown that this scheme can supply effective TN fusion. The process of compression and preheating of DT fuel of shell target by X-ray radiation of Dynamic Hohlraum is simulated by the code TRITON with parameters of Z-generator of Sandia National Laboratory. The optimum parameters of target are obtained. The mechanism of ignitor creation by protons, accelerated by ultra-shot laser radiation is considered and corresponding laser parameters are evaluated. The mathematical simulation of the following thermonuclear (TN) burn wave propagation in DT target is carried out with the use of TERA code based upon the direct statistical simulation of kinetics of fast charged particles and quantum of thermal radiation on each time step of hydrodynamics. The released TN energy is obtained as a function of ignition energy. The theoretical explanations of obtained dependencies are presented. The laser parameters necessary to produce G>>1 are determined.

  2. 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

  3. Spherical strong-shock generation for shock-ignition inertial fusion

    SciTech Connect

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

    2015-05-12

    Recent experiments on the Laboratory for Laser Energetics’ OMEGA laser have been carried out to produce strong shocks in solid spherical targets with direct laser illumination. The shocks are launched at pressures of several hundred Mbars and reach Gbar upon convergence. The results are relevant to the validation of the shock-ignition scheme and to the development of an OMEGA experimental platform to study material properties at Gbar pressures. The experiments investigate the strength of the ablation pressure and the hot-electron production at incident laser intensities of ~2 to 6 x 10¹⁵W/cm² and demonstrate ablation pressures exceeding 300 Mbar, which is crucial to developing a shock-ignition target design for the National Ignition Facility. The timing of the x-ray flash from shock convergence in the center of the solid plastic target is used to infer the ablation and shock pressures. Laser–plasma instabilities produce hot-electrons with a moderate temperature (<100 keV). The instantaneous conversion efficiencies of laser power into hot-electron power reached up to ~15% in the intensity spike. The large amount of hot electrons is correlated with an earlier x-ray flash and a strong increase in its magnitude. This suggests that hot electrons contribute to the augmentation of the shock strength.

  4. Spherical strong-shock generation for shock-ignition inertial fusion

    SciTech Connect

    Theobald, W.; Seka, W.; Lafon, M.; Anderson, K. S.; Hohenberger, M.; Marshall, F. J.; Michel, D. T.; Solodov, A. A.; Stoeckl, C.; Edgell, D. H.; Yaakobi, B.; Shvydky, A.; Nora, R.; Betti, R.; Casner, A.; Reverdin, C.; Ribeyre, X.; Vallet, A.; Peebles, J.; Beg, F. N.; and others

    2015-05-15

    Recent experiments on the Laboratory for Laser Energetics' OMEGA laser have been carried out to produce strong shocks in solid spherical targets with direct laser illumination. The shocks are launched at pressures of several hundred Mbars and reach Gbar upon convergence. The results are relevant to the validation of the shock-ignition scheme and to the development of an OMEGA experimental platform to study material properties at Gbar pressures. The experiments investigate the strength of the ablation pressure and the hot-electron production at incident laser intensities of ∼2 to 6 × 10{sup 15 }W/cm{sup 2} and demonstrate ablation pressures exceeding 300 Mbar, which is crucial to developing a shock-ignition target design for the National Ignition Facility. The timing of the x-ray flash from shock convergence in the center of the solid plastic target is used to infer the ablation and shock pressures. Laser–plasma instabilities produce hot-electrons with a moderate temperature (<100 keV). The instantaneous conversion efficiencies of laser power into hot-electron power reached up to ∼15% in the intensity spike. The large amount of hot electrons is correlated with an earlier x-ray flash and a strong increase in its magnitude. This suggests that hot electrons contribute to the augmentation of the shock strength.

  5. Fast ignition without hole boring.

    PubMed

    Hain, S; Mulser, P

    2001-02-01

    A fast-ignitor scheme for inertial confinement fusion is proposed which works without hole boring. It is shown that a thermonuclear burn wave starts from the pellet corona when an adequate amount of energy (typically 10 kJ) is deposited in the critical layer by a petawatt laser ("coronal ignition"). Burn efficiencies as high as predicted for standard central spark ignition are achieved. In addition, the scheme is surprisingly insensitive to large deviations from spherical precompression symmetry. It may open a new prospect for direct drive. PMID:11177998

  6. National Ignition Facility: Experimental plan

    SciTech Connect

    Not Available

    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.

  7. The National Ignition Facility: Status and Plans for Laser Fusion and High-Energy-Density Experimental Studies

    SciTech Connect

    Wuest, C

    2001-10-29

    The National Ignition Facility (NIF) currently under construction at the University of California Lawrence Livermore National Laboratory (LLNL) is a 192-beam, 1.8-megajoule, 500-terawatt, 351-nm laser for inertial confinement fusion (ICF) and high-energy-density experimental studies. NIF is being built by the Department of Energy and the National Nuclear Security Agency (NNSA) to provide an experimental test bed for the U.S. Stockpile Stewardship Program to ensure the country's nuclear deterrent without underground nuclear testing. The experimental program will encompass a wide range of physical phenomena from fusion energy production to materials science. Of the roughly 700 shots available per year, about 10% will be dedicated to basic science research. Laser hardware is modularized into line replaceable units (LRUs) such as deformable mirrors, amplifiers, and multi-function sensor packages that are operated by a distributed computer control system of nearly 60,000 control points. The supervisory control room presents facility-wide status and orchestrates experiments using operating parameters predicted by physics models. A network of several hundred front-end processors (FEPs) implements device control. The object-oriented software system is implemented in the Ada and Java languages and emphasizes CORBA distribution of reusable software objects. NIF is currently scheduled to provide first light in 2004 and will be completed in 2008.

  8. Reactor Chamber and Balance-of-Plant Characteristics for a Fast-Ignition Heavy-Ion Fusion Power Plant

    SciTech Connect

    Medin, Stanislav; Churazov, Mikhail; Koshkarev, Dmitri; Sharkov, Boris; Orlov, Yurii; Suslin, Viktor; Zemskov, Eugeni

    2003-05-15

    The concept of a fast-ignition heavy-ion fusion (FIHIF) power plant involves a cylindrical target and superhigh energy ion beams. The driver produces one plus/minus charge state multimass platinum ions with energy of 100 GeV. The driver efficiency and the target gain are taken as 0.25 and 100, respectively. The preliminary data on the energy fluxes delivered to the reactor chamber wall by the 500-MJ fusion yield are presented. The reactor chamber designed has two sections. In the first section, the microexplosions occur, and in the second section of bigger volume the expansion and condensation of vapors take place. The response of the blanket and the thin liquid film at the first-wall surface is evaluated. Lithium-lead eutectic is taken as a coolant. The evaporated mass and the condensation time are estimated, taking into account major thermophysical effects. The estimated neutron spectrum from the FIHIF target gives an average neutron energy of 11.9 MeV. The mechanical stresses in the construction material due to neutron energy release are evaluated. The outlet coolant chamber temperature is taken as 550 deg. C. The heat conversion system consisting of three coolant loops provides a net efficiency of the FIHIF power plant of 0.37.

  9. Use of the National Ignition Facility for the development of inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Tobin, M.; Logan, G.; Anderson, A.; Delarubiadiaz, T.

    1994-06-01

    The primary purpose of the workshop was to gather input from the inertial confinement fusion (ICF) laboratories, private industry, and universities on the potential use of the NIF to conduct experiments in support of the development of Inertial Fusion Energy (IFE). To accomplish this, we asked over 60 workshop participants to identify key credibility and development issues for IFE in four areas: Target Physics --Issues related to the design and performance of targets for IFE; Chamber Dynamics -- Issues in IFE chambers resulting from the deposition of x-rays and debris; Inertial Fusion Power Technology -- Issues for energy conversion, tritium breeding and processing, and radiation shielding; interactions of neutrons with materials; and chamber design; Target System -- Issues related to automated, high-production-rate manufacture of low-cost targets for IFE, target handling and transport, target injection, tracking, and beam pointing. These topics are discussed in this report.

  10. 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.

  11. A method for achieving ignition of a low voltage gas discharge device

    DOEpatents

    Kovarik, Vincent J.; Hershcovitch, Ady; Prelec, Krsto

    1988-01-01

    An electronic device of the type wherein current flow is conducted by an ionized gas comprising a cathode of the type heated by ionic bombardment, an anode, means for maintaining a predetermined pressure in the region between the anode and the cathode and means for maintaining a field in the region. The field, which is preferably a combined magnetic and electric field, is oriented so that the mean distance traveled by electrons before reaching the anode is increased. Because of this increased distance traveled electrons moving to the anode will ionize a larger number of gas atoms, thus reducing the voltage necesary to initiate gas breakdown. In a preferred embodiment the anode is a main hollow cathode and the cathode is a smaller igniter hollow cathode located within and coaxial with the main hollow cathode. An axial magnetic field is provided in the region between the hollow cathodes in order to facilitate gas breakdown in that region and initiate plasma discharge from the main hollow cathode.

  12. Monte-Carlo simulation of the kinetics of nuclear and radiative processes upon fast ignition of the fusion target in a `double liner' system

    NASA Astrophysics Data System (ADS)

    Andreev, Aleksandr A.; Gus'kov, Sergei Yu; Zakharov, S. V.; Il'in, Dmitrii V.; Levkovskii, Aleksei A.; Platonov, Konstantin Yu; Rozanov, Vladislav B.; Sherman, Vladimir E.

    2004-05-01

    A laser ignition scheme is considered for a fusion target placed in the cavity of a radiating plasma liner produced in a `double liner' system. It is shown that this scheme can be employed to realise an efficient thermonuclear burst. The precompression and heating of a deuterium — tritium target with an iron shell by a thermal radiation pulse was simulated using the TRITON mathematical code for the parameters of the Z-generator at the Sandia National Laboratories (USA). Laser and target parameters were optimised for the ignition of the deuterium — tritium fuel by protons accelerated by laser radiation. The propagation of the thermonuclear burning wave during the fast ignition was calculated employing the TERA mathematical code, which involves Monte-Carlo simulation of the kinetics of fast thermonuclear particles and hard gamma-ray quanta at each time step of hydrodynamic calculations. The dependence of the fusion energy gain G on the ignition energy is theoretically explained. The laser parameters required to obtain G gg 1 are determined.

  13. Development of a polar direct-drive platform for studying inertial confinement fusion implosion mix on the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Schmitt, Mark J.; Bradley, Paul A.; Cobble, James A.; Fincke, James R.; Hakel, Peter; Hsu, Scott C.; Krasheninnikova, Natalia S.; Kyrala, George A.; Magelssen, Glenn R.; Montgomery, David S.; Murphy, Thomas J.; Obrey, Kimberly A.; Shah, Rahul C.; Tregillis, Ian L.; Baumgaertel, Jessica A.; Wysocki, Frederick J.; Batha, Steven H.; Stephen Craxton, R.; McKenty, Patrick W.; Fitzsimmons, Paul; Nikroo, Abbas; Wallace, Russell

    2013-05-01

    Experiments were performed to develop a platform for the simultaneous measurement of mix and its effects on fusion burn. Two polar direct drive implosions of all-plastic capsules were conducted for the first time on the National Ignition Facility (NIF). To measure implosion trajectory and symmetry, area image backlighting of these capsules was also employed for the first time on NIF, an advance over previous 1-D slit imaging experiments, providing detailed symmetry data of the capsules as they imploded. The implosion trajectory and low-mode asymmetry seen in the resultant radiographs agreed with pre-shot predictions even though the 700 kJ drive energy produced laser beam intensities exceeding laser-plasma instability thresholds. Post-shot simulations indicate that the capsule yield was reduced by a factor of two compared to pre-shot predictions owing to as-shot laser drive asymmetries. The pre-shot predictions of bang time agreed within 200 ps with the experimental results. The second shot incorporated a narrow groove encircling the equator of the capsule. A predicted yield reduction factor of three was not observed.

  14. Inertial Confinement Fusion alpha-heating signatures in prompt gamma-ray measurements at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Church, Jennifer; Herrmann, Hans; Cerjan, Charlie; Sayre, Daniel; Carpenter, Arthur; Liebman, Judy; Stoeffl, Wolfgang; Kim, Yongho

    2015-11-01

    Prompt gamma-rays measured at the National Ignition Facility (NIF) with the Gamma-ray Reaction History detector (GRH) supply vital diagnostic information, such as the peak burn time, burn width, and total neutron yield, from prompt DT-fusion gamma-ray emission during high convergence implosion experiments. Additionally, the stagnated cold shell density distribution may be inferred from the time-integrated, calibrated 12C (n,n' γ) signal, thus providing estimates of remaining ablator carbon areal density. Furthermore, simulations suggest that alpha heating signatures might be accessible using more highly resolved temporal gamma-ray emission. Correlation of these signatures with time-dependent neutron emission will constrain the implosion dynamics immediately prior to thermonuclear burn. Measurement of these gamma-ray signatures will be discussed along with updates on our work toward inferred total DT yield and 12C areal density. This work performed under the auspices of the U.S. Dept. of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07-NA27344, LLNL-ABS-670282.

  15. Kinetic simulations of stimulated Raman backscattering and related processes for the shock-ignition approach to inertial confinement fusion

    SciTech Connect

    Riconda, C.; Weber, S.; Tikhonchuk, V. T.; Heron, A.

    2011-09-15

    A detailed description of stimulated Raman backscattering and related processes for the purpose of inertial confinement fusion requires multi-dimensional kinetic simulations of a full speckle in a high-temperature, large-scale, inhomogeneous plasma. In particular for the shock-ignition scheme operating at high laser intensities, kinetic aspects are predominant. High- (I{lambda}{sub o}{sup 2}{approx}5x10{sup 15}W{mu}m{sup 2}/cm{sup 2}) as well as low-intensity (I{lambda}{sub o}{sup 2}{approx}10{sup 15}W{mu}m{sup 2}/cm{sup 2}) cases show the predominance of collisionless, collective processes for the interaction. While the two-plasmon decay instability and the cavitation scenario are hardly affected by intensity variation, inflationary Raman backscattering proves to be very sensitive. Brillouin backscattering evolves on longer time scales and dominates the reflectivities, although it is sensitive to the intensity. Filamentation and self-focusing do occur for all cases but on time scales too long to affect Raman backscattering.

  16. Development of a polar direct-drive platform for studying inertial confinement fusion implosion mix on the National Ignition Facility

    SciTech Connect

    Schmitt, Mark J.; Bradley, Paul A.; Cobble, James A.; Fincke, James R.; Hakel, Peter; Hsu, Scott C.; Krasheninnikova, Natalia S.; Kyrala, George A.; Magelssen, Glenn R.; Montgomery, David S.; Murphy, Thomas J.; Obrey, Kimberly A.; Shah, Rahul C.; Tregillis, Ian L.; Baumgaertel, Jessica A.; Wysocki, Frederick J.; Batha, Steven H.; Stephen Craxton, R.; McKenty, Patrick W.; Fitzsimmons, Paul; and others

    2013-05-15

    Experiments were performed to develop a platform for the simultaneous measurement of mix and its effects on fusion burn. Two polar direct drive implosions of all-plastic capsules were conducted for the first time on the National Ignition Facility (NIF). To measure implosion trajectory and symmetry, area image backlighting of these capsules was also employed for the first time on NIF, an advance over previous 1-D slit imaging experiments, providing detailed symmetry data of the capsules as they imploded. The implosion trajectory and low-mode asymmetry seen in the resultant radiographs agreed with pre-shot predictions even though the 700 kJ drive energy produced laser beam intensities exceeding laser-plasma instability thresholds. Post-shot simulations indicate that the capsule yield was reduced by a factor of two compared to pre-shot predictions owing to as-shot laser drive asymmetries. The pre-shot predictions of bang time agreed within 200 ps with the experimental results. The second shot incorporated a narrow groove encircling the equator of the capsule. A predicted yield reduction factor of three was not observed.

  17. 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.

  18. Proton Beam Fast Ignition Fusion: Nonlinear Generation of Bθ-Fields by Knock-on Electrons

    NASA Astrophysics Data System (ADS)

    Stefan, V. Alexander

    2011-10-01

    The knock-on electrons, generated by the fast proton beam in interaction with the free and bound electrons in a precompressed DT fusion pellet, outrun the proton beam, generating the Bθ-fields ahead of the beam, which may lead to the defocusing of the beam, if Bθ < 0. The Bθ-fields are generated due to the magnetic instability, ∂Bθ/ ∂t ~ (c/ σ) ∇ x jne, where jne is the knock-on electron current density, σ is the background plasma conductivity, and c the speed of light. The instability growth rate compensates for relatively low knock-on generation efficiency by a proton beam. The saturation level,(electron trapping mechanism), of the B-field ahead of the beam, is of the order of 10 MG and is reached on the time scale of 10 ps. M. Roth et al, Phys. Rev. Lett. 86, 436 (2001); M. Tabak et al, Phys. Plasmas 1 (5), 1626 (1994); H. L. Buchanan, F. W. Chambers, E. P. Lee, S. S. Yu, R. J. Briggs, and M. N. Rosenbluth, LLNL, UCRL Report 82586, 1979.

  19. Inertial-confinement fusion with lasers

    NASA Astrophysics Data System (ADS)

    Betti, R.; Hurricane, O. A.

    2016-05-01

    The quest for controlled fusion energy has been ongoing for over a half century. The demonstration of ignition and energy gain from thermonuclear fuels in the laboratory has been a major goal of fusion research for decades. Thermonuclear ignition is widely considered a milestone in the development of fusion energy, as well as a major scientific achievement with important applications in national security and basic sciences. The US is arguably the world leader in the inertial confinement approach to fusion and has invested in large facilities to pursue it, with the objective of establishing the science related to the safety and reliability of the stockpile of nuclear weapons. Although significant progress has been made in recent years, major challenges still remain in the quest for thermonuclear ignition via laser fusion. Here, we review the current state of the art in inertial confinement fusion research and describe the underlying physical principles.

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

    SciTech Connect

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

    2014-07-15

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

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

    SciTech Connect

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

    2010-04-12

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

  2. The Ignition of Cylindrical Fusion Targets by Multi-Mega-Ampere GeV Proton Beams below the Alfvén Limit

    NASA Astrophysics Data System (ADS)

    Winterberg, Friedwardt

    2014-11-01

    It is shown that cylindrical deuterium targets can be ignited with multi-mega-ampere GeV proton beams below the Alfvén limit and a small amount of tritium. The proton beams can be generated by discharging a magnetically insulated gigavolt capacitor. Surrounding the thermonuclear microexplosion with a thick layer of liquid hydrogen, heated to a ~ 105 K plasma by the thermalization of the fusion reaction neutrons, most of the energy released can be converted into electric energy by a magnetohydrodynamic generator.

  3. Robustness Studies of Ignition Targets for the National Ignition Facility in Two Dimensions

    SciTech Connect

    Clark, D S; Haan, S W; Salmonson, J D

    2007-11-07

    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 300 eV indirect drive target design for the National Ignition Facility [J. D. 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 two thousand 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.

  4. Comparison of the recently proposed super-Marx generator approach to thermonuclear ignition with the deuterium-tritium laser fusion-fission hybrid concept by the Lawrence Livermore National Laboratory

    DOE PAGESBeta

    Winterberg, F.

    2009-01-01

    The recently proposed super-Marx generator pure deuterium microdetonation ignition concept is compared to the Lawrence Livermore National Ignition Facility (NIF) Laser deuterium-tritium fusion-fission hybrid concept (LIFE). In a super-Marx generator, a large number of ordinary Marx generators charge up a much larger second stage ultrahigh voltage Marx generator from which for the ignition of a pure deuterium microexplosion an intense GeV ion beam can be extracted. Typical examples of the LIFE concept are a fusion gain of 30 and a fission gain of 10, making up a total gain of 300, with about ten times more energy released into fissionmore » as compared to fusion. This means the substantial release of fission products, as in fissionless pure fission reactors. In the super-Marx approach for the ignition of pure deuterium microdetonation, a gain of the same magnitude can, in theory, be reached. If feasible, the super-Marx generator deuterium ignition approach would make lasers obsolete as a means for the ignition of thermonuclear microexplosions.« less

  5. Comparison of the recently proposed super-Marx generator approach to thermonuclear ignition with the deuterium-tritium laser fusion-fission hybrid concept by the Lawrence Livermore National Laboratory

    SciTech Connect

    Winterberg, F.

    2009-01-01

    The recently proposed super-Marx generator pure deuterium microdetonation ignition concept is compared to the Lawrence Livermore National Ignition Facility (NIF) Laser deuterium-tritium fusion-fission hybrid concept (LIFE). In a super-Marx generator, a large number of ordinary Marx generators charge up a much larger second stage ultrahigh voltage Marx generator from which for the ignition of a pure deuterium microexplosion an intense GeV ion beam can be extracted. Typical examples of the LIFE concept are a fusion gain of 30 and a fission gain of 10, making up a total gain of 300, with about ten times more energy released into fission as compared to fusion. This means the substantial release of fission products, as in fissionless pure fission reactors. In the super-Marx approach for the ignition of pure deuterium microdetonation, a gain of the same magnitude can, in theory, be reached. If feasible, the super-Marx generator deuterium ignition approach would make lasers obsolete as a means for the ignition of thermonuclear microexplosions.

  6. Inertial-confinement fusion with lasers

    DOE PAGESBeta

    Betti, R.; Hurricane, O. A.

    2016-05-03

    Here, the quest for controlled fusion energy has been ongoing for over a half century. The demonstration of ignition and energy gain from thermonuclear fuels in the laboratory has been a major goal of fusion research for decades. Thermonuclear ignition is widely considered a milestone in the development of fusion energy, as well as a major scientific achievement with important applications to national security and basic sciences. The U.S. is arguably the world leader in the inertial con fment approach to fusion and has invested in large facilities to pursue it with the objective of establishing the science related tomore » the safety and reliability of the stockpile of nuclear weapons. Even though significant progress has been made in recent years, major challenges still remain in the quest for thermonuclear ignition via laser fusion.« less

  7. Monochromatic x-ray radiography for areal-density measurement of inertial fusion energy fuel in fast ignition experiment

    SciTech Connect

    Fujioka, Shinsuke; Fujiwara, Takashi; Tanabe, Minoru; Nishimura, Hiroaki; Nagatomo, Hideo; Ohira, Shinji; Shiraga, Hiroyuki; Azechi, Hiroshi; Inubushi, Yuichi

    2010-10-15

    Ultrafast, two-dimensional x-ray imaging is an important diagnostics for the inertial fusion energy research, especially in investigating implosion dynamics at the final stage of the fuel compression. Although x-ray radiography was applied to observing the implosion dynamics, intense x-rays emitted from the high temperature and dense fuel core itself are often superimposed on the radiograph. This problem can be solved by coupling the x-ray radiography with monochromatic x-ray imaging technique. In the experiment, 2.8 or 5.2 keV backlight x-rays emitted from laser-irradiated polyvinyl chloride or vanadium foils were selectively imaged by spherically bent quartz crystals with discriminating the out-of-band emission from the fuel core. This x-ray radiography system achieved 24 {mu}m and 100 ps of spatial and temporal resolutions, respectively.

  8. Performance metrics for inertial confinement fusion implosions: Aspects of the technical framework for measuring progress in the National Ignition Campaign

    SciTech Connect

    Spears, Brian K.; Glenzer, S.; Edwards, M. J.; Brandon, S.; Clark, D.; Town, R.; Cerjan, C.; Dylla-Spears, R.; Mapoles, E.; Munro, D.; Salmonson, J.; Sepke, S.; Weber, S.; Hatchett, S.; Haan, S.; Springer, P.; Moses, E.; Kline, J.; Kyrala, G.; Wilson, D.

    2012-05-15

    The National Ignition Campaign (NIC) uses non-igniting 'tritium hydrogen deuterium (THD)' capsules to study and optimize the hydrodynamic assembly of the fuel without burn. These capsules are designed to simultaneously reduce DT neutron yield and to maintain hydrodynamic similarity with the DT ignition capsule. We will discuss nominal THD performance and the associated experimental observables. We will show the results of large ensembles of numerical simulations of THD and DT implosions and their simulated diagnostic outputs. These simulations cover a broad range of both nominal and off-nominal implosions. We will focus on the development of an experimental implosion performance metric called the experimental ignition threshold factor (ITFX). We will discuss the relationship between ITFX and other integrated performance metrics, including the ignition threshold factor (ITF), the generalized Lawson criterion (GLC), and the hot spot pressure (HSP). We will then consider the experimental results of the recent NIC THD campaign. We will show that we can observe the key quantities for producing a measured ITFX and for inferring the other performance metrics. We will discuss trends in the experimental data, improvement in ITFX, and briefly the upcoming tuning campaign aimed at taking the next steps in performance improvement on the path to ignition on NIF.

  9. Performance metrics for Inertial Confinement Fusion implosions: aspects of the technical framework for measuring progress in the National Ignition Campaign

    SciTech Connect

    Spears, B K; Glenzer, S; Edwards, M J; Brandon, S; Clark, D; Town, R; Cerjan, C; Dylla-Spears, R; Mapoles, E; Munro, D; Salmonson, J; Sepke, S; Weber, S; Hatchett, S; Haan, S; Springer, P; Moses, E; Mapoles, E; Munro, D; Salmonson, J; Sepke, S

    2011-12-16

    The National Ignition Campaign (NIC) uses non-igniting 'THD' capsules to study and optimize the hydrodynamic assembly of the fuel without burn. These capsules are designed to simultaneously reduce DT neutron yield and to maintain hydrodynamic similarity with the DT ignition capsule. We will discuss nominal THD performance and the associated experimental observables. We will show the results of large ensembles of numerical simulations of THD and DT implosions and their simulated diagnostic outputs. These simulations cover a broad range of both nominal and off nominal implosions. We will focus on the development of an experimental implosion performance metric called the experimental ignition threshold factor (ITFX). We will discuss the relationship between ITFX and other integrated performance metrics, including the ignition threshold factor (ITF), the generalized Lawson criterion (GLC), and the hot spot pressure (HSP). We will then consider the experimental results of the recent NIC THD campaign. We will show that we can observe the key quantities for producing a measured ITFX and for inferring the other performance metrics. We will discuss trends in the experimental data, improvement in ITFX, and briefly the upcoming tuning campaign aimed at taking the next steps in performance improvement on the path to ignition on NIF.

  10. 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

  11. Design and Fabrication of a Novel Cryogenic Laser-Driven Ignition Target

    SciTech Connect

    Lawrence Livermore National Laboratory

    2007-03-12

    The targets used in the campaign to achieve fusion ignition at the National Ignition Facility (NIF), the world's largest laser, will be some of the most complex and precise ever built. Key to the success of the campaign is repeatable performance of the targets as components of each experiment. We have developed a target design that will achieve the necessary precision and manufacturability, and will also provide the necessary repeatability while retaining experimental flexibility.

  12. 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

  13. Two-dimensional simulations of thermonuclear burn in ignition-scale inertial confinement fusion targets under compressed axial magnetic fields

    SciTech Connect

    Perkins, L. J.; Logan, B. G.; Zimmerman, G. B.; Werner, C. J.

    2013-07-15

    We report for the first time on full 2-D radiation-hydrodynamic implosion simulations that explore the impact of highly compressed imposed magnetic fields on the ignition and burn of perturbed spherical implosions of ignition-scale cryogenic capsules. Using perturbations that highly convolute the cold fuel boundary of the hotspot and prevent ignition without applied fields, we impose initial axial seed fields of 20–100 T (potentially attainable using present experimental methods) that compress to greater than 4 × 10{sup 4} T (400 MG) under implosion, thereby relaxing hotspot areal densities and pressures required for ignition and propagating burn by ∼50%. The compressed field is high enough to suppress transverse electron heat conduction, and to allow alphas to couple energy into the hotspot even when highly deformed by large low-mode amplitudes. This might permit the recovery of ignition, or at least significant alpha particle heating, in submarginal capsules that would otherwise fail because of adverse hydrodynamic instabilities.

  14. Review of the National Ignition Campaign 2009-2012

    SciTech Connect

    Lindl, John; Landen, Otto; Edwards, John; Moses, Ed; Collaboration: NIC Team

    2014-02-15

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

  15. Resolving a central ICF issue for ignition: Implosion symmertry

    SciTech Connect

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

    1994-09-01

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

  16. Fast ignition experimental and theoretical studies

    NASA Astrophysics Data System (ADS)

    Akli, Kramer Ugerthen

    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 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 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 K-alpha yield from the imploded core revealed that 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. The contribution of the potential, induced by charge separation, in opposing the motion of the electrons was moderate. Second, temperature sensitivity of Cu K-alpha imaging efficiency using a spherical Bragg reflecting crystal is investigated. It was found that due to the shifting and broadening of the K-alpha line, with increasing temperature, both the brightness and the

  17. Fast Ignition Experimental and Theoretical Studies

    SciTech Connect

    Akli, K

    2006-10-20

    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 K{sub {alpha}} 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 K{sub {alpha}} imaging efficiency using a spherical Bragg reflecting crystal is investigated. It was found that due to the shifting and broadening of the K{sub {alpha

  18. Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

    SciTech Connect

    Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

    1998-04-01

    Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots ({approx}100 {micro}m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with {rho}r {approx} 2 g/cm{sup 2} for a small demo/pilot plant producing {approx}40 MJ of fusion yield per target, and (2) a large target with {rho}r {approx} 10 g/cm{sup 2} producing {approx}1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q {approx} 26) ion sources for short ({approx}5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of {approx}10 MG fields to provide steep focusing angles close-in to the target

  19. The National Ignition Facility: the path to a carbon-free energy future.

    PubMed

    Stolz, Christopher J

    2012-08-28

    The National Ignition Facility (NIF), the world's largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory. The NIF will enable exploration of scientific problems in national strategic security, basic science and fusion energy. One of the early NIF goals centres on achieving laboratory-scale thermonuclear ignition and energy gain, demonstrating the feasibility of laser fusion as a viable source of clean, carbon-free energy. This talk will discuss the precision technology and engineering challenges of building the NIF and those we must overcome to make fusion energy a commercial reality. PMID:22802504

  20. The National Ignition Facility: The Path to a Carbon-Free Energy Future

    SciTech Connect

    Stolz, C J

    2011-03-16

    The National Ignition Facility (NIF), the world's largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF will enable exploration of scientific problems in national strategic security, basic science and fusion energy. One of the early NIF goals centers on achieving laboratory-scale thermonuclear ignition and energy gain, demonstrating the feasibility of laser fusion as a viable source of clean, carbon-free energy. This talk will discuss the precision technology and engineering challenges of building the NIF and those we must overcome to make fusion energy a commercial reality.

  1. Progress Toward Ignition on the National Ignition Facility

    SciTech Connect

    Kauffman, R L

    2011-10-17

    experiments. Both yield and areal density show significant increases as a result of the optimization. The experimental Ignition Threshold Factor (ITFX) is a measure of the progress toward ignition. ITFX is analogous to the Lawson Criterion in Magnetic Fusion. Implosions have improved by over a factor of 50 since the first cryogenic layered experiments were done in September 2010. This increase is a measure of the progress made toward the ignition goal in the past year. Optimization experiments are planned in the coming year for continued improvement in implosion performance to achieve the ignition goal. In summary, NIF has made significant progress toward ignition in the 30 months since project completion. Diagnostics and all of the supporting equipment are in place for ignition experiments. The Ignition Campaign is under way as a national collaborative effort of all the National Nuclear Security Administration (NNSA) science laboratories as well as international partners.

  2. Future of Inertial Fusion Energy

    SciTech Connect

    Nuckolls, J H; Wood, L L

    2002-09-04

    In the past 50 years, fusion R&D programs have made enormous technical progress. Projected billion-dollar scale research facilities are designed to approach net energy production. In this century, scientific and engineering progress must continue until the economics of fusion power plants improves sufficiently to win large scale private funding in competition with fission and non-nuclear energy systems. This economic advantage must be sustained: trillion dollar investments will be required to build enough fusion power plants to generate ten percent of the world's energy. For Inertial Fusion Energy, multi-billion dollar driver costs must be reduced by up to an order of magnitude, to a small fraction of the total cost of the power plant. Major cost reductions could be achieved via substantial improvements in target performance-both higher gain and reduced ignition energy. Large target performance improvements may be feasible through a combination of design innovations, e.g., ''fast ignition,'' propagation down density gradients, and compression of fusion fuel with a combination of driver and chemical energy. The assumptions that limit projected performance of fusion targets should be carefully examined. The National Ignition Facility will enable development and testing of revolutionary targets designed to make possible economically competitive fusion power plants.

  3. Alternative Approaches to High Energy Density Fusion

    NASA Astrophysics Data System (ADS)

    Hammer, J.

    2016-03-01

    This paper explores selected approaches to High Energy Density (HED) fusion, beginning with discussion of ignition requirements at the National Ignition Facility (NIF). The needed improvements to achieve ignition are closely tied to the ability to concentrate energy in the implosion, manifested in the stagnation pressure, Pstag . The energy that must be assembled in the imploded state to ignite varies roughly as Pstag -2, so among other requirements, there is a premium on reaching higher Pstag to achieve ignition with the available laser energy. The U.S. inertial confinement fusion program (ICF) is pursuing higher Pstag on NIF through improvements to capsule stability and symmetry. One can argue that recent experiments place an approximate upper bound on the ultimate ignition energy requirement. Scaling the implosions consistently in spatial, temporal and energy scales shows that implosions of the demonstrated quality ignite robustly at 9-15 times the current energy of NIF. While lasers are unlikely to reach that bounding energy, it appears that pulsed-power sources could plausibly do so, giving a range of paths forward for ICF depending on success in improving energy concentration. In this paper, I show the scaling arguments then discuss topics from my own involvement in HED fusion. The recent Viewfactor experiments at NIF have shed light on both the observed capsule drive deficit and errors in the detailed modelling of hohlraums. The latter could be important factors in the inability to achieve the needed symmetry and energy concentration. The paper then recounts earlier work in Fast Ignition and the uses of pulsed- power for HED and fusion applications. It concludes with a description of a method for improving pulsed-power driven hohlraums that could potentially provide a factor of 10 in energy at NIF-like drive conditions and reach the energy bound for indirect drive ICF.

  4. Achieving competitive excellence in nuclear energy: The threat of proliferation; the challenge of inertial confinement fusion

    SciTech Connect

    Nuckolls, J.H.

    1994-06-01

    Nuclear energy will have an expanding role in meeting the twenty-first-century challenges of population and economic growth, energy demand, and global warming. These great challenges are non-linearly coupled and incompletely understood. In the complex global system, achieving competitive excellence for nuclear energy is a multi-dimensional challenge. The growth of nuclear energy will be driven by its margin of economic advantage, as well as by threats to energy security and by growing evidence of global warming. At the same time, the deployment of nuclear energy will be inhibited by concerns about nuclear weapons proliferation, nuclear waste and nuclear reactor safety. These drivers and inhibitors are coupled: for example, in the foreseeable future, proliferation in the Middle East may undermine energy security and increase demand for nuclear energy. The Department of Energy`s nuclear weapons laboratories are addressing many of these challenges, including nuclear weapons builddown and nonproliferation, nuclear waste storage and burnup, reactor safety and fuel enrichment, global warming, and the long-range development of fusion energy. Today I will focus on two major program areas at the Lawrence Livermore National Laboratory (LLNL): the proliferation of nuclear weapons and the development of inertial confinement fusion (ICF) energy.

  5. (Fusion energy research)

    SciTech Connect

    Phillips, C.A.

    1988-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices (FY88); tokamak fusion test reactor; Princeton beta Experiment-Modification; S-1 Spheromak; current drive experiment; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical plasma; tokamak modeling; compact ignition tokamak; international thermonuclear experimental reactor; Engineering Department; Project Planning and Safety Office; quality assurance and reliability; and technology transfer.

  6. Divertor conditions relevant for fusion reactors achieved with linear plasma generator

    SciTech Connect

    Eck, H. J. N. van; Lof, A.; Meiden, H. J. van der; Rooij, G. J. van; Scholten, J.; Zeijlmans van Emmichoven, P. A.; Kleyn, A. W.

    2012-11-26

    Intense magnetized hydrogen and deuterium plasmas have been produced with electron densities up to 3.6 Multiplication-Sign 10{sup 20} m{sup -3} and electron temperatures up to 3.7 eV with a linear plasma generator. Exposure of a W target has led to average heat and particle flux densities well in excess of 4 MW m{sup -2} and 10{sup 24} m{sup -2} s{sup -1}, respectively. We have shown that the plasma surface interactions are dominated by the incoming ions. The achieved conditions correspond very well to the projected conditions at the divertor strike zones of fusion reactors such as ITER. In addition, the machine has an unprecedented high gas efficiency.

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

    SciTech Connect

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

    1997-08-26

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

  8. The experimental plan for cryogenic layered target implosions on the National Ignition Facility - The inertial confinement approach to fusion

    SciTech Connect

    Edwards, M. J.; Lindl, J. D.; Spears, B. K.; Weber, S. V.; Atherton, L. J.; Bleuel, D. L.; Bradley, D. K.; Callahan, D. A.; Cerjan, C. J.; Clark, D; Collins, G. W.; Fair, J. E.; Fortner, R. J.; Glenzer, S. H.; Haan, S. W.; Hammel, B. A.; Hamza, A. V.; Hatchett, S. P.; Izumi, N.; Jacoby, B.

    2011-05-15

    Ignition requires precisely controlled, high convergence implosions to assemble a dense shell of deuterium-tritium (DT) fuel with {rho}R>{approx}1 g/cm{sup 2} surrounding a 10 keV hot spot with {rho}R {approx} 0.3 g/cm{sup 2}. A working definition of ignition has been a yield of {approx}1 MJ. At this yield the {alpha}-particle energy deposited in the fuel would have been {approx}200 kJ, which is already {approx}10 x more than the kinetic energy of a typical implosion. The National Ignition Campaign includes low yield implosions with dudded fuel layers to study and optimize the hydrodynamic assembly of the fuel in a diagnostics rich environment. The fuel is a mixture of tritium-hydrogen-deuterium (THD) with a density equivalent to DT. The fraction of D can be adjusted to control the neutron yield. Yields of {approx}10{sup 14-15} 14 MeV (primary) neutrons are adequate to diagnose the hot spot as well as the dense fuel properties via down scattering of the primary neutrons. X-ray imaging diagnostics can function in this low yield environment providing additional information about the assembled fuel either by imaging the photons emitted by the hot central plasma, or by active probing of the dense shell by a separate high energy short pulse flash. The planned use of these targets and diagnostics to assess and optimize the assembly of the fuel and how this relates to the predicted performance of DT targets is described. It is found that a good predictor of DT target performance is the THD measurable parameter, Experimental Ignition Threshold Factor, ITFX {approx} Y x dsf {sup 2.3}, where Y is the measured neutron yield between 13 and 15 MeV, and dsf is the down scattered neutron fraction defined as the ratio of neutrons between 10 and 12 MeV and those between 13 and 15 MeV.

  9. Range shortening, radiation transport, and Rayleigh-Taylor instability phenomena in ion-beam-driven inertial-fusion-reactor-size targets: Implosion, ignition, and burn phases

    SciTech Connect

    Long, K.A.; Tahir, N.A.

    1987-03-15

    In this paper we present an analysis of the theory of the energy deposition of ions in cold materials and hot dense plasmas together with numerical calculations for heavy and light ions of interest to ion-beam fusion. We have used the g-smcapso-smcapsr-smcapsg-smcapso-smcapsn-smcaps computer code of Long, Moritz, and Tahir (which is an extension of the code originally written for protons by Nardi, Peleg, and Zinamon) to carry out these calculations. The energy-deposition data calculated in this manner has been used in the design of heavy-ion-beam-driven fusion targets suitable for a reactor, by its inclusion in the m-smcapse-smcapsd-smcapsu-smcapss-smcapsa-smcaps code of Christiansen, Ashby, and Roberts as extended by Tahir and Long. A number of other improvements have been made in this code and these are also discussed. Various aspects of the theoretical analysis of such targets are discussed including the calculation of the hydrodynamic stability, the hydrodynamic efficiency, and the gain. Various different target designs have been used, some of them new. In general these targets are driven by Bi/sup +/ ions of energy 8--12 GeV, with an input energy of 4--6.5 MJ, with output energies in the range 600--900 MJ, and with gains in the range 120--180. The peak powers are in the range of 500--750 TW. We present detailed calculations of the ablation, compression, ignition, and burn phases. By the application of a new stability analysis which includes ablation and density-gradient effects we show that these targets appear to implode in a stable manner. Thus the targets designed offer working examples suited for use in a future inertial-confinement fusion reactor.

  10. Present status and future prospect of Fast Ignition Realization Experiment (FIREX) Project at ILE, Osaka

    SciTech Connect

    Nishimura, H.; Azechi, H.; Mima, K.; Fujimoto, Y.; Fujioka, S.; Homma, H.; Jitsuno, T.; Johzaki, T.; Koga, M.; Kawanaka, J.; Kawasaki, T.; Miyanaga, N.; Murakami, H.; Murakami, M.; Nagatomo, H.; Morio, N.; Nagai, K.; Nakai, M.; Nakamura, T.; Nakazato, T.

    2010-02-02

    Thermonuclear ignition and subsequent burn are key physics for achieving laser fusion. In fast ignition, a highly compressed fusion fuel generated with multiple ns-laser beams is rapidly heated with a large energy, ps-laser pulse in prior to core disassembly. This scheme has a high potential to achieve ignition and burn since driver energy required for high fusion gain is predicted to be about one tenth of that needed for the central ignition scheme. In Japan, Fast Ignition Realization Experiment (FIREX) project has been started to clarify the physics of energy transport and deposition in the core plasma and to demonstrate fuel temperature of above 5 keV. After the success, FIREX-I will be followed by the second phase of the project (FIREX-II) to demonstrate ignition and burn. LFEX laser, designed to deliver a laser pulse of 10 kJ in 10 ps, are operational and the first phase of FIREX experiments has been stated. A new target is proposed to attain dense compression of fuel and improve laser-core coupling efficiency by adopting double-cone structure, a low-density inner liner, low-Z outer coating, and Br-doped fuel shell. In this paper, present status and near term prospects of the FIREX-I project will be reported together with activities on target designing, laser development, and plasma diagnostics.

  11. Laser-optical path to nuclear energy without radioactivity: Fusion of hydrogen-boron by nonlinear force driven plasma blocks

    NASA Astrophysics Data System (ADS)

    Hora, H.; Miley, G. H.; Ghoranneviss, M.; Malekynia, B.; Azizi, N.

    2009-10-01

    Anomalous interaction of terawatt-picosecond laser pulses allows side-on ignition of solid state density fusion fuel with the unexpected possibility of igniting uncompressed hydrogen-boron p- 11B. Suppression of relativistic self-focusing by using very clean laser pulses with an extremely high contrast ratio is essential to achieve ignition thresholds only ten times more difficult than fusion of deuterium-tritium (DT). This opens the possibility for laser driven fusion energy without neutrons and less radioactivity than from burning coal. The complex nonlinear optical properties involved are elaborated.

  12. Status of the National Ignition Facility project

    SciTech Connect

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

    1997-04-01

    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-um 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. Franceand the United Kingdom are collaborating on development of required technology under bilateral agreements with the US. This paper presents thestatus of the laser design and development of its principal components and optical elements.

  13. Accelerators for Inertial Fusion Energy Production

    NASA Astrophysics Data System (ADS)

    Bangerter, R. O.; Faltens, A.; Seidl, P. A.

    2014-02-01

    Since the 1970s, high energy heavy ion accelerators have been one of the leading options for imploding and igniting targets for inertial fusion energy production. Following the energy crisis of the early 1970s, a number of people in the international accelerator community enthusiastically began working on accelerators for this application. In the last decade, there has also been significant interest in using accelerators to study high energy density physics (HEDP). Nevertheless, research on heavy ion accelerators for fusion has proceeded slowly pending demonstration of target ignition using the National Ignition Facility (NIF), a laser-based facility at Lawrence Livermore National Laboratory. A recent report of the National Research Council recommends expansion of accelerator research in the US if and when the NIF achieves ignition. Fusion target physics and the economics of commercial energy production place constraints on the design of accelerators for fusion applications. From a scientific standpoint, phase space and space charge considerations lead to the most stringent constraints. Meeting these constraints almost certainly requires the use of multiple beams of heavy ions with kinetic energies > 1 GeV. These constraints also favor the use of singly charged ions. This article discusses the constraints for both fusion and HEDP, and explains how they lead to the requirements on beam parameters. RF and induction linacs are currently the leading contenders for fusion applications. We discuss the advantages and disadvantages of both options. We also discuss the principal issues that must yet be resolved.

  14. Laser Burnt-through Cone for the Control of Plasma Instabilities in Fast Ignition Thermonuclear Fusion Pellets

    NASA Astrophysics Data System (ADS)

    Stefan, V. Alexander

    2010-11-01

    I propose a laser burnt-through cone for the suppression, (elimination), of plasma instabilities in fast ignition pellets.ootnotetextM. Tabak, J. Hammer, M.E. Glinsky, W.L. Kruer, S. C. Wilks, J. Woodworth, E. M. Campbell, and M.D. Perry, Phys. Plasmas 1 (5), 1626 (1994).^,ootnotetextV. Alexander Stefan, Bulletin APS-DPP, 2006;2007. Laser-REB, relativistic electron beam, hybridootnotetextV. Alexander Stefan, Nonlinear Electromagnetic Radiation Plasma Interactions, (S-U-Press, 2008). may prove to be, (if the burnt-through laser intensity is 20% of the total intensity), an effective tool for the control of variety of plasma instabilities, in particular for instabilities leading to the generation of colossal B-fields: Weibel instabilities and filamentation of the REB. In the latter case, (B-fields due to ∇n x ∇T mechanism), laser radiation, (φo, ko), ``breaks'' the unstable waves, k ˜ k0 (φpe/φo), through the Kolmogorovootnotetext A. N. Kolmogorov, Doklady Academii. Nauk SSSR, 30, 301, (1941). cascades into shorter wavelengths, transferring the energy into a nonlinear Landau damping domain. The stabilization take place on the time scale ˜REB propagation length/ion acoustic velocity.

  15. Repetitive Solid Spherical Pellet Injection and Irradiation toward the Repetitive-mode Fast-Ignition Fusion miniReactor CANDY.

    NASA Astrophysics Data System (ADS)

    HANAYAMA, Ryohei; KOMEDA, Osamu; NISHIMURA, Yasuhiko; MORI, Yoshitaka; ISHII, Katsuhiro; NAKAYAMA, Suisei; OKIHARA, Shinichiro; FUJITA, Kazuhisa; SEKINE, Takashi; SATO, Nakahiro; KURITA, Takashi; KAWASHIMA, Toshiyuki; KAN, Hirofumi; NAKAMURA, Naoki; KONDO, Takuya; FUJINE, Manabu; AZUMA, Hirozumi; HIOKI, Tatsumi; KAKENO, Mitsutaka; MOTOHIRO, Tomoyoshi; SUNAHARA, Atsushi; SENTOKU, Yasuhiko; MIURA, Eisuke; KITAGAWA, Yoneyoshi

    2016-03-01

    Pellet injection and repetitive laser illumination are key technologies for realizing inertial fusion energy[1-4]. Neutron generator using lasers also requires a repeating pellet target supplier. Here we present the first demonstration of target injection and neutron generation[5]. We injected more than 1300 spherical deuterated polystyrene(C8D8) bead pellet targets during 23 minutes at 1 Hz(Fig. 1). After the pellet targets fell for a distance of 18 cm, we applied the synchronized laser-diode-pumped ultra-intense laser HAMA. The laser intensity at the focal point is 5 x 1018 W/cm2, which is high enough to generate neutrons. As a result of the irradiation, we produced 2.45-MeV DD neutrons. Figure 2 shows the neutron time-of-flight signals detected by plastic scintillators coupled to photomultipliers. The neutron energy was calculated by the time-of-flight method. The maximum neutron yield was 9.5 x 104/4π sr. The result is a step toward fusion power and also suggests possible industrial neutron sources.

  16. Activation analysis of the compact ignition tokamak

    SciTech Connect

    Selcow, E.C.

    1986-01-01

    The US fusion program has completed the conceptual design of a compact tokamak device that achieves ignition. The high neutron wall loadings associated with this compact deuterium-tritium-burning device indicate that radiation-related issues may be significant considerations in the overall system design. Sufficient shielding will be requied for the radiation protection of both reactor components and occupational personnel. A close-in igloo shield has been designed around the periphery of the tokamak structure to permit personnel access into the test cell after shutdown and limit the total activation of the test cell components. This paper describes the conceptual design of the igloo shield system and discusses the major neutronic concerns related to the design of the Compact Ignition Tokamak.

  17. National Ignition Facility design, performance, and cost

    SciTech Connect

    Hogan, W.J.; Paisner, J.A.; Lowdermilk, W.H.

    1994-09-16

    A conceptual design for the National Ignition Facility (NIF) has been completed and its cost has been estimated by a multilaboratory team. To maximize the performance/cost ratio a compact, segmented amplifier is used in a multipass architecture. Many recent optical and laser technology developments have been incorporated into the final design. The Beamlet project has successfully demonstrated the new concept. The mission of ICF Program using the NEF is to achieve ignition and gain in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects experiments, and for civilian applications such as inertial fusion energy development and fundamental studies of matter at high energy density.

  18. The Technology of the National Ignition Facility

    SciTech Connect

    Moses, E I

    2001-08-31

    The National Ignition Facility (NIF), currently under construction at the University of California's Lawrence Livermore National Laboratory is a 192-beam, 1.8-Megajoule, 500-Terawat, 351-nm laser for inertial confinement fusion and high energy density experimental studies. NIF is being built by the Department of Energy and the National Nuclear Security Agency to provide an experimental test bed for the U.S. Stockpile Stewardship Program to ensure the country's nuclear deterrent without underground nuclear testing. A number of significant technology breakthroughs have been achieved in the course of designing NIF. This presentation will discuss some of the technology challenges and solutions that have made NIF possible.

  19. Preliminary Results of Bioactive Amniotic Suspension with Allograft for Achieving One and Two-Level Lumbar Interbody Fusion

    PubMed Central

    Kerr, Eubulus J.; Utter, Philip A.; Cavanaugh, David A.; Frank, Kelly A.; Moody, Devan; McManus, Brian; Stone, Marcus B.

    2016-01-01

    Background Bone graft material for lumbar fusion was historically autologous bone graft (ABG). In recent years alternatives such as allograft, demineralized bone matrix (DBM), ceramics, and bone morphogenetic protein (BMP) have gained favor, although the complications of these are not fully understood. Bioactive amniotic suspension (BAS) with allograft is a new class of material derived from human amniotic tissue. Methods Eligible patients receiving a one or two level lumbar interbody fusion with Nucel, a BAS with allograft, were contacted and scheduled for a mininmim 12 month follow-up visit. Patients were evaluated for fusion using CT's and plain radiographs. Clincal outcomes, including ODI, VAS back and leg were collected, as well as comorbidities including BMI, smoking status, diabetes and previous lumbar surgery. Results One-level patients (N=38) were 71.1% female with mean age of 58.4 ± 12.7 and mean BMI of 30.6 ± 6.08. Two-level patients (N=34) were 58.8% female with mean age of 49.3 ±10.9 and mean BMI of 30.1 ± 5.82. Kinematic fusion was achieved in 97.4% of one-level patients and 100% of two-level patients. Baseline comorbidities were present in 89.5% of one-level patients and 88.2% of two-level patients. No adverse events related to BAS were reported in this study. Conclusion Fusion status is evaluated with many different biologics and varying methods in the literature. BAS with allograft in this study demonstrated high fusion rates with no complications within a largely comorbid population. Although a small population, BAS with allograft results were encouraging for one and two-level lumbar interbody fusion in this study. Further prospective studies should be conducted to investigate safety and efficacy in a larger population. PMID:27162714

  20. Polar-Drive--Ignition Experimental Plan on the NIF

    NASA Astrophysics Data System (ADS)

    Meyerhofer, D. D.; Froula, D. H.; Goncharov, V. N.; Igumenshchev, I. V.; Loucks, S. J.; McKenty, P. W.; McCrory, R. L.; Radha, P. B.; Sangster, T. C.

    2012-10-01

    The University of Rochester's Laboratory for Laser Energetics has proposed a multi-campaign series of experiments on the National Ignition Facility (NIF)footnotetext E. I. Moses et al., Phys. Plasmas 16, 041006 (2009). to develop polar-drive ignition.footnotetext S. Skupsky et al., Phys. Plasmas 11, 2763 (2004). Polar drive is predicted to couple significantly more energy to the compressed core than the baseline indirect-drive approach. This presentation provides an overview of the plan to achieve polar-drive ignition on the NIF and describes the initial experiments that can be performed without changes in the NIF infrastructure. The first proposed experiments will assess the symmetry of moderate convergence ratio, polar-driven capsule implosions. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

  1. Ignition conditions relaxation for central hot-spot ignition with an ion-electron non-equilibrium model

    NASA Astrophysics Data System (ADS)

    Fan, Zhengfeng; Liu, Jie; Liu, Bin; Yu, Chengxin; He, X. T.

    2016-01-01

    Fusion ignition experiments on the National Ignition Facility have demonstrated >5 keV hot spot with ρRh lower than 0.3 g/cm2 [Döppner et al., Phys. Rev. Lett. 115, 055001 (2015)]. We present an ion-electron non-equilibrium model, in which the hot-spot ion temperature is higher than its electron temperature so that the hot-spot nuclear reactions are enhanced while energy leaks are considerably reduced. Theoretical analysis shows that the ignition region would be significantly enlarged in the hot-spot ρR-T space as compared with the commonly used equilibrium model. Simulations show that shocks could be utilized to create and maintain non-equilibrium conditions within the hot spot, and the hot-spot ρR requirement is remarkably reduced for achieving self-heating.

  2. The Ignition Target for the National Ignition Facility

    SciTech Connect

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

    2007-03-12

    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. Targets for the National Ignition Campaign are both complex and precise, and are extraordinarily demanding in materials fabrication, machining, assembly, cryogenics and characterization. An overview of the campaign for ignition will be presented, along with technologies for target fabrication, assembly and metrology and advances in growth and x-ray imaging of DT ice layers. The sum of these efforts represents a quantum leap in target precision, characterization, manufacturing rate and flexibility over current state-of-the-art.

  3. Effects of non-local electron transport in one-dimensional and two-dimensional simulations of shock-ignited inertial confinement fusion targets

    NASA Astrophysics Data System (ADS)

    Marocchino, A.; Atzeni, S.; Schiavi, A.

    2014-01-01

    In some regions of a laser driven inertial fusion target, the electron mean-free path can become comparable to or even longer than the electron temperature gradient scale-length. This can be particularly important in shock-ignited (SI) targets, where the laser-spike heated corona reaches temperatures of several keV. In this case, thermal conduction cannot be described by a simple local conductivity model and a Fick's law. Fluid codes usually employ flux-limited conduction models, which preserve causality, but lose important features of the thermal flow. A more accurate thermal flow modeling requires convolution-like non-local operators. In order to improve the simulation of SI targets, the non-local electron transport operator proposed by Schurtz-Nicolaï-Busquet [G. P. Schurtz et al., Phys. Plasmas 7, 4238 (2000)] has been implemented in the DUED fluid code. Both one-dimensional (1D) and two-dimensional (2D) simulations of SI targets have been performed. 1D simulations of the ablation phase highlight that while the shock profile and timing might be mocked up with a flux-limiter; the electron temperature profiles exhibit a relatively different behavior with no major effects on the final gain. The spike, instead, can only roughly be reproduced with a fixed flux-limiter value. 1D target gain is however unaffected, provided some minor tuning of laser pulses. 2D simulations show that the use of a non-local thermal conduction model does not affect the robustness to mispositioning of targets driven by quasi-uniform laser irradiation. 2D simulations performed with only two final polar intense spikes yield encouraging results and support further studies.

  4. Effects of non-local electron transport in one-dimensional and two-dimensional simulations of shock-ignited inertial confinement fusion targets

    SciTech Connect

    Marocchino, A.; Atzeni, S.; Schiavi, A.

    2014-01-15

    In some regions of a laser driven inertial fusion target, the electron mean-free path can become comparable to or even longer than the electron temperature gradient scale-length. This can be particularly important in shock-ignited (SI) targets, where the laser-spike heated corona reaches temperatures of several keV. In this case, thermal conduction cannot be described by a simple local conductivity model and a Fick's law. Fluid codes usually employ flux-limited conduction models, which preserve causality, but lose important features of the thermal flow. A more accurate thermal flow modeling requires convolution-like non-local operators. In order to improve the simulation of SI targets, the non-local electron transport operator proposed by Schurtz-Nicolaï-Busquet [G. P. Schurtz et al., Phys. Plasmas 7, 4238 (2000)] has been implemented in the DUED fluid code. Both one-dimensional (1D) and two-dimensional (2D) simulations of SI targets have been performed. 1D simulations of the ablation phase highlight that while the shock profile and timing might be mocked up with a flux-limiter; the electron temperature profiles exhibit a relatively different behavior with no major effects on the final gain. The spike, instead, can only roughly be reproduced with a fixed flux-limiter value. 1D target gain is however unaffected, provided some minor tuning of laser pulses. 2D simulations show that the use of a non-local thermal conduction model does not affect the robustness to mispositioning of targets driven by quasi-uniform laser irradiation. 2D simulations performed with only two final polar intense spikes yield encouraging results and support further studies.

  5. Fuel gain exceeding unity in an inertially confined fusion implosion.

    PubMed

    Hurricane, O A; Callahan, D A; Casey, D T; Celliers, P M; Cerjan, C; Dewald, E L; Dittrich, T R; Döppner, T; Hinkel, D E; Berzak Hopkins, L F; Kline, J L; Le Pape, S; Ma, T; MacPhee, A G; Milovich, J L; Pak, A; Park, H-S; Patel, P K; Remington, B A; Salmonson, J D; Springer, P T; Tommasini, R

    2014-02-20

    Ignition is needed to make fusion energy a viable alternative energy source, but has yet to be achieved. A key step on the way to ignition is to have the energy generated through fusion reactions in an inertially confined fusion plasma exceed the amount of energy deposited into the deuterium-tritium fusion fuel and hotspot during the implosion process, resulting in a fuel gain greater than unity. Here we report the achievement of fusion fuel gains exceeding unity on the US National Ignition Facility using a 'high-foot' implosion method, which is a manipulation of the laser pulse shape in a way that reduces instability in the implosion. These experiments show an order-of-magnitude improvement in yield performance over past deuterium-tritium implosion experiments. We also see a significant contribution to the yield from α-particle self-heating and evidence for the 'bootstrapping' required to accelerate the deuterium-tritium fusion burn to eventually 'run away' and ignite. PMID:24522535

  6. 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, 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.

  7. Fusion

    NASA Astrophysics Data System (ADS)

    Herman, Robin

    1990-10-01

    The book abounds with fascinating anecdotes about fusion's rocky path: the spurious claim by Argentine dictator Juan Peron in 1951 that his country had built a working fusion reactor, the rush by the United States to drop secrecy and publicize its fusion work as a propaganda offensive after the Russian success with Sputnik; the fortune Penthouse magazine publisher Bob Guccione sank into an unconventional fusion device, the skepticism that met an assertion by two University of Utah chemists in 1989 that they had created "cold fusion" in a bottle. Aimed at a general audience, the book describes the scientific basis of controlled fusion--the fusing of atomic nuclei, under conditions hotter than the sun, to release energy. Using personal recollections of scientists involved, it traces the history of this little-known international race that began during the Cold War in secret laboratories in the United States, Great Britain and the Soviet Union, and evolved into an astonishingly open collaboration between East and West.

  8. A new metric of the low-mode asymmetry for ignition target designs

    SciTech Connect

    Gu, Jianfa Dai, Zhensheng; Fan, Zhengfeng; Zou, Shiyang Ye, Wenhua; Pei, Wenbing; Zhu, Shaoping

    2014-01-15

    In the deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility, the measured neutron yield and hot spot pressure are significantly lower than simulations. Understanding the underlying physics of the deficit is essential to achieving ignition. This paper investigates the low-mode areal density asymmetry in the main fuel of ignition capsule. It is shown that the areal density asymmetry breaks up the compressed shell and significantly reduces the conversion of implosion kinetic energy to hot spot internal energy, leading to the calculated hot spot pressure and neutron yield quite close to the experimental data. This indicates that the low-mode shell areal density asymmetry can explain part of the large discrepancy between simulations and experiments. Since only using the hot spot shape term could not adequately characterize the effects of the shell areal density asymmetry on implosion performance, a new metric of the low-mode asymmetry is developed to accurately measure the probability of ignition.

  9. Using wavelet fusion approach at panchromatic imagery to achieve dynamic range compression

    NASA Astrophysics Data System (ADS)

    Wan, Hung-Sen; Hsu, Chau-Yun; Hsu, Yuan Hung

    2008-10-01

    The image fusion technique is to maximize the information in images at same area or object taken by different sensors. It enhances unapparent features at each image and wildly applied at remote sensing, medical image, machine vision, and military identification. In remote sensing, the latest sensors usually provide 11-bit panchromatic data which compose more radiometric information; however the standard visual equipment can only produce 8-bit resolution content that limits the analysis of imagery on the screen or paper. This paper shows how to preserve the original 11-bit information after the DRA (Dynamic Range Adjustment) approaches and keep the output from color distortion during the following pan/multi-spectrum image fusion process. We propose a good dynamic range compression method converting the original IKONOS panchromatic image into high, low luminance and typical linear stretched images and using wavelet fusion to enhance the radiometric visualization and keeping good correlation with the multi-spectrum images in order to produce fine pan-sharpened product.

  10. A review of indirect-drive ignition design options for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Dittrich, Thomas R.

    1998-11-01

    As construction continues on the National Ignition Facility (NIF) laser at Livermore, ignition capsule design and fabrication efforts also continue at both LLNL and LANL. These efforts are directed toward finding the inertial confinement fusion (ICF) capsule most likely to achieve ignition and propagated burn when imploded by x-rays obtained from the conversion of laser light in a gold hohlraum, i. e., the indirect drive method. At this time, copper doped beryllium (Be+Cu) and polyimide (C_22H_10N_2O_4) remain as possible capsule ablator material candidates. We choose these materials based on both successful implosion performance as predicted by one-, two-, and three dimensional numerical simulations and on suitable fabrication and material characteristics. These characteristics include attainable surface finishes, permeability, strength, radio frequency and/or infrared radiation transmission, thermal conductivity, and material homogeneity. Numerical simulations predict that capsules with either a Be+Cu or a polyimide ablator have less sensitivity to initial surface roughnesses than polystyrene (CH) ablator capsules. We have designed ignition capsules using these two ablator materials to operate at both low peak drive temperature (250 eV) and low total laser energy (900 kJ). These drive conditions are significantly less than NIF and fuel confinement time consistent with achieving ignition. Fabrication of Be+Cu shells appears feasible by two different methods: LANL has demonstrated shell assembly by brazing together machined hemispheres and LLNL has successfully sputter deposited Be on spherical mandrels. To enhance surface smoothness, this latter technique may require the addition of boron during the sputtering process. Polyimide material has the advantage of being transparent to optical, infrared, and radio frequency radiation. These properties will allow visual inspection of the DT ice layer formation, and enhancement of the ice surface smoothness once formed

  11. 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.

  12. The velocity campaign for ignition on NIFa)

    NASA Astrophysics Data System (ADS)

    Callahan, D. A.; Meezan, N. B.; Glenzer, S. H.; MacKinnon, A. J.; Benedetti, L. R.; Bradley, D. K.; Celeste, J. R.; Celliers, P. M.; Dixit, S. N.; Döppner, T.; Dzentitis, E. G.; Glenn, S.; Haan, S. W.; Haynam, C. A.; Hicks, D. G.; Hinkel, D. E.; Jones, O. S.; Landen, O. L.; London, R. A.; MacPhee, A. G.; Michel, P. A.; Moody, J. D.; Ralph, J. E.; Robey, H. F.; Rosen, M. D.; Schneider, M. B.; Strozzi, D. J.; Suter, L. J.; Town, R. P. J.; Widmann, K.; Williams, E. A.; Edwards, M. J.; MacGowan, B. J.; Lindl, J. D.; Atherton, L. J.; Kyrala, G. A.; Kline, J. L.; Olson, R. E.; Edgell, D.; Regan, S. P.; Nikroo, A.; Wilkins, H.; Kilkenny, J. D.; Moore, A. S.

    2012-05-01

    Achieving inertial confinement fusion ignition requires a symmetric, high velocity implosion. Experiments show that we can reach 95 ± 5% of the required velocity by using a 420 TW, 1.6 MJ laser pulse. In addition, experiments with a depleted uranium hohlraum show an increase in capsule performance which suggests an additional 18 ± 5 μm/ns of velocity with uranium hohlraums over gold hohlraums. Combining these two would give 99 ± 5% of the ignition velocity. Experiments show that we have the ability to tune symmetry using crossbeam transfer. We can control the second Legendre mode (P2) by changing the wavelength separation between the inner and outer cones of laser beams. We can control the azimuthal m = 4 asymmetry by changing the wavelength separation between the 23.5 and 30 degree beams on NIF. This paper describes our "first pass" tuning the implosion velocity and shape on the National Ignition Facility laser [Moses et al., Phys. Plasmas, 16, 041006 (2009)].

  13. Inertially confined fusion plasmas dominated by alpha-particle self-heating

    NASA Astrophysics Data System (ADS)

    Hurricane, O. A.; Callahan, D. A.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Döppner, T.; Haan, S.; Hinkel, D. E.; Berzak Hopkins, L. F.; Jones, O.; Kritcher, A. L.; Le Pape, S.; Ma, T.; Macphee, A. G.; Milovich, J. L.; Moody, J.; Pak, A.; Park, H.-S.; Patel, P. K.; Ralph, J. E.; Robey, H. F.; Ross, J. S.; Salmonson, J. D.; Spears, B. K.; Springer, P. T.; Tommasini, R.; Albert, F.; Benedetti, L. R.; Bionta, R.; Bond, E.; Bradley, D. K.; Caggiano, J.; Celliers, P. M.; Cerjan, C.; Church, J. A.; Dylla-Spears, R.; Edgell, D.; Edwards, M. J.; Fittinghoff, D.; Barrios Garcia, M. A.; Hamza, A.; Hatarik, R.; Herrmann, H.; Hohenberger, M.; Hoover, D.; Kline, J. L.; Kyrala, G.; Kozioziemski, B.; Grim, G.; Field, J. E.; Frenje, J.; Izumi, N.; Gatu Johnson, M.; Khan, S. F.; Knauer, J.; Kohut, T.; Landen, O.; Merrill, F.; Michel, P.; Moore, A.; Nagel, S. R.; Nikroo, A.; Parham, T.; Rygg, R. R.; Sayre, D.; Schneider, M.; Shaughnessy, D.; Strozzi, D.; Town, R. P. J.; Turnbull, D.; Volegov, P.; Wan, A.; Widmann, K.; Wilde, C.; Yeamans, C.

    2016-08-01

    Alpha-particle self-heating, the process of deuterium-tritium fusion reaction products depositing their kinetic energy locally within a fusion reaction region and thus increasing the temperature in the reacting region, is essential for achieving ignition in a fusion system. Here, we report new inertial confinement fusion experiments where the alpha-particle heating of the plasma is dominant with the fusion yield produced exceeding the fusion yield from the work done on the fuel (pressure times volume change) by a factor of two or more. These experiments have achieved the highest yield (26 +/- 0.5 kJ) and stagnation pressures (≍220 +/- 40 Gbar) of any facility-based inertial confinement fusion experiments, although they are still short of the pressures required for ignition on the National Ignition Facility (~300-400 Gbar). These experiments put us in a new part of parameter space that has not been extensively studied so far because it lies between the no-alpha-particle-deposition regime and ignition.

  14. National Ignition Facility Project Execution Plan

    SciTech Connect

    Moses, E

    2000-08-14

    The ''National Ignition Facility (NIF) Justification of Mission Need'', which was approved by the Secretary of Energy in January 1993, defines the mission of the National Inertial Confinement Fusion (ICF) Program and discusses the specific mission of the NIF Project. The NIF experimental capability will allow nuclear-weapons scientists to assess stockpile problems, verify computational tools, test for nuclear-weapons effects, and increase their understanding of weapons physics. The three weapons laboratory directors and the National Nuclear Security Administration (NNSA) Deputy Administrator for Defense Programs have reviewed the role of the NIT; in Stockpile Stewardship in a joint letter. Along with the Accelerated Strategic Computing Initiative numerical simulations and other aboveground experimental facilities, the NIF will provide critical data that will allow the United States to maintain its technical capabilities in nuclear weapons in the absence of underground testing. As a secondary objective, the NIF will advance our understanding of ICF and help to assess its potential as an energy source. Achieving fusion ignition in the NIF will advance both defense and energy objectives. In affirming the Project's Critical Decision 2,* ''Approval of New Start'', the Secretary of Energy verified the mission need and emphasized that the NIF has the potential to contribute significantly to the DOE missions.

  15. Recent progress on the Compact Ignition Tokamak (CIT)

    SciTech Connect

    Ignat, D.W.

    1987-01-01

    This report describes work done on the Compact Ignition Tokamak (CIT), both at the Princeton Plasma Physics Laboratory (PPPL) and at other fusion laboratories in the United States. The goal of CIT is to reach ignition in a tokamak fusion device in the mid-1990's. Scientific and engineering features of the design are described, as well as projected cost and schedule.

  16. 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.

  17. Fusion in Magnetically Compressed Targets

    NASA Astrophysics Data System (ADS)

    Mokhov, V. N.

    2004-11-01

    A comparative analysis is presented of the positive and negative features of systems using magnetic compression of the thermonuclear fusion target (MAGO/MTF) aimed at solving the controlled thermonuclear fusion (CTF) problem. The niche for the MAGO/MTF system, among the other CTF systems, in the parameter space of the energy delivered to the target, and its input time to the target, is shown. This approach was investigated at RFNC-VNIIEF for more than 15 years using the unique technique of applying explosive magnetic generators (EMG) as the energy source to preheat fusion plasma, and accelerate a liner to compress the preheated fusion plasma to the parameters required for ignition. EMG based systems produce already fusion neutrons, and their relatively low cost and record energy yield enable full scale experiments to study the possibility of achieving ignition threshold without constructing expensive stationary installations. A short review of the milestone results on the road to solving the CTF problem in the MAGO/MTF system is given.

  18. 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

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

    SciTech Connect

    Anderson, K. S.; McKenty, P. W.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Marozas, J. A.; Skupsky, S.; Shvydky, A.; Betti, R.; Hohenberger, M.; Theobald, W.; Lafon, M.; Nora, R.

    2013-05-15

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

  20. 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.

  1. 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 is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. The beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being recombined with the first portion after a delay before injection into the ignitor laser. 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.

  2. Tokamak and RFP ignition requirements

    SciTech Connect

    Werley, K.A.

    1991-01-01

    A plasma model is applied to calculate numerically transport- confinement (n{tau}{sub E}) requirements and steady-state operation tokamak. The CIT tokamak and RFP ignition conditions are examined. Physics differences between RFP and tokamaks, and their consequences for a DT ignition machine, are discussed. The ignition RFP, compared to a tokamak, has many physics advantages, including ohmic heating to ignition (no need for auxiliary heating systems), higher beta, low ignition current, less sensitivity of ignition requirements to impurity effects, no hard disruptions (associated with beta or density limits), and successful operation with high radiation fractions (f{sub RAD} {approximately} 0.95). These physics advantages, coupled with important engineering advantages associated with lower external magnetic fields, larger aspect ratios, and smaller plasma cross sections translate into significant cost reductions for both ignition and power reactor. The primary drawback of the RFP is the uncertainty that the present confinement scaling will extrapolate to reactor regimes. The 4-MA ZTH was expected to extend the n{tau}{sub E} transport scaling data three order of magnitude above ZT-40M results, and if the present scaling held, to achieve a DT-equivalent scientific energy breakeven, Q=1. A basecase RFP ignition point is identified with a plasma current of 8.1 MA and no auxiliary heating. 16 refs., 4 figs., 1 tab.

  3. Research of laser ignition detection system

    NASA Astrophysics Data System (ADS)

    Yang, Feng; Zhao, Dong; Xu, Qie; Ai, Xin

    2010-10-01

    Laser ignition is an important means of detonation but the accuracy and security is requested strictly. Based on the above, two points were considered in the design: achieve ignition-Fiber-optical health monitoring in the condition of low-intensity light (ensure the safety of gunpowder); observant the explosive imaging. In the paper, the laser ignition equipment was designed with optical detection and inner optical imaging system for the real-time monitoring to the optical fiber and the process of ignition. This design greatly improved the reliability and the safety of laser ignition system and provided the guarantee for usage and industrialization.

  4. Plasma breakdown and combustion ignition

    NASA Astrophysics Data System (ADS)

    McNeill, Donald H.; Tran, Phuoc

    2001-10-01

    Ignition in chemically reactive media and electrical breakdown are among the most widely used transient processes. The two phenomena operate together during electrical (and laser) spark ignition of combustible gases. Analogs between them show up in Semenov's early (1920's) work on chemical chain reactions and on thermal breakdown of dielectrics. Both breakdown and ignition are under active study today. The energy source for breakdown is an applied electric field, and that for ignition, an applied flux of heat or radicals. Electrons and intermediate reactants are the corresponding driver particles, with a velocity difference that implies a vast difference in the growth rates for the two processes. Combustion takes place in a fuel-oxidant mixture, and an ignited reaction can proceed until the fuel or oxidant is depleted, while a (non-afterglow, non-fusion) plasma is sustained by an external power supply. The energy balance, propagation behavior, and time evolution of some specific forms of plasma breakdown and chemical ignition are further compared in order to illustrate their physical nature.

  5. The National Ignition Facility: A New Era in High Energy Density Science

    SciTech Connect

    Moses, E

    2009-06-10

    The National Ignition Facility, the world's most energetic laser system, is now operational. This talk will describe NIF, the ignition campaign, and new opportunities in fusion energy and high energy density science enabled by NIF.

  6. Assessing and improving the robustness of shock ignition targets

    NASA Astrophysics Data System (ADS)

    Atzeni, Stefano; Marocchino, A.; Schiavi, A.; Temporal, M.

    2010-11-01

    Shock ignition is a promising approach to inertial confinement fusion. Like fast ignition, it separates the stages of compression and ignition, but does not require ultraintense lasers. In addition, it may allow for relatively simple spherical targets. Here, we report studies concerning a simple all D-T target and a target with CH ablator, which could be tested at the National Ignition facility. They achieve (1D) gain in the range 60-100 at laser energy 0.5 -- 1 MJ. These targets are driven by shaped laser pulses preceded by an an adiabat-shaping picket, which (according to our 2D simulations) is required to reduce both RMI and RTI growth at the ablation front. We have performed a wide 1D scan of performance sensitivity to changes in pulse shaping and target parameters (including initial temperature). By 2D simulations we have then studied how irradiation nonuniformities associated to the beam configuration, as well as to beam imbalance and mispointing and to target mispositioning degrade target performance. We discuss how robustness to such errors can be improved by optimizing beam configuration and target design.

  7. Review of progress in Fast Ignition

    SciTech Connect

    Tabak, M.; Clark, D.S.; Hatchett, S.P.; Key, M.H.; Lasinski, B.F.; Snavely, R.A.; Wilks, S.C.; Town, R.P.J.; Stephens, R.; Campbell, E.M.; Kodama, R.; Mima, K.; Tanaka, K.A.; Atzeni, S.; Freeman, R.

    2005-05-15

    Marshall Rosenbluth's extensive contributions included seminal analysis of the physics of the laser-plasma interaction and review and advocacy of the inertial fusion program. Over the last decade he avidly followed the efforts of many scientists around the world who have studied Fast Ignition, an alternate form of inertial fusion. In this scheme, the fuel is first compressed by a conventional inertial confinement fusion driver and then ignited by a short ({approx}10 ps) pulse, high-power laser. Due to technological advances, such short-pulse lasers can focus power 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 describe how these are modified, as more detailed physics understanding is included. The critical design issues revolve around two questions: How can the compressed fuel be efficiently assembled? And how can power from the driver be delivered efficiently to the ignition region? Schemes to shorten the distance between the critical surface where the ignitor laser energy is nominally deposited and the ignition region will de discussed. The current status of Fast Ignition research is compared with our requirements for success. Future research directions will also be outlined.

  8. Prospects for Tokamak Fusion Reactors

    SciTech Connect

    Sheffield, J.; Galambos, J.

    1995-04-01

    This paper first reviews briefly the status and plans for research in magnetic fusion energy and discusses the prospects for the tokamak magnetic configuration to be the basis for a fusion power plant. Good progress has been made in achieving fusion reactor-level, deuterium-tritium (D-T) plasmas with the production of significant fusion power in the Joint European Torus (up to 2 MW) and the Tokamak Fusion Test Reactor (up to 10 MW) tokamaks. Advances on the technologies of heating, fueling, diagnostics, and materials supported these achievements. The successes have led to the initiation of the design phases of two tokamaks, the International Thermonuclear Experimental Reactor (ITER) and the US Toroidal Physics Experiment (TPX). ITER will demonstrate the controlled ignition and extended bum of D-T plasmas with steady state as an ultimate goal. ITER will further demonstrate technologies essential to a power plant in an integrated system and perform integrated testing of the high heat flux and nuclear components required to use fusion energy for practical purposes. TPX will complement ITER by testing advanced modes of steady-state plasma operation that, coupled with the developments in ITER, will lead to an optimized demonstration power plant.

  9. 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.

  10. 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 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 the embodiment of the invention claimed herein, the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being combined with either the first portion after a delay before injection into the ignitor laser.

  11. 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.

  12. Reduced instability growth with high-adiabat high-foot implosions at the National Ignition Facility.

    PubMed

    Casey, D T; Smalyuk, V A; Raman, K S; Peterson, J L; Berzak Hopkins, L; Callahan, D A; Clark, D S; Dewald, E L; Dittrich, T R; Haan, S W; Hinkel, D E; Hoover, D; Hurricane, O A; Kroll, J J; Landen, O L; Moore, A S; Nikroo, A; Park, H-S; Remington, B A; Robey, H F; Rygg, J R; Salmonson, J D; Tommasini, R; Widmann, K

    2014-07-01

    Hydrodynamic instabilities are a major obstacle in the quest to achieve ignition as they cause preexisting capsule defects to grow and ultimately quench the fusion burn in experiments at the National Ignition Facility. Unstable growth at the ablation front has been dramatically reduced in implosions with "high-foot" drives as measured using x-ray radiography of modulations at the most dangerous wavelengths (Legendre mode numbers of 30-90). These growth reductions have helped to improve the performance of layered DT implosions reported by O. A. Hurricane et al. [Nature (London) 506, 343 (2014)], when compared to previous "low-foot" experiments, demonstrating the value of stabilizing ablation-front growth and providing directions for future ignition designs. PMID:25122242

  13. The national ignition facility: path to ignition in the laboratory

    NASA Astrophysics Data System (ADS)

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

    2007-08-01

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

  14. National Ignition Facility Quarterly Status Report Second Quarter 2000, Jan-Mar 2000

    SciTech Connect

    Moses, E.

    2000-04-30

    The Project provides for the design, procurement, construction, assembly, installation, and acceptance testing of the National Ignition Facility (NIF), an experimental inertial confinement fusion facility intended to achieve controlled thermonuclear fusion in the laboratory by imploding a small capsule containing a mixture of the hydrogen isotopes deuterium and tritium. The NIF will be constructed at the Lawrence Livermore National Laboratory (LLNL), Livermore, California as determined by the Record of Decision made on December 19, 1996, as a part of the Stockpile Stewardship and Management Programmatic Environmental Impact Statement.

  15. National Ignition Facility Quarterly Status Report - First Quarter 2000, Dec 1999

    SciTech Connect

    Yatabe, J.

    2000-01-30

    The Project provides for the design, procurement, construction, assembly, installation, and acceptance testing of the National Ignition Facility (NIF), an experimental inertial confinement fusion facility intended to achieve controlled thermonuclear fusion in the laboratory by imploding a small capsule containing a mixture of the hydrogen isotopes deuterium and tritium. The NIF will be constructed at the Lawrence Livermore National Laboratory (LLNL), Livermore, California as determined by the Record of Decision made on December 19, 1996, as a part of the Stockpile Stewardship and Management Programmatic Environmental Impact Statement (SSM PEIS).

  16. 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.

  17. Effects On Beam Alignment Due To Neutron-Irradiated CCD Images At The National Ignition Facility

    SciTech Connect

    Awwal, A; Manuel, A; Datte, P; Burkhart, S

    2011-02-28

    The 192 laser beams in the National Ignition Facility (NIF) are automatically aligned to the target-chamber center using images obtained through charged coupled device (CCD) cameras. Several of these cameras are in and around the target chamber during an experiment. Current experiments for the National Ignition Campaign are attempting to achieve nuclear fusion. Neutron yields from these high energy fusion shots expose the alignment cameras to neutron radiation. The present work explores modeling and predicting laser alignment performance degradation due to neutron radiation effects, and demonstrates techniques to mitigate performance degradation. Camera performance models have been created based on the measured camera noise from the cumulative single-shot fluence at the camera location. We have found that the effect of the neutron-generated noise for all shots to date have been well within the alignment tolerance of half a pixel, and image processing techniques can be utilized to reduce the effect even further on the beam alignment.

  18. Shock-Ignition Studies on OMEGA

    NASA Astrophysics Data System (ADS)

    Hohenberger, M.; Theobald, W.; Anderson, K. S.; Betti, R.; Meyerhofer, D. D.; Stoeckl, C.; Casner, A.; Ribeyre, X.; Schurtz, G.

    2010-11-01

    Recent theoretical workootnotetextR. Betti et al., Phys. Rev. Lett. 98, 155001 (2007) has shown that the gain in an inertial confinement fusion (ICF) experiment can be significantly increased through separation of the compression and ignition stage by launching a strong, spherically convergent shock at the end of a compression pulse. This scheme, referred to as shock ignition, reduces the energy required for ignition compared to ``conventional'' ICF or fast ignition. Through potentially relaxed requirements for the ignitor-shock spherical symmetry, it can be carried out in a polar-drive configuration and is therefore applicable to the National Ignition Facility. The results of a series of spherical and planar-target experiments on OMEGA to study the shock-ignition technique and to infer the shock strength, hot-electron generation, and light reflectivity at the high intensities relevant to shock ignition will be presented. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement Nos. DE-FC52-08NA28302 and DE-FC02-04ER54789.

  19. 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.

  20. 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.

  1. Scope of Work for Integration Management and Installation Services of the National Ignition Facility Beampath Infrastructure System

    SciTech Connect

    Coyle, P.D.

    2000-04-25

    The goal of the National Ignition Facility (NIF) project is to provide an aboveground experimental capability for maintaining nuclear competence and weapons effects simulation and to provide a facility capable of achieving fusion ignition using solid-state lasers as the energy driver. The facility will incorporate 192 laser beams, which will be focused onto a small target located at the center of a spherical target chamber--the energy from the laser beams will be deposited in a few billionths of a second. The target will then implode, forcing atomic nuclei to sufficiently high temperatures and densities necessary to achieve a miniature fusion reaction. The NIF is under construction, at Livermore, California, located approximately 50 miles southeast of San Francisco, California.

  2. Scope of Work for Integration Management and Installation Services of the National Ignition Facility Beampath Infrastructure System

    SciTech Connect

    Coyle, P.D.

    2000-03-19

    The goal of the National Ignition Facility (NIF) project is to provide an aboveground experimental capability for maintaining nuclear competence and weapons effects simulation and to provide a facility capable of achieving fusion ignition using solid-state lasers as the energy driver. The facility will incorporate 192 laser beams, which will be focused onto a small target located at the center of a spherical target chamber--the energy from the laser beams will be deposited in a few billionths of a second. The target will then implode, forcing atomic nuclei to sufficiently high temperatures and densities necessary to achieve a miniature fusion reaction. The NIF is under construction, at Livermore, California, located approximately 50 miles southeast of San Francisco, California.

  3. A novel method to recover DD fusion proton CR-39 data corrupted by fast ablator ions at OMEGA and the National Ignition Facility

    DOE PAGESBeta

    Sutcliffe, G. D.; Milanese, L. M.; Orozco, D.; Lahmann, B.; Gatu Johnson, M.; Séguin, F. H.; Sio, H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.; et al

    2016-08-05

    CR-39 detectors are used routinely in inertial confinement fusion (ICF) experiments as a part of nuclear diagnostics. CR-39 is filtered to stop fast ablator ions which have been accelerated from an ICF implosion due to electric fields caused by laser-plasma interactions. In some experiments, the filtering is insufficient to block these ions and the fusion-product signal tracks are lost in the large background of accelerated ion tracks. A technique for recovering signal in these scenarios has been developed, tested, and implemented successfully. The technique involves removing material from the surface of the CR-39 to a depth beyond the endpoint ofmore » the ablator ion tracks. The technique preserves signal magnitude (yield) as well as structure in radiograph images. The technique is effective when signal particle range is at least 10 μm deeper than the necessary bulk material removal.« less

  4. 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. PMID:23629062

  5. 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.

  6. Fusion applications of high power millimeter wave sources

    SciTech Connect

    Freeman, R.L.; George, T.V.

    1994-01-01

    Heating by means of high power electron cyclotron (EC) waves in the mm wavelength range is considered to be one of the most attractive approaches for heating fusion plasmas to the temperatures required to achieve ignition. EC waves have also been used to drive plasma current by using directional launch and to stabilize MHD instabilities in tokamak plasmas through localized heating or current drive. Experiments are planned on both JET and TFTR to measure the alpha particle distribution by scattering EC waves.

  7. Review of Progress in Fast Ignition

    SciTech Connect

    Tabak, M; Town, R; Lasinski, B; Snavely, R; Clark, D; Wilks, S; Key, M; Hatchett, S; Stevens, R; Campbell, E; Mima, K; Tanaka, K; Kodama, R; Atzeni, S

    2004-11-08

    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 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 the compressed fuel be efficiently assembled? And how can power from the driver be delivered to the ignition region? Schemes to shorten the distance between the critical surface and the ignition region will de discussed. The status of the project is compared with our requirements for success. Future research directions will be outlined.

  8. Generalized Lawson Criteria for Inertial Confinement Fusion

    SciTech Connect

    Tipton, Robert E.

    2015-08-27

    The Lawson Criterion was proposed by John D. Lawson in 1955 as a general measure of the conditions necessary for a magnetic fusion device to reach thermonuclear ignition. Over the years, similar ignition criteria have been proposed which would be suitable for Inertial Confinement Fusion (ICF) designs. This paper will compare and contrast several ICF ignition criteria based on Lawson’s original ideas. Both analytical and numerical results will be presented which will demonstrate that although the various criteria differ in some details, they are closely related and perform similarly as ignition criteria. A simple approximation will also be presented which allows the inference of each ignition parameter directly from the measured data taken on most shots fired at the National Ignition Facility (NIF) with a minimum reliance on computer simulations. Evidence will be presented which indicates that the experimentally inferred ignition parameters on the best NIF shots are very close to the ignition threshold.

  9. In-vessel remote maintenance of the Compact Ignition Tokamak

    SciTech Connect

    Tabor, M.A.; Hager, E.R.; Creedon, R.L.; Fisher, M.V.; Atkin, S.D.

    1987-01-01

    The Compact Ignition Tokamak (CIT) is the first deuterium-tritium (D-T) fusion device that will study the physics of an ignited plasma. The ability of the tokamak vacuum vessel to be maintained remotely while under vacuum has not been fully demonstrated on previous machines, and this ability will be critical to the efficient and safe operation of ignition devices. Although manned entry into the CIT vacuum vessel will be possible during the nonactivated stages of operation, remotely automated equipment will be used to assist in initial assembly of the vessel as well as to maintain all in-vessel components once the D-T burn is achieved. Remote maintenance and operation will be routinely required for replacement of thermal protection tiles, inspection of components, leak detection, and repair welding activities. Conceptual design to support these remote maintenance activities has been integrated with the conceptual design of the in-vessel components to provide a complete and practical remote maintenance system for CIT. The primary remote assembly and maintenance operations on CIT will be accomplished through two dedicated 37- x 100-cm ports on the main toroidal vessel. Each port contains a single articulated boom manipulator (ABM), which is capable of accessing half of the torus. The proposed ABM consists of a movable carriage assembly, telescoping two-part mast, and articulated link sections. 1 ref.

  10. Experiments and Computational Modeling of Pulverized-Clak Ignition.

    SciTech Connect

    Chen, J.C.

    1997-08-01

    Under typical conditions of pulverized-coal combustion, which is characterized by fine particles heated at very high rates, there is currently a lack of certainty regarding the ignition mechanism of bituminous and lower rank coals. It is unclear whether ignition occurs first at the particle-oxygen interface (heterogeneous ignition) or if it occurs in the gas phase due to ignition of the devolatilization products (homogeneous ignition). Furthermore, there have been no previous studies aimed at determining the dependence of the ignition mechanism on variations in experimental conditions, such as particle size, oxygen concentration, and heating rate. Finally, there is a need to improve current mathematical models of ignition to realistically and accurately depict the particle-to-particle variations that exist within a coal sample. Such a model is needed to extract useful reaction parameters from ignition studies, and to interpret ignition data in a more meaningful way. We propose to examine fundamental aspects of coal ignition through (1) experiments to determine the ignition mechanism of various coals by direct observation, and (2) modeling of the ignition process to derive rate constants and to provide a more insightful interpretation of data from ignition experiments. We propose to use a novel laser-based ignition experiment to achieve our objectives.

  11. Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition

    SciTech Connect

    Shimaoka, T. Kaneko, J. H.; Tsubota, M.; Arikawa, Y.; Nagai, T.; Kojima, S.; Abe, Y.; Sakata, S.; Fujioka, S.; Nakai, M.; Shiraga, H.; Azechi, H.; Isobe, M.; Sato, Y.; Chayahara, A.; Umezawa, H.; Shikata, S.

    2015-05-15

    A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 10{sup 7} cm/s and 1.0 ± 0.3 × 10{sup 7} cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5–1 keV and neutron yield of more than 10{sup 9} neutrons/shot.

  12. Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition

    NASA Astrophysics Data System (ADS)

    Shimaoka, T.; Kaneko, J. H.; Arikawa, Y.; Isobe, M.; Sato, Y.; Tsubota, M.; Nagai, T.; Kojima, S.; Abe, Y.; Sakata, S.; Fujioka, S.; Nakai, M.; Shiraga, H.; Azechi, H.; Chayahara, A.; Umezawa, H.; Shikata, S.

    2015-05-01

    A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 107 cm/s and 1.0 ± 0.3 × 107 cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5-1 keV and neutron yield of more than 109 neutrons/shot.

  13. Scaling laws for ignition at the National Ignition Facility from first principles.

    PubMed

    Cheng, Baolian; Kwan, Thomas J T; Wang, Yi-Ming; Batha, Steven H

    2013-10-01

    We have developed an analytical physics model from fundamental physics principles and used the reduced one-dimensional model to derive a thermonuclear ignition criterion and implosion energy scaling laws applicable to inertial confinement fusion capsules. The scaling laws relate the fuel pressure and the minimum implosion energy required for ignition to the peak implosion velocity and the equation of state of the pusher and the hot fuel. When a specific low-entropy adiabat path is used for the cold fuel, our scaling laws recover the ignition threshold factor dependence on the implosion velocity, but when a high-entropy adiabat path is chosen, the model agrees with recent measurements. PMID:24229109

  14. Toroidal Alfven wave stability in ignited tokamaks

    SciTech Connect

    Cheng, C.Z.; Fu, G.Y.; Van Dam, J.W.

    1989-01-01

    The effects of fusion-product alpha particles on the stability of global-type shear Alfven waves in an ignited tokamak plasma are investigated in toroidal geometry. Finite toroidicity can lead to stabilization of the global Alfven eigenmodes, but it induces a new global shear Alfven eigenmodes, which is strongly destabilized via transit resonance with alpha particles. 8 refs., 2 figs.

  15. Efficient acceleration of dense plasma bunches for fusion-related applications in the LICPA accelerator

    NASA Astrophysics Data System (ADS)

    Badziak, Jan; Jabłoński, Slawomir

    2014-05-01

    The results of particle-in-cell simulations of acceleration of carbon ions and a heavy (0.5 μg) gold micro-projectile in the laser-induced cavity pressure acceleration (LICPA) scheme at the conditions relevant to fast ignition of deuterium-tritium (DT) fusion are presented. It is shown that the LICPA accelerator employing a picosecond 100 kJ laser driver can produce quasi-monoenergetic carbon ion beams of parameters significantly higher than those achieved in the conventional radiation pressure acceleration (RPA) scheme and the beam parameters meet the ion fast ignition requirements fairly well. The LICPA accelerator can also efficiently accelerate the heavy micro-projectile to high velocities (> 5 × 108 cm s-1) required for the impact ignition of DT fusion and the acceleration efficiency for LICPA is almost an order of magnitude higher than that for RPA.

  16. 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.

  17. 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.

  18. UK fusion breakthrough revealed at last

    NASA Astrophysics Data System (ADS)

    Evans, Roger

    2010-03-01

    Fusion-energy research is commonly associated with huge toroidal magnetic devices such as JET and ITER, surrounded by even larger diagnostic systems and power supplies, all promising cheap energy in 30 years' time. However, increasing attention is now being paid to the complementary field of inertial-confinement fusion, thanks in part to the recent opening of the National Ignition Facility (NIF) in the US. It seeks to focus some 2 MJ of energy from 192 powerful lasers onto a tiny sphere containing deuterium and tritium nuclei, heating them up until they fuse. Having recently announced that they had made a crucial breakthrough in achieving this "laser fusion", researchers at NIF hope to have generated the conditions for a sustained nuclear reaction by the end of the year.

  19. Laser fusion

    SciTech Connect

    Smit, W.A.; Boskma, P.

    1980-12-01

    Unrestricted laser fusion offers nations an opportunity to circumvent arms control agreements and develop thermonuclear weapons. Early laser weapons research sought a clean radiation-free bomb to replace the fission bomb, but this was deceptive because a fission bomb was needed to trigger the fusion reaction and additional radioactivity was induced by generating fast neutrons. As laser-implosion experiments focused on weapons physics, simulating weapons effects, and applications for new weapons, the military interest shifted from developing a laser-ignited hydrogen bomb to more sophisticated weapons and civilian applications for power generation. Civilian and military research now overlap, making it possible for several countries to continue weapons activities and permitting proliferation of nuclear weapons. These countries are reluctant to include inertial confinement fusion research in the Non-Proliferation Treaty. 16 references. (DCK)

  20. Nova Upgrade: A proposed ICF facility to demonstrate ignition and gain, revision 1

    NASA Astrophysics Data System (ADS)

    1992-07-01

    The present objective of the national Inertial Confinement Fusion (ICF) Program is to determine the scientific feasibility of compressing and heating a small mass of mixed deuterium and tritium (DT) to conditions at which fusion occurs and significant energy is released. The potential applications of ICF will be determined by the resulting fusion energy yield (amount of energy produced) and gain (ratio of energy released to energy required to heat and compress the DT fuel). Important defense and civilian applications, including weapons physics, weapons effects simulation, and ultimately the generation of electric power will become possible if yields of 100 to 1,000 MJ and gains exceeding approximately 50 can be achieved. Once ignition and propagating bum producing modest gain (2 to 10) at moderate drive energy (1 to 2 MJ) has been achieved, the extension to high gain (greater than 50) is straightforward. Therefore, the demonstration of ignition and modest gain is the final step in establishing the scientific feasibility of ICF. Lawrence Livermore National Laboratory (LLNL) proposes the Nova Upgrade Facility to achieve this demonstration by the end of the decade. This facility would be constructed within the existing Nova building at LLNL for a total cost of approximately $400 M over the proposed FY 1995-1999 construction period. This report discusses this facility.

  1. Direct-drive laser fusion: status and prospects

    SciTech Connect

    Afeyan, B B; Bodner, S E; Gardner, J H; Knauer, J P; Lee, P; Lehmberg, R H; McCrory, R L; Obenschain, S P; Powell, H T; Schmitt, A J; Seka, W; Sethian, J D; Verdon, C P

    1998-01-14

    Techniques have been developed to improve the uniformity of the laser focal profile, to reduce the ablative Rayleigh-Taylor instability, and to suppress the various laser-plasma instabilities. There are now three direct-drive ignition target designs that utilize these techniques. Evaluation of these designs is still ongoing. Some of them may achieve the gains above 100 that are necessary for a fusion reactor. Two laser systems have been proposed that may meet all of the requirements for a fusion reactor.

  2. Relevance of advanced nuclear fusion research: Breakthroughs and obstructions

    NASA Astrophysics Data System (ADS)

    Coppi, Bruno

    2016-03-01

    An in depth understanding of the collective modes that can be excited in a wide range of high-energy plasmas is necessary to advance nuclear fusion research in parallel with other fields that include space and astrophysics in particular. Important achievements are shown to have resulted from implementing programs based on this reality, maintaining a tight connection with different areas of investigations. This involves the undertaking of a plurality of experimental approaches aimed at understanding the physics of fusion burning plasmas. At present, the most advanced among these is the Ignitor experiment involving international cooperation, that is designed to investigate burning plasma regimes near ignition for the first time.

  3. A Kirkpatrick-Baez microscope for the National Ignition Facility.

    PubMed

    Pickworth, L A; McCarville, T; Decker, T; Pardini, T; Ayers, J; Bell, P; Bradley, D; Brejnholt, N F; Izumi, N; Mirkarimi, P; Pivovaroff, M; Smalyuk, V; Vogel, J; Walton, C; Kilkenny, J

    2014-11-01

    Current pinhole x ray imaging at the National Ignition Facility (NIF) is limited in resolution and signal throughput to the detector for Inertial Confinement Fusion applications, due to the viable range of pinhole sizes (10-25 μm) that can be deployed. A higher resolution and throughput diagnostic is in development using a Kirkpatrick-Baez microscope system (KBM). The system will achieve <9 μm resolution over a 300 μm field of view with a multilayer coating operating at 10.2 keV. Presented here are the first images from the uncoated NIF KBM configuration demonstrating high resolution has been achieved across the full 300 μm field of view. PMID:25430187

  4. A Kirkpatrick-Baez microscope for the National Ignition Facility

    SciTech Connect

    Pickworth, L. A. McCarville, T.; Decker, T.; Pardini, T.; Ayers, J.; Bell, P.; Bradley, D.; Brejnholt, N. F.; Izumi, N.; Mirkarimi, P.; Pivovaroff, M.; Smalyuk, V.; Vogel, J.; Walton, C.; Kilkenny, J.

    2014-11-15

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

  5. Systems reliability analysis for the national ignition facility

    SciTech Connect

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

    1996-06-12

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

  6. Sandia National Laboratories participation in the National Ignition Facility project

    SciTech Connect

    Boyes, J.; Boyer, W.; Chael, J.; Cook, D.; Cook, W.; Downey, T.; Hands, J.; Harjes, C.; Leeper, R.; McKay, P.; Micano, P.; Olson, R.; Porter, J.; Quintenz, J.; Roberts, V.; Savage, M.; Simpson, W.; Seth, A.; Smith, R.; Wavrik, M.; Wilson, M.

    1996-08-01

    The National Ignition Facility is a $1.1B DOE Defense Programs Inertial Confinement Fusion facility supporting the Science Based Stockpile Stewardship Program. The goal of the facility is to achieve fusion ignition and modest gain in the laboratory. The NIF project is responsible for the design and construction of the 192 beam, 1.8 MJ laser necessary to meet that goal. - The project is a National project with participation by Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Sandia National Laboratory (SNL), the University of Rochester Laboratory for Laser Energetics (URLLE) and numerous industrial partners. The project is centered at LLNL which has extensive expertise in large solid state lasers. The other partners in the project have negotiated their participation based on the specific expertise they can bring to the project. In some cases, this negotiation resulted in the overall responsibility for a WBS element; in other cases, the participating laboratories have placed individuals in the project in areas that need their individual expertise. The main areas of Sandia`s participation are in the management of the conventional facility design and construction, the design of the power conditioning system, the target chamber system, target diagnostic instruments, data acquisition system and several smaller efforts in the areas of system integration and engineering analysis. Sandia is also contributing to the technology development necessary to support the project by developing the power conditioning system and several target diagnostics, exploring alternate target designs, and by conducting target experiments involving the ``foot`` region of the NIF power pulse. The project has just passed the mid-point of the Title I (preliminary) design phase. This paper will summarize Sandia`s role in supporting the National Ignition Facility and discuss the areas in which Sandia is contributing. 3 figs.

  7. Mini-fission fusion explosive devices (mini-nukes) for nuclear pulse propulsion

    NASA Astrophysics Data System (ADS)

    Winterberg, F.

    2005-11-01

    Nuclear pulse propulsion demands low-yield nuclear explosive devices. Because the critical mass of a fission explosive is rather large, this leads to extravagant fission devices with a very low fuel burn-up. For non-fission ignited pure fusion microexplosions the problem is the large ignition apparatus (laser, particle beam, etc.). Fission ignited large fusion explosive devices are for obvious reasons even less desirable. A third category (mini-nukes) are devices where the critical mass of the fission explosive is substantially reduced by its coupling to a DT fusion reaction, with the DT fusion neutrons increasing the fission rate. Whereas in pure fission devices a reduction of the critical mass is achieved by the implosive compression of the fissile core with a chemical high explosive, in the third category the implosion must at the same time heat the DT surrounding the fissile core to a temperature of ⩾107K, at which enough fusion neutrons are generated to increase the fission rate which in turn further increases the temperature and fusion neutron production rate. As has been shown by the author many years ago, such mini-nukes lead to astonishingly small critical masses. In their application to nuclear pulse propulsion the combustion products from the chemical high explosive are further heated by the neutrons and are becoming part of the propellant.

  8. Capsule performance optimization in the National Ignition Campaign

    SciTech Connect

    Landen, O. L.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Michel, P.; Milovich, J.; Munro, D. H.; Robey, H. F.; Spears, B. K.; Thomas, C. A.

    2010-05-15

    A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

  9. Capsule performance optimization in the National Ignition Campaigna)

    NASA Astrophysics Data System (ADS)

    Landen, O. L.; Boehly, T. R.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Hoffman, N.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Kyrala, G. A.; Michel, P.; Milovich, J.; Munro, D. H.; Nikroo, A.; Olson, R. E.; Robey, H. F.; Spears, B. K.; Thomas, C. A.; Weber, S. V.; Wilson, D. C.; Marinak, M. M.; Suter, L. J.; Hammel, B. A.; Meyerhofer, D. D.; Atherton, J.; Edwards, J.; Haan, S. W.; Lindl, J. D.; MacGowan, B. J.; Moses, E. I.

    2010-05-01

    A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

  10. 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.

  11. Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition.

    PubMed

    Shimaoka, T; Kaneko, J H; Arikawa, Y; Isobe, M; Sato, Y; Tsubota, M; Nagai, T; Kojima, S; Abe, Y; Sakata, S; Fujioka, S; Nakai, M; Shiraga, H; Azechi, H; Chayahara, A; Umezawa, H; Shikata, S

    2015-05-01

    A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 10(7) cm/s and 1.0 ± 0.3 × 10(7) cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5-1 keV and neutron yield of more than 10(9) neutrons/shot. PMID:26026521

  12. Electrostatic-discharge ignition

    NASA Technical Reports Server (NTRS)

    Stephens, J. B.; Miller, C. G.

    1977-01-01

    Electrode in cylinder permits charge to transfer during top dead center compression stroke in modified Otto-cycle engine. Charge transfer produces spark which causes ignition of droplets without resorting to other ignition devices which are incapable of igniting ultralean mixtures.

  13. 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.

  14. Novel characterization of capsule x-ray drive at the National Ignition Facility.

    PubMed

    MacLaren, S A; Schneider, M B; Widmann, K; Hammer, J H; Yoxall, B E; Moody, J D; Bell, P M; Benedetti, L R; Bradley, D K; Edwards, M J; Guymer, T M; Hinkel, D E; Hsing, W W; Kervin, M L; Meezan, N B; Moore, A S; Ralph, J E

    2014-03-14

    Indirect drive experiments at the National Ignition Facility are designed to achieve fusion by imploding a fuel capsule with x rays from a laser-driven hohlraum. Previous experiments have been unable to determine whether a deficit in measured ablator implosion velocity relative to simulations is due to inadequate models of the hohlraum or ablator physics. ViewFactor experiments allow for the first time a direct measure of the x-ray drive from the capsule point of view. The experiments show a 15%-25% deficit relative to simulations and thus explain nearly all of the disagreement with the velocity data. In addition, the data from this open geometry provide much greater constraints on a predictive model of laser-driven hohlraum performance than the nominal ignition target. PMID:24679301

  15. Laser induced ignition

    NASA Astrophysics Data System (ADS)

    Liedl, G.; Schuöcker, D.; Geringer, B.; Graf, J.; Klawatsch, D.; Lenz, H. P.; Piock, W. F.; Jetzinger, M.; Kapus, P.

    2007-05-01

    Nowadays, combustion engines and other combustion processes play an overwhelming and important role in everyday life. As a result, ignition of combustion processes is of great importance, too. Usually, ignition of a combustible material is defined in such a way that an ignition initiates a self-sustained reaction which propagates through the inflammable material even in the case that the ignition source has been removed. In most cases, a well defined ignition location and ignition time is of crucial importance. Spark plugs are well suited for such tasks but suffer from some disadvantages, like erosion of electrodes or restricted positioning possibilities. In some cases, ignition of combustible materials by means of high power laser pulses could be beneficial. High power lasers offer several different possibilities to ignite combustible materials, like thermal ignition, resonant ignition or optical breakdown ignition. Since thermal and resonant ignitions are not well suited on the requirements mentioned previously, only optical breakdown ignition will be discussed further. Optical breakdown of a gas within the focal spot of a high power laser allows a very distinct localization of the ignition spot in a combustible material. Since pulse duration is usually in the range of several nanoseconds, requirements on the ignition time are fulfilled easily, too. Laser peak intensities required for such an optical breakdown are in the range of 10 11 W/cm2. The hot plasma which forms during this breakdown initiates the following self-propagating combustion process. It has been shown previously that laser ignition of direct injection engines improves the fuel consumption as well as the exhaust emissions of such engines significantly. The work presented here gives a brief overview on the basics of laser induced ignition. Flame propagation which follows a successful ignition event can be distinguished into two diffrent regimes. Combustion processes within an engine are usually

  16. 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.

  17. 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.

  18. Simulations of electron transport and ignition for direct-drive fast-ignition targets

    NASA Astrophysics Data System (ADS)

    Solodov, A. A.; Anderson, K. S.; Betti, R.; Gotcheva, V.; Myatt, J.; Delettrez, J. A.; Skupsky, S.; Theobald, W.; Stoeckl, C.

    2008-11-01

    The performance of high-gain, fast-ignition fusion targets is investigated using one-dimensional hydrodynamic simulations of implosion and two-dimensional (2D) hybrid fluid-particle simulations of hot-electron transport, ignition, and burn. The 2D/3D hybrid-particle-in-cell code LSP [D. R. Welch et al., Nucl. Instrum. Methods Phys. Res. A 464, 134 (2001)] and the 2D fluid code DRACO [P. B. Radha et al., Phys. Plasmas 12, 056307 (2005)] are integrated to simulate the hot-electron transport and heating for direct-drive fast-ignition targets. LSP simulates the transport of hot electrons from the place where they are generated to the dense fuel core where their energy is absorbed. DRACO includes the physics required to simulate compression, ignition, and burn of fast-ignition targets. The self-generated resistive magnetic field is found to collimate the hot-electron beam, increase the coupling efficiency of hot electrons with the target, and reduce the minimum energy required for ignition. Resistive filamentation of the hot-electron beam is also observed. The minimum energy required for ignition is found for hot electrons with realistic angular spread and Maxwellian energy-distribution function.

  19. Direct-Drive Inertial Fusion Research at the University of Rochester's Laboratory for Laser Energetics: A Review

    SciTech Connect

    McCrory, R.L.; Meyerhofer, D.D.; Loucks, S.J.; Skupsky, S.; Bahr, R.E.; Betti, R.; Boehly, T.R.; Craxton, R.S.; Collins, T.J.B.; Delettrez, J.A.; Donaldson, W.R.; Epstein, R.; Fletcher, K.A.; Freeman, C.; Frenje, J.A.; Glebov, V.Yu.; Goncharov, V.N.; Harding, D.R.; Jaanimagi, P.A.; Keck, R.L.; Kelly, J.H.; Kessler, T.J.; Kilkenny, J.D.; Knauer, J.P.; Li, C.K.; Lund, L.D.; Marozas, J.A.; McKenty, P.W.; Marshall, F.J.; Morse, S.F.B.; Padalino, S.; Petrasso, R.D.; Radha, P.B.; Regan, S.P.; Roberts, S.; Sangster, T.C.; Seguin, F.H.; Seka, W.; Smalyuk, V.A.; Soures, J.M.; Stoeckl, C.; Thorp, K.A.; Yaakobi, B.; Zuegel, J.D.

    2010-04-16

    This paper reviews the status of direct-drive inertial confinement fusion (ICF) research at the University of Rochester's Laboratory for Laser Energetics (LLE). LLE's goal is to demonstrate direct-drive ignition on the National Ignition Facility (NIF) by 2014. Baseline "all-DT" NIF direct-drive ignition target designs have been developed that have a predicted gain of 45 (1-D) at a NIF drive energy of ~1.6 MJ. Significantly higher gains are calculated for targets that include a DT-wicked foam ablator. This paper also reviews the results of both warm fuel and initial cryogenic-fuel spherical target implosion experiments carried out on the OMEGA UV laser. The results of these experiments and design calculations increase confidence that the NIF direct-drive ICF ignition goal will be achieved.

  20. Igniters for Liquid Oxygen/Liquid Methane Technology Development

    NASA Technical Reports Server (NTRS)

    Osborne, Robin J.; Elam, Sandra K.; Peschel, William P.

    2008-01-01

    As part of NASA's technology development of liquid methane / liquid oxygen engines for future exploration missions, two different igniters were recently studied at NASA Marshall Space Flight Center. The first igniter tested was an impinging injection, spark-initiated torch igniter, and the second was a microwave-generated plasma igniter. The purpose of the ignition tests was to define the ignition limits under vacuum conditions and characterize the transient start-up performance as a function of propellant mixture ratio (MR), mass flow rates, inlet temperatures, and pre-ignition chamber pressure. In addition, for the impinging igniter two different spark plugs were tested, and for the microwave igniter the magnetron filament warm-up time and the magnetron input power were both varied. The results gathered from these tests indicated that the impinging igniter is capable of operating over an MR range of 2 - 27, with methane and oxygen inlet temperatures as low as -161 F and -233 F, respectively. The microwave igniter was tested over an MR range of 2 - 9, with methane and oxygen inlet temperatures as low as -90 F and -200 F, respectively. The microwave igniter achieved ignition over this range, although an upper ignition limit was determined for the oxidizer mass flow rate. In general, the torch exhaust temperatures for the microwave igniter were not as high as those attained with the impinging igniter. The microwave igniter, however, was hot-fired 17 times and was still operational, whereas the impinging igniter spark plugs experienced thermal shock and erosion over nine hot-fire tests. It was concluded that for the microwave igniter better mixing of the propellants might be required in order to both raise the torch exhaust temperature and decrease the required magnetron input power, and for the impinging igniter the spark plug position within the igniter chamber should be varied in future tests to identify a more optimal location. All of the igniter tests were

  1. 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.

  2. 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.

  3. Isochoric Implosions for Fast Ignition

    SciTech Connect

    Clark, D S; Tabak, M

    2007-04-04

    Various gain models have shown the potentially great advantages of Fast Ignition (FI) Inertial Confinement Fusion (ICF) over its conventional hot spot ignition counterpart [e.g., S. Atzeni, Phys. Plasmas 6, 3316 (1999); M. Tabak et al., Fusion Sci. & Technology 49, 254 (2006)]. These gain models, however, all assume nearly uniform-density fuel assemblies. In contrast, conventional ICF implosions yield hollowed fuel assemblies with a high-density shell of fuel surrounding a low-density, high-pressure hot spot. Hence, to realize fully the advantages of FI, an alternative implosion design must be found which yields nearly isochoric fuel assemblies without substantial hot spots. 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 yield precisely such quasi-isochoric imploded states. The difficulty remains, however, of accessing these self-similarly imploding configurations from initial conditions representing an actual ICF target, namely a uniform, solid-density shell at rest. Furthermore, these specialized implosions must be realized for practicable drive parameters and at the scales and energies of interest in ICF. A direct-drive implosion scheme is presented which meets all of these requirements and reaches a nearly isochoric assembled density of 300 g=cm{sup 3} and areal density of 2.4 g=cm{sup 2} using 485 kJ of laser energy.

  4. Discharge ignition behavior of the Space Station plasma contactor

    NASA Technical Reports Server (NTRS)

    Sarver-Verhey, Timothy R.; Hamley, John A.

    1995-01-01

    Ignition testing of hollow cathode assemblies being developed for the Space Station plasma contactor system has been initiated to validate reliable multiple restart capability. An ignition approach was implemented that was derived from an earlier arcjet program that successfully demonstrated over 11,600 ignitions. For this, a test profile was developed to allow accelerated cyclic testing at expected operating conditions. To date, one hollow cathode assembly has been used to demonstrate multiple ignitions. A prototype hollow cathode assembly has achieved 3,615 successful ignitions at a nominal anode voltage of 18.0 V. During the ignition testing several parameters were investigated, of which the heater power and pre-heat time were the only parameters found to significantly impact ignition rate.

  5. Achieving Accuracy Requirements for Forest Biomass Mapping: A Data Fusion Method for Estimating Forest Biomass and LiDAR Sampling Error with Spaceborne Data

    NASA Technical Reports Server (NTRS)

    Montesano, P. M.; Cook, B. D.; Sun, G.; Simard, M.; Zhang, Z.; Nelson, R. F.; Ranson, K. J.; Lutchke, S.; Blair, J. B.

    2012-01-01

    The synergistic use of active and passive remote sensing (i.e., data fusion) demonstrates the ability of spaceborne light detection and ranging (LiDAR), synthetic aperture radar (SAR) and multispectral imagery for achieving the accuracy requirements of a global forest biomass mapping mission. This data fusion approach also provides a means to extend 3D information from discrete spaceborne LiDAR measurements of forest structure across scales much larger than that of the LiDAR footprint. For estimating biomass, these measurements mix a number of errors including those associated with LiDAR footprint sampling over regional - global extents. A general framework for mapping above ground live forest biomass (AGB) with a data fusion approach is presented and verified using data from NASA field campaigns near Howland, ME, USA, to assess AGB and LiDAR sampling errors across a regionally representative landscape. We combined SAR and Landsat-derived optical (passive optical) image data to identify forest patches, and used image and simulated spaceborne LiDAR data to compute AGB and estimate LiDAR sampling error for forest patches and 100m, 250m, 500m, and 1km grid cells. Forest patches were delineated with Landsat-derived data and airborne SAR imagery, and simulated spaceborne LiDAR (SSL) data were derived from orbit and cloud cover simulations and airborne data from NASA's Laser Vegetation Imaging Sensor (L VIS). At both the patch and grid scales, we evaluated differences in AGB estimation and sampling error from the combined use of LiDAR with both SAR and passive optical and with either SAR or passive optical alone. This data fusion approach demonstrates that incorporating forest patches into the AGB mapping framework can provide sub-grid forest information for coarser grid-level AGB reporting, and that combining simulated spaceborne LiDAR with SAR and passive optical data are most useful for estimating AGB when measurements from LiDAR are limited because they minimized

  6. Radiochemistry diagnostics for the National Ignition Facility

    SciTech Connect

    Hoffman, R D; Cerjan, C J; Shaughnessy, D A; Moody, K J; Nelson, S L; Bernstein, L A; Stoyer, M A; Fortner, R J; Schneider, D H

    2010-02-22

    Radiochemistry-based techniques will be an important complement to x-ray implosion diagnostics. Simulations demonstrate the value of alpha-induced or deuteron-induced reactions as a direct measurement of static mix contamination in DT-filled ignition capsules. In this proceedings we examine to what extent neutron-induced reactions might be highly correlated with the energetically down-scattered neutron fraction which is, in turn, related to the critical quantity of fuel areal density, {rho}R. Although alpha and deuteron reactions are highly suppressed in HT/D-filled capsules, neutron-induced reactions produce robust abundances and 2% measurements of the relevant radiological ratios is achievable. We conclude that radiochemical data are strongly correlated with the down-scattered fraction and fuel areal density. Unknown physics, primarily uncertainties in the direct T-T fusion neutron cross section and, to a lesser extent, various radiochemical production cross sections are important but calibration shots can be used to reduce these errors. The primary advantage of radiochemistry remains - it is the only technique that samples down-scattered neutrons from the entire capsule during the burn. In particular radiochemistry correlated with other diagnostics can be used to minimize experimental uncertainties and thus maximize gain.

  7. 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.

  8. Ignition of Cellulosic Paper at Low Radiant Fluxes

    NASA Technical Reports Server (NTRS)

    White, K. Alan

    1996-01-01

    The ignition of cellulosic paper by low level thermal radiation is investigated. Past work on radiative ignition of paper is briefly reviewed. No experimental study has been reported for radiative ignition of paper at irradiances below 10 Watts/sq.cm. An experimental study of radiative ignition of paper at these low irradiances is reported. Experimental parameters investigated and discussed include radiant power levels incident on the sample, the method of applying the radiation (focussed vs. diffuse Gaussian source), the presence and relative position of a separate pilot ignition source, and the effects of natural convection (buoyancy) on the ignition process in a normal gravity environment. It is observed that the incident radiative flux (in W/sq.cm) has the greatest influence on ignition time. For a given flux level, a focussed Gaussian source is found to be advantageous to a more diffuse, lower amplitude, thermal source. The precise positioning of a pilot igniter relative to gravity and to the fuel sample affects the ignition process, but the precise effects are not fully understood. Ignition was more readily achieved and sustained with a horizontal fuel sample, indicating the buoyancy plays a role in the ignition process of cellulosic paper. Smoldering combustion of doped paper samples was briefly investigated, and results are discussed.

  9. 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

  10. Assessment of Potential for Ion Driven Fast Ignition

    SciTech Connect

    Logan, B. Grant; Bangerter, Roger O.; Callahan, Debra A.; Tabak, Max; Roth, Markus; Perkins, L. John; Caporaso, George

    2004-12-01

    Critical issues and ion beam requirements are explored for fast ignition using ion beams to provide fuel compression using indirect drive and to provide separate short pulse ignition heating using direct drive. Several ion species with different hohlraum geometries are considered for both accelerator-produced and laser-produced ion ignition beams. Ion-driven fast ignition targets are projected to have modestly higher gains than with conventional heavy-ion fusion, and may offer some other advantages for target fabrication and for use of advanced fuels. However, much more analysis and experiments are needed before conclusions can be drawn regarding the feasibility for meeting the ion beam transverse and longitudinal emittances, focal spots, pulse lengths, and target standoff distances required for ion-driven fast ignition.

  11. Assessment of Potential for Ion Driven Fast Ignition

    SciTech Connect

    Logan, B. Grant; Bangerter, Roger O.; Callahan, Debra A.; Tabak,Max; Roth, Markus; Perkins, L. John; Caporaso, George

    2005-05-01

    Critical issues and ion beam requirements are explored for fast ignition using ion beams to provide fuel compression using indirect drive and to provide separate short pulse ignition heating using direct drive. Several ion species with different hohlraum geometries are considered for both accelerator-produced and laser-produced ion ignition beams. Ion-driven fast ignition targets are projected to have modestly higher gains than with conventional heavy-ion fusion, and may offer some other advantages for target fabrication and for use of advanced fuels. However, much more analysis and experiments are needed before conclusions can be drawn regarding the feasibility for meeting the ion beam transverse and longitudinal emittances, focal spots, pulse lengths, and target stand-off distances required for ion-driven fast ignition.

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

    SciTech Connect

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

    2014-05-01

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

  13. Flare ignition system

    SciTech Connect

    Sorelle, R.R.

    1984-05-22

    A flare ignition system is claimed for oil well flaring of combustible gases. It includes a central control unit, low voltage interconnect line and plural remote igniter units which include alternate first and second spark gaps coordinated in fail-safe operation. Coordination is carried out by pulse counting and validating circuitry which assures that one of the spark gaps will always be ignitable or alarm condition will exist.

  14. The National Ignition Facility: Status and Plans for the Experimental Program

    SciTech Connect

    Moses, E I

    2002-11-12

    The National Ignition Facility (NIF), currently under construction at the University of California's Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, 351-nm laser system and a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. NIF is being built by the National Nuclear Security Administration and when completed will be the world's largest laser experimental system, providing a national center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF's 192 energetic laser beams will compress fusion targets to conditions where they will ignite and burn, liberating more energy than required to initiate the fusion reactions. NIF experiments will allow the study of physical processes at temperatures approaching 100 million K and 100 billion times atmospheric pressure. These conditions exist naturally only in the interior of stars and in nuclear weapons explosions. In the course of designing the world's most energetic laser system, a number of significant technology breakthroughs have been achieved. NIF is now entering the first phases of its laser commissioning program. Low-energy preamplifier rod laser shots have been successfully propagated through the entire laser chain. Higher energy shots are planned through the end of 2002. NIF's target experimental systems are also being installed in preparation for laser performance and experimental capability commissioning starting in 2003.

  15. Laser design basis for the National Ignition Facility

    SciTech Connect

    Hunt, J.T.; Manes, K.R.; Murray, J.R.; Renard, P.A.; Sawicki, R.; Trenholme, J.B.; Williams, W.

    1994-06-01

    Controlled nuclear fusion initiated by highly intense laser beams has been the subject of experiment for many years. The National Ignition Facility (NIF) represents the culmination of design efforts to provide a laser facility that will successfully demonstrate fusion ignition in the laboratory. In this so-called inertial confinement approach, energetic driver beams (laser, X-ray, or charged particle) heat the outer surface of a spherical capsule containing deuterium and tritium (DT) fuel. As the capsule surface explosively evaporates, reaction pressure compresses the DT fuel causing the central core of the fuel to reach extreme density and temperature. When the central temperature is high enough, DT fusion reactions occur. The energy released from these reactions further heats the compressed fuel, and fusion burn propagates outward through the colder regions of the capsule much more rapidly than the inertially confined capsule can expand. The resulting fusion reactions yield many times more energy than was absorbed from the driver beams.

  16. 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.

  17. 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.

  18. 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. PMID:24593362

  19. 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.

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

    SciTech Connect

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

    2014-02-15

    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.

  1. Indirect-Drive Noncryogenic Double-Shell Ignition Targets for the National Ignition Facility: Design and Analysis

    SciTech Connect

    Amendt, P.; Colvin, J.; Tipton, R.E.; Hinkel, D.; Edwards, J.J.; Landen, O.I.; Ramshaw, J.D.; Suter, L.J.; Watt, W.G.

    2001-10-15

    , indicates a possibility of achieving ignition, i.e., fusion yields greater than 1 MJ. Planned experiments on the Omega laser to test current understanding of high-energy radiation flux asymmetry and mix-induced yield degradation in double-shell targets are described.

  2. Point design targets, specifications, and requirements for the 2010 ignition campaign on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Haan, S. W.; Lindl, J. D.; Callahan, D. A.; Clark, D. S.; Salmonson, J. D.; Hammel, B. A.; Atherton, L. J.; Cook, R. C.; Edwards, M. J.; Glenzer, S.; Hamza, A. V.; Hatchett, S. P.; Herrmann, M. C.; Hinkel, D. E.; Ho, D. D.; Huang, H.; Jones, O. S.; Kline, J.; Kyrala, G.; Landen, O. L.; MacGowan, B. J.; Marinak, M. M.; Meyerhofer, D. D.; Milovich, J. L.; Moreno, K. A.; Moses, E. I.; Munro, D. H.; Nikroo, A.; Olson, R. E.; Peterson, K.; Pollaine, S. M.; Ralph, J. E.; Robey, H. F.; Spears, B. K.; Springer, P. T.; Suter, L. J.; Thomas, C. A.; Town, R. P.; Vesey, R.; Weber, S. V.; Wilkens, H. L.; Wilson, D. C.

    2011-05-01

    Point design targets have been specified for the initial ignition campaign on the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)]. The targets contain D-T fusion fuel in an ablator of either CH with Ge doping, or Be with Cu. These shells are imploded in a U or Au hohlraum with a peak radiation temperature set between 270 and 300 eV. Considerations determining the point design include laser-plasma interactions, hydrodynamic instabilities, laser operations, and target fabrication. Simulations were used to evaluate choices, and to define requirements and specifications. Simulation techniques and their experimental validation are summarized. Simulations were used to estimate the sensitivity of target performance to uncertainties and variations in experimental conditions. A formalism is described that evaluates margin for ignition, summarized in a parameter the Ignition Threshold Factor (ITF). Uncertainty and shot-to-shot variability in ITF are evaluated, and sensitivity of the margin to characteristics of the experiment. The formalism is used to estimate probability of ignition. The ignition experiment will be preceded with an experimental campaign that determines features of the design that cannot be defined with simulations alone. The requirements for this campaign are summarized. Requirements are summarized for the laser and target fabrication.

  3. Reaching ignition in the tokamak

    SciTech Connect

    Furth, H.P.

    1985-06-01

    This review covers the following areas: (1) the physics of burning plasmas, (2) plasma physics requirements for reaching ignition, (3) design studies for ignition devices, and (4) prospects for an ignition project. (MOW)

  4. Deceleration Phase of Inertial Confinement Fusion Implosions

    NASA Astrophysics Data System (ADS)

    Betti, R.

    2001-10-01

    In inertial confinement fusion (ICF) implosions, a spherical shell of cryogenic deuterium and tritium (DT) filled with DT gas is accelerated by direct laser irradiation (direct drive) or x-rays produced by a high-Z enclosure (indirect drive). Hydrodynamic instabilities, growing on the outer shell surface during the acceleration phase, cause the outer nonuniformities to feed through the shell onto the inner surface. As the shell starts to decelerate, the inner surface is unstable to the Rayleigh-Taylor instability and the inner surface nonuniformities grow exponentially in time, causing the cold shell material to penetrate and cool the hot spot. Such a cooling could prevent the hot spot from achieving the ignition conditions. We have developed a model to study the deceleration phase of imploding capsules, including the onset of ignition. The model yields all the hot-spot profiles and the hydrodynamic parameters of interest to the deceleration phase instability: ablation velocity [Ref.1] off the shell's inner surface, density-gradient scale length, and deceleration. It is shown [Ref. 1] that the growth rates of the deceleration-phase instability are significantly reduced by the finite ablative flow and the unstable spectrum exhibits a cutoff at short wavelengths. For a direct-drive NIF-like capsule, the cutoff mode number occurs for l ~= 90. The marginal ignition scaling law of Ref. 2 is also recovered analytically. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC03-92SF19460. [1] V. Lobatchev and R. Betti, Phys. Rev. Lett. 85, 4522 (2000); [2] M. C. Herrmann, M. Tabak, and J. D. Lindl, Nucl. Fusion 41, 99 (2001).

  5. Realizing Technologies for Magnetized Target Fusion

    SciTech Connect

    Wurden, Glen A.

    2012-08-24

    Researchers are making progress with a range of magneto-inertial fusion (MIF) concepts. All of these approaches use the addition of a magnetic field to a target plasma, and then compress the plasma to fusion conditions. The beauty of MIF is that driver power requirements are reduced, compared to classical inertial fusion approaches, and simultaneously the compression timescales can be longer, and required implosion velocities are slower. The presence of a sufficiently large Bfield expands the accessibility to ignition, even at lower values of the density-radius product, and can confine fusion alphas. A key constraint is that the lifetime of the MIF target plasma has to be matched to the timescale of the driver technology (whether liners, heavy ions, or lasers). To achieve sufficient burn-up fraction, scaling suggests that larger yields are more effective. To handle the larger yields (GJ level), thick liquid wall chambers are certainly desired (no plasma/neutron damage materials problem) and probably required. With larger yields, slower repetition rates ({approx}0.1-1 Hz) for this intrinsically pulsed approach to fusion are possible, which means that chamber clearing between pulses can be accomplished on timescales that are compatible with simple clearing techniques (flowing liquid droplet curtains). However, demonstration of the required reliable delivery of hundreds of MJ of energy, for millions of pulses per year, is an ongoing pulsed power technical challenge.

  6. 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.

  7. Reactor for boron fusion with picosecond ultrahigh power laser pulses and ultrahigh magnetic field trapping

    NASA Astrophysics Data System (ADS)

    Miley, G. H.; Hora, H.; Kirchhoff, G.

    2016-05-01

    Compared with the deuterium tritium (DT) fusion, the environmentally clean fusion of protons with 11B is extremely difficult. When instead of nanosecond laser pulses for thermal-ablating driven ignition, picosecond pulses are used, a drastic change by nonlinearity results in ultrahigh acceleration of plasma blocks. This radically changes to economic boron fusion by a measured new avalanche ignition.

  8. Dropwise ignition versus external ignition for multicomponent fuel sprays

    NASA Astrophysics Data System (ADS)

    Mawid, M.; Aggarwal, S. K.

    1988-07-01

    An attempt has been made to identify conditions for dropwise ignition and spray ignition. Both pure as well as multicomponent fuels are considered. For dropwise ignition, an existing ignition criterion has been modified to account for the nonlinear dependence of reaction rate on fuel and oxygen concentrations and to account for the multicomponent nature of the fuel. The external or spray ignition is considered through the zero heat flux condition at the ignition source. The effect of chemical kinetics is examined by employing reaction schemes with unity as well as non-unity exponents of fuel and oxygen concentrations. Results indicate that for most of the conditions considered, the individual droplet ignition is favored over the external ignition. Only when the drop diameter is smaller than 30 microns, the spray ignites earlier than droplets. The addition of a small amount of a volatile component significantly enhances the ignitability of both modes. However, the effect is stronger for the dropwise ignition mode.

  9. 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.

  10. MINIMARS: an attractive small tandem mirror fusion reactor

    SciTech Connect

    Perkins, L.J.; Logan, B.G.; Doggett, J.N.; Devoto, R.S.; Nelson, W.D.; Lousteau, D.C.; Kulcinski, G.L.; Santarius, J.F.; Gordon, J.D.; Campbell, R.B.

    1985-11-13

    Through the innovative design of a novel end plug scheme employing octopole MHD stabilization, we present the conceptual design of ''MIMIMARS'', a small commercial fusion reactor based on the tandem mirror principle. The current baseline for MINIMARS has a net electric output of 600 MWe and we have configured the design for short construction times, factory-built modules, inherently safe blanket systems, and multiplexing in station sizes of approx. 600 to 2400 MWe. We demonstrate that the compact octopole end cell provides a number of advantages over the more conventional quadrupole (yin-yang) end cell encountered in the MARS tandem mirror reactor study, and enables ignition to be achieved with much shorter central cell lengths. Accordingly, being economic in small sizes, MINIMARS provides an attractive alternative to the more conventional larger conceptual fusion reactors encountered to date, and would contribute significantly to the lowering of utility financial risk in a developing fusion economy.

  11. Status Of The National Ignition Campaign And National Ignition Facility Integrated Computer Control System

    SciTech Connect

    Lagin, L; Brunton, G; Carey, R; Demaret, R; Fisher, J; Fishler, B; Ludwigsen, P; Marshall, C; Reed, R; Shelton, R; Townsend, S

    2011-03-18

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility that will contains 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. NIF is operated by the Integrated Computer Control System (ICCS) in an object-oriented, CORBA-based system distributed among over 1800 frontend processors, embedded controllers and supervisory servers. In the fall of 2010, a set of experiments began with deuterium and tritium filled targets as part of the National Ignition Campaign (NIC). At present, all 192 laser beams routinely fire to target chamber center to conduct fusion and high energy density experiments. During the past year, the control system was expanded to include automation of cryogenic target system and over 20 diagnostic systems to support fusion experiments were deployed and utilized in experiments in the past year. This talk discusses the current status of the NIC and the plan for controls and information systems to support these experiments on the path to ignition.

  12. 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.

  13. Multi-focus image fusion algorithm based on adaptive PCNN and wavelet transform

    NASA Astrophysics Data System (ADS)

    Wu, Zhi-guo; Wang, Ming-jia; Han, Guang-liang

    2011-08-01

    Being an efficient method of information fusion, image fusion has been used in many fields such as machine vision, medical diagnosis, military applications and remote sensing. In this paper, Pulse Coupled Neural Network (PCNN) is introduced in this research field for its interesting properties in image processing, including segmentation, target recognition et al. and a novel algorithm based on PCNN and Wavelet Transform for Multi-focus image fusion is proposed. First, the two original images are decomposed by wavelet transform. Then, based on the PCNN, a fusion rule in the Wavelet domain is given. This algorithm uses the wavelet coefficient in each frequency domain as the linking strength, so that its value can be chosen adaptively. Wavelet coefficients map to the range of image gray-scale. The output threshold function attenuates to minimum gray over time. Then all pixels of image get the ignition. So, the output of PCNN in each iteration time is ignition wavelet coefficients of threshold strength in different time. At this moment, the sequences of ignition of wavelet coefficients represent ignition timing of each neuron. The ignition timing of PCNN in each neuron is mapped to corresponding image gray-scale range, which is a picture of ignition timing mapping. Then it can judge the targets in the neuron are obvious features or not obvious. The fusion coefficients are decided by the compare-selection operator with the firing time gradient maps and the fusion image is reconstructed by wavelet inverse transform. Furthermore, by this algorithm, the threshold adjusting constant is estimated by appointed iteration number. Furthermore, In order to sufficient reflect order of the firing time, the threshold adjusting constant αΘ is estimated by appointed iteration number. So after the iteration achieved, each of the wavelet coefficient is activated. In order to verify the effectiveness of proposed rules, the experiments upon Multi-focus image are done. Moreover

  14. 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.

  15. Fusion Breeding for Sustainable, Mid Century, Carbon Free Power

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2015-11-01

    If ITER achieves Q ~10, it is still very far from useful fusion. The fusion power, and the driver power will allow only a small amount of power to be delivered, <~50MW for an ITER scale tokamak. It is unlikely, considering ``conservative design rules'' that tokamaks can ever be economical pure fusion power producers. Considering the status of other magnetic fusion concepts, it is also very unlikely that any alternate concept will either. Laser fusion does not seem to be constrained by any conservative design rules, but considering the failure of NIF to achhieve ignition, at this point it has many more obstacles to overcome than magnetic fusion. One way out of this dilemma is to use an ITER size tokamak, or a NIF size laser, as a fuel breeder for searate nuclear reactors. Hence ITER and NIF become ends in themselves, instead of steps to who knows what DEMO decades later. Such a tokamak can easily live within the consrtaints of conservative design rules. This has led the author to propose ``The Energy Park'' a sustainable, carbon free, economical, and environmently viable power source without prolifertion risk. It is one fusion breeder fuels 5 conventional nuclear reactors, and one fast neutron reactor burns the actinide wastes.

  16. The National Ignition Facility: an experimental platform for studying behavior of matter under extreme conditions

    NASA Astrophysics Data System (ADS)

    Moses, Edward

    2011-11-01

    The National Ignition Facility (NIF), a 192-beam Nd-glass laser facility capable of producing 1.8 MJ and 500 TW of ultraviolet light, is now operational at Lawrence Livermore National Laboratory (LLNL). As the world's largest and most energetic laser system, NIF serves as the national center for the U.S. Department of Energy (DOE) and National Nuclear Security Administration to achieve thermonuclear burn in the laboratory and to explore the behavior of matter at extreme temperatures and energy densities. By concentrating the energy from all of its 192 extremely energetic laser beams into a mm3-sized target, NIF can reach the conditions required to initiate fusion reactions. NIF can also provide access to extreme scientific environments: temperatures about 100 million K, densities of 1,000 g/cm3, and pressures 100 billion times atmospheric pressure. These conditions have never been created before in a laboratory and exist naturally only in interiors of the planetary and stellar environments as well as in nuclear weapons. Since August 2009, the NIF team has been conducting experiments in support of the National Ignition Campaign (NIC)—a partnership among LLNL, Los Alamos National Laboratory, General Atomics, the University of Rochester, Sandia National Laboratories, as well as a number of universities and international collaborators. The results from these initial experiments show promise for the relatively near-term achievement of ignition. Capsule implosion experiments at energies up to 1.2 MJ have demonstrated laser energetics, radiation temperatures, and symmetry control that scale to ignition conditions. Of particular importance is the demonstration of peak hohlraum temperatures near 300 eV with overall backscatter less than 10%. Cryogenic target capability and additional diagnostics are being installed in preparation for layered target deuterium-tritium implosions to be conducted later in 2010. Important national security and basic science experiments have

  17. 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

  18. Isochoric Implosions for Fast Ignition

    NASA Astrophysics Data System (ADS)

    Clark, Daniel; Tabak, Max

    2006-10-01

    Various gain models have shown the potentially great advantages of Fast Ignition (FI) Inertial Confinement Fusion (ICF) over its conventional hotspot ignition counterpart. These gain models, however, all assume nearly uniform-density fuel assemblies. By contrast, typical ICF implosions yield hollowed fuel assemblies with a high-density shell of fuel surrounding a low-density, high-pressure hotspot. To realize fully the advantages of FI, then, an alternative implosion design must be found which yields nearly isochoric fuel assemblies without substantial hotspots. 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 yield precisely such quasi-isochoric imploded states. The difficulty remains, however, of accessing these self-similarly imploding configurations from initial conditions representing an actual ICF target, namely a uniform, solid-density shell at rest. Furthermore, these specialized implosions must be realized for practicable drive parameters, i.e., accessible peak pressures, shell aspect ratios, etc. An implosion scheme is presented which meets all of these requirements, suggesting the possibility of genuinely isochoric implosions for FI.

  19. Plasma transport in a compact ignition tokamak

    SciTech Connect

    Singer, C.E.; Ku, L.P; Bateman, G.

    1987-02-01

    Nominal predicted plasma conditions in a compact ignition tokamak are illustrated by transport simulations using experimentally calibrated plasma transport models. The range of uncertainty in these predictions is explored by using various models which have given almost equally good fits to experimental data. Using a transport model which best fits the data, thermonuclear ignition occurs in a Compact Ignition Tokamak design with major radius 1.32 m, plasma half-width 0.43 m, elongation 2.0, and toroidal field and plasma current ramped in six seconds from 1.7 to 10.4 T and 0.7 to 10 MA, respectively. Ignition is facilitated by 20 MW of heating deposited off the magnetic axis near the /sup 3/He minority cyclotron resonance layer. Under these conditions, sawtooth oscillations are small and have little impact on ignition. Tritium inventory is minimized by preconditioning most discharges with deuterium. Tritium is injected, in large frozen pellets, only after minority resonance preheating. Variations of the transport model, impurity influx, heating profile, and pellet ablation rates, have a large effect on ignition and on the maximum beta that can be achieved.

  20. PREFACE: The fifth International Conference on Inertial Fusion Sciences and Applications (IFSA2007)

    NASA Astrophysics Data System (ADS)

    Azechi, Hiroshi; Hammel, Bruce; Gauthier, Jean-Claude

    2008-06-01

    The Fifth International Conference on Inertial Fusion Sciences and Applications (IFSA 2007) was held on 9-14 September 2007 at Kobe International Conference Center in Kobe, Japan. The host organizations for this conference were Osaka University and the Institute of Laser Engineering (ILE) at Osaka University; and co-organized by the Institute Lasers and Plasmas (ILP) in France, the Commissariatá l'Energie Atomique (CEA), Lawrence Livermore National Laboratory (LLNL), National Institute for Fusion Science (NIFS) in Japan, and Kansai Photon Science Institute (KPSI), Japan Atomic Energy Agency (JAEA). The conference objective was to review the state of the art of research in inertial fusion sciences and applications since the last conference held in Biarritz, France, in 2005. 470 abstracts were accepted, and 448 persons from 18 countries attended the conference. These Proceedings contain 287 of the papers presented at IFSA 2007. This collection of papers represents the manuscripts submitted to and passing the peer review process. The program was organized with some specific features: The reviews of influential programs appeared both at the very beginning and at the very end of the Conference to attract attendance throughout the Conference. Each poster session had the same time period as a single oral session, thereby avoiding overlap with oral talks. The everyday program was structured to be as similar as possible so the attendees could easily recognize the program. With a goal of achieving inertial fusion ignition and burn propagation in the laboratory, researchers presented the exciting advances in both traditional hot spot ignition and fast ignition approach, including status report of USA's National Ignition Facility (NIF), French Laser Magajoule (LMJ), Japanese Fast Ignition Realization Experiment (FIREX), and European High Power laser Energy Research (HiPER). A particular emphasis of the meeting was that the `physics of inertial fusion' category was dominated

  1. Energy Gain Investigation in Fast Ignition ICF with Electron Ignition Beam by Changing Fuel Characteristics

    NASA Astrophysics Data System (ADS)

    Moosavi, Mohadeseh; Ahmadi, Masoume; Ghasemizad, Abbas

    2014-02-01

    Fast ignition is a method in inertial confinement fusion (ICF) in which an ignition spark in pre-compression fuel is formed by an ultra-intense laser beam. In applying this method, a hot spot is built by relative electrons which are produced by the ultra-intense laser beam. For a better understanding, a fuel energy gain curve based on density is drawn and it can be observed that the ignition by an electron beam has the maximum energy gain. The maximum energy gain has been observed in equimolar DT fuel with a density of 500 g/cm3 and in fuel with tritium (10%) with a density of 1000 g/cm3.

  2. Accelerators for Fusion Materials Testing

    NASA Astrophysics Data System (ADS)

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes >1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa (“displacement-per-atom”, the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  3. Accelerators for Fusion Materials Testing

    NASA Astrophysics Data System (ADS)

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes > 1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa ("displacement-per-atom", the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  4. 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.

  5. 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.

  6. Cryogenic thermonuclear fuel implosions on the National Ignition Facility

    SciTech Connect

    Glenzer, S. H.; Callahan, D. A.; MacKinnon, A. J.; Alger, E. T.; Berger, R. L.; Bernstein, L. A.; Bleuel, D. L.; Bradley, D. K.; Burkhart, S. C.; Burr, R.; Caggiano, J. A.; Castro, C.; Choate, C.; Clark, D. S.; Celliers, P.; Cerjan, C. J.; Collins, G. W.; Dewald, E. L.; DiNicola, P.; DiNicola, J. M.; and others

    2012-05-15

    The first inertial confinement fusion implosion experiments with equimolar deuterium-tritium thermonuclear fuel have been performed on the National Ignition Facility. These experiments use 0.17 mg of fuel with the potential for ignition and significant fusion yield conditions. The thermonuclear fuel has been fielded as a cryogenic layer on the inside of a spherical plastic capsule that is mounted in the center of a cylindrical gold hohlraum. Heating the hohlraum with 192 laser beams for a total laser energy of 1.6 MJ produces a soft x-ray field with 300 eV temperature. The ablation pressure produced by the radiation field compresses the initially 2.2-mm diameter capsule by a factor of 30 to a spherical dense fuel shell that surrounds a central hot-spot plasma of 50 {mu}m diameter. While an extensive set of x-ray and neutron diagnostics has been applied to characterize hot spot formation from the x-ray emission and 14.1 MeV deuterium-tritium primary fusion neutrons, thermonuclear fuel assembly is studied by measuring the down-scattered neutrons with energies in the range of 10 to 12 MeV. X-ray and neutron imaging of the compressed core and fuel indicate a fuel thickness of (14 {+-} 3) {mu}m, which combined with magnetic recoil spectrometer measurements of the fuel areal density of (1 {+-} 0.09) g cm{sup -2} result in fuel densities approaching 600 g cm{sup -3}. The fuel surrounds a hot-spot plasma with average ion temperatures of (3.5 {+-} 0.1) keV that is measured with neutron time of flight spectra. The hot-spot plasma produces a total fusion neutron yield of 10{sup 15} that is measured with the magnetic recoil spectrometer and nuclear activation diagnostics that indicate a 14.1 MeV yield of (7.5{+-}0.1) Multiplication-Sign 10{sup 14} which is 70% to 75% of the total fusion yield due to the high areal density. Gamma ray measurements provide the duration of nuclear activity of (170 {+-} 30) ps. These indirect-drive implosions result in the highest areal densities

  7. Cryogenic thermonuclear fuel implosions on the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Glenzer, S. H.; Callahan, D. A.; MacKinnon, A. J.; Kline, J. L.; Grim, G.; Alger, E. T.; Berger, R. L.; Bernstein, L. A.; Betti, R.; Bleuel, D. L.; Boehly, T. R.; Bradley, D. K.; Burkhart, S. C.; Burr, R.; Caggiano, J. A.; Castro, C.; Casey, D. T.; Choate, C.; Clark, D. S.; Celliers, P.; Cerjan, C. J.; Collins, G. W.; Dewald, E. L.; DiNicola, P.; DiNicola, J. M.; Divol, L.; Dixit, S.; Döppner, T.; Dylla-Spears, R.; Dzenitis, E.; Eckart, M.; Erbert, G.; Farley, D.; Fair, J.; Fittinghoff, D.; Frank, M.; Frenje, L. J. A.; Friedrich, S.; Casey, D. T.; Gatu Johnson, M.; Gibson, C.; Giraldez, E.; Glebov, V.; Glenn, S.; Guler, N.; Haan, S. W.; Haid, B. J.; Hammel, B. A.; Hamza, A. V.; Haynam, C. A.; Heestand, G. M.; Hermann, M.; Hermann, H. W.; Hicks, D. G.; Hinkel, D. E.; Holder, J. P.; Holunda, D. M.; Horner, J. B.; Hsing, W. W.; Huang, H.; Izumi, N.; Jackson, M.; Jones, O. S.; Kalantar, D. H.; Kauffman, R.; Kilkenny, J. D.; Kirkwood, R. K.; Klingmann, J.; Kohut, T.; Knauer, J. P.; Koch, J. A.; Kozioziemki, B.; Kyrala, G. A.; Kritcher, A. L.; Kroll, J.; La Fortune, K.; Lagin, L.; Landen, O. L.; Larson, D. W.; LaTray, D.; Leeper, R. J.; Le Pape, S.; Lindl, J. D.; Lowe-Webb, R.; Ma, T.; McNaney, J.; MacPhee, A. G.; Malsbury, T. N.; Mapoles, E.; Marshall, C. D.; Meezan, N. B.; Merrill, F.; Michel, P.; Moody, J. D.; Moore, A. S.; Moran, M.; Moreno, K. A.; Munro, D. H.; Nathan, B. R.; Nikroo, A.; Olson, R. E.; Orth, C. D.; Pak, A. E.; Patel, P. K.; Parham, T.; Petrasso, R.; Ralph, J. E.; Rinderknecht, H.; Regan, S. P.; Robey, H. F.; Ross, J. S.; Rosen, M. D.; Sacks, R.; Salmonson, J. D.; Saunders, R.; Sater, J.; Sangster, C.; Schneider, M. B.; Séguin, F. H.; Shaw, M. J.; Spears, B. K.; Springer, P. T.; Stoeffl, W.; Suter, L. J.; Thomas, C. A.; Tommasini, R.; Town, R. P. J.; Walters, C.; Weaver, S.; Weber, S. V.; Wegner, P. J.; Whitman, P. K.; Widmann, K.; Widmayer, C. C.; Wilde, C. H.; Wilson, D. C.; Van Wonterghem, B.; MacGowan, B. J.; Atherton, L. J.; Edwards, M. J.; Moses, E. I.

    2012-05-01

    The first inertial confinement fusion implosion experiments with equimolar deuterium-tritium thermonuclear fuel have been performed on the National Ignition Facility. These experiments use 0.17 mg of fuel with the potential for ignition and significant fusion yield conditions. The thermonuclear fuel has been fielded as a cryogenic layer on the inside of a spherical plastic capsule that is mounted in the center of a cylindrical gold hohlraum. Heating the hohlraum with 192 laser beams for a total laser energy of 1.6 MJ produces a soft x-ray field with 300 eV temperature. The ablation pressure produced by the radiation field compresses the initially 2.2-mm diameter capsule by a factor of 30 to a spherical dense fuel shell that surrounds a central hot-spot plasma of 50 μm diameter. While an extensive set of x-ray and neutron diagnostics has been applied to characterize hot spot formation from the x-ray emission and 14.1 MeV deuterium-tritium primary fusion neutrons, thermonuclear fuel assembly is studied by measuring the down-scattered neutrons with energies in the range of 10 to 12 MeV. X-ray and neutron imaging of the compressed core and fuel indicate a fuel thickness of (14 ± 3) μm, which combined with magnetic recoil spectrometer measurements of the fuel areal density of (1 ± 0.09) g cm-2 result in fuel densities approaching 600 g cm-3. The fuel surrounds a hot-spot plasma with average ion temperatures of (3.5 ± 0.1) keV that is measured with neutron time of flight spectra. The hot-spot plasma produces a total fusion neutron yield of 1015 that is measured with the magnetic recoil spectrometer and nuclear activation diagnostics that indicate a 14.1 MeV yield of (7.5±0.1)×1014 which is 70% to 75% of the total fusion yield due to the high areal density. Gamma ray measurements provide the duration of nuclear activity of (170 ± 30) ps. These indirect-drive implosions result in the highest areal densities and neutron yields achieved on laser facilities to date

  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. Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures.

    PubMed

    Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

    2016-04-15

    The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. PMID:26799221

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

    NASA Astrophysics Data System (ADS)

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

    2004-02-01

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

  11. Alcohol ignition interlock programs.

    PubMed

    Beirness, D J; Marques, P R

    2004-09-01

    The alcohol ignition interlock is an in-vehicle DWI control device that prevents a car from starting until the operator provides a breath alcohol concentration (BAC) test below a set level, usually .02% (20 mg/dl) to .04% (40 mg/dl). The first interlock program was begun as a pilot test in California 18 years ago; today all but a few US states, and Canadian provinces have interlock enabling legislation. Sweden has recently implemented a nationwide interlock program. Other nations of the European Union and as well as several Australian states are testing it on a small scale or through pilot research. This article describes the interlock device and reviews the development and current status of interlock programs including their public safety benefit and the public practice impediments to more widespread adoption of these DWI control devices. Included in this review are (1) a discussion of the technological breakthroughs and certification standards that gave rise to the design features of equipment that is in widespread use today; (2) a commentary on the growing level of adoption of interlocks by governments despite the judicial and legislative practices that prevent more widespread use of them; (3) a brief overview of the extant literature documenting a high degree of interlock efficacy while installed, and the rapid loss of their preventative effect on repeat DWI once they are removed from the vehicles; (4) a discussion of the representativeness of subjects in the current research studies; (5) a discussion of research innovations, including motivational intervention efforts that may extend the controlling effect of the interlock, and data mining research that has uncovered ways to use the stored interlock data record of BAC tests in order to predict high risk drivers; and (6) a discussion of communication barriers and conceptual rigidities that may be preventing the alcohol ignition interlock from taking a more prominent role in the arsenal of tools used to control

  12. 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.

  13. 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.

  14. 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.

  15. Optimization with Telios of the Polar-Drive Point Design for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Collins, T. J. B.; Marozas, J. A.; McKenty, P. W.

    2012-10-01

    Polar drivefootnotetextS. Skupsky et al., Phys. Plasmas 11, 2763 (2004). (PD) will make it possible to conduct direct-drive--ignition experiments at the National Ignition Facilityfootnotetext G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004). while the facility is configured for x-ray drive. A PD-ignition design has been developedfootnotetextT. J. B. Collins et al., Phys. Plasmas 19, 056308 (2012). achieving high gain in simulations including single- and multiple-beam nonuniformities, and ice and outer-surface roughness. This design has been further optimized to reduce the in-flight aspect ratio and implosion speed, increasing target stability while maintaining moderately high thermonuclear gains. The dependence of target properties on implosion speed has been examined using the optimization shell Telios. Telios has the capability to drive complex radiation--hydrodynamic simulations and optimized results over an arbitrarily large parameter space, including ring pointing angles, spot-shape parameters, target dimensions, pulse timing, and relative pulse energies. Telios is capable of extracting output from a variety of sources and combining them to form arbitrarily complex, user-specified metrics. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

  16. Laser fusion neutron source employing compression with short pulse lasers

    DOEpatents

    Sefcik, Joseph A; Wilks, Scott C

    2013-11-05

    A method and system for achieving fusion is provided. The method includes providing laser source that generates a laser beam and a target that includes a capsule embedded in the target and filled with DT gas. The laser beam is directed at the target. The laser beam helps create an electron beam within the target. The electron beam heats the capsule, the DT gas, and the area surrounding the capsule. At a certain point equilibrium is reached. At the equilibrium point, the capsule implodes and generates enough pressure on the DT gas to ignite the DT gas and fuse the DT gas nuclei.

  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. Ignition and combustion of coal particles

    SciTech Connect

    Gomez, C.O.; Vastola, F.J.

    1983-09-01

    A subbituminous coal was used in this study. Particles from the 850 to 1000 ..mu.. sieve fraction were injected into a reaction furnace swept with air at temperature levels of 928/sup 0/, 980/sup 0/, 1076/sup 0/, 1118/sup 0/ and 1273/sup 0/K. The experimental technique, based upon the simultaneous measurement of the carbon monoxide, carbon dioxide, and the intensity of the light generated during the combustion, provides quantitative information about the ignition and the subsequent burn-off of the residual particle. Homogeneous ignition is detected at temperatures of 1076/sup 0/K and higher. The apparatus designed provides the special characteristics required in this study, and the transition between the ignition mechanisms is achieved within the range of operation conditions for this particular coal. The ignition mechanism is determined not only from the measurement of light intensity during the combustion, but also from the gas evolution curves. The results show the convenience of using these complementary techniques for the measurement of the ignition mechanism. 4 figures, 2 tables.

  20. Hohlraum Modeling of Hybrid Shock Ignition Target

    NASA Astrophysics Data System (ADS)

    Dodd, E. S.; Baumgaertel, J. A.; Loomis, E. N.

    2014-10-01

    Hybrid Shock Ignition (HSI) combines a hohlraum driven capsule with a directly driven shock for heating. Unlike standard Shock Ignition, the capsule is imploded with X-rays from a laser driven hohlraum to compress the fuel, which is too cold to ignite. However, as in Shock Ignition, the compressed fuel is subsequently heated to ignition temperatures with a directly-driven shock. The use of indirect and direct drive in the same target necessitates complex beam geometry, and thus HSI is being pursued with spherical hohlraums. More importantly for the NIF, the beam repointing required for polar direct drive will not be needed for the implosion phase with this target. Spherical hohlraums have been fielded previously at the OMEGA laser as a part of the Tetrahedral Hohlraum Campaign. They were originally proposed as an alternative to cylindrical hohlraums to achieve highly symmetric radiation drive. The new HSI hohlraums will require six laser entrance holes in hexahedral symmetry to accommodate all beams. This presentation will show radiation-hydrodynamic calculations of the current hexahedral OMEGA hohlraum design, as well as benchmark calculations of the old tetrahedral targets. Supported under the US DOE by the Los Alamos National Security, LLC under Contract DE-AC52-06NA25396. LA-UR-14-24945.

  1. Magneto-Inertial Fusion

    DOE PAGESBeta

    Wurden, G. A.; Hsu, S. C.; Intrator, T. P.; Grabowski, T. C.; Degnan, J. H.; Domonkos, M.; Turchi, P. J.; Campbell, E. M.; Sinars, D. B.; Herrmann, M. C.; et al

    2015-11-17

    In this community white paper, we describe an approach to achieving fusion which employs a hybrid of elements from the traditional magnetic and inertial fusion concepts, called magneto-inertial fusion (MIF). The status of MIF research in North America at multiple institutions is summarized including recent progress, research opportunities, and future plans.

  2. Autocatalytic fission-fusion microexplosions for nuclear pulse propulsion

    NASA Astrophysics Data System (ADS)

    Winterberg, F.

    2000-12-01

    Autocatalytic fission-fusion microexplosions, mutually amplifying fission and fusion reactions, are proposed for propulsion. Autocatalytic fission-fusion microexplosions can be realized by imploding a shell of uranium 235 (or plutonium) onto a magnetized deuterium-tritium (DT) plasma. After having reached a high temperature, the DT plasma releases fusion neutrons making fission reactions in the fissile shell increasing the implosion velocity which in turn increases the fusion reaction rate until full ignition of the DT plasma. To implode the fissile shell a small amount of high explosive and to magnetize the DT plasma a small auxiliary electric discharge are required. In comparison to nuclear bomb pulse propulsion, the energy released per pulse is much smaller and the efficiency higher. And in comparison to laser- or particle-beam-ignited fusion microexplosions, there is no need for a massive fusion ignition driver.

  3. The High-Foot Implosion Campaign on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Hurricane, Omar

    2013-10-01

    The `High-Foot' platform manipulates the laser pulse-shape coming from the National Ignition Facility (NIF) laser to create an indirect drive 3-shock implosion that is significantly more robust against instability growth involving the ablator and also modestly reduces implosion convergence ratio. This tactic gives up on theoretical high-gain in an inertial confinement fusion implosion in order to obtain better control of the implosion and bring experimental performance in-line with calculated performance, yet keeps the absolute capsule performance relatively high. This approach is generally consistent with the philosophy laid out in a recent international workshop on the topic of ignition science on NIF [``Workshop on the Science of Fusion Ignition on NIF,'' Lawrence Livermore National Laboratory Report, LLNL-TR-570412 (2012). Op cit. V. Gocharov and O.A. Hurricane, ``Panel 3 Report: Implosion Hydrodynamics,'' LLNL-TR-562104 (2012)]. Side benefits our the High-Foot pulse-shape modification appear to be improvements in hohlraum behavior--less wall motion achieved through higher pressure He gas fill and improved inner cone laser beam propagation. Another consequence of the `High-Foot' is a higher fuel adiabat, so there is some relation to direct-drive experiments performed at the Laboratory for Laser Energetics (LLE). In this talk, we will cover the various experimental and theoretical motivations for the High-Foot drive as well as cover the experimental results that have come out of the High-Foot experimental campaign. Most notably, at the time of this writing record DT layer implosion performance with record low levels of inferred mix and excellent agreement with one-dimensional implosion models without the aid of mix models. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  4. 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.

  5. Implosion dynamics measurements at the National Ignition Facility

    SciTech Connect

    Hicks, D. G.; Meezan, N. B.; Dewald, E. L.; Mackinnon, A. J.; Callahan, D. A.; Doeppner, T.; Benedetti, L. R.; Bradley, D. K.; Celliers, P. M.; Clark, D. S.; Di Nicola, P.; Dixit, S. N.; Dzenitis, E. G.; Eggert, J. E.; Farley, D. R.; Glenn, S. M.; Glenzer, S. H.; Hamza, A. V.; Heeter, R. F.; Holder, J. P.; and others

    2012-12-15

    Measurements have been made of the in-flight dynamics of imploding capsules indirectly driven by laser energies of 1-1.7 MJ at the National Ignition Facility [Miller et al., Nucl. Fusion 44, 228 (2004)]. These experiments were part of the National Ignition Campaign [Landen et al., Phys. Plasmas 18, 051002 (2011)] to iteratively optimize the inputs required to achieve thermonuclear ignition in the laboratory. Using gated or streaked hard x-ray radiography, a suite of ablator performance parameters, including the time-resolved radius, velocity, mass, and thickness, have been determined throughout the acceleration history of surrogate gas-filled implosions. These measurements have been used to establish a dynamically consistent model of the ablative drive history and shell compressibility throughout the implosion trajectory. First results showed that the peak velocity of the original 1.3-MJ Ge-doped polymer (CH) point design using Au hohlraums reached only 75% of the required ignition velocity. Several capsule, hohlraum, and laser pulse changes were then implemented to improve this and other aspects of implosion performance and a dedicated effort was undertaken to test the sensitivity of the ablative drive to the rise time and length of the main laser pulse. Changing to Si rather than Ge-doped inner ablator layers and increasing the pulse length together raised peak velocity to 93% {+-} 5% of the ignition goal using a 1.5 MJ, 420 TW pulse. Further lengthening the pulse so that the laser remained on until the capsule reached 30% (rather than 60%-70%) of its initial radius, reduced the shell thickness and improved the final fuel {rho}R on companion shots with a cryogenic hydrogen fuel layer. Improved drive efficiency was observed using U rather than Au hohlraums, which was expected, and by slowing the rise time of laser pulse, which was not. The effect of changing the Si-dopant concentration and distribution, as well as the effect of using a larger initial shell

  6. Implosion dynamics measurements at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Hicks, D. G.; Meezan, N. B.; Dewald, E. L.; Mackinnon, A. J.; Olson, R. E.; Callahan, D. A.; Döppner, T.; Benedetti, L. R.; Bradley, D. K.; Celliers, P. M.; Clark, D. S.; Di Nicola, P.; Dixit, S. N.; Dzenitis, E. G.; Eggert, J. E.; Farley, D. R.; Frenje, J. A.; Glenn, S. M.; Glenzer, S. H.; Hamza, A. V.; Heeter, R. F.; Holder, J. P.; Izumi, N.; Kalantar, D. H.; Khan, S. F.; Kline, J. L.; Kroll, J. J.; Kyrala, G. A.; Ma, T.; MacPhee, A. G.; McNaney, J. M.; Moody, J. D.; Moran, M. J.; Nathan, B. R.; Nikroo, A.; Opachich, Y. P.; Petrasso, R. D.; Prasad, R. R.; Ralph, J. E.; Robey, H. F.; Rinderknecht, H. G.; Rygg, J. R.; Salmonson, J. D.; Schneider, M. B.; Simanovskaia, N.; Spears, B. K.; Tommasini, R.; Widmann, K.; Zylstra, A. B.; Collins, G. W.; Landen, O. L.; Kilkenny, J. D.; Hsing, W. W.; MacGowan, B. J.; Atherton, L. J.; Edwards, M. J.

    2012-12-01

    Measurements have been made of the in-flight dynamics of imploding capsules indirectly driven by laser energies of 1-1.7 MJ at the National Ignition Facility [Miller et al., Nucl. Fusion 44, 228 (2004)]. These experiments were part of the National Ignition Campaign [Landen et al., Phys. Plasmas 18, 051002 (2011)] to iteratively optimize the inputs required to achieve thermonuclear ignition in the laboratory. Using gated or streaked hard x-ray radiography, a suite of ablator performance parameters, including the time-resolved radius, velocity, mass, and thickness, have been determined throughout the acceleration history of surrogate gas-filled implosions. These measurements have been used to establish a dynamically consistent model of the ablative drive history and shell compressibility throughout the implosion trajectory. First results showed that the peak velocity of the original 1.3-MJ Ge-doped polymer (CH) point design using Au hohlraums reached only 75% of the required ignition velocity. Several capsule, hohlraum, and laser pulse changes were then implemented to improve this and other aspects of implosion performance and a dedicated effort was undertaken to test the sensitivity of the ablative drive to the rise time and length of the main laser pulse. Changing to Si rather than Ge-doped inner ablator layers and increasing the pulse length together raised peak velocity to 93% ± 5% of the ignition goal using a 1.5 MJ, 420 TW pulse. Further lengthening the pulse so that the laser remained on until the capsule reached 30% (rather than 60%-70%) of its initial radius, reduced the shell thickness and improved the final fuel ρR on companion shots with a cryogenic hydrogen fuel layer. Improved drive efficiency was observed using U rather than Au hohlraums, which was expected, and by slowing the rise time of laser pulse, which was not. The effect of changing the Si-dopant concentration and distribution, as well as the effect of using a larger initial shell thickness

  7. Pre-Amplifier Module for Laser Inertial Confinement Fusion

    SciTech Connect

    Heebner, J E; Bowers, M W

    2008-02-06

    The Pre-Amplifier Modules (PAMs) are the heart of the National Ignition Facility (NIF), providing most of the energy gain for the most energetic laser in the world. Upon completion, NIF will be the only laboratory in which scientists can examine the fusion processes that occur inside stars, supernovae, and exploding nuclear weapons and that may someday serve as a virtually inexhaustible energy source for electricity. Consider that in a fusion power plant 50 cups of water could provide the energy comparable to 2 tons of coal. Of paramount importance for achieving laser-driven fusion ignition with the least energy input is the synchronous and symmetric compression of the target fuel--a condition known as laser power balance. NIF's 48 PAMs thus must provide energy gain in an exquisitely stable and consistent manner. While building one module that meets performance requirements is challenging enough, our design has already enabled the construction and fielding of 48 PAMs that are stable, uniform, and interchangeable. PAM systems are being tested at the University of Rochester's Laboratory for Laser Energetics, and the Atomic Weapons Enterprise of Great Britain has purchased the PAM power system.

  8. Igniter Testing and Development for Liquid Oxygen/Liquid Methane (LOX/LCH4) and Liquid Oxygen/Gaseous Hydrogen (LOX/GH2) Injectors

    NASA Technical Reports Server (NTRS)

    Osborne, Robin J.; Elam, Sandra K.; Peschel, William P.

    2010-01-01

    In support of NASA's efforts to advance methane technology for future exploration missions, two different igniter concepts were developed and tested at NASA's Marshall Space Flight Center for ignition of oxygen/methane propellants. The first type of igniter, an impinging injection, spark-initiated torch igniter (impinging igniter), used traditional spark plug technology to produce a small, but very intense, pulsed plasma as the ignition source. The second type of igniter, a microwave-generated plasma igniter (microwave igniter), used a microwave magnetron to produce a continuous, larger-volume plasma as the ignition source. Two new designs for both types of igniters were leveraged off past oxygen/methane igniter designs that were tested at MSFC and documented in a 2008 JANNAF paper. In this most recent work, the two new igniters were to be tested at the component level as well as inside a liquid oxygen/liquid methane (LOX/LCH4) 40-element swirl coaxial injector. Although the microwave igniter achieved ignition in every test, it encountered technical difficulties that prevented it from being tested with the injector. The impinging igniter required several design iterations as well as testing at different mixture ratios and mass flow rates before reliable operation with minimal ignition delay was achieved. The final design of the impinging igniter was successfully tested in the LOX/LCH4 injector. The same igniter was later re-configured and component-tested to demonstrate reliable ignition of oxygen/hydrogen propellants. Future tests of the impinging igniter will include ignition of a LOX/hydrogen two-stage swirl injector, which is one of several injector concepts being tested in the Lunar Lander Descent Engine Test Bed at MSFC. All igniter and injector tests have been funded by the Propulsion & Cryogenics Advanced Development project managed by Glenn Research Center and sponsored by NASA s Exploration Technology Development Program.

  9. 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

  10. 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.

  11. Spallation as a dominant source of pusher-fuel and hot-spot mix in inertial confinement fusion capsules

    NASA Astrophysics Data System (ADS)

    Orth, Charles D.

    2016-02-01

    We suggest that a potentially dominant but previously neglected source of pusher-fuel and hot-spot "mix" may have been the main degradation mechanism for fusion energy yields of modern inertial confinement fusion (ICF) capsules designed and fielded to achieve high yields—not hydrodynamic instabilities. This potentially dominant mix source is the spallation of small chunks or "grains" of pusher material into the fuel regions whenever (1) the solid material adjacent to the fuel changes its phase by nucleation and (2) this solid material spalls under shock loading and sudden decompression. We describe this mix mechanism, support it with simulations and experimental evidence, and explain how to eliminate it and thereby allow higher yields for ICF capsules and possibly ignition at the National Ignition Facility.

  12. Spallation as a dominant source of pusher-fuel and hot-spot mix in inertial confinement fusion capsules

    DOE PAGESBeta

    Orth, Charles D.

    2016-02-23

    We suggest that a potentially dominant but previously neglected source of pusher-fuel and hot-spot “mix” may have been the main degradation mechanism for fusion energy yields of modern inertial confinement fusion (ICF) capsules designed and fielded to achieve high yields — not hydrodynamic instabilities. This potentially dominant mix source is the spallation of small chunks or “grains” of pusher material into the fuel regions whenever (1) the solid material adjacent to the fuel changes its phase by nucleation, and (2) this solid material spalls under shock loading and sudden decompression. Finally, we describe this mix mechanism, support it with simulationsmore » and experimental evidence, and explain how to eliminate it and thereby allow higher yields for ICF capsules and possibly ignition at the National Ignition Facility.« less

  13. 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.

  14. 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.

  15. The cumulative energy effect for improved ignition timing

    SciTech Connect

    Markhotok, A.

    2015-04-15

    A technique capable of improving timing in ignition applications is proposed. It is based on the use of shock waves propagating in a specific medium that allows achieving extremely high speeds and energies. The model uses the energy cumulation effect in the presence of the shock wave refraction on an interface with plasma. The problem was solved analytically and the effects were demonstrated for a cylindrically symmetrical geometry. Numerical results show very quick and uneven acceleration of different portions of the shock front. Its strong distortions lead to formation of a sharply focused jet near the axis of symmetry. The ability of the shock to achieve extremely high speeds and energies can be useful in design of efficient combustors for hypersonic systems, and possibly offers an alternative way of construction of a nuclear fusion reactor. Recommendations are given in terms of adjustment parameters and can be applied at any problem scale and for various combinations of the strengths of the effects involved in the problem.

  16. The cumulative energy effect for improved ignition timing

    NASA Astrophysics Data System (ADS)

    Markhotok, A.

    2015-04-01

    A technique capable of improving timing in ignition applications is proposed. It is based on the use of shock waves propagating in a specific medium that allows achieving extremely high speeds and energies. The model uses the energy cumulation effect in the presence of the shock wave refraction on an interface with plasma. The problem was solved analytically and the effects were demonstrated for a cylindrically symmetrical geometry. Numerical results show very quick and uneven acceleration of different portions of the shock front. Its strong distortions lead to formation of a sharply focused jet near the axis of symmetry. The ability of the shock to achieve extremely high speeds and energies can be useful in design of efficient combustors for hypersonic systems, and possibly offers an alternative way of construction of a nuclear fusion reactor. Recommendations are given in terms of adjustment parameters and can be applied at any problem scale and for various combinations of the strengths of the effects involved in the problem.

  17. 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.

  18. Inertial Confinement Fusion Materials Science

    SciTech Connect

    Hamza, A V

    2004-06-01

    Demonstration of thermonuclear ignition and gain on a laboratory scale is one of science's grand challenges. The National Ignition Facility (NIF) is committed to achieving inertial confinement fusion (ICF) by 2010. Success in this endeavor depends on four elements: the laser driver performance, target design, experimental diagnostics performance, and target fabrication and target materials performance. This article discusses the current state of target fabrication and target materials performance. The first three elements will only be discussed insofar as they relate to target fabrication specifications and target materials performance. Excellent reviews of the physics of ICF are given by Lindl [Lindl 1998] and Lindl et al. [Lindl 2004]. To achieve conditions under which inertial confinement is sufficient to achieve thermonuclear burn, an imploded fuel capsule is compressed to conditions of high density and temperature. In the laboratory a driver is required to impart energy to the capsule to effect an implosion. There are three drivers currently being considered for ICF in the laboratory: high-powered lasers, accelerated heavy ions, and x rays resulting from pulsed power machines. Of these, high-powered lasers are the most developed, provide the most symmetric drive, and provide the most energy. Laser drive operates in two configurations. The first is direct drive where the laser energy impinges directly on the ICF capsule and drives the implosion. The second is indirect drive, where the energy from the laser is first absorbed in a high-Z enclosure or hohlraum surrounding the capsule, and the resulting x-rays emitted by the hohlraum material drives the implosion. Using direct drive the laser beam energy is absorbed by the electrons in the outer corona of the target. The electrons transport the energy to the denser shell region to provide the ablation and the resulting implosion. Laser direct drive is generally less efficient and more hydrodynamically unstable than

  19. The Automotive Ignition Coil

    NASA Technical Reports Server (NTRS)

    Darnell, T H

    1932-01-01

    This report gives the results of a series of measurements on the secondary voltage induced in an ignition coil of typical construction under a variety of operating conditions. These results show that the theoretical predictions hitherto made as to the behavior of this type of apparatus are in satisfactory agreement with the observed facts. The large mass of data obtained is here published both for the use of other investigators who may wish to compare them with other theoretical predictions and for the use of automotive engineers who will here find definite experimental results showing the effect of secondary capacity and resistance on the crest voltage produced by ignition apparatus.

  20. Inertial Fusion Sciences and Applications 2003: State of the Art 2003, Published by the American Nuclear Society

    SciTech Connect

    Editors: B. A. Hammel; D. D. Meyerhofer; J. Meyer-ter-Vehn; H. Azechi. Organizing Chair: W. J. Hogan

    2004-06-01

    Collection of all papers presented and submitted at the IFSA2003 conference. Topics included target design and performance, fast ignition, plasma instabilities, laser technology, fusion reactor technology

  1. A1.5 Fusion Performance

    SciTech Connect

    Amendt, P

    2011-03-31

    Analysis and radiation hydrodynamics simulations for expected high-gain fusion target performance on a demonstration 1-GWe Laser Inertial Fusion Energy (LIFE) power plant in the mid-2030s timeframe are presented. The required laser energy driver is 2.2 MJ at a 0.351-{micro}m wavelength, and a fusion target gain greater than 60 at a repetition rate of 16 Hz is the design goal for economic and commercial attractiveness. A scaling-law analysis is developed to benchmark the design parameter space for hohlraum-driven central hot-spot ignition. A suite of integrated hohlraum simulations is presented to test the modeling assumptions and provide a basis for a near-term experimental resolution of the key physics uncertainties on the National Ignition Facility (NIF). The NIF is poised to demonstrate ignition by 2012 based on the central hot spot (CHS) mode of ignition and propagating thermonuclear burn [1]. This immediate prospect underscores the imperative and timeliness of advancing inertial fusion as a carbon-free, virtually limitless source of energy by the mid-21st century to substantially offset fossil fuel technologies. To this end, an intensive effort is underway to leverage success at the NIF and to provide the foundations for a prototype 'LIFE.1' engineering test facility by {approx}2025, followed by a commercially viable 'LIFE.2' demonstration power plant operating at 1 GWe by {approx}2035. The current design goal for LIFE.2 is to accommodate {approx}2.2 MJ of laser energy (entering the high-Z radiation enclosure or 'hohlraum') at a 0.351-{micro}m wavelength operating at a repetition rate of 16 Hz and to provide a fusion target yield of 132 MJ. To achieve this design goal first requires a '0-d' analytic gain model that allows convenient exploration of parameter space and target optimization. This step is then followed by 2- and 3-dimensional radiation-hydrodynamics simulations that incorporate laser beam transport, x-ray radiation transport, atomic physics, and

  2. Overview of small optics for the National Ignition Facility

    SciTech Connect

    Aikens, D; Bissinger, H D

    1999-07-01

    LLNL's project to construct the National Ignition Facility (NIF), a 192 beam laser system capable of generating enough light energy necessary to achieve fusion ignition, will require 26,641 small optics, many of which will be supplied in the form of cleaned, tested and aligned assemblies. These assemblies will be built to print, cleaned to specifications, and tested to performance specifications, ready to be installed in the laser system. A wide range of potential suppliers will participate in the manufacture of these sophisticated opto-mechanical systems. The injection laser system requires 7,440 precision optical components manufactured to state of the art performance specifications. In addition to 550 aspheric lenses, almost 2,000 precision spherical elements are required. Wave-fronts are specified in terms of P-V, RMS and RMS Gradient wave-front error, with strict requirements on the filtering and resolution which is required. Precision polarizers, high reflectors, leaking mirrors, high damage threshold coatings and cleanliness levels of 50 to 100 are also specified for this section of the NIF laser. The alignment and diagnostics systems for the NIF require 19,201 optics, many of which have requirements that exceed those of the injection laser system. All of these optics will be purchased using the ISO 10110 drawing notations. Other sections of the laser system will utilize commercial, off the shelf components to control cost. This paper will give an overview of the project and its objectives, with specific attention to the small optics required for the NIF. Keywords: NIF, small optics, overview, components.

  3. Space Station Cathode Ignition Test Status at 32,000 Cycles

    NASA Technical Reports Server (NTRS)

    Zakany, James S.; Pinero, Luis R.

    1997-01-01

    A plasma contactor system has been baselined for the International Space Station for structural potential control. An ignition procedure was developed for the plasma contactor hollow cathode assembly (HCA). To demonstrate the required 99% HCA ignition reliability over 6,000 cycles, an ignition test was conducted. An accelerated test procedure was employed to rapidly accumulate ignition cycles. The test procedure minimized the differences between accelerated and non-accelerated test results. The development HCA used in this test has achieved 32,000 ignitions to date. The HCA has been qualified for cyclic operation, which could reduce xenon consumption and extend the life of the plasma contactor system.

  4. Spinal fusion

    MedlinePlus

    ... Anterior spinal fusion; Spine surgery - spinal fusion; Low back pain - fusion; Herniated disk - fusion ... If you had chronic back pain before surgery, you will likely still have some pain afterward. Spinal fusion is unlikely to take away all your pain ...

  5. Demonstration of the shock-timing technique for ignition targets on the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Boehly, T. R.; Munro, D.; Celliers, P. M.; Olson, R. E.; Hicks, D. G.; Goncharov, V. N.; Collins, G. W.; Robey, H. F.; Hu, S. X.; Morozas, J. A.; Sangster, T. C.; Landen, O. L.; Meyerhofer, D. D.

    2009-05-01

    A high-performance inertial confinement fusion capsule is compressed by multiple shock waves before it implodes. To minimize the entropy acquired by the fuel, the strength and timing of those shock waves must be accurately controlled. Ignition experiments at the National Ignition Facility (NIF) will employ surrogate targets designed to mimic ignition targets while making it possible to measure the shock velocities inside the capsule. A series of experiments on the OMEGA laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)] validated those targets and the diagnostic techniques proposed. Quartz was selected for the diagnostic window and shock-velocity measurements were demonstrated in Hohlraum targets heated to 180 eV. Cryogenic experiments using targets filled with liquid deuterium further demonstrated the entire timing technique in a Hohlraum environment. Direct-drive cryogenic targets with multiple spherical shocks were used to further validate this technique, including convergence effects at relevant pressures (velocities) and sizes. These results provide confidence that shock velocity and timing can be measured in NIF ignition targets, allowing these critical parameters to be optimized.

  6. Design of laser-driven shock ignition targets

    NASA Astrophysics Data System (ADS)

    Schmitt, Andrew J.; Bates, J. W.; Obenschain, S. P.; Fyfe, D. E.; Zalesak, S. T.

    2009-11-01

    Shock ignition target designs can produce high gains at modest driver energies.footnotetextR. Betti, C.D. Zhou, K.S. Anderson, et al., Phys. Rev. Lett. 98, 155001 High resolution 2D simulations that include nominal pellet perturbations have shown that gains well over 100 can be generated with targets driven by short-wavelength sub-megajoule KrF lasers.footnotetextA.J. Schmitt, J.W. Bates, S.P. Obenschain et al., Fusion Sci.Tech. 56, 377 (2009). A key feature of shock ignition is the separation of the compression and ignition parts of the target assembly. allowing independent control. We use a simple theoretical model of the assembled pellet to demonstrate how to optimize this separation, and show how it differs from optimized fast ignition and conventional central ignition designs. We also address the issue of high convergence ratios found in previous simulations of shock ignition targets,^2 which can lead to greater sensitivity of the target gain to low-mode pellet asymmetries. We investigate techniques to minimize both this sensitivity, and present 2D simulations that demonstrate the effectiveness of these strategies. Work supported by US DoE/NNSA.

  7. Ignition timing control

    SciTech Connect

    Lambert, J.E.; Bedross, G.M.

    1993-05-25

    An engine ignition control system for controlling the timing of the spark for initiating burning in the combustion chamber of a four stroke cycle, single cylinder, internal combustion engine is described; said engine having a cylinder, a piston in said cylinder, a crankshaft connected to said piston, said piston being adapted to reciprocate between a top dead center position and a bottom dead center position; a speed sensor means for developing periodic sensor voltage timing pulses, the cycle time between timing pulses being an indication of engine crankshaft speed; means for developing ignition timing pulses, each timing pulse having a leading edge corresponding to a voltage change in a timing voltage pulse and a trailing edge corresponding to an opposite voltage change in a timing voltage pulse; means for developing a spark voltage including an ignition coil and a source of ignition coil current, said spark voltage occurring at a coil primary current interrupt point; means for measuring in real-time, cycle time and a timing pulse time for one engine cycle; and means for computing an optimum delay time from the leading edge of a timing pulse for said one cycle to said interrupt point whereby combustion is initiated at a time in advance of the top dead center position.

  8. Pathway to a lower cost high repetition rate ignition facility

    SciTech Connect

    Obenschain, S.P.; Colombant, D.G.; Schmitt, A.J.; Sethian, J.D.; McGeoch, M. W.

    2006-05-15

    An approach to a high-repetition ignition facility based on direct drive with the krypton-fluoride laser is presented. The objective is development of a 'Fusion Test Facility' that has sufficient fusion power to be useful as a development test bed for power plant materials and components. Calculations with modern pellet designs indicate that laser energies well below a megajoule may be sufficient. A smaller driver would result in an overall smaller, less complex and lower cost facility. While this facility might appear to have most direct utility to inertial fusion energy, the high flux of neutrons would also be able to address important issues concerning materials and components for other approaches to fusion energy. The physics and technological basis for the Fusion Test Facility are presented along with a discussion of its applications.

  9. Fielding the NIF Cryogenic Ignition Target

    SciTech Connect

    Malsbury, T; Haid, B; Gibson, C; Atkinson, D; Skulina, K; Klingmann, J; Atherton, J; Mapoles, E; Kozioziemski, B; Dzenitis, E

    2008-02-28

    The United States Department of Energy has embarked on a campaign to conduct credible fusion ignition experiments on the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in 2010. The target assembly specified for this campaign requires the formation of a deuterium/tritium (DT) fuel ice layer on the inside of a 2 millimeter diameter capsule positioned at the center of a 9 millimeter long by 5 millimeter diameter cylinder, called a hohlraum. The ice layer requires micrometer level accuracy and must be formed and maintained at temperatures below 19 K. At NIF shot time, the target must be positioned at the center of the NIF 10 meter diameter target chamber, aligned to the laser beam lines and held stable to less than 7 micrometers rms. We have completed the final design and are integrating the systems necessary to create, characterize and field the cryogenic target for ignition experiments. These designs, with emphasis on the challenges of fielding a precision cryogenic positioning system will be presented.

  10. Diagnostics for fast ignition science (invited)

    SciTech Connect

    MacPhee, A. G.; Chen, C. D.; Chen, H.; Hey, D. S.; Kemp, A. J.; Key, M. H.; Le Pape, S.; Patel, P. K.; Phillips, T. W.; Town, R.; Mackinnon, A. J.; Akli, K. U.; Stephens, R. B.; Beg, F. N.; King, J. A.; Ma, T. Y.; Wei, M. S.; Clarke, R.; Freeman, R. R.; Link, A.

    2008-10-15

    The ignition concept for electron fast ignition inertial confinement fusion requires sufficient energy be transferred from an {approx}20 ps laser pulse to the compressed fuel via approximately MeV electrons. We have assembled a suite of diagnostics to characterize such transfer, simultaneously fielding absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256 eV; spherically bent crystal imagers at 4.5 and 8 keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung, electron and proton spectrometers (along the same line of sight), and a picosecond optical probe interferometer. These diagnostics allow careful measurement of energy transport and deposition during and following the laser-plasma interactions at extremely high intensities in both planar and conical targets. Together with accurate on-shot laser focal spot and prepulse characterization, these measurements are yielding new insights into energy coupling and are providing critical data for validating numerical particle-in-cell (PIC) and hybrid PIC simulation codes in an area crucial for fast ignition and other applications. Novel aspects of these diagnostics and how they are combined to extract quantitative data on ultrahigh intensity laser-plasma interactions are discussed.

  11. Laser–plasma interactions for fast ignition

    SciTech Connect

    Kemp, A. J.; Fiuza, F.; Debayle, A.; Johzaki, T.; Mori, W. B.; Patel, P. K.; Sentoku, Y.; Silva, L. O.

    2014-04-17

    In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser- plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multidimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporal evolution. Scaling with irradiation conditions such as laser intensity, f-number and wavelength are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the comparison of simulation results with experimental observables. In particular, we address the question of surrogacy of today's experiments for the full-scale fast ignition problem.

  12. Laser–plasma interactions for fast ignition

    DOE PAGESBeta

    Kemp, A. J.; Fiuza, F.; Debayle, A.; Johzaki, T.; Mori, W. B.; Patel, P. K.; Sentoku, Y.; Silva, L. O.

    2014-04-17

    In the electron-driven fast-ignition approach to inertial confinement fusion, petawatt laser pulses are required to generate MeV electrons that deposit several tens of kilojoules in the compressed core of an imploded DT shell. We review recent progress in the understanding of intense laser- plasma interactions (LPI) relevant to fast ignition. Increases in computational and modeling capabilities, as well as algorithmic developments have led to enhancement in our ability to perform multidimensional particle-in-cell (PIC) simulations of LPI at relevant scales. We discuss the physics of the interaction in terms of laser absorption fraction, the laser-generated electron spectra, divergence, and their temporalmore » evolution. Scaling with irradiation conditions such as laser intensity, f-number and wavelength are considered, as well as the dependence on plasma parameters. Different numerical modeling approaches and configurations are addressed, providing an overview of the modeling capabilities and limitations. In addition, we discuss the comparison of simulation results with experimental observables. In particular, we address the question of surrogacy of today's experiments for the full-scale fast ignition problem.« less

  13. Diagnostics for fast ignition science (invited).

    PubMed

    MacPhee, A G; Akli, K U; Beg, F N; Chen, C D; Chen, H; Clarke, R; Hey, D S; Freeman, R R; Kemp, A J; Key, M H; King, J A; Le Pape, S; Link, A; Ma, T Y; Nakamura, H; Offermann, D T; Ovchinnikov, V M; Patel, P K; Phillips, T W; Stephens, R B; Town, R; Tsui, Y Y; Wei, M S; Van Woerkom, L D; Mackinnon, A J

    2008-10-01

    The ignition concept for electron fast ignition inertial confinement fusion requires sufficient energy be transferred from an approximately 20 ps laser pulse to the compressed fuel via approximately MeV electrons. We have assembled a suite of diagnostics to characterize such transfer, simultaneously fielding absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256 eV; spherically bent crystal imagers at 4.5 and 8 keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung, electron and proton spectrometers (along the same line of sight), and a picosecond optical probe interferometer. These diagnostics allow careful measurement of energy transport and deposition during and following the laser-plasma interactions at extremely high intensities in both planar and conical targets. Together with accurate on-shot laser focal spot and prepulse characterization, these measurements are yielding new insights into energy coupling and are providing critical data for validating numerical particle-in-cell (PIC) and hybrid PIC simulation codes in an area crucial for fast ignition and other applications. Novel aspects of these diagnostics and how they are combined to extract quantitative data on ultrahigh intensity laser-plasma interactions are discussed. PMID:19044615

  14. The Progress of Research Project for Magnetized Target Fusion in China

    NASA Astrophysics Data System (ADS)

    Yang, Xian-Jun

    2015-11-01

    The fusion of magnetized plasma called Magnetized Target Fusion (MTF) is a hot research area recently. It may significantly reduce the cost and size. Great progress has been achieved in past decades around the world. Five years ago, China initiated the MTF project and has gotten some progress as follows: 1. Verifying the feasibility of ignition of MTF by means of first principle and MHD simulation; 2. Generating the magnetic field over 1400 Tesla, which can be suppress the heat conduction from charged particles, deposit the energy of alpha particle to promote the ignition process, and produce the stable magnetized plasma for the target of ignition; 3. The imploding facility of FP-1 can put several Mega Joule energy to the solid liner of about ten gram in the range of microsecond risen time, while the simulating tool has been developed for design and analysis of the process; 4. The target of FRC can be generated by ``YG 1 facility'' while some simulating tools have be developed. Next five years, the above theoretical work and the experiments of MTF may be integrated to step up as the National project, which may make my term play an important lead role and be supposed to achieve farther progress in China. Supported by the National Natural Science Foundation of China under Grant No 11175028.

  15. Study of Rayleigh–Taylor growth in laser irradiated planar SiO{sub 2} targets at ignition-relevant conditions

    SciTech Connect

    Hager, J. D.; Collins, T. J. B.; Knauer, J. P.; Meyerhofer, D. D.; Sangster, T. C.; Smalyuk, V. A.

    2013-07-15

    Rayleigh–Taylor (RT) growth experiments were performed on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] using planar SiO{sub 2} targets seeded with a single mode 60-μm wavelength perturbation driven at peak laser intensities up to 9 × 10{sup 14} W/cm{sup 2}. These are the first RT measurements in SiO{sub 2} at conditions relevant to direct-drive inertial confinement fusion ignition. The measured average modulation growth rates agree with the 2-D hydrodynamics code DRACO, providing an important step in the development of target ablators that are robust to RT growth and hot- electron preheat considerations when driven at the intensities required to achieve thermonuclear ignition.

  16. Ushering in A New Era in Lasers: The National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Moses, Edward I.

    2008-04-01

    The world's largest ultraviolet laser, the National Ignition Facility (NIF), under construction at Lawrence Livermore National Laboratory, is scheduled to be complete by March 2009. NIF focuses on three main missions: support of stockpile stewardship to ensure a safe and reliable nuclear stockpile, demonstrating the feasibility of inertial confinement fusion (ICF) as a clean source of energy, and enabling high-energy-density (HED) science to help understand the physical processes that drive the cosmos. These three missions share the need to study materials at extreme conditions: temperatures up to 108 K, densities approaching 1000 grams per cc, and pressures up to 10^10 megapascals. Moreover, in fusion events NIF will produce, for a short time, a neutron density up to 10^21 cm-3. These conditions occur only in the interiors of stars, during thermonuclear burn, and in supernova events. NIF's next set of experiments, to study the systematics of ICF, is scheduled to begin in 2008 with the goal of conducting a credible ignition experiment by 2010. NIF will also conduct a variety of basic science experiments that will include laser-plasma interactions; solids at extremely high pressure leading to information about planetary interiors; hydrodynamic instabilities; and nuclear astrophysics. By 2010, NIF will be managed as a national user facility to best exploit its scientific potential. Users of NIF will include researchers from the Department of Energy national laboratories, scientists from academia, and other national and international users. Nuckolls, Wood, and Thiessen proposed ICF half a century ago, within weeks of the first demonstration of a working laser. Successive generations of lasers were built with the goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory for more than half a century. With the completion of NIF that long-sought goal will be much closer to realization. The talk will focus on NIF technical capabilities and the

  17. Design and Construction of a Gamma Reaction History Diagnostic for the National Ignition Facility

    SciTech Connect

    R.M. Malone, B.C. Cox, B.C. Frogget, M.I. Kaufman, T.W. Tunnell; H.W. Herrmann, S.C. Evans, J.M. Mack, C.S. Young; W. Stoeffl

    2009-06-05

    Gas Cherenkov detectors have been used to convert fusion gammas into photons to achieve gamma reaction history (GRH) measurements. These gas detectors include a converter, pressurized gas volume, relay optics, and a photon detector. A novel design for the National Ignition Facility (NIF) using 90º Off-Axis Parabolic mirrors efficiently collects signal from fusion gammas with 8-ps time dispersion.1 Fusion gammas are converted to Compton electrons, which generate broadband Cherenkov light (our response is from 250 to 700 nm) in a pressurized gas cell. This light is relayed into a high-speed detector using three parabolic mirrors. The detector optics collect light from a 125-mm-diameter by 600-mm-long interchangeable gas (CO2 or SF6) volume. Because light is collected from source locations throughout the gas volume, the detector is positioned at the stop position rather than at an image position. The stop diameter and its position are independent of the light-generation locations along the gas cell. This design incorporates a fixed time delay that allows the detector to recover from prompt radiation. Optical ray tracings demonstrate how light can be collected from different angled trajectories of the Compton electrons as they traverse the gas volume. A Monte Carlo model of the conversion process from gammas to Cherenkov photons is used to generate photon trajectories. The collection efficiencies for different gamma energies are evaluated. At NIF, a cluster of four channels will allow for increased dynamic range, as well as different gamma energy thresholds. This GRH design is compared to a gas Cherenkov detector that utilizes a Cassegrain reflector now used at the OMEGA laser facility. 1. R. M. Malone, H. W. Herrmann, W. Stoeffl, J. M. Mack, C. S. Young, “Gamma bang time/reaction history diagnostics for the National Ignition Facility using 90º off-axis parabolic mirrors,” Rev. Sci. Instrum. 79, 10E532 (2008).

  18. Inertial Confinement Fusion R&D and Nuclear Proliferation

    SciTech Connect

    Robert J. Goldston

    2011-04-28

    In a few months, or a few years, the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory may achieve fusion gain using 192 powerful lasers to generate x-rays that will compress and heat a small target containing isotopes of hydrogen. This event would mark a major milestone after decades of research on inertial confinement fusion (ICF). It might also mark the beginning of an accelerated global effort to harness fusion energy based on this science and technology. Unlike magnetic confinement fusion (ITER, 2011), in which hot fusion fuel is confined continuously by strong magnetic fields, inertial confinement fusion involves repetitive fusion explosions, taking advantage of some aspects of the science learned from the design and testing of hydrogen bombs. The NIF was built primarily because of the information it would provide on weapons physics, helping the United States to steward its stockpile of nuclear weapons without further underground testing. The U.S. National Academies' National Research Council is now hosting a study to assess the prospects for energy from inertial confinement fusion. While this study has a classified sub-panel on target physics, it has not been charged with examining the potential nuclear proliferation risks associated with ICF R&D. We argue here that this question urgently requires direct and transparent examination, so that means to mitigate risks can be assessed, and the potential residual risks can be balanced against the potential benefits, now being assessed by the NRC. This concern is not new (Holdren, 1978), but its urgency is now higher than ever before.

  19. Equilibrium ignition for ICF capsules

    SciTech Connect

    Lackner, K.S.; Colgate, S.A.; Johnson, N.L.; Kirkpatrick, R.C.; Menikoff, R.; Petschek, A.G.

    1993-12-31

    There are two fundamentally different approaches to igniting DT fuel in an ICF capsule which can be described as equilibrium and hot spot ignition. In both cases, a capsule which can be thought of as a pusher containing the DT fuel is imploded until the fuel reaches ignition conditions. In comparing high-gain ICF targets using cryogenic DT for a pusher with equilibrium ignition targets using high-Z pushers which contain the radiation. The authors point to the intrinsic advantages of the latter. Equilibrium or volume ignition sacrifices high gain for lower losses, lower ignition temperature, lower implosion velocity and lower sensitivity of the more robust capsule to small fluctuations and asymmetries in the drive system. The reduction in gain is about a factor of 2.5, which is small enough to make the more robust equilibrium ignition an attractive alternative.

  20. Alpha Heating and Burning Plasmas in Inertial Confinement Fusion

    NASA Astrophysics Data System (ADS)

    Betti, R.; Christopherson, A. R.; Bose, A.; Woo, K. M.

    2016-05-01

    Assessing the degree to which fusion alpha particles contribute to the fusion yield is essential to understanding the onset of the thermal runaway process of thermonuclear ignition. It is shown that in inertial confinement fusion, the yield enhancement due to alpha particle heating (before ignition occurs) depends on the generalized Lawson parameter that can be inferred from experimental observables. A universal curve valid for arbitrary laser-fusion targets shows the yield amplification due to alpha heating for a given value of the Lawson parameter. The same theory is used to determine the onset of the burning plasma regime when the alpha heating exceeds the compression work. This result can be used to assess the performance of current ignition experiments at the National Ignition Facility.

  1. PROGRESS TOWARDS MICROWAVE IGNITION OF EXPLOSIVES

    SciTech Connect

    Curling, Mark; Collins, Adam; Dima, Gabriel; Proud, William

    2009-12-28

    It is known that various materials are caused to spark when subjected to microwave radiation, and others can be heated to extremely high temperatures. This paper studies the behaviour of graphite under microwave radiation using a multi-mode 2.45 GHz+-50 Hz microwave cavity, and its potential applications in propellant ignition systems. Evidence for a correlation between sample mass and arcing intensity is presented, and a linear relationship between sample mass and temperature is found. Both graphite powder and flakes show increasing arcing intensity with increasing mass up to approx150 mg, after which the behaviour is more dispersed. The temperature achieved increases linearly with increasing mass, with maximum temperatures of 1,011 deg. C and 657 deg. C achieved for powder (<0.1 mm) and flakes respectively--well above thermal ignition temperatures for most common explosives.

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

    SciTech Connect

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

    2014-05-15

    Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of α ≃ 4, an implosion velocity of 3.8 × 10{sup 7} cm/s, and a laser intensity of ∼10{sup 15} W/cm{sup 2}. These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.

  3. Status of fusion research and implications for D/He-3 systems

    NASA Astrophysics Data System (ADS)

    Miley, George H.

    1988-09-01

    World wide programs in both magnetic confinement and inertial confinement fusion research have made steady progress towards the experimental demonstration of energy breakeven. However, after breakeven is achieved, considerable time and effort must still be expended to develop a usable power plant. The main program described is focused on Deuterium-Tritium devices. In magnetic confinement, three of the most promising high beta approaches with a reasonable experimental data base are the Field Reversed Configuration, the high field tokamak, and the dense Z-pinch. The situation is less clear in inertial confinement where the first step requires an experimental demonstration of D/T spark ignition. It appears that fusion research has reached a point in time where an R and D plan to develop a D/He-3 fusion reactor can be laid out with some confidence of success.

  4. Status of fusion research and implications for D/He-3 systems

    NASA Technical Reports Server (NTRS)

    Miley, George H.

    1988-01-01

    World wide programs in both magnetic confinement and inertial confinement fusion research have made steady progress towards the experimental demonstration of energy breakeven. However, after breakeven is achieved, considerable time and effort must still be expended to develop a usable power plant. The main program described is focused on Deuterium-Tritium devices. In magnetic confinement, three of the most promising high beta approaches with a reasonable experimental data base are the Field Reversed Configuration, the high field tokamak, and the dense Z-pinch. The situation is less clear in inertial confinement where the first step requires an experimental demonstration of D/T spark ignition. It appears that fusion research has reached a point in time where an R and D plan to develop a D/He-3 fusion reactor can be laid out with some confidence of success.

  5. Simulation Study of Ignition and Burn Characteristics of Fast Ignition DT Targets

    NASA Astrophysics Data System (ADS)

    Johzaki, Tomoyuki; Mima, Kunioki; Nakao, Yasuyuki

    The ignition and burn properties of fast ignition DT targets are evaluated for various-sized core (ignition experiment ˜ high gain) on the basis of two-dimensional (2D) burn simulations. A core size of ρR 2.0 g/cm2 is required to achieve explosive burning and then high gain. When the core size is smaller, the target gain drops sharply as core size decreases. Assuming the energy coupling efficiencies from laser to core of 5 % for implosion and 30 % for heating, a target gain of ˜170 is obtained with a 1 MJ implosion laser and a 70 kJ heating laser, under optimum heating conditions (10 ps duration, 15 μm spot radius, and 1.0 g/cm2 heating depth). This requires a very high intensity heating laser (˜ 1 × 1021 W/cm2). In accordance with a scaling for temperature of fast electrons generated by long-duration intense lasers, such a intense laser will generate fast electrons having suitable stopping range for efficient core heating. The sensitivities of ignition condition and gain performance to heating conditions, and the influence of high-Z ions contained in a foam layer on ignition and gain performance are also discussed.

  6. Ablation driven by hot electrons generated during the ignitor laser pulse in shock ignition

    NASA Astrophysics Data System (ADS)

    Piriz, A. R.; Rodriguez Prieto, G.; Tahir, N. A.; Zhang, Y.; Liu, S. D.; Zhao, Y. T.

    2012-12-01

    An analytical model for the ablation driven by hot electrons is presented. The hot electrons are assumed to be generated during the high intensity laser spike used to produce the ignitor shock wave in the shock ignition driven inertial fusion concept, and to carry on the absorbed laser energy in its totality. Efficient energy coupling requires to keep the critical surface sufficiently close to the ablation front and this goal can be achieved for high laser intensities provided that the laser wavelength is short enough. Scaling laws for the ablation pressure and the other relevant magnitudes of the ablation cloud are found in terms of the laser and target parameters. The effect of the preformed plasma assembled by the compression pulse, previous to the ignitor, is also discussed. It is found that a minimum ratio between the compression and the ignitor pulses would be necessary for the adequate matching of the corresponding scale lengths.

  7. A Randomized Controlled Trial of the Impact of the Fusion Reading Intervention on Reading Achievement and Motivation for Adolescent Struggling Readers

    ERIC Educational Resources Information Center

    Schiller, Ellen; Wei, Xin; Thayer, Sara; Blackorby, Jose; Javitz, Harold; Williamson, Cyndi

    2012-01-01

    This study estimates the effect of one year of Fusion Reading implementation, a multistrategy intervention, builds on the work of the Strategic Instruction Model's Learning Strategies Curriculum and Xtreme Reading by integrating some of the same strategies (e.g., paraphrasing, visual imagery, and self-questioning for information acquisition;…

  8. Understanding Fuel Magnetization and Mix Using Secondary Nuclear Reactions in Magneto-Inertial Fusion

    NASA Astrophysics Data System (ADS)

    Schmit, P. F.; Knapp, P. F.; Hansen, S. B.; Gomez, M. R.; Hahn, K. D.; Sinars, D. B.; Peterson, K. J.; Slutz, S. A.; Sefkow, A. B.; Awe, T. J.; Harding, E.; Jennings, C. A.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Geissel, M.; Harvey-Thompson, A. J.; Herrmann, M. C.; Hess, M. H.; Johns, O.; Lamppa, D. C.; Martin, M. R.; McBride, R. D.; Porter, J. L.; Robertson, G. K.; Rochau, G. A.; Rovang, D. C.; Ruiz, C. L.; Savage, M. E.; Smith, I. C.; Stygar, W. A.; Vesey, R. A.

    2014-10-01

    Magnetizing the fuel in inertial confinement fusion relaxes ignition requirements by reducing thermal conductivity and changing the physics of burn product confinement. Diagnosing the level of fuel magnetization during burn is critical to understanding target performance in magneto-inertial fusion (MIF) implosions. In pure deuterium fusion plasma, 1.01 MeV tritons are emitted during deuterium-deuterium fusion and can undergo secondary deuterium-tritium reactions before exiting the fuel. Increasing the fuel magnetization elongates the path lengths through the fuel of some of the tritons, enhancing their probability of reaction. Based on this feature, a method to diagnose fuel magnetization using the ratio of overall deuterium-tritium to deuterium-deuterium neutron yields is developed. Analysis of anisotropies in the secondary neutron energy spectra further constrain the measurement. Secondary reactions also are shown to provide an upper bound for the volumetric fuel-pusher mix in MIF. The analysis is applied to recent MIF experiments [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014), 10.1103/PhysRevLett.113.155003] on the Z Pulsed Power Facility, indicating that significant magnetic confinement of charged burn products was achieved and suggesting a relatively low-mix environment. Both of these are essential features of future ignition-scale MIF designs.

  9. Understanding fuel magnetization and mix using secondary nuclear reactions in magneto-inertial fusion.

    PubMed

    Schmit, P F; Knapp, P F; Hansen, S B; Gomez, M R; Hahn, K D; Sinars, D B; Peterson, K J; Slutz, S A; Sefkow, A B; Awe, T J; Harding, E; Jennings, C A; Chandler, G A; Cooper, G W; Cuneo, M E; Geissel, M; Harvey-Thompson, A J; Herrmann, M C; Hess, M H; Johns, O; Lamppa, D C; Martin, M R; McBride, R D; Porter, J L; Robertson, G K; Rochau, G A; Rovang, D C; Ruiz, C L; Savage, M E; Smith, I C; Stygar, W A; Vesey, R A

    2014-10-10

    Magnetizing the fuel in inertial confinement fusion relaxes ignition requirements by reducing thermal conductivity and changing the physics of burn product confinement. Diagnosing the level of fuel magnetization during burn is critical to understanding target performance in magneto-inertial fusion (MIF) implosions. In pure deuterium fusion plasma, 1.01 MeV tritons are emitted during deuterium-deuterium fusion and can undergo secondary deuterium-tritium reactions before exiting the fuel. Increasing the fuel magnetization elongates the path lengths through the fuel of some of the tritons, enhancing their probability of reaction. Based on this feature, a method to diagnose fuel magnetization using the ratio of overall deuterium-tritium to deuterium-deuterium neutron yields is developed. Analysis of anisotropies in the secondary neutron energy spectra further constrain the measurement. Secondary reactions also are shown to provide an upper bound for the volumetric fuel-pusher mix in MIF. The analysis is applied to recent MIF experiments [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] on the Z Pulsed Power Facility, indicating that significant magnetic confinement of charged burn products was achieved and suggesting a relatively low-mix environment. Both of these are essential features of future ignition-scale MIF designs. PMID:25375715

  10. Progress of laser fusion in the last 40 years and expected prosperous applications

    NASA Astrophysics Data System (ADS)

    Yamanaka, C.

    2008-05-01

    Inertial confinement fusion has remarkably developed in the last 40 years. In the 21st century, we can expect fusion energy for civilian use. We had performed two types of fusion experiments: High Temperature Demonstration and High Density Demonstration. The former experiment attained a neutron yield 1013 using the LHART target driven by the GEKKO XII laser. The latter achieved the 1000 times normal density using the random phased laser beams which realized the Edward Teller proposal of IQEC 1972. Now, the FIREX project to explore fast ignition is going on. The heating process of energetic electrons as well as ions is a key issue of the fast ignition. Investigation on the extreme condition of plasma in high density and high temperature which are introduced by the PW laser give us a new field of nuclear science. On the way to the final fusion goal, we can expect various fruits in the field of high power laser applications, such as laser-induced nuclear reaction, EUV light source for lithography, nuclear transmutation, laser astrophysics, medical application of particle beam and so on.

  11. 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.

  12. Monolithic catalytic igniters

    NASA Technical Reports Server (NTRS)

    La Ferla, R.; Tuffias, R. H.; Jang, Q.

    1993-01-01

    Catalytic igniters offer the potential for excellent reliability and simplicity for use with the diergolic bipropellant oxygen/hydrogen as well as with the monopropellant hydrazine. State-of-the-art catalyst beds - noble metal/granular pellet carriers - currently used in hydrazine engines are limited by carrier stability, which limits the hot-fire temperature, and by poor thermal response due to the large thermal mass. Moreover, questions remain with regard to longevity and reliability of these catalysts. In this work, Ultramet investigated the feasibility of fabricating monolithic catalyst beds that overcome the limitations of current catalytic igniters via a combination of chemical vapor deposition (CVD) iridium coatings and chemical vapor infiltration (CVI) refractory ceramic foams. It was found that under all flow conditions and O2:H2 mass ratios tested, a high surface area monolithic bed outperformed a Shell 405 bed. Additionally, it was found that monolithic catalytic igniters, specifically porous ceramic foams fabricated by CVD/CVI processing, can be fabricated whose catalytic performance is better than Shell 405 and with significantly lower flow restriction, from materials that can operate at 2000 C or higher.

  13. 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.

  14. A pathway to laser fusion energy in Japan

    NASA Astrophysics Data System (ADS)

    Azechi, Hiroshi

    2016-05-01

    High-density compression of DT to one thousand times its liquid density is the critical path of inertial fusion and was demonstrated in Japan and US in late 1980's. The Osaka group has achieved high-density compression that meets one of the critical requirements for thermonuclear ignition and burn. Although the compression densities were well reproduced by computer simulations, the neutron yields were much lower than the simulation predictions by three orders of magnitudes, suggesting catastrophic collapse of a hot spark, from which thermonuclear reactions are triggered. In order to overcome this difficulty the international ICF community has adopted two approaches: one is to generate a larger hot spark than the mixed layer with MJ-Class lasers, such as NIF and LMJ. The other approach is to externally heat the compressed fuel. The second approach is the fast ignition. After the proof-of-concept experiment in 2002, we started the Fast Ignition Realization Experiment (FIREX) project to complete the world most powerful high-energy peta-watt laser “LFEX” as a heating laser.

  15. Target area chamber system design for the National Ignition Facility

    SciTech Connect

    Wavrik, R.; Boyes, J.; Olson, C.; Dempsey, F.; Garcia, R.; Karpenko, V.; Anderson, A.; Tobin, M.; Latkowski, J.

    1994-06-01

    The National Ignition Facility (NIF) is a proposed Department of Energy facility which will contribute to the resolution of important Defense Program and inertial fusion energy issues for energy production in the future. The NIF will consist of a laser system with 192 independent beamlets transported to a target chamber. The target chamber is a multi-purpose structure that provides the interface between the target and the laser optics. The chamber must be capable of achieving moderate vacuum levels in reasonable times; it must remain dimensionally stable within micron tolerances, provide support for the optics, diagnostics, and target positioner; it must minimize the debris from the x-ray and laser light environments; and it must be capable of supporting external neutron shielding. The chamber must also be fabricated from a low activation material. The fusion reaction in the target gives off neutrons, x-ray and gamma rays. The x-rays and gamma rays interact with the interior of the target chamber wall while neutrons penetrate the wall. In order to minimize the neutron activation of components outside the target chamber and to absorb gammas emitted from the activated chamber, shielding will be placed immediately outside the chamber. The target chamber contains the target positioner. The target positioner moves the target from outside the chamber to the center of the chamber and positions the target at the focal spot of the laser beams. The target positioner must be survivable in a harsh radioactive environment. The materials used must be low activation and have a high stiffness to weight ratio to maintain target stability. This paper describes the conceptual design of the target chamber, target postioner, and shielding for the NIF.

  16. Site selection study for Sandia National Laboratories/New Mexico as an alternative site for the National Ignition Facility

    SciTech Connect

    Miller, D.; Wheeler, T.; McClellan, Y.

    1996-03-01

    The Department of Energy (DOE) proposes to construct and operate the National Ignition Facility (NIF) in support of the Stockpile Stewardship and Management (SSM) Programmatic Environmental impact Statement (PEIS). The National Environmental Policy Act requires the DOE to look at alternative sites for the NIF. The SSM PEIS will evaluate four alternative locations for the NIF. This study documents the process and results of a site selection study for a preferred site for the NIF at SNL/NM. The NIF research objectives are to provide the world`s most powerful laser systems to be used in ignition of fusion fuel and energy gain to perform high energy density and radiation effects experiments in support of the DOE`s national security, energy, and basic science research mission. The most immediate application of the NIF will be to provide nuclear-weapon-related physics data, since many phenomena occurring on the laboratory scale are similar to those that occur in weapons. The NIF may also provide an important capability for weapons effects simulation. The NIF is designed to achieve propagating fusion bum and modest energy gain for development as a source of civilian energy.

  17. Comparison of measured soft x-ray drive with shock and capsule implosion velocity for ignition tuning experiments on NIF

    NASA Astrophysics Data System (ADS)

    Kline, J.; Callahan, D.; Meezan, N.; Glenzer, S.; MacKinnon, A.; Dixit, S.; Kyrala, G.; Widmann, K.; Robey, H.; Clark, D.; Jones, O.; Hicks, D.; Celliers, P.; Farley, D.; Town, R.; Kalantar, D.; Dewald, E.; Moore, A.; Olson, R.; Doeppner, T.; Moody, J.; Ralph, J.; Thomas, C.; Landen, O.; Edwards, M.

    2011-10-01

    Indirect drive inertial confinement fusion experiments use high-Z hohlraums to convert laser energy to soft x-ray energy. The soft x-rays then drive the capsule via material ablation to compress the fuel payload and heat the central hot spot to initiate ignition. To achieve the highest fuel compression, a shaped radiation drive is used launching multiple shocks timed minimizes fuel entropy. The strength and velocity of these shocks depend directly on the radiation drive. The main laser pulse is then used to drive the implosion such that the PdV work can heat the central core to fusion conditions. To diagnose the soft x-ray drive in the hohlraum, Dante, an 18 channel soft x-ray spectrometer, measures the flux escaping the laser entrance hole. Measurements of this flux are used to assess the conditions for the capsule implosion. In this presentation, we will examine correlations between the soft x-ray measurements and shock velocity, as well as implosion velocity for recent ignition tuning experiments on NIF.

  18. Major Survey of the National Ignition Facility

    SciTech Connect

    Curnow, G; Nelson, D

    2000-07-27

    The National Ignition Facility (NIF) is an inertial confinement fusion project being built at Lawrence Livermore National Laboratory (LLNL) for the Department of Energy (DOE). The project is comprised of two buildings and the high technology equipment. The NIF houses 192 separate laser beams that generate approximately two megajoules of energy and 500 terawatts of power. The laser beams travel through a large optical system that contains over 7,500 large-aperture optical components (40 cm by 40 cm) and approximately 30,000 small-aperture optical components (less than 20 cm diameter). The NIF laser will be enclosed in a building that is approximately 200 meters in length (l) by 100 meters in width (w) by 15 meters in height (h) scheduled for completion by the end of 2002. A 0.5 mm target will be positioned inside a 10 meter sphere in the Target Building which measures approximately 35 meters (l) by 90 meters (w) by 30 meters (h). To achieve optimum laser operation the optics will require precision positioning and alignment. As a result, the mechanical components that support the optics require accurate positioning. State-of-the-art surveying, measuring techniques, and uncertainty and error analyses are being used to measure the control network and mechanical components. These include laser trackers, total stations, precision digital levels, and simulations of measurement scenarios. In February of this year the Lawrence Livermore National Laboratory NIF Precision Survey Group (PSG) completed a planned survey of the facility to establish an intermediate control network. This control network is to be used to begin installing the mechanical components, which include over 40 large vessels (3 x 3 x 10 meters), over the next year. The requirement is to have a control network accurate to +/- 3 mm, 3 sigma. The majority of the control network was measured using total stations and precision leveling. A laser tracker, in combination with total station and precision level

  19. Review of the magnetic fusion program by the 1986 ERAB Fusion Panel

    NASA Astrophysics Data System (ADS)

    Davidson, Ronald C.

    1987-09-01

    The 1986 ERAB Fusion Panel finds that fusion energy continues to be an attractive energy source with great potential for the future, and that the magnetic fusion program continues to make substantial technical progress. In addition, fusion research advances plasma physics, a sophisticated and useful branch of applied science, as well as technologies important to industry and defense. These factors fully justify the substantial expenditures by the Department of Energy in fusion research and development (R&D). The Panel endorses the overall program direction, strategy, and plans, and recognizes the importance and timeliness of proceeding with a burning plasma experiment, such as the proposed Compact Ignition Tokamak (CIT) experiment.

  20. Central ignition scenarios for TFTR

    SciTech Connect

    Zweben, S.J.; Redi, M.H.; Bateman, G.

    1986-03-01

    The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs.

  1. Ignition dynamics of high explosives

    SciTech Connect

    Ali, A.N.; Son, S.F.; Sander, R.K.; Asay, B.W.; Brewster, M.Q.

    1999-04-01

    The laser ignition of the explosives HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, C{sub 4}H{sub 8}N{sub 8}O{sub 8}), {delta}-phase HMX, PBX 9501 (95% HMX, 2.5% Estane, 2.5% BDNPA/BDNPF), TATB (1,3,5-triamino-2,4,6-trinitrobenzene, C{sub 6}H{sub 6}N{sub 6}O{sub 6}), and PBX 9502 (95% TATB, 5% Kel-F) and aged PBX 9502 has been conducted with the intent to compare the relative sensitivities of those explosives and to investigate the effect of beam profile, binder addition, and porosity. It has been found that there was little difference between a gaussian beam and a top hat profile on the laser ignition of HMX. The authors observe that the addition of binder in the amounts present in PBX 9501 resulted in longer ignition delays than that of HMX. In contrast to HMX, the addition of binder to TATB in PBX 9502 shows no measurable effect. Porosity effects were considered by comparing the ignition of granular HMX and pressed HMX pellets. Porosity appears to increase ignition delay due to an increased effective absorption scale and increased convective heat loss. This porosity effect also resulted in longer ignition delays for {delta}-phase HMX than for {beta}-phase HMX. In order to simulate ignition in voids or cracks, the standard ignition experiment was modified to include a NaCl window placed at variable distances above the sample surface. When ignition experiments were performed at 29 W/cm{sup 2} and 38 W/cm{sup 2} a critical gap distance was observed of 6 {+-} 0.4 mm below which ignition was severely inhibited. This result underscores the importance of gas phase processes in ignition and illustrates that conditions can exist where simple ignition criteria such as surface temperature is inadequate.

  2. Near-vacuum hohlraums for driving fusion implosions with high density carbon ablators

    NASA Astrophysics Data System (ADS)

    Berzak Hopkins, Laura

    2014-10-01

    Achieving ignition requires reaching fast implosion velocities, which highlights the need for a highly efficient hohlraum to drive indirect-drive inertial confinement fusion implosions. Gas-filled hohlraums are typically utilized due to the pulse length (15-20 ns) needed to drive plastic (CH) capsules. With the recent use of 3× denser high-density carbon (HDC) capsules, ignition pulses can be less than 10 ns in duration, providing the opportunity to utilize near-vacuum hohlraums (NVH) to drive ignition-relevant implosions on the National Ignition Facility (NIF) with minimal laser-plasma instabilities which complicate standard gas-filled hohlraums. Initial NVH implosions on the NIF have demonstrated coupling efficiency significantly higher than observed in gas-filled hohlraums - backscatter losses less than 2% and virtually no suprathermal electron generation. A major design challenge for the NVH is symmetry control. Without tamping gas, the hohlraum wall quickly expands filling the volume with gold plasma. However, results to-date indicate that the inner-cone beams propagate freely to the hohlraum wall for at least 6.5 ns. With minimal predicted cross-beam power transfer, this propagation enables symmetry control via dynamic beam phasing - time-dependent direct adjustment of the inner- and outer-cone laser pulses. A series of experiments with an HDC ablator and NVH culminated in a 6 ns, 1.2 MJ cryogenic DT layered implosion yielding 1.8 × 1015 neutrons--significantly higher yield than any CH implosion at comparable energy. This implosion reached an ignition-relevant velocity -350 km/s - with no observed ablator mix in the hot spot. Recent experiments have explored two-shock designs in a larger, 6.72 mm hohlraum, and upcoming experiments will incrementally extend the pulse duration toward a 9 ns long, three-shock ignition design. Prepared by LLNL under Contract DE-AC52-07NA27344.

  3. Next generation laser optics for a hybrid fusion-fission power plant

    SciTech Connect

    Stolz, C J; Latkowski, J T; Schaffers, K I

    2009-09-10

    The successful completion of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL), followed by a campaign to achieve ignition, creates the proper conditions to begin exploring what development work remains to construct a power plant based on Inertial Confinement Fusion (ICF) technology. Fundamentally, two distinct NIF laser properties must be overcome. The repetition rate must increase from a shot every four hours to several shots per second. Additionally, the efficiency of converting electricity to laser light must increase by 20x to roughly 10 percent. Solid state diode pumped lasers, commercially available for table top applications, have adequate repetition rates and power conversion efficiencies, however, they operate at a tiny fraction of the required energy for an ICF power plant so would need to be scaled in energy and aperture. This paper describes the optics and coatings that would be needed to support this type of laser architecture.

  4. Inhibition of turbulence in inertial-confinement-fusion hot spots by viscous dissipation

    NASA Astrophysics Data System (ADS)

    Weber, C. R.; Clark, D. S.; Cook, A. W.; Busby, L. E.; Robey, H. F.

    2014-05-01

    Achieving ignition in inertial confinement fusion (ICF) requires the formation of a high-temperature (>10 keV) central hot spot. Turbulence has been suggested as a mechanism for degrading the hot-spot conditions by altering transport properties, introducing colder, mixed material, or reducing the conversion of radially directed kinetic energy to hot-spot heating. We show, however, that the hot spot is very viscous, and the assumption of turbulent conditions in the hot spot is incorrect. This work presents the first high-resolution, three-dimensional simulations of National Ignition Facility (NIF) implosion experiments using detailed knowledge of implosion dynamics and instability seeds and including an accurate model of physical viscosity. We find that when viscous effects are neglected, the hot spot can exhibit a turbulent kinetic energy cascade. Viscous effects, however, are significant and strongly damp small-scale velocity structures, with a hot-spot Reynolds number in the range of only 10--100.

  5. Symmetric inertial confinement fusion implosions at ultra-high laser energies

    SciTech Connect

    Glenzer, S H; MacGowan, B J; Michel, P; Meezan, N B; Suter, L J; Dixit, S N; Kline, J L; Kyrala, G A; Callahan, D A; Dewald, E L; Divol, L; Dzenitis, E; Edwards, J; Hamza, A V; Haynam, C A; Hinkel, D E; Kalantar, D H; Kilkenny, J D; Landen, O L; Lindle, J D; LePape, S; Moody, J D; Nikroo, A; Parham, T; Schneider, M B; Town, R J; Wegner, P; Widmann, K; Whitman, P; Young, B F; Van Wonterghem, B; Atherton, J E; Moses, E I

    2009-12-03

    The first indirect-drive hohlraum experiments at the National Ignition Facility have demonstrated symmetric capsule implosions at unprecedented laser drive energies of 0.7 MJ. 192 simultaneously fired laser beams heat ignition hohlraums to radiation temperatures of 3.3 million Kelvin compressing 1.8-millimeter capsules by the soft x rays produced by the hohlraum. Self-generated plasma-optics gratings on either end of the hohlraum tune the laser power distribution in the hohlraum producing symmetric x-ray drive as inferred from capsule self-emission measurements. These experiments indicate conditions suitable for compressing deuterium-tritium filled capsules with the goal to achieve burning fusion plasmas and energy gain in the laboratory.

  6. Symmetric inertial confinement fusion implosions at ultra-high laser energies.

    PubMed

    Glenzer, S H; MacGowan, B J; Michel, P; Meezan, N B; Suter, L J; Dixit, S N; Kline, J L; Kyrala, G A; Bradley, D K; Callahan, D A; Dewald, E L; Divol, L; Dzenitis, E; Edwards, M J; Hamza, A V; Haynam, C A; Hinkel, D E; Kalantar, D H; Kilkenny, J D; Landen, O L; Lindl, J D; LePape, S; Moody, J D; Nikroo, A; Parham, T; Schneider, M B; Town, R P J; Wegner, P; Widmann, K; Whitman, P; Young, B K F; Van Wonterghem, B; Atherton, L J; Moses, E I

    2010-03-01

    Indirect-drive hohlraum experiments at the National Ignition Facility have demonstrated symmetric capsule implosions at unprecedented laser drive energies of 0.7 megajoule. One hundred and ninety-two simultaneously fired laser beams heat ignition-emulate hohlraums to radiation temperatures of 3.3 million kelvin, compressing 1.8-millimeter-diameter capsules by the soft x-rays produced by the hohlraum. Self-generated plasma optics gratings on either end of the hohlraum tune the laser power distribution in the hohlraum, which produces a symmetric x-ray drive as inferred from the shape of the capsule self-emission. These experiments indicate that the conditions are suitable for compressing deuterium-tritium-filled capsules, with the goal of achieving burning fusion plasmas and energy gain in the laboratory. PMID:20110465

  7. Sparking fusion: A step toward laser-initiated nuclear fusion reactions

    SciTech Connect

    Peterson, I.

    1996-10-19

    The fusion furnace at the sun`s core burns hydrogen to make helium. Each time two hydrogen nuclei, or protons, merge to create a deuterium nucleus, the process releases energy. A chain of additional energy-producing nuclear reactions then converts deuterium into helium. Because protons, with their like electric charges, naturally repel each other, high temperatures and tremendous pressures are needed to force them together closely enough to initiate and sustain the reactions. These mergers cost energy initially, but the return on that investment proves prodigious. On Earth, such an energy payoff has been achieved only in the uncontrolled fury of a detonated hydrogen bomb. The vision of harnessing and controlling nuclear fusion as a terrestrial energy source has yet to be fulfilled. The proposed National Ignition Facility (NIF) represents an ambitious effort to use powerful lasers to deposit sufficient energy in a small capsule of nuclear fuel to trigger fusion. The main justification for the project is to ensure that a core group of physicists and engineers maintains its expertise in the physics of nuclear weapons. This article presents both the scientific and political sides of the NIF facility.

  8. Time-dependent simulations of a Compact Ignition Tokamak

    SciTech Connect

    Stotler, D.P.; Bateman, G.

    1988-05-01

    Detailed simulations of the Compact Ignition Tokamak are carried out using a 1-1/2-D transport code. The calculations include time-varying densities, fields, and plasma shape. It is shown that ignition can be achieved in this device if somewhat better than L-mode energy confinement time scaling is possible. We also conclude that the performance of such a compact, short-pulse device can depend greatly on how the plasma is evolved to its flat-top parameters. Furthermore, in cases such as the ones discussed here, where there is not a great deal of ignition margin and the electron density is held constant, ignition ends if the helium ash is not removed. In general, control of the deuterium--tritium density is equivalent to burn control. 48 refs., 15 figs.

  9. The Neutron Imaging System Fielded at the National Ignition Facility

    SciTech Connect

    Fittinghoff, D N; Atkinson, D P; Bower, D E; Drury, O B; Dzenitis, J M; Felker, B; Frank, M; Liddick, S N; Moran, M J; Roberson, G P; Weiss, P B; Grim, G P; Aragonez, R J; Archuleta, T N; Batha, S H; Clark, D D; Clark, D J; Danly, C R; Day, R D; Fatherley, V E; Finch, J P; Garcia, F P; Gallegos, R A; Guler, N; Hsu, A H; Jaramillo, S A; Loomis, E N; Mares, D; Martinson, D D; Merrill, F E; Morgan, G L; Munson, C; Murphy, T J; Oertel, J A; Polk, P J; Schmidt, D W; Tregillis, I L; Valdez, A C; Volegov, P L; Wang, T F; Wilde, C H; Wilke, M D; Wilson, D C; Buckles, R A; Cradick, J R; Kaufman, M I; Lutz, S S; Malone, R M; Traille, A

    2011-10-24

    We have fielded a neutron imaging system at the National Ignition Facility to collect images of fusion neutrons produced in the implosion of inertial confinement fusion experiments and scattered neutrons from (n, n') reactions of the source neutrons in the surrounding dense material. A description of the neutron imaging system will be presented, including the pinhole array aperture, the line-of-sight collimation, the scintillator-based detection system and the alignment systems and methods. Discussion of the alignment and resolution of the system will be presented. We will also discuss future improvements to the system hardware.

  10. The neutron imaging system fielded at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Fittinghoff, D. N.; Atkinson, D. P.; Bower, D. E.; Drury, O. B.; Dzenitis, J. M.; Frank, M.; Liddick, S. N.; Moran, M. J.; Roberson, G. P.; Weiss, P. B.; Grim, G. P.; Aragonez, R. J.; Archuleta, T. N.; Batha, S. H.; Clark, D. D.; Clark, D. J.; Danly, C. R.; Day, R. D.; Fatherley, V. E.; Finch, J. P.; Garcia, F. P.; Gallegos, R. A.; Guler, N.; Hsu, A. H.; Jaramillo, S. A.; Loomis, E. N.; Mares, D.; Martinson, D. D.; Merrill, F. E.; Morgan, G. L.; Munson, C.; Murphy, T. J.; Oertel, J. A.; Polk, P. J.; Schmidt, D. W.; Tregillis, I. L.; Valdez, A. C.; Volegov, P. L.; Wang, T. F.; Wilde, C. H.; Wilke, M. D.; Wilson, D. C.; Buckles, R. A.; Cradick, J. R.; Kaufman, M. I.; Lutz, S. S.; Malone, R. M.; Traille, A.

    2013-11-01

    We have fielded a neutron imaging system at the National Ignition Facility to collect images of fusion neutrons produced in the implosion of inertial confinement fusion experiments and scattered neutrons from (n, n') reactions of the source neutrons in the surrounding dense material. A description of the neutron imaging system is presented, including the pinhole array aperture, the line-of-sight collimation, the scintillator-based detection system and the alignment systems and methods. Discussion of the alignment and resolution of the system is presented. We also discuss future improvements to the system hardware.

  11. Thermonuclear targets for direct-drive ignition by a megajoule laser pulse

    NASA Astrophysics Data System (ADS)

    Bel'kov, S. A.; Bondarenko, S. V.; Vergunova, G. A.; Garanin, S. G.; Gus'kov, S. Yu.; Demchenko, N. N.; Doskoch, I. Ya.; Kuchugov, P. A.; Zmitrenko, N. V.; Rozanov, V. B.; Stepanov, R. V.; Yakhin, R. A.

    2015-10-01

    Central ignition of a thin two-layer-shell fusion target that is directly driven by a 2-MJ profiled pulse of Nd laser second-harmonic radiation has been studied. The parameters of the target were selected so as to provide effective acceleration of the shell toward the center, which was sufficient for the onset of ignition under conditions of increased hydrodynamic stability of the ablator acceleration and compression. The aspect ratio of the inner deuterium-tritium layer of the shell does not exceed 15, provided that a major part (above 75%) of the outer layer (plastic ablator) is evaporated by the instant of maximum compression. The investigation is based on two series of numerical calculations that were performed using one-dimensional (1D) hydrodynamic codes. The first 1D code was used to calculate the absorption of the profiled laser-radiation pulse (including calculation of the total absorption coefficient with allowance for the inverse bremsstrahlung and resonance mechanisms) and the spatial distribution of target heating for a real geometry of irradiation using 192 laser beams in a scheme of focusing with a cubo-octahedral symmetry. The second 1D code was used for simulating the total cycle of target evolution under the action of absorbed laser radiation and for determining the thermonuclear gain that was achieved with a given target.

  12. Time and motion study for the National Ignition Facility target area

    SciTech Connect

    Latkowski, J.F.; Tobin, M.T.

    1996-06-10

    The Department of Energy (DOE) is proposing to construct the National Ignition Facility (NIF) to embark on a program to achieve ignition and modest gain in the laboratory. With annual fusion yields of up to 1200 MJ/year, neutron activation of nearby components is an important issue. Calculations must be performed to ensure that Target Area structures are designed and activities are planned in a way that ensures that such activities can be completed at the required times while meeting all requirements for occupational exposure to radiation. These calculations are referred to as {open_quotes}Lime-motion{close_quotes} studies. In the present work, key Target Area activities are identified and a detailed time-motion study has been completed for the task of debris shield change-out. Results of a preliminary time-motion study for debris shield change-out were used to influence the design. Subsequent analyses have been completed for several point designs of the NIF Final Optics Assembly (FOA). For each FOA point design, a total annual occupational dose equivalent, in person-Sv, has been estimated. Estimates range from 0.19 person-Sv/year (19 person-rem/year) for a composite FOA with a polyethylene plug to 1.38 person-Sv/year (138 person-rem/year) for the baseline FOA design.

  13. Thermonuclear targets for direct-drive ignition by a megajoule laser pulse

    SciTech Connect

    Bel’kov, S. A.; Bondarenko, S. V.; Vergunova, G. A.; Garanin, S. G.; Gus’kov, S. Yu. Demchenko, N. N.; Doskoch, I. Ya.; Kuchugov, P. A.; Zmitrenko, N. V.; Rozanov, V. B.; Stepanov, R. V.; Yakhin, R. A.

    2015-10-15

    Central ignition of a thin two-layer-shell fusion target that is directly driven by a 2-MJ profiled pulse of Nd laser second-harmonic radiation has been studied. The parameters of the target were selected so as to provide effective acceleration of the shell toward the center, which was sufficient for the onset of ignition under conditions of increased hydrodynamic stability of the ablator acceleration and compression. The aspect ratio of the inner deuterium-tritium layer of the shell does not exceed 15, provided that a major part (above 75%) of the outer layer (plastic ablator) is evaporated by the instant of maximum compression. The investigation is based on two series of numerical calculations that were performed using one-dimensional (1D) hydrodynamic codes. The first 1D code was used to calculate the absorption of the profiled laser-radiation pulse (including calculation of the total absorption coefficient with allowance for the inverse bremsstrahlung and resonance mechanisms) and the spatial distribution of target heating for a real geometry of irradiation using 192 laser beams in a scheme of focusing with a cubo-octahedral symmetry. The second 1D code was used for simulating the total cycle of target evolution under the action of absorbed laser radiation and for determining the thermonuclear gain that was achieved with a given target.

  14. Studies of electron and proton isochoric heating for fast ignition

    SciTech Connect

    Mackinnon, A; Key, M; Akli, K; Beg, F; Clarke, R; Clarke, D; Chen, M; Chung, H; Chen, S; Freeman, R; Green, J; Gu, P; Gregori, G; Highbarger, K; Habara, H; Hatchett, S; Hey, D; Heathcote, R; Hill, J; King, J; Kodama, R; Koch, J; Lancaster, K; Langdon, B; Murphy, C; Norreys, P; Neely, D; Nakatsutsumi, M; Nakamura, H; Patel, N; Patel, P; Pasley, J; Snavley, R; Stephens, R; Stoeckl, C; Foord, M; Tabak, M; Theobald, W; Storm, M; Tanaka, K; Tempo, M; Toley, M; Town, R; Wilks, S; VanWoerkom, L; Weber, R; Yabuuchi, T; Zhang, B

    2006-10-02

    Isochoric heating of inertially confined fusion plasmas by laser driven MeV electrons or protons is an area of great topical interest in the inertial confinement fusion community, particularly with respect to the fast ignition (FI) proposal to use this technique to initiate burn in a fusion capsule. Experiments designed to investigate electron isochoric heating have measured heating in two limiting cases of interest to fast ignition, small planar foils and hollow cones. Data from Cu K{alpha} fluorescence, crystal x-ray spectroscopy of Cu K shell emission, and XUV imaging at 68eV and 256 eV are used to test PIC and Hybrid PIC modeling of the interaction. Isochoric heating by focused proton beams generated at the concave inside surface of a hemi-shell and from a sub hemi-shell inside a cone have been studied with the same diagnostic methods plus imaging of proton induced K{alpha}. Conversion efficiency to protons has also been measured and modeled. Conclusions from the proton and electron heating experiments will be presented. Recent advances in modeling electron transport and innovative target designs for reducing igniter energy and increasing gain curves will also be discussed.

  15. Possible energy gain for a plasma-liner-driven magneto-inertial fusion concept

    SciTech Connect

    Knapp, C. E.; Kirkpatrick, R. C.

    2014-07-15

    A one-dimensional parameter study of a Magneto-Inertial Fusion (MIF) concept indicates that significant gain may be achievable. This concept uses a dynamically formed plasma shell with inwardly directed momentum to drive a magnetized fuel to ignition, which in turn partially burns an intermediate layer of unmagnetized fuel. The concept is referred to as Plasma Jet MIF or PJMIF. The results of an adaptive mesh refinement Eulerian code (Crestone) are compared to those of a Lagrangian code (LASNEX). These are the first published results using the Crestone and LASNEX codes on the PJMIF concept.

  16. Quasispherical fuel compression and fast ignition in a heavy-ion-driven X-target with one-sided illumination

    NASA Astrophysics Data System (ADS)

    Henestroza, Enrique; Logan, B. Grant; Perkins, L. John

    2011-03-01

    The HYDRA radiation-hydrodynamics code [M. M. Marinak et al., Phys. Plasmas 8, 2275 (2001)] is used to explore one-sided axial target illumination with annular and solid-profile uranium ion beams at 60 GeV to compress and ignite deuterium-tritium fuel filling the volume of metal cases with cross sections in the shape of an "X" (X-target). Quasi-three-dimensional, spherical fuel compression of the fuel toward the X-vertex on axis is obtained by controlling the geometry of the case, the timing, power, and radii of three annuli of ion beams for compression, and the hydroeffects of those beams heating the case as well as the fuel. Scaling projections suggest that this target may be capable of assembling large fuel masses resulting in high fusion yields at modest drive energies. Initial two-dimensional calculations have achieved fuel compression ratios of up to 150X solid density, with an areal density ρR of about 1 g/cm2. At these currently modest fuel densities, fast ignition pulses of 3 MJ, 60 GeV, 50 ps, and radius of 300 μm are injected through a hole in the X-case on axis to further heat the fuel to propagating burn conditions. The resulting burn waves are observed to propagate throughout the tamped fuel mass, with fusion yields of about 300 MJ. Tamping is found to be important, but radiation drive to be unimportant, to the fuel compression. Rayleigh-Taylor instability mix is found to have a minor impact on ignition and subsequent fuel burn-up.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  18. The National Ignition Facility: Experimental Capability

    SciTech Connect

    Miller, G H

    2003-09-22

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. NIF will be the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion and matter at extreme energy densities and pressures. NIF's energetic laser beams will compress fusion targets to conditions required for thermonuclear 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, planets and in nuclear weapons. NIF has completed the first phases of its laser commissioning program. The first four beams of NIF have generated 106 kilojoules of infrared light and over 16 kJ at the third harmonic (351 nm). NIF's target experimental systems are being commissioned and experiments have begun. This paper discusses NIF's current and future experimental capability, plans for facility diagnostics, cryogenic target systems, specialized optics for experiments, and potential enhancements to NIF such as green laser operation and high-energy short pulse operation.

  19. Z-Pinch Driven Isentropic Compression for Inertial Fusion

    SciTech Connect

    Asay, J.R.; Hall, C.A.; Holland, K.G.; Slutz, S.A.; Spielman, R.B.; Stygar, W.A.

    1999-02-01

    The achievement of high gain with inertial fusion requires the compression of hydrogen isotopes to high density and temperatures. High densities can be achieved most efficiently by isentropic compression. This requires relatively slow pressure pulses on the order of 10-20 nanoseconds; however, the pressure profile must have the appropriate time. We present 1-D numerical simulations that indicate such a pressure profile can be generated by using pulsed power driven z pinches. Although high compression is calculated, the initial temperature is too low for ignition. Ignition could be achieved by heating a small portion of this compressed fuel with a short (-10 ps) high power laser pulse as previously described. Our 1-D calculations indicate that the existing Z-accelerator could provide the driving current (-20 MA) necessary to compress fuel to roughly 1500 times solid density. At this density the required laser energy is approximately 10 kJ. Multidimensional effects such as the Rayleigh-Taylor were not addressed in this brief numerical study. These effects will undoubtedly lower fuel compression for a given chive current. Therefore it is necessary to perform z-pinch driven compression experiments. Finally, we present preliminary experimental data from the Z-accelerator indicating that current can be efficiently delivered to appropriately small loads (- 5 mm radius) and that VISAR can be used measure high pressure during isentropic compression.

  20. Integrated Simulations of Hot-Electron Transport and Ignition for Direct-Drive, Fast-Ignition Targets

    NASA Astrophysics Data System (ADS)

    Solodov, A.

    2008-11-01

    A thorough understanding of future integrated fast-ignition experiments combining compression and heating for high-density thermonuclear fuel require hybrid (fluid+particle) simulations of the implosion and ignition process. Very different spatial and temporal scales need to be resolved to model the entire fast-ignition experiment. The 2-D axisymmetric hydrocode DRACO and the 2-D/3-D hybrid-PIC code LSP have been integrated to simulate the implosion and heating of direct-drive fast-ignition fusion targets. DRACO includes the physics required to simulate compression, ignition, and burn of fast-ignition targets. LSP simulates the transport of hot electrons from the place where they are generated by a petawatt laser pulse to the dense fuel core where their energy is absorbed. The results of integrated simulations of optimized spherically symmetric and cone-in-shell DT, high-gain, fast-ignition targets will be presented. The minimum energy required for ignition is found for hot electrons with a realistic angular spread and Maxwellian energy-distribution function. The results from simulations of cone-in-shell plastic targets designed for fast-ignition experiments on OMEGA EP will be presented. Target heating and neutron yield are computed. Resistive Weibel instability is found to break the hot-electron beam into filaments. The global self-generated resistive magnetic field of the beam is found to collimate the hot electrons. The self-generated field increases the coupling efficiency of hot electrons with the target core and reduces the minimum energy required for ignition. This work was supported by the U.S. Department of Energy under Cooperative Agreement Nos. DE-FC02-04ER54789 and DE-FC52-08NA28302. Contributors: K.S. Anderson, R. Betti, V. Gotcheva, J.F. Myatt, J.A. Delettrez, S. Skupsky. P. B. Radha et al., Phys. Plasmas 12, 056307 (2005). D. R. Welch et al., Phys. Plasmas 13, 063105 (2006). R. Betti and C. Zhou, Phys. Plasmas 12, 110702 (2005). B. Chrisman, Y

  1. Hydrogen/Air-Ignition Torch

    NASA Technical Reports Server (NTRS)

    Repas, George A.

    1988-01-01

    Torch is simple, reliable, and economical. Airflow cools inner tube prior to flowing through openings in inner tube and mixing with gaseous hydrogen. Spark plug connected to constant-duty simple ignition transformer threaded into side of torch and into inner tube. Transformer used to excite spark plug for period long enough to ignite gas. Transformer is turned off.

  2. 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.

  3. 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.

  4. Inertial Confinement Fusion Annual Report 1997

    SciTech Connect

    Correll, D

    1998-06-01

    The ICF Annual Report provides documentation of the achievements of the LLNL ICF Program during the fiscal year by the use of two formats: (1) an Overview that is a narrative summary of important results for the fiscal year and (2) a compilation of the articles that previously appeared in the ICF Quarterly Report that year. Both the Overview and Quarterly Report are also on the Web at http://lasers.llnl.gov/lasers/pubs/icfq.html. Beginning in Fiscal Year 1997, the fourth quarter issue of the ICF Quarterly was no longer printed as a separate document but rather included in the ICF Annual. This change provided a more efficient process of documenting our accomplishments with-out unnecessary duplication of printing. In addition we introduced a new document, the ICF Program Monthly Highlights. Starting with the September 1997 issue and each month following, the Monthly Highlights will provide a brief description of noteworthy activities of interest to our DOE sponsors and our stakeholders. The underlying theme for LLNL's ICF Program research continues to be defined within DOE's Defense Programs missions and goals. In support of these missions and goals, the ICF Program advances research and technology development in major interrelated areas that include fusion target theory and design, target fabrication, target experiments, and laser and optical science and technology. While in pursuit of its goal of demonstrating thermonuclear fusion ignition and energy gain in the laboratory, 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 of inertial fusion energy for civilian power production. ICF technologies continue to have spin-off applications for additional government and industrial use. In addition to these topics, the ICF Annual Report covers non-ICF funded, but related, laser research and development and associated applications. We also

  5. Magnetized Target Fusion Driven by Plasma Liners

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Kirkpatrick, Ronald C.; Knapp, Charles E.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Magnetized target fusion is an emerging, relatively unexplored approach to fusion for electrical power and propulsion application. The physical principles of the concept are founded upon both inertial confinement fusion (ICF) and magnetic confinement fusion (MCF). It attempts to combine the favorable attributes of both these orthogonal approaches to fusion, but at the same time, avoiding the extreme technical challenges of both by exploiting a fusion regime intermediate between them. It uses a material liner to compress, heat and contain the fusion reacting plasma (the target plasma) mentally. By doing so, the fusion burn could be made to occur at plasma densities as high as six orders of magnitude higher than conventional MCF such as tokamak, thus leading to an approximately three orders of magnitude reduction in the plasma energy required for ignition. It also uses a transient magnetic field, compressed to extremely high intensity (100's T to 1000T) in the target plasma, to slow down the heat transport to the liner and to increase the energy deposition of charged-particle fusion products. This has several compounding beneficial effects. It leads to longer energy confinement time compared with conventional ICF without magnetized target, and thus permits the use of much lower plasma density to produce reasonable burn-up fraction. The compounding effects of lower plasma density and the magneto-insulation of the target lead to greatly reduced compressional heating power on the target. The increased energy deposition rate of charged-particle fusion products also helps to lower the energy threshold required for ignition and increasing the burn-up fraction. The reduction in ignition energy and the compressional power compound to lead to reduced system size, mass and R&D cost. It is a fusion approach that has an affordable R&D pathway, and appears attractive for propulsion application in the nearer term.

  6. 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.

  7. Ignition target design and robustness studies for the National Ignition Facility

    SciTech Connect

    Krauser, W.J.; Hoffman, N.M.; Wilson, D.C.

    1995-12-01

    Recent results are presented from two-dimensional LASNEX calculations of the indirectly driven hohlraum and ignition capsules proposed for the National Ignition Facility (NIF). The calculations concentrate on two capsule designs, the baseline design which has a bromine-doped plastic ablator, and the beryllium design which has a copper-doped beryllium ablator. Both capsules have a cryogenic fuel layer. Primary emphasis in these calculations is placed upon robustness studies detailing various sensitivities. These studies fall naturally into two categories, those performed with integrated modeling where the capsule, hohlraum, and laser rays all are modeled simultaneously with the laser power levels as the only energy input, and those performed in a capsule-only mode where an externally imposed drive is applied to the exterior of the ignition capsule and only the capsule performance is modeled. Integrated modeling calculations address sensitivities to, e.g., the laser pointing; among other things, capsule-only calculations address yield degradation due to the growth of hydrodynamic instabilities seeded by initial surface roughnesses on the capsules. Limitations of the calculational models and directions for future research are discussed. The results of the robustness studies performed to date enhance the authors` confidence that the NIF can achieve ignition and produce 10--15 MJ of capsule yield with one or more capsule designs.

  8. System studies of Compact Ignition Tokamaks

    SciTech Connect

    Galambos, J.D.; Peng, Y.K.M.; Blackfield, D.T.

    1986-11-01

    The Fusion Engineering Design Center (FEDC) Tokamak Systems Code is used to perform trade studies in accordance with the Compact Ignition Tokamak (CIT) physics and engineering guidelines. The authors examine various toroidal field coil (TFC) configurations, preload levels, and coil materials. Use of Inconel-copper composite material results in the smallest sized devices for both bucked and wedged TFCs and wedged-only TFCs. Preload levels of 23 Mkg are needed for the minimum sized devices, and for the lower strength materials, the minimum size is sensitive to the preload level. Results from these trade studies help lead to the choice of the baseline CIT point at R = 1.25 m and B = 10.4 T.

  9. 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.

  10. Initial assessments of ignition spherical torus

    SciTech Connect

    Peng, Y.K.M.; Borowski, S.K.; Bussell, G.T.; Dalton, G.R.; Gorker, G.E.; Haines, J.R.; Hamilton, W.R.; Kalsi, S.S.; Lee, V.D.; Miller, J.B.

    1985-12-01

    Initial assessments of ignition spherical tori suggest that they can be highly cost effective and exceptionally small in unit size. Assuming advanced methods of current drive to ramp up the plasma current (e.g., via lower hybrid wave at modest plasma densities and temperatures), the inductive solenoid can largely be eliminated. Given the uncertainties in plasma energy confinement times and the effects of strong paramagnetism on plasma pressure, and allowing for the possible use of high-strength copper alloys (e.g., C-17510, Cu-Ni-Be alloy), ignition spherical tori with a 50-s burn are estimated to have major radii ranging from 1.0 to 1.6 m, aspect ratios from 1.4 to 1.7, vacuum toroidal fields from 2 to 3 T, plasma currents from 10 to 19 MA, and fusion power from 50 to 300 MW. Because of its modest field strength and simple poloidal field coil configuration, only conventional engineering approaches are needed in the design. A free-standing toroidal field coil/vacuum vessel structure is assessed to be feasible and relatively independent of the shield structure and the poloidal field coils. This exceptionally simple configuration depends significantly, however, on practical fabrication approaches of the center conductor post, about which there is presently little experience. 19 refs.

  11. System studies of compact ignition tokamaks

    SciTech Connect

    Galambos, J.D.; Peng, Y.K.M.; Blackfield, D.T.

    1986-01-01

    A new version of the FEDC Tokamak System Code (TSC) has been developed to analyze the Compact Ignition Tokamak (CIT). These proposed experiments have small (major radius F 1.5m) and high magnetic fields (B J 10T), and are characterized by reduced cost. Key design constraints of CIT include limits to the high stress levels in the magnetic coils, limits to the large temperature rises in the coils and on the first wall or divertor plate, minimizing power supply requirements, and assuring adequate plasma performance in fusion ignition and burn time consistent with the latest physics understanding. We present systems code level studies of CIT parameter space here for a range of design options with various design constraints. The present version of the TSC incorporates new models for key components of CIT. For example, new algorithms have been incorporated for calculating stress levels in the TFC and ohmic solenoid, temperature rise in the magnetic coils, peak power requirements, plasma MHD equilibrium and volt-second capability. The code also incorporates a numerical optimizer to find combinations of engineering quantities (device size, coil sizes, coil current densities etc.) and physics quantities (plasma density temperature, and beta, etc.) which satisfy all the constraints and can minimize or maximize a figure of merit (e.g., the major radius). This method was recently used in a mirror reactor system code (3) for the Minimara concept development.

  12. 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.

  13. Hydrogen-fueled diesel engine without timed ignition

    NASA Technical Reports Server (NTRS)

    Homan, H. S.; De Boer, P. C. T.; Mclean, W. J.; Reynolds, R. K.

    1979-01-01

    Experiments were carried out to investigate the feasibility of converting a diesel engine to hydrogen-fueled operation without providing a timed ignition system. Use was made of a glow plug and a multiple-strike spark plug. The glow plug was found to provide reliable ignition and smooth engine operation. It caused the hydrogen to ignite almost immediately upon the start of injection. Indicated mean effective pressures were on the order of 1.3 MPa for equivalence ratios between 0.1 and 0.4 at a compression ratio of 18. This is significantly higher than the corresponding result obtained with diesel oil (about 0.6 MPa for equivalence ratios between 0.3 and 0.9). Indicated thermal efficiencies were on the order of 0.4 for hydrogen and 0.20-0.25 for diesel oil. Operation with the multiple-strike spark system yielded similar values for IMEP and efficiency, but gave rise to large cycle-to-cycle variations in the delay between the beginning of injection and ignition. Large ignition delays were associated with large amplitude pressure waves in the combustion chamber. The measured NO(x) concentrations in the exhaust gas were of the order of 50-100 ppm. This is significantly higher than the corresponding results obtained with premixed hydrogen and air at low equivalence ratios. Compression ignition could not be achieved even at a compression ratio of 29.

  14. Research in Inertial Fusion Sciences: Now and in the Future

    SciTech Connect

    Powell, H T; Campbell, E M; Hogan, W J; Orth, C D

    2001-04-10

    We review the current and future state of research in inertial fusion sciences. We describe the National Ignition Facility (NIF), the IFE development plan, applications of inertial confinement fusion (ICF) to various high-energy sciences, uses of petawatt laser systems, and concepts for the ICF integrated research experiment (IRE) and IFE power plants.

  15. Ignition and combustion characteristics of metallized propellants

    NASA Technical Reports Server (NTRS)

    Turns, S. R.; Mueller, D. C.; Scott, M. J.

    1990-01-01

    Research designed to develop detailed knowledge of the secondary atomization and ignition characteristics of aluminum slurry propellants was started. These processes are studied because they are the controlling factors limiting the combustion efficiency of aluminum slurry propellants in rocket applications. A burner and spray rig system allowing the study of individual slurry droplets having diameters from about 10 to 100 microns was designed and fabricated. The burner generates a near uniform high temperature environment from the merging of 72 small laminar diffusion flames above a honeycomb matrix. This design permits essentially adiabatic operation over a wide range of stoichiometries without danger of flashback. A single particle sizing system and velocimeter also were designed and assembled. Light scattered from a focused laser beam is related to the particle (droplet) size, while the particle velocity is determined by its transit time through the focal volume. Light from the combustion of aluminum is also sensed to determine if ignition was achieved. These size and velocity measurements will allow the determination of disruption and ignition times as functions of drop sizes and ambient conditions.

  16. 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

  17. Radiological analysis of the National Ignition Facility

    SciTech Connect

    Singh, M.S.

    1993-10-26

    The National Ignition Facility (NIF) will be capable of providing a laser output pulse at 0.35 {mu}m wavelength with an energy of 1.8 MJ and a power of 500 TW. The NIF will house a multi-beamline, Nd-doped-glass laser capable of delivering such pulses into a target chamber. In the target chamber, a positioner will center a target containing fusion fuel (a deuterium-tritium mixture) for each ignition shot. Diagnostics in the chamber will provide the test data (e.g., neutron and x-ray yields). The NIF baseline case would result in deuterium-tritium (DT) neutron yields of about 10{sup 16} to 10{sup 19} per fusion shot. The baseline fusion shots would use 2 Ci of tritium per capsule, with an annual input of about 600 Ci (60 mg). The resulting anticipated annual airborne emissions would consist of approximately 10 Ci of tritium and small amounts of activated air species. The NEF shielding configuration would limit the direct and skyshine radiation intensities around the facility to less than 0.1 rem/y on site and to less than 0.001 rem/y off site. This report presents the results of atmospheric transport calculations for tritium and activated air emissions; neutron and secondary gamma-ray shielding calculations; and results of benchmark studies for validating the EPA CAP88-PC code (for the transport of tritium) and the Lawrence Livermore National Laboratory neutron-photon transport code TART. All calculations were normalized to the annual baseline case of 1.4 {times} 10{sup 20} DT-fusion neutrons. Tritium emissions were normalized to 10 Ci/y. Radiological analyses show that normal NIF operations would result in off-site radiation intensities that would represent insignificant increases over the natural background radiation intensity. The NIF is a national facility, and the DOE has not completed the site evaluation process. Although the results presented in this report are for LLNL, the analytical approach is applicable to any site.

  18. Optimal conditions for shock ignition of scaled cryogenic deuterium-tritium targets

    NASA Astrophysics Data System (ADS)

    Lafon, M.; Ribeyre, X.; Schurtz, G.

    2013-02-01

    Within the framework of the shock-ignition (SI) scheme, ignition conditions are reached following the separation of the compression and heating phases. First, the shell is compressed at a sub-ignition implosion velocity; then an intense laser spike is launched at the end of the main drive, leading to the propagation of a strong shock through the precompressed fuel. The minimal laser energy required for ignition of scaled deuterium-tritium (DT) targets is assessed by calculations. A semi-empiric model describing the ignitor shock generation and propagation in the fuel assembly is defined. The minimal power needed in the laser spike pulse to achieve ignition is derived from the hydrodynamic model. Optimal conditions for ignition of scaled targets are explored in terms of laser intensity, shell-implosion velocity, and target scale range for the SI process. Curves of minimal laser requirements for ignition are plotted in the energy-power diagram. The most economic and reliable conditions for ignition of a millimeter DT target are observed in the 240- to 320-km/s implosion velocity range and for the peak laser intensity ranging from ˜2 × 1015 W/cm2 up to 5 × 1015 W/cm2. These optimal conditions correspond to shock-ignited targets for a laser energy of ˜250 kJ and a laser power of 100 to 200 TW. Large, self-ignited targets are particularly attractive by offering ignition at a lower implosion velocity and a reduced laser intensity than for conventional ignition. The SI scheme allows for the compression and heating phases of the high power laser energy research facility target to be performed at a peak laser intensity below 1016 W/cm2. A better control of parametric and hydrodynamic instabilities within the SI scheme sets it as an optimal and reliable approach to attain ignition of large targets.

  19. Propellant Flow Actuated Piezoelectric Igniter for Combustion Engines

    NASA Technical Reports Server (NTRS)

    Wollen, Mark A. (Inventor)

    2015-01-01

    A propellant flow actuated piezoelectric igniter device using one or more hammer balls retained by one or more magnets, or other retaining method, until sufficient fluid pressure is achieved to release and accelerate the hammer ball, such that it impacts a piezoelectric crystal to produce an ignition spark. Certain preferred embodiments provide a means for repetitively capturing and releasing the hammer ball after it impacts one or more piezoelectric crystals, thereby oscillating and producing multiple, repetitive ignition sparks. Furthermore, an embodiment is presented for which oscillation of the hammer ball and repetitive impact to the piezoelectric crystal is maintained without the need for a magnet or other retaining mechanism to achieve this oscillating impact process.

  20. Emergency ignition shutoff system

    SciTech Connect

    Gomes, L.R. Jr.

    1987-01-13

    An emergency shut-off mechanism is described for a racing car having a roll bar framework forming a driver's cage. The mechanism comprises, in combination, a toggle switch wired in series with an ignition switch of the car, the toggle switch being mounted on a dashboard of the car, one end of a flexible cord being connected to the toggle switch, and an ''L''-shaped conduit affixed to the driver's cage through which the cord slidably extends. A snap hook is affixed to an opposite end of the cord and a ring is affixed to a rear portion of a driver's helmet for detachable attachment to the snap hook. The conduit extends from the dashboard to a position rearward of a driver's seat and of the helmet. Sufficient movement of the helmet pulls the cord, thereby actuating the switch and shutting off the car.

  1. 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.

  2. 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.

  3. 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)

  4. OMEGA Experiments on the Shock-Ignition ICF Concept

    NASA Astrophysics Data System (ADS)

    Theobald, W.

    2007-11-01

    Shock ignition is an ICF concept that assembles thermonuclear fuel to high areal densities and then ignites it by launching a strong shock wave into the compressed fuel. The low-adiabat fuel assembly implodes with a velocity that is less than that required for hot-spot ignition. An intensity spike at the end of the main drive pulse generates a strong shock that is timed to meet the return shock bouncing back from the capsule center in the hot spot. The resulting fuel assembly is non-isobaric and will ignite with less energy than a conventional isobaric implosion.^1 Experiments to study the shock-ignition concept were performed on the OMEGA Laser System using 40-μm-thick, 0.9-mm-diam plastic shells filled with D2 gas. The targets were driven by a relaxation adiabat-shaping laser pulse with a short picket pulse and a high-intensity spike. The implosion was optimized by measuring the fuel assembly performance as a function of the timing of the picket pulse and the spike. Neutron-averaged areal densities of ˜200 mg/cm^2 were measured. The shock-generated implosion showed fusion product yields enhanced by a factor of ˜4 compared to an implosion without the spike. The measured neutron yield for a 25-atm fill, an adiabat of 1.6, and 17 kJ of laser energy was ˜10% of the 1-D simulation prediction. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreements DE-FC52-92SF19460 and DE-FC02-04ER54789. Contributors: R. Betti,^* C. Stoeckl, K.S. Anderson,^* J.A. Delettrez, V.Yu. Glebov, F.J. Marshall, D.N. Maywar, R.L. McCrory, D.D. Meyerhofer, P.B. Radha, T.C. Sangster, V.A. Smalyuk, A.A. Solodov,^* B. Yaakobi, and C.D. Zhou, UR/LLE; J.A. Frenje, C.K. Li, R.D. Petrasso, and F.H. S'eguin, MIT-PSFC; L.J. Perkins, LLNL; D. Shvarts, NRCN (Israel). ^*Also at the Fusion Science Center for Extreme States of Matter and Fast Ignition.

  5. 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

  6. Targets for the National Ignition Campaign

    NASA Astrophysics Data System (ADS)

    Atherton, L. J.

    2008-05-01

    The National Ignition Facility (NIF) is a 192 beam Nd-glass laser facility presently under construction at Lawrence Livermore National Laboratory (LLNL) for performing inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. When completed in 2009, NIF will be able to produce 1.8 MJ, 500 TW of ultraviolet light for target experiments that will create conditions of extreme temperatures (>108 K), pressures (10 GBar) and matter densities (>100 g/cm3). 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 75-μm-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. The ablator

  7. Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite: a histomorphometric study in rabbit bone

    PubMed Central

    Johansson, Pär; Jimbo, Ryo; Naito, Yoshihito; Kjellin, Per; Currie, Fredrik; Wennerberg, Ann

    2016-01-01

    Polyether ether ketone (PEEK) possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA) minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants in the rabbit femur were histologically evaluated at 3 weeks and 12 weeks after surgery. Twelve of the 24 implants were HA coated (test), and the remaining 12 served as uncoated PEEK controls. At 3 weeks and 12 weeks, the mean bone–implant contact was higher for test compared to control (P<0.05). The bone area inside the threads was comparable in the two groups, but the perforating hole showed more bone area for the HA-coated implants at both healing points (P<0.01). With these results, we conclude that nano-sized HA coating on PEEK implants significantly improved the osteogenic properties, and in a clinical situation this material composition may serve as an implant where a rapid bone fusion is essential. PMID:27103801

  8. Conceptual Design - Polar Drive Ignition Campaign

    SciTech Connect

    Hansen, R

    2012-04-05

    to be defined. In all cases, the facility modifications represent functional changes to existing systems or capabilities. The bulk of the scope yet to be identified is associated with the DPR's and MultiFM beam smoothing. Detailed development plans for these two subsystems are provided in Appendices H and I; additional discussion of subsystem requirements based on the physics of PD ignition is given in Section 3. Accordingly, LLE will work closely with LLNL to develop detailed conceptual designs for the PD-specific facility modifications, including assessments of the operational impact of implementation (e.g., changing optics for direct rather than indirect-drive illumination and swapping from a hohlraum-based ITIC to one that supports PD). Furthermore, the experimental implementation plan represents the current best understanding of the experimental campaigns required to achieve PD ignition. This plan will evolve based on the lessons learned from the National Ignition Campaign (NIC) and ongoing indirect-drive ignition experiments. The plan does not take the operational realities of the PD configuration into account; configuration planning for the proposed PD experiments is beyond the scope of this document.

  9. Hot-Spot Mix in Ignition-Scale Implosions at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Regan, S. P.

    2011-10-01

    Ignition of an inertial confinement fusion 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 ignition targets consist of a plastic ablator surrounding a thin shell of cryogenic thermonuclear fuel (i.e., hydrogen isotopes), with fuel vapor filling the interior volume.The 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 < λ < 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 mass-equivalent CH layer, was examined. The amount of hot-spot mix mass, estimated from the Ge K-shell line brightness using a detailed atomic physics code, is typically below the 100-ng allowance for hot-spot mix.1 Predictions of a simple mix model, based on linear growth of the measured surface-mass modulations, are consistent with the experimental results. The measured dependence of hot-spot mix on the implosion velocity and on the high-mode ablator-surface perturbations will be presented. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302. In collaboration with the National Ignition Campaign Mix Working Group. S. W. Haan et. al., Phys. Plasmas 18, 051001 (2011>).

  10. Calculations of Electron Transport in Fast Ignition Targets.

    NASA Astrophysics Data System (ADS)

    Town, R. P. J.; Kruer, W. L.; Langdon, A. B.; Lasinski, B. F.; Tabak, M.; Welch, D. R.

    2002-11-01

    A crucial issue for the viability of the fast ignition approach [1] to inertial fusion energy is the transport of the ignition pulse energy from the critical surface to the high-density compressed fuel. For example, the ignition beam energy depends on the cross section area of the electron beam. Experiments of the interaction of short-pulse high intensity lasers with surrogate solid-density thin targets with buried K-α diagnostic layers have shown a fairly well collimated beam although with a larger radius than the laser beam spot [2]. We report on LSP calculations of these experiments. These calculations include the effects of non-normal electron beam injection, an effect previously not included in simulations. The LSP code [3] uses a direct implicit particle-in-cell algorithm in 3 dimensions to solve for the beam particles. The background particles are treated as a fluid. The implications for fast ignition will be discussed. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract W-7405-ENG-48. [1] M. Tabak, et al, Phys. Plasmas 1, 1626 (1994). [2] J. A. Koch, et al, Phys. Rev. E 65, 016410-1 (2001). [3] D. R. Welch, D. V. Rose, B. V. Oliver, and R. E. Clark, Nucl. Inst. Meth. Phys. Res. A 242, 134 (2001).

  11. Ignition of Aluminum Particles and Clouds

    SciTech Connect

    Kuhl, A L; Boiko, V M

    2010-04-07

    Here we review experimental data and models of the ignition of aluminum (Al) particles and clouds in explosion fields. The review considers: (i) ignition temperatures measured for single Al particles in torch experiments; (ii) thermal explosion models of the ignition of single Al particles; and (iii) the unsteady ignition Al particles clouds in reflected shock environments. These are used to develop an empirical ignition model appropriate for numerical simulations of Al particle combustion in shock dispersed fuel explosions.

  12. Engine ignition timing control apparatus

    SciTech Connect

    Takahashi, N.

    1988-03-01

    An apparatus for controlling the timing of ignition of an internal combustion engine including at least one cylinder is described comprising: sensor means sensitive to combustion pressure in the cylinder for providing a sensor signal indicative of a sensed cylinder combustion pressure; and a control circuit including means coupled to the sensor means for measuring a crankshaft angle at which the cylinder combustion pressure is at maximum, means for retarding the ignition timing in response to the measured crankshaft angle being less than a first value, means for retaining the ignition timing in response to the measured crankshaft angle being between the first and a second value greater than the first value, and means for advancing the ignition timing in response to the measured crankshaft angle being greater than the second value.

  13. Magnetic-confinement fusion

    NASA Astrophysics Data System (ADS)

    Ongena, J.; Koch, R.; Wolf, R.; Zohm, H.

    2016-05-01

    Our modern society requires environmentally friendly solutions for energy production. Energy can be released not only from the fission of heavy nuclei but also from the fusion of light nuclei. Nuclear fusion is an important option for a clean and safe solution for our long-term energy needs. The extremely high temperatures required for the fusion reaction are routinely realized in several magnetic-fusion machines. Since the early 1990s, up to 16 MW of fusion power has been released in pulses of a few seconds, corresponding to a power multiplication close to break-even. Our understanding of the very complex behaviour of a magnetized plasma at temperatures between 150 and 200 million °C surrounded by cold walls has also advanced substantially. This steady progress has resulted in the construction of ITER, a fusion device with a planned fusion power output of 500 MW in pulses of 400 s. ITER should provide answers to remaining important questions on the integration of physics and technology, through a full-size demonstration of a tenfold power multiplication, and on nuclear safety aspects. Here we review the basic physics underlying magnetic fusion: past achievements, present efforts and the prospects for future production of electrical energy. We also discuss questions related to the safety, waste management and decommissioning of a future fusion power plant.

  14. 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.

  15. Laser channeling in mm-scale underdense plasmas of fast ignition targets

    NASA Astrophysics Data System (ADS)

    Ren, C.; Li, G.; Yan, R.; Wang, T.-L.; Tonge, J.; Mori, W. B.

    2008-04-01

    In the fast ignition approach to laser fusion, non-linear laser-plasma interactions could cause significant energy loss for an ignition laser in an underdense plasma. One way to avoid this is to use a channeling pulse to create a low-density channel for the ignition pulse. Two dimensional Particle-in-cell simulations show that laser channeling in mm-scale underdense plasmas has many new phenomena that are not present in previous short-scale experiments and simulations, including plasma buildup to nc in front of the laser, laser hosing/refraction, channel bifurcation, and self-correction and electron heating to relativistic temperatures. The channeling speed is much less than the linear group velocity of the laser. The simulations find that low- intensity channeling pulses are preferred to minimize the required laser energy. The channel is also shown to significantly increase the transmission of an ignition pulse.

  16. Edward Teller medal lecture: high intensity lasers and the road to ignition

    SciTech Connect

    Key, M.H.

    1997-06-02

    There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement.

  17. The Edward teller medal lecture: High intensity lasers and the road to ignition

    SciTech Connect

    Key, M.H.

    1997-04-01

    There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement. {copyright} {ital 1997 American Institute of Physics.}

  18. The Edward Teller medal lecture: High intensity lasers and the road to ignition

    SciTech Connect

    Key, M. H.

    1997-04-15

    There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement.

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

    SciTech Connect

    Brereton, S.J., LLNL

    1998-05-27

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

  20. The Edward teller medal lecture: High intensity lasers and the road to ignition

    NASA Astrophysics Data System (ADS)

    Key, M. H.

    1997-04-01

    There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement.

  1. Theoretical Prediction of Microgravity Ignition Delay of Polymeric Fuels in Low Velocity Flows

    NASA Technical Reports Server (NTRS)

    Fernandez-Pello, A. C.; Torero, J. L.; Zhou, Y. Y.; Walther, D.; Ross, H. D.

    2001-01-01

    A new flammability apparatus and protocol, FIST (Forced Flow Ignition and Flame Spread Test), is under development. Based on the LIFT (Lateral Ignition and Flame Spread Test) protocol, FIST better reflects the environments expected in spacebased facilities. The final objective of the FIST research is to provide NASA with a test methodology that complements the existing protocol and provides a more comprehensive assessment of material flammability of practical materials for space applications. Theoretical modeling, an extensive normal gravity data bank and a few validation space experiments will support the testing methodology. The objective of the work presented here is to predict the ignition delay and critical heat flux for ignition of solid fuels in microgravity at airflow velocities below those induced in normal gravity. This is achieved through the application of a numerical model previously developed of piloted ignition of solid polymeric materials exposed to an external radiant heat flux. The model predictions will provide quantitative results about ignition of practical materials in the limiting conditions expected in space facilities. Experimental data of surface temperature histories and ignition delay obtained in the KC-135 aircraft are used to determine the critical pyrolysate mass flux for ignition and this value is subsequently used to predict the ignition delay and the critical heat flux for ignition of the material. Surface temperature and piloted ignition delay calculations for Polymethylmethacrylate (PMMA) and a Polypropylene/Fiberglass (PP/GL) composite were conducted under both reduced and normal gravity conditions. It was found that ignition delay times are significantly shorter at velocities below those induced by natural convection.

  2. HYPERFUSE: a hypervelocity inertial confinement system for fusion energy production and fission waste transmutation

    SciTech Connect

    Makowitz, H; Powell, J R; Wiswall, R

    1980-01-01

    Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., /sup 137/Cs, /sup 90/Sr, /sup 129/I, /sup 99/Tc, etc. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n,2n), (n,..cap alpha..), (n,..gamma..), etc.) that convert the long-lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product. The transmutation parametric studies conclude that the design of the hypervelocity projectiles should emphasize the achievement of high densities in the transmutation regions (greater than the DT fusion fuel density), as well as the DT ignition and burn criterion (rho R=1.0 to 3.0) requirements.

  3. Plasma Stopping Power Measurements Relevant to Inertial Confinement Fusion

    NASA Astrophysics Data System (ADS)

    McEvoy, Aaron; Herrmann, Hans; Kim, Yongho; Hoffman, Nelson; Schmitt, Mark; Rubery, Michael; Garbett, Warren; Horsfield, Colin; Gales, Steve; Zylstra, Alex; Gatu Johnson, Maria; Frenje, Johan; Petrasso, Richard; Marshall, Frederic; Batha, Steve

    2015-11-01

    Ignition in inertial confinement fusion (ICF) experiments may be achieved if the alpha particle energy deposition results in a thermonuclear burn wave induced in the dense DT fuel layer surrounding the hotspot. As such, understanding the physics of particle energy loss in a plasma is of critical importance to designing ICF experiments. Experiments have validated various stopping power models under select ne and Te conditions, however there remain unexplored regimes where models predict differing rates of energy deposition. An upcoming experiment at the Omega laser facility will explore charged particle stopping in CH plastic capsule ablators across a range of plasma conditions (ne between 1024 cm-3 and 1025 cm-3 and Te on the order of hundreds of eV). Plasma conditions will be measured using x-ray and gamma ray diagnostics, while plasma stopping power will be measured using charged particle energy loss measurements. Details on the experiment and the theoretical models to be tested will be presented.

  4. High convergence, indirect drive inertial confinement fusion experiments at Nova

    SciTech Connect

    Lerche, R.A.; Cable, M.D.; Hatchett, S.P.

    1995-06-02

    High convergence, indirect drive implosion experiments have been done at the Nova Laser Facility. The targets were deuterium and deuterium/tritium filled, glass microballoons driven symmetrically by x rays produced in a surrounding uranium hohlraum. Implosions achieved convergence ratios of 24:1 with fuel densities of 19 g/cm{sup 3}; this is equivalent to the range required for the hot spot of ignition scale capsules. The implosions used a shaped drive and were well characterized by a variety of laser and target measurements. The primary measurement was the fuel density using the secondary neutron technique (neutrons from the reaction {sup 2}H({sup 3}H,n){sup 4}He in initially pure deuterium fuel). Laser measurements include power, energy and pointing. Simultaneous measurement of neutron yield, fusion reaction rate, and x-ray images provide additional information about the implosion process. Computer models are in good agreement with measured results.

  5. Laser Fusion: The First Ten Years 1962-1972

    SciTech Connect

    Kidder, R E

    2006-07-06

    This account of the beginning of the program on laser fusion at Livermore in 1962, and its subsequent development during the decade ending in 1972, was originally prepared as a contribution to the January 1991 symposium 'Achievements in Physics' honoring Professor Keith Brueckner upon his retirement from the University of San Diego at La Jolla. It is a personal recollection of work at Livermore from my vantage point as its scientific leader, and of events elsewhere that I thought significant. This period was one of rapid growth in which the technology of high-power short-pulse lasers needed to drive the implosion of thermonuclear fuel to the temperature and density needed for ignition was developed, and in which the physics of the interaction of intense light with plasmas was explored both theoretically and experimentally.

  6. Implications of polarized DT plasmas for toroidal fusion reactors

    SciTech Connect

    Micklich, B.J.; Jassby, D.L.

    1983-05-01

    Spin polarization of the deuterons and tritons in a reacting plasma can result in an increase in the fusion reactivity and variation of the angular distribution of emission of the fusion neutrons. The increased fusion reactivity relaxes the confinement-temperature conditions for breakeven and ignition. We have determined the effect of varying the angular distribution of the fusion neutrons on the spatial distribution of fusion neturon current and flux at the first wall, on the global tritium breeding ratio, and on the first-wall radiation damage in low-aspect-ratio toroidal geometry.

  7. Dual schedule ignition system

    SciTech Connect

    Remmers, G.M.

    1991-08-13

    This patent describes a time base generator for an ignition system of an internal combustion engine having a crankshaft. It comprises an encoder disk which rotates synchronously with the crankshaft of the engine and includes a plurality of timing features of a predetermined width which are at fixed locations relative to the crankshaft and includes at least one synchronizing feature which is at a fixed location relative to the crankshaft and to at least one of the timing features; detector means for detecting the presence or absence of the timing features and the at least one synchronizing feature and for generating digital signals representative thereof; and pulse generating means for generating a first pulse train from the trailing edge of each timing feature represented in the digital signal and for generating a second pulse train from the leading edge of each timing feature represented in the digital signal whereby the pulses of the second pulse train are advanced from the pulses of the first pulse train by a predetermined angular rotation of the crankshaft determined by the width of each timing feature.

  8. On the Utility of Antiprotons as Drivers for Inertial Confinement Fusion

    SciTech Connect

    Perkins, L J; Orth, C D; Tabak, M

    2003-10-20

    By contrast to the large mass, complexity and recirculating power of conventional drivers for inertial confinement fusion (ICF), antiproton annihilation offers a specific energy of 90MJ/{micro}g and thus a unique form of energy packaging and delivery. In principle, antiproton drivers could provide a profound reduction in system mass for advanced space propulsion by ICF. We examine the physics underlying the use of antiprotons ({bar p}) to drive various classes of high-yield ICF targets by the methods of volumetric ignition, hotspot ignition and fast ignition. The useable fraction of annihilation deposition energy is determined for both {bar p}-driven ablative compression and {bar p}-driven fast ignition, in association with 0-D and 1-D target burn models. Thereby, we deduce scaling laws for the number of injected antiprotons required per capsule, together with timing and focal spot requirements. The kinetic energy of the injected antiproton beam required to penetrate to the desired annihilation point is always small relative to the deposited annihilation energy. We show that heavy metal seeding of the fuel and/or ablator is required to optimize local deposition of annihilation energy and determine that a minimum of {approx}3x10{sup 15} injected antiprotons will be required to achieve high yield (several hundred megajoules) in any target configuration. Target gains - i.e., fusion yields divided by the available p - {bar p} annihilation energy from the injected antiprotons (1.88GeV/{bar p}) - range from {approx}3 for volumetric ignition targets to {approx}600 for fast ignition targets. Antiproton-driven ICF is a speculative concept, and the handling of antiprotons and their required injection precision - temporally and spatially - will present significant technical challenges. The storage and manipulation of low-energy antiprotons, particularly in the form of antihydrogen, is a science in its infancy and a large scale-up of antiproton production over present supply

  9. Neutron Spectroscopy on the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Knauer, J. P.

    2012-10-01

    The performance of cryogenic fuel implosion experiments in progress at the National Ignition Facility (NIF) is measured by an experimental threshold factorfootnotetextM. J. Edwards et al., Phys. Plasmas 18, 051003 (2011). (ITFX) and a generalized Lawson Criterion.footnotetextC. D. Zhou and R. Betti, Phys. Plasmas 15, 102707 (2008); P. Y. Chang et al., Phys. Rev. Lett. 104, 135002 (2010); and R. Betti et al., Phys. Plasmas 17, 058102 (2010). The ITFX metric is determined by the fusion yield and the areal density of an assembled deuterium-tritium (DT) fuel mass. Typical neutron yields from NIF implosions are greater than 10^14 allowing the neutron energy spectrum to be measured with unprecedented precision. A NIF spectrum is composed of neutrons created by fusion (DT, DD, and TT reactions) and neutrons scattered by the dense, cold fuel layer. Neutron scattering is used to determine the areal density of a NIF implosion and is measured along four lines of sight by two neutron time-of-flight detectors, a neutron imaging system, and the magnetic recoil spectrometer. An accurate measurement of the instrument response function for these detectors allows for the routine production of neutron spectra showing DT fuel areal densities up to 1.3 g/cm^2. Spectra over neutron energies of 10 to 17 MeV show areal-density asymmetries of 20% that are inconsistent with simulations. New calibrations and analyses have expended the spectral coverage down to energies less than the deuterium backscatter edge (1.5 MeV for 14 MeV neutrons). These data and analyses are presented along with a compilation of other nuclear diagnostic data that show a larger-than-expected variation in the areal density over the cold fuel mass. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No DE-FC52-08NA28302. In collaboration with NIC.

  10. A Study on Homogeneous Charge Compression Ignition Gasoline Engines

    NASA Astrophysics Data System (ADS)

    Kaneko, Makoto; Morikawa, Koji; Itoh, Jin; Saishu, Youhei

    A new engine concept consisting of HCCI combustion for low and midrange loads and spark ignition combustion for high loads was introduced. The timing of the intake valve closing was adjusted to alter the negative valve overlap and effective compression ratio to provide suitable HCCI conditions. The effect of mixture formation on auto-ignition was also investigated using a direct injection engine. As a result, HCCI combustion was achieved with a relatively low compression ratio when the intake air was heated by internal EGR. The resulting combustion was at a high thermal efficiency, comparable to that of modern diesel engines, and produced almost no NOx emissions or smoke. The mixture stratification increased the local A/F concentration, resulting in higher reactivity. A wide range of combustible A/F ratios was used to control the compression ignition timing. Photographs showed that the flame filled the entire chamber during combustion, reducing both emissions and fuel consumption.

  11. A Hybrid Ion/Electron Beam Fast Ignition Concept

    NASA Astrophysics Data System (ADS)

    Albright, B. J.

    2009-11-01

    Fast ignition (FI) inertial confinement fusion is an approach to high-gain inertial fusion, whereby a dense core of deuterium/tritium fuel is assembled via direct or indirect drive and then a hot spot within the core is heated rapidly (over a time scale of order 10 ps) to ignition conditions by beams of fast charged particles. These particle beams are generated outside the capsule by the interaction of ultra-intense laser pulses with solid density targets. Most study of FI to date has focused on the use of electron [Tabak et al., Phys. Plasmas 1, 1696 (1994)] or ion [Fern'andez et al., Nuclear Fusion 49, 065004 (2009)] beams, however a hybrid approach involving both may have advantages. This paper will describe recent work in this arena. Work performed under the auspices of the U. S. Dept. of Energy by the Los Alamos National Security, Los Alamos National Laboratory. This work was supported by LANL Laboratory Directed Research and Development (LDRD).

  12. Progress in Fast Ignition Studies with Electrons and Protons

    SciTech Connect

    MacKinnon, A. J.; Chen, H.; Hey, D.; Key, M. H.; MacPhee, A. G.; Patel, P. K.; Ping, Y.; Akli, K. U.; Stephens, R. B.; Bartal, T.; Beg, F. N.; Chawla, S.; Chen, S.; Higginson, D.; King, J. A.; Ma, T.; Wei, M. S.; Chen, C. D.; Chowdhury, E.; Link, A.

    2009-09-10

    Isochoric heating of inertially confined fusion plasmas by laser driven MeV electrons or protons is an area of great topical interest in the inertial confinement fusion community, particularly with respect to the fast ignition (FI) concept for initiating burn in a fusion capsule. In order to investigate critical aspects needed for a FI point design, experiments were performed to study 1) laser-to-electrons or protons conversion issues and 2) laser-cone interactions including prepulse effects. A large suite of diagnostics was utilized to study these important parameters. Using cone--wire surrogate targets it is found that pre-pulse levels on medium scale lasers such as Titan at Lawrence Livermore National Laboratory produce long scale length plasmas that strongly effect coupling of the laser to FI relevant electrons inside cones. The cone wall thickness also affects coupling to the wire. Conversion efficiency to protons has also been measured and modeled as a function of target thickness, material. Conclusions from the proton and electron source experiments will be presented. Recent advances in modeling electron transport and innovative target designs for reducing igniter energy and increasing gain curves will also be discussed. In conclusion, a program of study will be presented based on understanding the fundamental physics of the electron or proton source relevant to FI.

  13. 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

  14. National Ignition Facility monthly status report--February 2000

    SciTech Connect

    Moses, E

    2000-02-29

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

  15. The National Ignition Facility Diagnostic Set at the Completion of the National Ignition Campaign, September 2012

    DOE PAGESBeta

    Kilkenny, J. D.; Bell, P. M.; Bradley, D. K.; Bleuel, D. L.; Caggiano, J. A.; Dewald, E. L.; Hsing, W. W.; Kalantar, D. H.; Kauffman, R. L.; Larson, D. J.; et al

    2016-01-06

    At the completion of the National Ignition Campaign (NIC), the National Ignition Facility (NIF) had about 36 different types of diagnostics. These were based on several decades of development on Nova and OMEGA and involved the whole U.S. inertial confinement fusion community. In 1994, the Joint Central Diagnostic Team documented a plan for a limited set of NIF diagnostics in the NIF Conceptual Design Report. Two decades later, these diagnostics, and many others, were installed workhorse tools for all users of NIF. We give a short description of each of the 36 different types of NIC diagnostics grouped by themore » 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 in 1999. Although NIF diagnostics have a much greater degree of automation and rigor than Nova’s, new diagnostics are limited such as the higher-speed X-ray imager. Lastly, recommendations for future diagnostics on the NIF are discussed.« less

  16. Using laser entrance hole shields to increase coupling efficiency in indirect drive ignition targets for the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Callahan, D. A.; Amendt, P. A.; Dewald, E. L.; Haan, S. W.; Hinkel, D. E.; Izurni, N.; Jones, O. S.; Landen, O. L.; Lindl, J. D.; Pollaine, S. M.; Suter, L. J.; Tabak, M.; Turner, R. E.

    2006-05-01

    Coupling efficiency, the ratio of the capsule absorbed energy to the driver energy, is a key parameter in ignition target designs. The hohlraum originally proposed for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, S228 (2004)] coupled ˜11% of the absorbed laser energy to the capsule as x rays. Described here is a second generation of the hohlraum target which has a higher coupling efficiency, ˜16%. Because the ignition capsule's ability to withstand three-dimensional effects increases rapidly with absorbed energy, the additional energy can significantly increase the likelihood of ignition. The new target includes laser entrance hole (LEH) shields as a principal method for increasing coupling efficiency while controlling symmetry in indirect-drive inertial confinement fusion. The LEH shields are high Z disks placed inside the hohlraum on the symmetry axis to block the capsule's view of the relatively cold LEHs. The LEH shields can reduce the amount of laser energy required to drive a target to a given temperature via two mechanisms: (1) keeping the temperature high near the capsule pole by putting a barrier between the capsule and the pole; (2) because the capsule pole does not have a view of the cold LEHs, good symmetry requires a shorter hohlraum with less wall area. Current integrated simulations of this class of target couple 140kJ of x rays to a capsule out of 865kJ of absorbed laser energy and produce ˜10MJ of yield. In the current designs, which continue to be optimized, the addition of the LEH shields saves ˜95kJ of energy (about 10%) over hohlraums without LEH shields.

  17. 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.

  18. Inertial Confinement Fusion quarterly report, January--March 1995. Volume 5, No. 2

    SciTech Connect

    1995-09-01

    The ICF quarterly report is published by the Inertial Confinement Fusion Program at the Lawrence Livermore National Laboratory. Topics included this quarter include: the role of the National Ignition Facility in the development of Inertial Confinement Fusion, laser-plasma interactions in large gas-filled hohlraums, evolution of solid-state induction modulators for a heavy-ion recirculator, the National Ignition Facility project, and terminal-level relaxation in Nd-doped laser material.

  19. National Ignition Campaign Hohlraum energetics

    SciTech Connect

    Meezan, N. B.; Atherton, L. J.; Callahan, D. A.; Dewald, E. L.; Dixit, S.; 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. P. J.; Warrick, A. L.; Weber, S. V.

    2010-05-15

    The first series of experiments of the National Ignition Facility (NIF) [E. I. Moses et al., 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.

  20. 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}.

  1. Inertial fusion features in degenerate plasmas

    NASA Astrophysics Data System (ADS)

    León, Pablo T.; Eliezer, Shalom; Piera, Mireia; Martínez-Val, José M.

    2005-04-01

    Very high plasma densities can be obtained at the end of the implosion phase in inertial fusion targets, particularly in the so-called fast-ignition scheme (Tabak et al., 1994; Mulser & Bauer, 2004), where a central hot spark is not needed at all. By properly tailoring the fuel compression stage, degenerate states can be reached (Azechi et al., 1991; Nakai et al., 1991; McCory, 1998). In that case, most of the relevant energy transfer mechanisms involving electrons are affected (Honrubia & Tikhonchuk, 2004; Bibi & Matte, 2004; Bibi et al., 2004). For instance, bremsstrahlung emission is highly suppressed (Eliezer et al., 2003). In fact, a low ignition-temperature regime appears at very high plasma densities, due to radiation leakage reduction (León et al., 2001). Stopping power and ion-electron coulomb collisions are also changed in this case, which are important mechanisms to trigger ignition by the incoming fast jet, and to launch the fusion wave from the igniting region into the colder, degenerate plasma. All these points are reviewed in this paper. Although degenerate states would not be easy to obtain by target implosion, they present a very interesting upper limit that deserves more attention in order to complete the understanding on the different domains for inertial confinement fusion.

  2. Conceptual design of the National Ignition Facility

    SciTech Connect

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

    1995-08-02

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

  3. Ignition characterization of LOX/hydrocarbon propellants

    NASA Technical Reports Server (NTRS)

    Lawver, B. R.; Rousar, D. C.; Wong, K. Y.

    1985-01-01

    The results of an evaluation of the ignition characteristics of the gaseous oxygen (Gox)/Ethanol propellant combination are presented. Ignition characterization was accomplished through the analysis, design, fabrication and testing of a spark initiated torch igniter and prototype 620 lbF thruster/igniter assembly. The igniter was tested over a chamber pressure range of 74 to 197 psia and mixture ratio range of 0.778 to 3.29. Cold (-92 to -165 F) and ambient (44 to 80 F) propellant temperatures were used. Spark igniter ignition limits and thruster steady state and pulse mode, performance, cooling and stability data are presented. Spark igniter ignition limits are presented in terms of cold flow pressure, ignition chamber diameter and mixture ratio. Thruster performance is presented in terms of vacuum specific impulse versus engine mixture ratio. Gox/Ethanol propellants were shown to be ignitable over a wide range of mixture ratios. Cold propellants were shown to have a minor effect on igniter ignition limits. Thruster pulse mode capability was demonstrated with multiple pulses of 0.08 sec duration and less.

  4. Systematic analysis of advanced fusion fuel in inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Velarde, G.; Eliezer, S.; Henis, Z.; Piera, M.; Martinez-Val, J. M.

    1997-04-01

    Aneutronic fusion reactions can be considered as the cleanest way to exploit nuclear energy. However, these reactions present in general two main drawbacks.—very high temperatures are needed to reach relevant values of their cross sections—Moderate (and even low) energy yield per reaction. This value is still lower if measured in relation to the Z number of the reacting particles. It is already known that bremsstrahlung overruns the plasma reheating by fusion born charged-particles in most of the advanced fuels. This is for instance the case for proton-boron-11 fusion in a stoichiometric plasma and is also so in lithium isotopes fusion reactions. In this paper, the use of deuterium-tritium seeding is suggested to allow to reach higher burnup fractions of advanced fuels, starting at a lower ignition temperature. Of course, neutron production increases as DT contents does. Nevertheless, the ratio of neutron production to energy generation is much lower in DT-advanced fuel mixtures than in pure DT plasmas. One of the main findings of this work is that some natural resources (as D and Li-7) can be burned-up in a catalytic regime for tritium. In this case, neither external tritium breeding nor tritium storage are needed, because the tritium inventory after the fusion burst is the same as before it. The fusion reactor can thus operate on a pure recycling of a small tritium inventory.

  5. Integrated ignition calculations for indirectly driven targets

    SciTech Connect

    Krauser, W.J.; Wilde, B.H.; Wilson, D.C.; Bradley, P.; Swenson, F.

    1995-07-01

    We present two-dimensional LASNEX calculations of the hohlraum and ignition capsules proposed for the National Ignition Facility (NIF). Our current hohlraum design is a 2.76 mm radius, 9.49 mm long gold cylinder with 1.39 mm radius laser entrance holes (LEH) which are covered by 1 {mu}m thick polyamide foils. Laser beams with less that 1.4 MJ total energy and less than 400 TW peak power irradiate the cylinder wall from two separate cones entering each LEH. The hohlraum interior is filled with hydrogen-helium gas (50-50 atomic) at a density of 0.83 mg/cm{sup 3} to suppress the inward expansion of the wall. The capsule uses either a 160 {mu}m plastic ablator doped with bromine (the baseline design), or a 155 {mu}m beryllium ablator doped with copper (the beryllium design). The ablator surrounds an 80 {mu}m thick deuterium-tritium (DT) ice layer with an inner radius of 0.87 mm. We will show the results of integrated, two-dimensional calculations of the hohlraum and the capsule. Plasma conditions within the hohlraum will be described. Peak radiation temperatures in the hohlraum are about 300 eV. These calculations proceed through the implosion, ignition, and burn of the DT capsule. Current peak calculated yields are 12 MJ for the baseline design and 6.9 MJ for the capsule with the beryllium ablator, although higher yields should be achievable with improved ``tuning`` of the laser power levels.

  6. Ignition and combustion of aluminum/magnesium alloy particles in O2 at high pressures

    NASA Technical Reports Server (NTRS)

    Roberts, Ted A.; Burton, Rodney L.; 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 wt pct Mg alloyed with Al, and are ignited in oxygen using the reflected shock in a single-pulse 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 that 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.

  7. Research on fusion neutron sources

    NASA Astrophysics Data System (ADS)

    Gryaznevich, M. P.

    2012-06-01

    The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. "Fusion for Neutrons" (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

  8. Overview of recent progress in US fast ignition research

    SciTech Connect

    Freeman, R R; Akli, K; Beg, F; Betti, R; Chen, S; Clark, D J; Gu, P; Gregori, G; Hatchett, S P; Hey, D; Highbarger, K; Hill, J M; Izumi, N; Key, M H; King, J A; Koch, J A; Lasinski, B; Langdon, B; Mackinnon, A J; Meyerhofer, D; Patel, N; Patel, P; Pasley, J; Park, H; Ren, C; Snavely, R A; Stephens, R B; Stoeckl, C; Tabak, M; Town, R; Van Woerkom, L; Weber, R; Wilks, S C; Zhang, B

    2005-09-28

    The Fast Ignition Program in the United States has enjoyed increased funding in various forms from the Office of Fusion Energy Sciences of the Department of Energy. The program encompasses experiments on large laser facilities at various world-wide locations, and benefits enormously from collaborations with many international scientists. The program includes exploratory work in cone-target design and implosion dynamics, high electron current transport measurements in normal density materials, development of diagnostics for heating measurements, generation of protons from shaped targets, theoretical work on high gain target designs, and extensive modeling development using PIC and hybrid codes.

  9. Advanced charged particle beam ignited nuclear pulse propulsion

    NASA Astrophysics Data System (ADS)

    Winterberg, F.

    2009-06-01

    It is shown that the mass of the driver for nuclear microexplosion—Orion type—pulse propulsion can be substantially reduced with a special fusion-fast fission configuration, which permits to replace an inefficient laser beam driver with a much more efficient and less massive relativistic electron beam (or light ion beam) driver. The driver mass can be further reduced, and the propulsion efficiency increased, by surrounding the nuclear microexplosion assembly with a shell of conventional hydrogen-rich explosive, helping to ignite the nuclear reaction and dissipating the otherwise lost kinetic neutron energy in the shell which becomes part of the propellant.

  10. 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.

  11. FIRE, A Next Step Option for Magnetic Fusion

    SciTech Connect

    Meade, D.M.

    2002-09-12

    The next major frontier in magnetic fusion physics is to explore and understand the strong nonlinear coupling among confinement, MHD stability, self-heating, edge physics, and wave-particle interactions that is fundamental to fusion plasma behavior. The Fusion Ignition Research Experiment (FIRE) Design Study has been undertaken to define the lowest cost facility to attain, explore, understand, and optimize magnetically confined fusion-dominated plasmas. The FIRE is envisioned as an extension of the existing Advanced Tokamak Program that could lead to an attractive magnetic fusion reactor. The FIRE activities have focused on the physics and engineering assessment of a compact, high-field tokamak with the capability of achieving Q approximately equal to 10 in the ELMy H-mode for a duration of about 1.5 plasma current redistribution times (skin times) during an initial burning-plasma science phase, and the flexibility to add Advanced Tokamak hardware (e.g., lower-hybrid current drive) later. The configuration chosen for FIRE is similar to that of ARIES-RS, the U.S. Fusion Power Plant study utilizing an Advanced Tokamak reactor. The key ''Advanced Tokamak'' features are: strong plasma shaping, double-null pumping divertors, low toroidal field ripple (<0.3%), internal control coils, and space for wall stabilization capabilities. The reference design point is R subscript ''o'' = 2.14 m, a = 0.595 m, B subscript ''t''(R subscript ''o'') = 10 T, I subscript ''p'' = 7.7 MA with a flattop time of 20 s for 150 MW of fusion power. The baseline magnetic fields and pulse lengths can be provided by wedged BeCu/OFHC toroidal-field (TF) coils and OFHC poloidal-field (PF) coils that are pre-cooled to 80 K prior to the pulse and allowed to warm up to 373 K at the end of the pulse. A longer-term goal of FIRE is to explore Advanced Tokamak regimes sustained by noninductive current drive (e.g., lower-hybrid current drive) at high fusion gain (Q > 5) for a duration of 1 to 3 current

  12. 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.

  13. 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.

  14. Laser-fusion rocket for interplanetary propulsion

    SciTech Connect

    Hyde, R.A.

    1983-09-27

    A rocket powered by fusion microexplosions is well suited for quick interplanetary travel. Fusion pellets are sequentially injected into a magnetic thrust chamber. There, focused energy from a fusion Driver is used to implode and ignite them. Upon exploding, the plasma debris expands into the surrounding magnetic field and is redirected by it, producing thrust. This paper discusses the desired features and operation of the fusion pellet, its Driver, and magnetic thrust chamber. A rocket design is presented which uses slightly tritium-enriched deuterium as the fusion fuel, a high temperature KrF laser as the Driver, and a thrust chamber consisting of a single superconducting current loop protected from the pellet by a radiation shield. This rocket can be operated with a power-to-mass ratio of 110 W gm/sup -1/, which permits missions ranging from occasional 9 day VIP service to Mars, to routine 1 year, 1500 ton, Plutonian cargo runs.

  15. Spark ignition of flowing gases

    NASA Technical Reports Server (NTRS)

    Swett, Clyde C , Jr

    1956-01-01

    Research conducted at the NACA Lewis Laboratory on ignition of flowing gases by means of long-duration discharges is summarized and analyzed. Data showing the effect of a flowing combustible mixture on the physical and electrical characteristics of spark discharges and data showing the effects of variables on the spark energy required for ignition that has been developed to predict the effect of many of the gas-stream and spark variables is described and applied to a limited amount of experimental data.

  16. Integral magnetic ignition pickup trigger

    SciTech Connect

    King, R.

    1992-10-27

    This patent describes a trigger system for the ignition system of an internal combustion engine having a crankcase with a rotatable crankshaft therein, and a flywheel on one end of the crankcase connected to an end of the crankshaft. It comprises: a nonferromagnetic disk-shaped hub for connection to the crankshaft and rotatable therewith on the end opposite the flywheel; and a stationary sensor mounted adjacent the hub for detecting impulses from the magnetically responsive elements as the hub rotates and utilizing the impulses to trigger the ignition system.

  17. 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.

  18. 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.

  19. 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.

  20. 75 FR 47520 - Standards of Performance for Stationary Compression Ignition and Spark Ignition Internal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... rulemaking published in the Federal Register on June 8, 2010 (75 FR 32612). That notice proposed revisions to... Compression Ignition and Spark Ignition Internal Combustion Engines AGENCY: Environmental Protection Agency... the standards of performance for stationary compression ignition and spark ignition...

  1. Experiments and computational modeling of pulverized-coal ignition. Semiannual report, Apr 1, 1998--Sep 30, 1998

    SciTech Connect

    John C. Chen; Samuel Owusu-Ofori

    1998-10-31

    Under typical conditions of pulverized-coal combustion, which is characterized by fine particles heated at very high rates, there is currently a lack of certainty regarding the ignition mechanism of bituminous and lower rank coals. It is unclear whether ignition occurs first at the particle-oxygen interface (heterogeneous ignition) or if it occurs in the gas phase due to ignition of the devolatilization products (homogeneous ignition). Furthermore, there have been no previous studies aimed at determining the dependence of the ignition mechanism on variations in experimental conditions, such as particle size, oxygen concentration, and heating rate. Finally, there is a need to improve current mathematical models of ignition to realistically and accurately depict the particle-to-particle variations that exist within a coal sample. Such a model is needed to extract useful reaction parameters from ignition studies, and to interpret ignition data in a more meaningful way. The authors propose to examine fundamental aspects of coal ignition through (1) experiments to determine the ignition mechanism of various coals by direct observation, and (2) modeling of the ignition process to derive rate constants and to provide a more insightful interpretation of data from ignition experiments. They propose to use a novel laser-based ignition experiment to achieve their objectives. The heating source will be a pulsed, carbon dioxide laser in which both the pulse energy and pulse duration are independently variable, allowing for a wide range of heating rates and particle temperatures--both of which are decoupled from each other and from the particle size. This level of control over the experimental conditions is truly novel in ignition and combustion experiments. Laser-ignition experiments also offer the distinct advantage of easy optical access to the particles because of the absence of a furnace or radiating walls, and thus permit direct observation and particle temperature

  2. Fundamental Interactions in Gasoline Compression Ignition Engines with Fuel Stratification

    NASA Astrophysics Data System (ADS)

    Wolk, Benjamin Matthew

    Transportation accounted for 28% of the total U.S. energy demand in 2011, with 93% of U.S. transportation energy coming from petroleum. The large impact of the transportation sector on global climate change necessitates more-efficient, cleaner-burning internal combustion engine operating strategies. One such strategy that has received substantial research attention in the last decade is Homogeneous Charge Compression Ignition (HCCI). Although the efficiency and emissions benefits of HCCI are well established, practical limits on the operating range of HCCI engines have inhibited their application in consumer vehicles. One such limit is at high load, where the pressure rise rate in the combustion chamber becomes excessively large. Fuel stratification is a potential strategy for reducing the maximum pressure rise rate in HCCI engines. The aim is to introduce reactivity gradients through fuel stratification to promote sequential auto-ignition rather than a bulk-ignition, as in the homogeneous case. A gasoline-fueled compression ignition engine with fuel stratification is termed a Gasoline Compression Ignition (GCI) engine. Although a reasonable amount of experimental research has been performed for fuel stratification in GCI engines, a clear understanding of how the fundamental in-cylinder processes of fuel spray evaporation, mixing, and heat release contribute to the observed phenomena is lacking. Of particular interest is gasoline's pressure sensitive low-temperature chemistry and how it impacts the sequential auto-ignition of the stratified charge. In order to computationally study GCI with fuel stratification using three-dimensional computational fluid dynamics (CFD) and chemical kinetics, two reduced mechanisms have been developed. The reduced mechanisms were developed from a large, detailed mechanism with about 1400 species for a 4-component gasoline surrogate. The two versions of the reduced mechanism developed in this work are: (1) a 96-species version and (2

  3. Antiproton Driven Fusion Propulsion System

    NASA Astrophysics Data System (ADS)

    Tang, Ricky; Kammash, Terry; Gallimore, Alec

    A fusion propulsion system in which the plasma is heated to thermonuclear temperature by antiproton annihilation reactions is proposed. It makes use of an open-ended magnetic confinement device known as the gasdynamic mirror (GDM) in which the plasma - such as deuteriumtritium (DT) - is confined long enough to be heated before being ejected through one mirror (serving as a magnetic nozzle) to produce thrust. The heating process is based on recent theoretical and experimental physics research which revealed that "at rest" annihilation of antiprotons in uranium-238 targets causes fission at nearly 100% efficiency. Thus, heating in the proposed system can be achieved by inserting U238 targets (in the form of foils or atomic beams) in the proper position and then striking them with antiprotons released from a trap attached to one end of the asymmetric GDM device. The resulting fission fragments and annihilation products, namely pions and muons, are highly ionizing and energetic and could readily heat the background plasma to very high temperatures leading to its ignition. We have examined in detail the various phenomena that underlie the operation of such a propulsion system, ranging from the propagation of antiprotons in plasma, to the confinement of the various species by the mirror-type magnetic field, to the role of ambipolar potential in accelerating the plasma, as well as other relevant processes, and have concluded that the proposed system is capable of producing very impressive propulsive capabilities such as specific impulse and thrust. When applied to a round trip mission to Mars, as an example, we find that it can be accomplished in about 59 days and requires less than 4 micrograms of antiprotons. Although roughly nanograms of antiprotons are currently produced annually, it is expected that hundreds of milligrams or possibly several grams will be produced annually in the next decade or so when Mars missions might be contemplated.

  4. 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.

  5. 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.

  6. Overview of the compact ignition tokamak

    SciTech Connect

    Flanagan, C.A.

    1986-01-01

    A national team has developed a baseline concept for a Compact Ignition Tokamak (CIT). The CIT mission is to achieve ignition and provide experimental capability to study the behavior of burning plasma. The design uses large magnetic fields on axis (about 10 T) and large plasma currents (about 9-10 MA). The magnet structure derives high strength from the use of a copper-Inconel composite plate design in the nose of region of the toroidal field (TF) coil and in the ohmic heating solenoid. Inertial cooling is used;liquid nitrogen temperatures are established at the beginning of each pulse. Capability is provided to operate either with a divertor or limiter based plasma. The design is very compact (1.32-m major radius, 0.43-m plasma radius), has 16 TF coils, and has 16 major horizontal access ports, about 30 cm by 80 cm, located between TF coils. The schedule is for a construction project to be authorized for the period FY 1988-93.

  7. Stockpile Stewardship and the National Ignition Facility

    SciTech Connect

    Moses, E

    2012-01-04

    The National Ignition Facility (NIF), the world's most energetic laser system, is operational at Lawrence Livermore National Laboratory (LLNL). Since the completion of the construction project in March 2009, NIF has completed nearly 150 target experiments for the National Ignition Campaign (NIC), High Energy Density Stewardship Science (HEDSS) in the areas of radiation transport, material dynamics at high pressure in the solid state, as well as fundamental science and other national security missions. NIF capabilities and infrastructure are in place to support all of its missions with over 50 X-ray, optical and nuclear diagnostic systems and the ability to shoot cryogenic targets and DT layered capsules. NIF is now qualified for use of tritium and other special materials as well as to perform high yield experiments and classified experiments. DT implosions with record indirect-drive neutron yield of 4.5 x 10{sup 14} neutrons have been achieved. A series of 43 experiments were successfully executed over a 27-day period, demonstrating the ability to perform precise experiments in new regimes of interest to HEDSS. This talk will provide an update of the progress on the NIF capabilities, NIC accomplishments, as well as HEDSS and fundamental science experimental results and an update of the experimental plans for the coming year.

  8. Catalyzed Ignition of Bipropellants in Microtubes

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.; Boyarko, George A.; Sung, Chih-Jen

    2003-01-01

    This paper addresses the need to understand the physics and chemistry involved in propellant combustion processes in micro-scale combustors for propulsion systems on micro-spacecraft. These spacecraft are planned to have a mass less than 50 kilograms with attitude control estimated to be in the 10 milli-Newton thrust class. These combustors are anticipated to be manufactured using Micro Electrical Mechanical Systems (MEMS) technology and are expected to have diameters approaching the quenching diameter of the propellants. Combustors of this size are expected to benefit significantly from surface catalysis processes. Miniature flame tube apparatus is chosen for this study because microtubes can be easily fabricated from known catalyst materials and their simplicity in geometry can be used in fundamental simulations to more carefully characterize the measured heat transfer and pressure losses for validation purposes. Experimentally, we investigate the role of catalytically active surfaces within 0.4 and 0.8 mm internal diameter micro-tubes, with special emphases on ignition and extinction processes in fuel rich gaseous hydrogen and gaseous oxygen. Flame thickness and reaction zone thickness calculations predict that the diameters of our test apparatus are below the quenching diameter of the propellants in sub-atmospheric tests. Temperature and pressure rises in resistively heated platinum and palladium micro-tubes are used as an indication of exothermic reactions. Specific data on mass flow versus preheat temperature required to achieve ignition are presented.

  9. 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.

  10. 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.

  11. 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.

  12. Integrated simulations of implosion, electron transport, and heating for direct-drive fast-ignition targetsa)

    NASA Astrophysics Data System (ADS)

    Solodov, A. A.; Anderson, K. S.; Betti, R.; Gotcheva, V.; Myatt, J.; Delettrez, J. A.; Skupsky, S.; Theobald, W.; Stoeckl, C.

    2009-05-01

    A thorough understanding of future integrated fast-ignition experiments combining compression and heating of high-density thermonuclear fuel requires hybrid (fluid+particle) simulations of the implosion and ignition process. Different spatial and temporal scales need to be resolved to model the entire fast-ignition experiment. The two-dimensional (2D) axisymmetric hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 056307 (2005)] and the 2D/three-dimensional hybrid particle-in-cell code LSP [D. R. Welch et al., Nucl. Instrum. Methods Phys. Res. A 464, 134 (2001)] have been integrated to simulate the implosion and heating of direct-drive, fast-ignition fusion targets. DRACO includes the physics required to simulate compression, ignition, and burn of fast-ignition targets. LSP simulates the transport of hot electrons from the place where they are generated to the dense fuel core where their energy is absorbed. The results from integrated simulations of cone-in-shell CD targets designed for fast-ignition experiments on OMEGA [T. R. Boehly et al., Opt. Commun. 133, 495 (1997); C. Stoeckl et al., Fusion Sci. Technol. 49, 367 (2006)] are presented. Target heating and neutron yields are computed. The results from LSP simulations of electron transport in solid-density plastic targets are also presented. They confirm an increase in the electron divergence angle with the laser intensity in the current experiments. The self-generated resistive magnetic field is found to collimate the hot-electron beam and increase the coupling efficiency of hot electrons with the target. Resistive filamentation of the hot-electron beam is also observed.

  13. 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.

  14. The National Ignition Facility: The world's largest optical system

    SciTech Connect

    Stolz, C J

    2007-10-15

    The National Ignition Facility (NIF), a 192-beam fusion laser, is presently under construction at the Lawrence Livermore National Laboratory with an expected completion in 2008. The facility contains 7,456 meter-scale optics for amplification, beam steering, vacuum barriers, focusing, polarization rotation, and wavelength conversion. A multiphase program was put in place to increase the monthly optical manufacturing rate by up to 20x while simultaneously reducing cost by up to 3x through a sub-scale development, full-scale facilitization, and a pilot production phase. Currently 80% of the optics are complete with over 50% installed. In order to manufacture the high quality optics at desired manufacturing rate of over 100 precision optics per month, new more deterministic advanced fabrication technologies had to be employed over those used to manufacture previous fusion lasers.

  15. Hydrodynamic growth and mix experiments at National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Smalyuk, V. A.; Caggiano, J.; Casey, D.; Cerjan, C.; Clark, D. S.; Edwards, J.; Grim, G.; Haan, S. W.; Hammel, B. A.; Hamza, A.; Hsing, W.; Hurricane, O.; Kilkenny, J.; Kline, J.; Knauer, J.; Landen, O.; McNaney, J.; Mintz, M.; Nikroo, A.; Parham, T.; Park, H.-S.; Pino, J.; Raman, K.; Remington, B. A.; Robey, H. F.; Rowley, D.; Tipton, R.; Weber, S.; Yeamans, C.

    2016-03-01

    Hydrodynamic growth and its effects on implosion performance and mix were studied at the National Ignition Facility (NIF). Spherical shells with pre-imposed 2D modulations were used to measure Rayleigh-Taylor (RT) instability growth in the acceleration phase of implosions using in-flight x-ray radiography. In addition, implosion performance and mix have been studied at peak compression using plastic shells filled with tritium gas and imbedding localized CD diagnostic layer in various locations in the ablator. Neutron yield and ion temperature of the DT fusion reactions were used as a measure of shell-gas mix, while neutron yield of the TT fusion reaction was used as a measure of implosion performance. The results have indicated that the low-mode hydrodynamic instabilities due to surface roughness were the primary culprits to yield degradation, with atomic ablator-gas mix playing a secondary role.

  16. 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

  17. Design, Assembly, and Testing of the Neutron Imaging Lens for the National Ignition Facility

    SciTech Connect

    Malone, R. M., Kaufman, M. I.

    2010-12-01

    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.

  18. Capsule implosion optimization during the indirect-drive National Ignition Campaign

    SciTech Connect

    Landen, O. L.; Edwards, J.; Haan, S. W.; Robey, H. F.; Milovich, J.; Spears, B. K.; Weber, S. V.; Clark, D. S.; Lindl, J. D.; MacGowan, B. J.; Moses, E. I.; Atherton, J.; Amendt, P. A.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.

    2011-05-15

    Capsule performance optimization campaigns will be conducted at the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition. The campaigns will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models using a variety of ignition capsule surrogates before proceeding to cryogenic-layered implosions and ignition experiments. The quantitative goals and technique options and down selections for the tuning campaigns are first explained. The computationally derived sensitivities to key laser and target parameters are compared to simple analytic models to gain further insight into the physics of the tuning techniques. The results of the validation of the tuning techniques at the OMEGA facility [J. M. Soures et al., Phys. Plasmas 3, 2108 (1996)] under scaled hohlraum and capsule conditions relevant to the ignition design are shown to meet the required sensitivity and accuracy. A roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget. Finally, we show how the tuning precision will be improved after a number of shots and iterations to meet an acceptable level of residual uncertainty.

  19. Capsule implosion optimization during the indirect-drive National Ignition Campaign

    NASA Astrophysics Data System (ADS)

    Landen, O. L.; Edwards, J.; Haan, S. W.; Robey, H. F.; Milovich, J.; Spears, B. K.; Weber, S. V.; Clark, D. S.; Lindl, J. D.; MacGowan, B. J.; Moses, E. I.; Atherton, J.; Amendt, P. A.; Boehly, T. R.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Frenje, J. A.; Glenzer, S. H.; Hamza, A.; Hammel, B. A.; Hicks, D. G.; Hoffman, N.; Izumi, N.; Jones, O. S.; Kilkenny, J. D.; Kirkwood, R. K.; Kline, J. L.; Kyrala, G. A.; Marinak, M. M.; Meezan, N.; Meyerhofer, D. D.; Michel, P.; Munro, D. H.; Olson, R. E.; Nikroo, A.; Regan, S. P.; Suter, L. J.; Thomas, C. A.; Wilson, D. C.

    2011-05-01

    Capsule performance optimization campaigns will be conducted at the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition. The campaigns will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models using a variety of ignition capsule surrogates before proceeding to cryogenic-layered implosions and ignition experiments. The quantitative goals and technique options and down selections for the tuning campaigns are first explained. The computationally derived sensitivities to key laser and target parameters are compared to simple analytic models to gain further insight into the physics of the tuning techniques. The results of the validation of the tuning techniques at the OMEGA facility [J. M. Soures et al., Phys. Plasmas 3, 2108 (1996)] under scaled hohlraum and capsule conditions relevant to the ignition design are shown to meet the required sensitivity and accuracy. A roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget. Finally, we show how the tuning precision will be improved after a number of shots and iterations to meet an acceptable level of residual uncertainty.

  20. Implosion of indirect-drive fast ignition targets with CH coated reentrant cone

    NASA Astrophysics Data System (ADS)

    Zhou, Weimin; Shan, Lianqiang; Gu, Yuqiu; Zhang, Baohan; Fast Ignition Team

    2014-10-01

    Compared with central ignition of laser fusion, fast ignition separates compression and ignition thus it can relax the requirements on the implosion symmetry and the driven energy. The implosion of indirect-drive fast ignition targets with CH coated reentrant cone was experimentally researched on SHENGUANG (SG) II laser facility. The small scale cone-in-shell target fast ignition was pre-compressed by the SG II eight 260 J/1 ns/3 ω laser beams indirectly since beam smoothing was not available currently. The maximum density of the compressed cone-in-shell target 1.37 ns after the lasers' irradiation on the inside wall of hohlraum is about 8.7 g/cm3, and the areal density is close to 8.9 mg/cm2, which are well consistent with the simulation results with two-dimensional radiation hydrodynamic code. To minimize the mixing of the compressed fuel and high-Z vapor produced by the M-line emission from the gold holhraum, a 3 μm CH foil was coated on the full outer surface of the cone and guiding wire. Experimental results and simulation results also demonstrated the coated CH foil could minimize the mixing effectively. By the appropriate design, target can remain robust before the maximum compression, that is, the time while the hot electrons produced by ignition laser pulse deposit energy in the compressed fuel.